Assessment of Groundwater Resources in Brazil: Current Status of Knowledge

Authored by: Fernando A. C. Feitosa , João Alberto O. Diniz , Roberto Eduardo Kirchheim , Chang Hung Kiang , Edilton Carneiro Feitosa

Groundwater Assessment, Modeling, and Management

Print publication date:  July  2016
Online publication date:  September  2016

Print ISBN: 9781498742849
eBook ISBN: 9781315369044
Adobe ISBN:

10.1201/9781315369044-5

 

Abstract

The South American continent hosts three large tec-tonic domains: the Andes, the Patagonic platform, and the South American platform. Exception should be made to a small part of Venezuela that belongs to the Caribbean plate. The South American plate, where Brazilian territory is situated, corresponds to the continental portion of the homonymous plate, which has remained stable as a foreland against the Andean and Caribbean mobile belt and continental drifting during the Meso-Cenozoic period. It has undergone multiple tectonic cycles between the Paleoarchean up to the Ordovician resulting in a complex framework. Phanerozoic covers have developed since then, setting the beginning of its stabilization phase (CPRM, 2003). The Brazilian orogenic cycle activities lasted up to the Upper Ordovician/Lower Silurian whereby the actual tectonic framework of the Brazilian territory has been built. Microcontinents and continental blocks were transformed giving rise to the actual cra-tonic areas (Amazônico, São Francisco, São Luis, and Paraná) allowing ocean development (Borborema, São Francisco, Goiano, and Adamastor), where a whole set of sedimentary rocks, insular and juvenile continental arc portion shad has undergone metamorphism, deformation, and emplacement of granitic intrusions across multiple events. During its stabilization period, large synecleses have been developed, such as Amazonas (500,000 km2), Solimões (600,000 km2), Parnaíba (700,000 km2), and Chaco-Paraná (1,700,000 km2). Besides the large basins, many other small ones were originated (Parecis/Alto Xingu, Alto Tapajós, Tacutu, Recôncavo/Tucano/Jatobá, Araripe, Iguatu, Rio do Peixe, and Bacia Sanfranciscana). Across its continental margin, a great number of mesozoic basins have been developed (Pelotas, Santos, Campos, Espírito Santo/Mucuri, Cumuruxatiba, Jequitinhonha/Camumu/Almada/Jacuípe, Sergipe/Alagoas, Pernambuco/Paraíba, Potiguar, Ceará, Barreirinhas, Pará/Maranhão, Foz do Amazonas, Cassiporé, Marajó, Bragança/São Luís, Barra de São João, and Taubaté). Widespread Cenozoic deposits with heterogeneous thickness cover large portions of the territory. The main units are formation Solimões, Içá, Boa Vista, Pantanal, Araguaia, and Barreiras. The continental area occupied by sedimentary basins is 4,898,050 km2, from which 4,513,450 km2 (70%) are intracratonic and the remaining 384,600 km2 (30%) are lying on the continental margin. Figure 3.1 presents the main basins and sedimentary cover within Brazil. The cratonic areas are composed of plutonic rocks, gneisses, migmatites TTG, and greenstone belts sequences while in the orogenic belts there is a predominance of metasedimentary sequences and intrusive bodies. Some neo-proterozoic and cambri-ordovician basins such as AltoParaguai, Bambuí, Chapada Diamantina, Paranoá, Santo Onofre, Estancia, Rio Pardo, and Jaibaras, among others contain sedimentary sequences bearing primary structures and low metamorphic grades behaving mostly as fractured aquifers.

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Assessment of Groundwater Resources in Brazil: Current Status of Knowledge

3.1  Geological Framework and Tectonic Scenario

The South American continent hosts three large tec-tonic domains: the Andes, the Patagonic platform, and the South American platform. Exception should be made to a small part of Venezuela that belongs to the Caribbean plate. The South American plate, where Brazilian territory is situated, corresponds to the continental portion of the homonymous plate, which has remained stable as a foreland against the Andean and Caribbean mobile belt and continental drifting during the Meso-Cenozoic period. It has undergone multiple tectonic cycles between the Paleoarchean up to the Ordovician resulting in a complex framework. Phanerozoic covers have developed since then, setting the beginning of its stabilization phase (CPRM, 2003). The Brazilian orogenic cycle activities lasted up to the Upper Ordovician/Lower Silurian whereby the actual tectonic framework of the Brazilian territory has been built. Microcontinents and continental blocks were transformed giving rise to the actual cra-tonic areas (Amazônico, São Francisco, São Luis, and Paraná) allowing ocean development (Borborema, São Francisco, Goiano, and Adamastor), where a whole set of sedimentary rocks, insular and juvenile continental arc portion shad has undergone metamorphism, deformation, and emplacement of granitic intrusions across multiple events. During its stabilization period, large synecleses have been developed, such as Amazonas (500,000 km2), Solimões (600,000 km2), Parnaíba (700,000 km2), and Chaco-Paraná (1,700,000 km2). Besides the large basins, many other small ones were originated (Parecis/Alto Xingu, Alto Tapajós, Tacutu, Recôncavo/Tucano/Jatobá, Araripe, Iguatu, Rio do Peixe, and Bacia Sanfranciscana). Across its continental margin, a great number of mesozoic basins have been developed (Pelotas, Santos, Campos, Espírito Santo/Mucuri, Cumuruxatiba, Jequitinhonha/Camumu/Almada/Jacuípe, Sergipe/Alagoas, Pernambuco/Paraíba, Potiguar, Ceará, Barreirinhas, Pará/Maranhão, Foz do Amazonas, Cassiporé, Marajó, Bragança/São Luís, Barra de São João, and Taubaté). Widespread Cenozoic deposits with heterogeneous thickness cover large portions of the territory. The main units are formation Solimões, Içá, Boa Vista, Pantanal, Araguaia, and Barreiras. The continental area occupied by sedimentary basins is 4,898,050 km2, from which 4,513,450 km2 (70%) are intracratonic and the remaining 384,600 km2 (30%) are lying on the continental margin. Figure 3.1 presents the main basins and sedimentary cover within Brazil. The cratonic areas are composed of plutonic rocks, gneisses, migmatites TTG, and greenstone belts sequences while in the orogenic belts there is a predominance of metasedimentary sequences and intrusive bodies. Some neo-proterozoic and cambri-ordovician basins such as AltoParaguai, Bambuí, Chapada Diamantina, Paranoá, Santo Onofre, Estancia, Rio Pardo, and Jaibaras, among others contain sedimentary sequences bearing primary structures and low metamorphic grades behaving mostly as fractured aquifers.

3.2  The Hydrogeological Map of Brazil

The hydrogeological map of Brazil, launched by the Brazilian Geological Survey—CPRM/SGB at the end of 2014, represents a synthesis of the hydrogeological information data sets available in the country. It aims at offering an overview of the water well location, aquifer use, and groundwater potential nationwide. It constitutes five main thematic layers.

3.2.1  Planialtimetry Base Map

The planialtimetry base map was obtained from the vector base—1:1.000.000 BCIM/IBGE (Brazilian Institute for Geography and Statistics 2010)—generated throughout the integration of the World International Chart (CIM) with the following information categories: hydrography, landform, political boundaries, transport system, economical structure, energy, communication, reference points, and vegetation.

3.2.2  Geological Database

The geological database was obtained from the GIS Brazil from the CPRM (2003) and based on a simplification of unit attributes and conversion into hydrogeology characteristics, such as groundwater transmissivity and storage.

3.2.3  Tubular Well Database

Data on tubular wells were taken from the SIAGAS— Groundwater Information System, operated and kept by the CPRM/SGB, which is equipped with query modules and report preparation modules. Regarding the hydro-geological map development, a set of 241,692 tubular wells was available for analysis.

3.2.4  Water-Level Database

Water level contour lines based on groundwater level data were developed for the following regional aquifers: Boa Vista, Itapecuru, Parecis, Guarani, Cabeças, and Urucuia. These outputs were transformed into potentiometric surfaces using topographical data gathered in the field with GPS. When such data were missing, groundwater level was determined after a digital terrain model (DTM).

Basins and sedimentary covers of Brazil. (Modified from Diniz, J. A. O. et al. 2014. de, Mapa hidrogeológico do Brasil ao milionésimo: Nota técnica. Recife: CPRM—Serviço Geológico do Brasil, Recife.)

Figure 3.1   Basins and sedimentary covers of Brazil. (Modified from Diniz, J. A. O. et al. 2014. de, Mapa hidrogeológico do Brasil ao milionésimo: Nota técnica. Recife: CPRM—Serviço Geológico do Brasil, Recife.)

3.3  Hydrological Database

The concept of “hydrographic regions” defined by the Water Resources National Council—CNRH has been adopted. The country was divided into 12 main hydrographic regions: Amazônica, Tocantins-Araguaia, Atlântico Nordeste Ocidental, Parnaíba, Atlântico Nordeste Oriental, São Francisco, Atlântico Leste, Atlântico Sudeste, Paraná, Paraguai, Uruguai, and Atlântico Sul.

The hydrogeological potential of each one of the mapped units has been classified according to the contribution of Struckmeier and Margat (1995), who defined six classes (Table 3.1):

  1. Very high
  2. High
  3. Moderate
  4. Generally low but locally moderate
  5. Generally low but locally very low
  6. Nonproductive or nonaquifer

According to this methodology, there are 18 hydro-stratigraphic mapping units that have similar storage and transmissibility properties with production classes at the same magnitude order, whose attributes need to be described. The map has also used the International Legend for Hydrogeological Maps developed by UNESCO (1970). Rebouças et al. (1969) and SADC (2009) were also used as important references in this chapter.

The hydrogeological map of Brazil (Figure 3.2) presents an innovative feature dealing with a simplification of the geological background information together with complementary representations of outcropping and nonoutcropping aquifers within its thematic layout. It has been developed within a GIS under a 1:1000.00 scale.

3.4  Paleozoic Sedimentary Basins

3.4.1  Amazonas Sedimentary Basin (1, 2, 3, 7)

The Amazonas Province sedimentary basins (Acre, Solimões, and Amazonas) start at the Andean region where they spread over into the Atlantic coast assuming a fan layout. Their greatest occurrence area corresponds to the flood plains of the Solimões River.

The Acre Basin is situated at the Brazilian territory of the Marañon–Ucayali–Acre Basin, whose total area comprises 905,000 km2 (CPRM, 2003), being the most distal part of the sedimentary edge dated between the Cretaceous and the Pliocene. The Iquitos arc acts as its eastern border toward the Solimões Basin. It presents thicknesses up to 6000 m distributed into four super-sequences: (i) Permian–Carboniferous, (ii) Jurassic, (iii) Cretaceous, and (iv) Tertiary.

Table 3.1   Productivity Classes

Q/s (m3/h/m)

T (m2/s)

K (m/s)

Q (m3/h)

Productivity

Classes

≥4.0

≥10−2

≥10−4

≥100

Very high—Regional relevance (supply source for urban and irrigation demands). Aquifers with national importance.

(1)

2.0 ≤ Q/s < 4.0

10−3 ≤ T < 10−2

10−5 ≤ K < 10−4

50 ≤ Q < 100

High—Same relevance of class 1 in terms of supply demands, but less-productive aquifers.

(2)

1.0 ≤ Q/s < 2.0

10−4 ≤ T < 10−3

10−6 ≤ K < 10−5

25 ≤ Q < 50

Moderate—Source of water supply for small communities, factories, and small irrigation scheme demands.

(3)

0.4 ≤ Q/s < 1.0

10−5 ≤ T < 10−4

10−7 ≤ K < 10−6

10 ≤ Q < 25

Generally low, but locally moderate—Source of water supply for local private demands.

(4)

0.04 ≤ Q/s < 0.4

10−6 ≤ T < 10−5

10−8 ≤ K < 10−7

1 ≤ Q < 10

Generally low but locally very low—Source of intermittent water supply for local private demands.

(5)

<0.04

<10−6

<10−8

<1

Nonproductive or nonaquifer—Insignificant water supply. Extraction restricted to manual devices.

(6)

Source: Modified from Struckmeier, W. F. and J. Margat. 1995. Hydrogeological Maps: A Guide and a Standard Legend. International Association of Hydrogeologists—Hannover (International Contributions to Hydrogeology; Vol. 17).

Q/s = specific yield; Q = flow rate; T = transmissivity; K = hydraulic conductivity.

The Permian–Carboniferous supersequence comprises the Apuí Formation, made up of a clastic edge of conglomerates, Cruzeiro do Sul, containing carbonates, evaporites, and sandstones (Rio do Moura). The Jurassic supersequence is entirely made up of the JuruáMirim formation bearing sandstones and red beds intercalated with evaporites and basalt flows, deposited at continental environment. Several formations belong to the Cretaceous supersequence: Moa, Rio Azul, Divisor, and Ramón, which are constituted by sandstones, shales, and calcarenites from fluviatile–lacustrine environments. The Tertiary supersequence is represented by the Solimões formation with onlap deposition against the basement. Together, they both (the Cretaceous and Tertiary sequences) sum up to 3000 m of thickness (Milani and Zalán, 1998). The Pliocene sandy–clayish sediments of the Solimões formation and the Pleistocene deposits of the Içá formation cover the entire basin.

Hydrogeologic map of Brazil. (Modified from CPRM—Serviço Geológico do Brasil. 2014. Mapa Hidrogeológico do Brasil ao Milionésimo. Organizadores: Diniz, J. A. O., Monteiro, A. B., De Paula, T. L. F., and Silva, R. C. Recife.)

Figure 3.2   Hydrogeologic map of Brazil. (Modified from CPRM—Serviço Geológico do Brasil. 2014. Mapa Hidrogeológico do Brasil ao Milionésimo. Organizadores: Diniz, J. A. O., Monteiro, A. B., De Paula, T. L. F., and Silva, R. C. Recife.)

The Solimões Basin has an area of about 500,000 km2 and a total sediment fill of 3800 m, divided by clear marked discordances building up six supersequences (Eiras et al., 1994).

The ordovician and silurian–devonian supersequences comprising, respectively, Benjamim Constant formation (neritic clastic) and Jutaí formation (clastic and neritic limestone) are restricted to the Jandiatuba subbasin (Eiras et al., 1994a). The devonian–carboniferous supersequence encompasses the marine sedimentary rocks and glacial–marine rocks from the Marimari group (Uerê and Jandiatuba formation), which outreach the Caruari arc, extending up to the Juruá subbasin.

The carboniferous–permian supersequence is made up of clastic sediments, limestones, marine evaporites, and continental evaporites from the Tefé group (Juruá, Carauari, and Fonte Boa formations). The Cretaceous sequence corresponds to the fluviatile deposits of the Alter do Chão formation, which are preserved due to the subsidence effects related to the Andean orogeny. Finally, the pelites and the Pliocene sandstones from the Solimões formation constitute the Tertiary super-sequence, while the Içá formation is a Pleistocene sedimentation product. The Içá formation is covered by eolic deposits that originate in the Araçá, Anauá, and Catrimâni dune fields. The sedimentary rocks of the Amazon Basin are in onlap form disposition covering basement rocks from the Guianas and the Brasil Central shields, limited by the Solimõesbasin (Purus arc) on the western side and by the Marajómesozoic rift through the Gurupá arc on the eastern side. Total rock thickness reaches 5000 m. Sedimentation begins at the rift phase, with the cambrian–ordovician rocks of the Prosperança formation, basically on analluvial–fluviatile fan environments. The syneclese phase started with the deposition of marine clastic sediments from the Autás-Mirim, Nhamundá, Pitinga, and Manacapuru, arranged in the Trombetas group, belonging to the ordovician–devonian supersequence. The devonian–carboniferous supersequence is composed of the Maecuru, Ererê, Curiri, Oriximiná, and Faro formations, which represent the fluviatile–deltaic and neritic sediments from the Urupadi and Curuá groups. This last one has been followed by a glacial sedimentation period and a posterior depositional gap.

The Tapajós group, constituted by the Monte Alegre, Itaituba, Nova Olinda, and Andirá formations, has a wide variety of sedimentation environments such as clastic, continental, and marine, building up the Permian–Carboniferous supersequence. This super-sequence is followed by the Sanrafaélica orogeny (ca. 260 Ma.) and by the Juruá diastrophism. At the very beginning of the Jurassic, an expressive basalt-type magmatism occurred placing Penatecaua dikes and flows between the Nova Olinda and Alter do Chão formations. The sedimentation of the Amazonas Basin ceased after the deposition of the continental sequences, one from the upper Cretaceous (Alter do Chão formation) and another Cenozoic (Solimões and Içá formations), generated by a fluviatile and fluviatile–lacustrine systems. The groundwater research in this region is still incipient and deals mainly with the Alter do Chão formation aquifer. There is overall information about the Solimões and Içá formations as well (Figure 3.3).

The geologic framework described before and the assessment of the water well logs and oil soundings suggest that the Alter do Chão formation is the main regional aquifer functioning under an unconfined regime. Based on existing data, the Alter do Chão aquifer covers an area of about 410,000 km2. Considering a mean thickness of 400 m and an effective porosity of 20%, the saturation volume reaches more than 30,000 km3. According to Souza et al. (2013), even though there are not sufficient data for the estimation of the pressure component, it is clear that this pressure volume is by far much less than saturation volumes, since the parameter S, in confined aquifers, does have magnitudes less than 10−4. Therefore, in terms of a regional estimation, the saturation volume may be a reasonable magnitude for the aquifer permanent reserve.

Regarding hydrodynamic parameters, the available data that have been taken as references were estimated by Tancredi (1996) for the region of Santarém, at Pará State. According to the author, T ranges from a minimum value of 1.5 × 10−3 m2/s and a maximum value of 9.1 × 10−3 m2/s. The storage coefficient, S, has values varying from 4.1 × 10−4 to 3.3 × 10−4 and finally the K values fall in between 2.1 × 10−4 and 5.0 × 10−5 m/s. The hydrodynamic parameters for the Içá-Solimões aquifers are T = 3 × 10−3 m2/s, S = 5 × 10−4, and K = 1 × 10−4 m/s, whose magnitudes are similar to the minimum values that were determined for the Alter do Chãosystem, in Santarém. Regarding the Içá-Solimões system, covering an area of 948,600 km2, the estimated reserves reach 7200 km3, less expressive and 22% than the ones found for the Alter do Chãoaquifer system. The water quality in almost all aquifers from the Amazonic Basin show generally low contents of cations and anions, with sodium-bicarbonate waters, bearing values for Na+ and HCO3 lower than 7 and 30 mg/L and expressive for K+ (maximum concentration reaching 5.5 mg/L). The lower ionic concentrations determine lower values for the electric conductivity, which ranges between 1212 and 100 μS/cm. The groundwater is generally acid and has pH values between 4 and 5.

Main aquifers in the Amazonic Basin.

Figure 3.3   Main aquifers in the Amazonic Basin.

3.4.2  Parecis Sedimentary Basin (15, 16)

The Parecis sedimentary basin is one of the largest intracratonic basins from Brazil, which is situated at the southwest border of the Amazon craton, assuming an elongated W–E form with 1250-km width. It occupies an area of about 500,000 km2 between the latitudes 10° and 15° S and longitudes of 64° and 54° W covering the states of Rondônia and Mato Grosso with almost 6000 m of siliclastic paleozoic, mesozoic, and cenozoic sediments (Figure 3.4). The paleozoic sequence is constituted by the Cacoal, Furnas, Ponta Grossa, Pimenta Bueno, and Fazenda da Casa Branca formation, outcropping on the west, southwestern, and southeastern border of the basin. The mesozoic sequence, on the other hand, formed by the Anari/Tapirapuã and Rio Ávila units and the Parecis group (Salto das Nuvens and Utiariti formations) occurs in the central and western portion of the basin. Finally, the Cenozoic sequence, represented by the detrital–laterite covers belonging to the Ronuro formation and by the quaternary sediments from the Guaporé river, is concentrated in the Alto-Xingú region. The Furnas aquifer constituted by sandstones, conglomerates, and siltstones show productivity classes between 3 and 4 (according to Table 3.1), with low-to-medium productivity, showing specific yields between 0.4 and 2.0 m3/h/m and mean discharge of about 10 and 50 m3/h. The Ponta Grossa formation, composed mainly by pelites (shales, fine sandstones, siltstones, and claystones) belong to class 6 (less productive or nonaquifer). The Pimenta Bueno formation (sandstones, conglomerate, shales, and siltstones), Fazenda Casa Branca formation (conglomerate, arcosean sandstones, and shales), and Anari/Tapirapuã formation (basalts and diabases) vary according to the productivity classification (Table 3.1) from classes 4 and 6. The Parecis group (sandstones, siltstones, and conglomerate) is considered to be the most important aquifer of the Parecis basin. It is classified as class 1 (very high productivity) showing high values for specific yield, reaching more than 4 m3/h/m and discharges higher than 100 m3/h. Finally, the Ronuro formation and the undifferentiated quaternary deposits constituted by sand, clay, and gravel were classified as class 4; nevertheless, due to the fact that they are easily tapped, a great part of the population tends to use them.

Geotectonical framework of the Amazon and Parecis Basins within the Amazonic Craton. (Modified from Bahia, R. B. C. Evolução Tectonossedimentar d Bacia dos Parecis—Amazônia. 2007. 115 f. Tese (Doutoramento em Ciências Naturais)—Escola de Minas, Universidade Federal de Ouro Preto, Ouro Preto. 2007.)

Figure 3.4   Geotectonical framework of the Amazon and Parecis Basins within the Amazonic Craton. (Modified from Bahia, R. B. C. Evolução Tectonossedimentar d Bacia dos Parecis—Amazônia. 2007. 115 f. Tese (Doutoramento em Ciências Naturais)—Escola de Minas, Universidade Federal de Ouro Preto, Ouro Preto. 2007.)

3.4.3  Parnaíba Sedimentary Basin

The Parnaíba sedimentary basin occupies an area of about 600,000 km2, embracing almost the entire area of the states of Piaui and Maranhão and expressive areas of the Pará and Tocantins States. The São Vicente Ferrer-Urbano Santos-Guamá Arc acts as its northern border, whereas the Tauá fault zone, the Senador Pompeu fault zone, the Tocantins-Araguaia fault zone, and the Tocantins arc are their borders on the eastern, southeastern, western, and northwestern portions. According to Goés and Feijó (1994) the basin hosts four depositional sites: Parnaíba basin, Alpercata basin, Grajaú basin, and Espigão Mestre basin (Figure 3.5). The depositional site called Parnaíba basin covers approximately half of the total area of the entire basin and is situated mainly in the center and southern area (Figure 3.5). It comprises the Silurian supersequences (Serra Grande group), devonian (Canindé group), and triassic–carboniferous (Balsas group). The Serra Grande group is composed of the Ipu, Tianguá, and Jaicós formation whereas the Canindé group is composed of the Itaim, Pimenteiras, Cabeças, Longá, and Poti formations. The Piauí, Pedra-de-Fogo, Motuca, and Sambaíba formations constitute the Balsas group (Figure 3.5). The Alpercatas basin covers 70,000 km2 (Figure 3.5) and is composed of the Jurassic supersequence (Mearim group), which is constituted of the Pastos Bons and Corda formations sealed, respectively, at the bottom and the top, by the igneous formations Mosquito (Jurassic) and Sardinha (lower Cretaceous). The Grajaú basin is situated at the northern side of the Alpercatas basin and gets isolated from the São Luis basin by the Ferrer-Urbano Santos arc, which does not exert any influence on the sedimentation continuity between both basins. It is filled by the Grajaú, Codó formations and the Itapecuru Grup belonging to the Cretaceous supersequence (Figure 3.5). The Espigão Mestre basin is covered by eolic sandstones and lies discordantly above the Parnaíba basin. It corresponds to the northern part of the Urucuia basin, which is the setentrional part of the Sanfranciscana basin.

The Parnaíba sedimentary basin has the largest groundwater potential in the northeast region of Brazil. The multilayered permeable geological strata gives rise to regional aquifer systems in heterogeneous hydraulic regimes, varying from unconfined to confined and sometimes artesian conditions (Figure 3.6). The most important aquifer units are the Serra Grande group followed by the Cabeças and Sambaíba formations and the Poti/Piauí system. The Corda and Itapecuru aquifers show slightly lower potential but a wide geographical distribution within the basin. On the upper part of the sedimentary sequence, one may find the Grajaú aquifer, the Barreira/Pirabas group, and the quaternary cover with low potential for groundwater production. The Serra Grande aquifer represents an extensive and important aquifer unity, which lies discordantly over the crystalline basement. It is constituted by an essentially clastic sequence, with conglomerates and consolidated kaolinite conglomerate sandstones (Ipu formation) followed by arcosean, fine to middle size grained sandstones (Tianguá formation) with conglomerate layers. The sequence ends with clastic pelites, which are situated predominantly in the southern part of the basin. This aquifer extends over 38,000 km2 in the eastern, southeastern, and southern border of the Parnaíba basin exhibiting lower potential at its recharge area, a narrow 2–15-km-width fringe. The region under confined conditions shows excellent hydrogeological properties with expressive artesianism regime in some areas. Its thickness varies from 400 to 1000 m. According to the classification adopted by the hydrogeological map of Brazil, the aquifer is classified as class 1, even though its outcropping areas have lower productivity, being classified as classes 5 and 6. The mean hydrodynamic coefficients are T = 3.0 × 10−3 m2/s; K = 1.0 × 10−5 m/s, and S = 4.3 × 10−4.

Parnaíba sedimentary basin. (Adapted from Góes, A. M. and F. J. Feijó.

Figure 3.5   Parnaíba sedimentary basin. (Adapted from Góes, A. M. and F. J. Feijó. 1994. Bacia do Parnaíba. Boletim de Geociências da PETROBRAS. Rio de Janeiro, 8 (1), 57–67.)

The Cabeças aquifer is constituted by sandstones with clay material, outcropping over 42,000 km2 of the middle part of the basin reaching a mean thickness of 300 m. It is classified as class 1, similar to the Serra Grande aquifer. Due to the topographical context of their out-cropping areas, productivity in those areas is situated between classes 3 and 5; hydrodynamic parameters are T = 1.3 × 10−2 m2/s, K = 5.4 × 10−5 m/s, and S = 3.7 × 10−4 (Feitosa and Demetrio, 2009). The Sambaiba aquifer occurs at the southeastern parts of the Maranhão and northeastern part of Tocantins states, both as an uncon-fined aquifer and as a confined aquifer as well. It is composed mainly by well-sorted sandstones bearing high permeability and therefore high to very high potential (classes 1 and 2). Its inflow is fed by direct infiltration from rainfall in recharge areas at plain areas covered by unconsolidated sands and by the drainage network. Its principal outlets are the natural drainage and river beds which keep basin discharges over the year, evapotranspiration, when clay-rich sequences hinder vertical infiltration, vertical bottom drainage, and artificial discharge as an effect of the well operation. It shows yields of more than 200 m3/h in some cases. The Poti and Piauí aquifer units constitute an important aquifer system covering an area of about 92,250 km2. In the largest part of its extension, mainly close to the Parnaíba River, it behaves as an unconfined aquifer whereas toward the middle of the basin it changes to a confined condition. It presents a lithological constitution based on massive sandstones with few intercalations of shale at the inferior part of the sequence. Their recharge originates directly from the rain vertical infiltration, drainage throughout-confining units, and the superficial drainage network. The main aquifer outlets are the drainage system and evapotranspiration at some aquifer portions richer in clay content.

Hydrogeological potential for the geological formations of the Parnaíba basin, according to the classification of

Figure 3.6   Hydrogeological potential for the geological formations of the Parnaíba basin, according to the classification of Table 3.1.

3.4.4  Paraná Sedimentary Basin

The Paraná sedimentary basin is an intracratônica phanerozoic basin established over the Archean and Proterozoic continental crust that is situated in the southern part of the South American platform (Almeida et al., 2000). The stratigraphic register of the basin comprehends a succession of approximately 7000-m thickness of sedimentary and volcanic rocks developed during the neo-Ordovician and the neo-Cretaceous, under marine to continental sedimentation environments (Milani, 2004; Milani et al., 2007). The Paraná basin occupies an area of about 1.1 million km2 in Brazil, distributed in eight Brazilian states, complemented by more than 400,000 km2 in Argentina, Paraguay, and Uruguay. Within its geological framework, the Paraná basin contains a diversity of sedimentary aquifers with intergranular porosity that has been generated in different depositional environments, such as fluviatile, marine, glacial, and desert. The predominant sedimentary processes and the postdiagenetical modifications ended up defining distinct hydraulic characteristics, resulting in different groundwater potential. Among these aquifers, the most important ones are the Tubarão aquifer (SAT), the Guarani aquifer (SAG), and the Bauru aquifer (SAB), whose storage and transmission conditions allow their wide exploitation for fulfilling of domestic, industrial, and agricultural demands. Emphasis should be given to the fractured aquifer developed by the volcanic rocks called the Serra Geral aquifer (SASG). Besides the main aquifers, there are also some aquifers with low permeability, such as the Passa Dois aquiclude, which is composed by a thicker permian elite sequence disrupting the hydraulic continuity between the SAT and SAG aquifers (Figure 3.7).

3.4.4.1  Tubarão Aquifer System (SAT)

The Tubarão aquifer system has its outcropping areas of about 99,000 km2 in a narrow fringe close to the northwestern, eastern, and southwestern borders of the basin. At the subsurface, it spreads over almost the entire basin reaching 750,000 km2. It is considered a granular porous aquifer constituted by the Tatuí, Palermo, Rio Bonito, Aquidauana, and Itararé stratigraphic units. Its lithological composition varies a lot, from diacmetites, siltstones, pelites, shales, ritmites, sandstones, and conglomerate sandstones deposited by marine, glacier, coastal, and fluviatile processes. It may reach 800 m of thickness in the outcropping areas (DAEE, 2005) and sometimes more than 1000 m in the remaining areas as shown by well drilling logs. The hydraulic conductivities range from 2.31 × 10−8 to 8.10 × 10−6 m/s (Diogo et al., 1981) whereas transmissivities vary between 3.5 × 10−6 and 4.63 × 10−4 m2/s. Locally, transmissivity values may reach 150 m2/day (DAEE, 1981, 1982). These values allow this aquifer to be classified as classes 3 and 4. The porosities are generally low in clay sandstones, but may reach up to 30% in sandstones with lower clay content (França and Potter, 1989). The porosity and the permeability of this reservoir are controlled mainly by grain size, grain selection and, secondarily, by the presence of carbonate cementation (Vidal, 2002). The high subsidence rates of this basin during deposition of the SAT unities has also affected the permo-porosity characteristics of the aquifer due to the chemical compaction effect, followed by an increase of the pressure and temperature conditions (Bocardi et al., 2008). Frequent intercalations between coarser and fine sediments, with distinct thicknesses set up a very heterogeneous framework that affects the groundwater storage and flow within aquifer media. (DAEE, 1981; Diogo et al., 1981). The pelite lithologies interlayered to the sandstones hinder the groundwater flow downward increasing its heterogeneity where vertical permeability is lower than horizontal permeability (DAEE, 1981; Diogo et al., 1981). The same happens with the frequent diabase sills, with variable thickness, which may affect badly the regional or local flow continuity (DAEE, 1981). At small depths, the SAT behaves generally as an unconfined aquifer (DAEE, 1981). At the outcropping areas, the permeable sediments receive direct recharge from rainfall and they do discharge expressive amounts of water into the fluvial network. Besides its expressive thickness, the SAT is being exploited by tubular wells not deeper than 300 m, extracting moderate yields between 10 and 20 m3/h (Diogo et al., 1981). The groundwater tends to be slightly saline, with total dissolved solids content between 100 and 200 mg/L and being classified as sodium bicarbonate or calcium bicarbonate (DAEE, 1984). Under extreme confined conditions, in depths more than 400 m, the groundwater may present elevated saline concentrations, above potable thresholds. This is why it is not being intensively exploited thus far.

3.4.4.2  Guarani Aquifer System (SAG)

The SAG is the most important hydroestratigraphic unit from the southern part of the South American continent and is considered to be one of the world’s largest trans-boundary aquifers, extending across wide territories of Brazil, Argentina, Paraguay, and Uruguay. The largest part of the aquifer is situated in Brazilian territory comprising 736,000 km2. The outcropping areas reach only 88,000 km2 and are situated along the basin border as a narrow belt whereas the confined areas, covered by volcanic sequences, sum up 648,000 km2 (OEA, 2009). The SAG is constituted by a sequence of mesozoic continental clastic rocks within the Paraná basin, being delimited by a regional permo-triassic discordancy (250 million) at the base and by volcanic flows from the Serra Geral formation (145–130 million) at the top. In almost all compartments of the basin, the stratigraphic units that constitute the SAG are, exclusively, the Piarambóia and Botucatu formations. Nevertheless at the southern parts of the basin, the SAG is also locally represented by the Santa Maria, Caturrita, and Guará formations (Machado and Faccini, 2004). The SAG framework comprehends predominant eolic continental deposits represented by fine-to-medium-size sandstones exhibiting large-size cross-stratification and secondarily fluviatile lacustrine sandstones and sandy pelites (Caetano-Chang, 1997). At the southern compartment of the basin, there is a basal succession composed of sandstones and pelites deposited by a fluviatile lacustrine system (Machado, 2005; Soares et al., 2008). In almost the entire basin extension, the SAG sequences are layered on top of thick permian units of low permeability, which integrate the Passa Dois aquiclude. At the western part of the basin, the SAG covers carbo-permian sediments of the Aquidauana formation (LEBAC, 2008). The thickness of the SAG increases gradually from outcropping areas, where they are only partially preserved, to the main axis of the basin. At the northern region, there is an elongated depocenter parallel to the main basin axis that accumulates a sediment thickness of 600 m (LEBAC, 2008). Close to the internal tectonic arcs (Ponta Grossa arc and Rio Grande arc) and to the Torres sinclinal, the thicknesses get drastically smaller until they are less than 100 m (LEBAC, 2008). At the eastern compartment of the basin, where there is an intensive groundwater exploitation, SAG thickness varies from 100 m at outcropping areas to 400 m toward the basin major axis (DAEE, 2005). Generally, the mean thickness of the SAG ranges between 200 and 250 m. At its largest part, SAG is covered by about 1700 m of volcanic rocks (LEBAC, 2008). The SAG eolic sandstones have mean porosities of 20% up to 30%, but fluvial ones may show lower values (OEA, 2009). The conductivity of the aquifer has been estimated at 2.6 m/day for the confined areas and 3.0 m/day at the unconfined areas (DAEE, 2005); transmissivity has been estimated at 3 × 10−3 m2/s for the outcropping areas and more than 1.4 × 10−2 m2/s for the confined areas (DAEE, 2005). The storage coefficient varies between 10−3 and 10−5 (DAEE, 1974). Due to the faciological features of the main hydroestratigraphic units of the SAG (Botucatu and Pirambóia formation) and the shallow burying history, the diagenetical modifications were not efficient enough to change original permo-porosity of these rocks (Gesicki, 2007). On the other hand, diluted water inflows, acting in depths up to 250 m within SAG layers, have removed carbonate cement and have leached feldspatic grains giving rise to a secondary porosity (França et al., 2003). The uncon-fined aquifer potentiometry reveals local and regional flows, being ruled by the topography within the hydro-graphic basin in the first case and from outcropping areas dipping toward the interior parts of the basin under confined flow regime. From there on, the aquifer remains mostly confined where in regional terms, flow tends to be from north to south, following the main basin axis (LEBAC, 2008). In some specific areas, water levels go far beyond surface levels building artesianism. The SAG presents excellent potentials, turning it into a strategic reservoir for satisfying water demands at small- and medium-sized cities. At the outcropping areas, well discharges are about 80–100 m3/h whereas in the confined areas, they yield more than 200 m3/h with specific capacity varying from 2 to 15 m3/h. The recharge rates of the SAG, from 1 to 3 km3/annual, are very small considering its extension (OEA, 2009) and extraction volumes for a variety of uses. In both situations, it is considered to be class 1 in terms of productivity. The hydrochemistry of the SAG shows different patterns depending on the aquifer flow regime. At the outcropping areas with unconfined regime, the water tends to be calcium bicarbonate with low electric conductivity. At the confined areas, in the other side, waters are sodium bicarbonate with higher mineralization degree. At the main basin axis, the groundwater tends to be sulfate, sodium chlorinated highly mineralized, however, and presenting great possibility of mixture with water originated in underlying formations.

Main hydrostratigraphic units of Paraná basin.

Figure 3.7   Main hydrostratigraphic units of Paraná basin.

3.4.4.3  Serra Geral Aquifer System (SASG)

The Serra Geral Aquifer System spreads over an area of about 735,000 km2 within the Paraná basin, from which 409,000 km2 constitutes outcropping areas of the Serra Geral formation. These volcanic sequences are partially covered by the sediments of the Bauru group and they may reach almost 1700 m of thickness at the main basin axis. Due to their wide spatial distribution, this system is considered to be an important groundwater reservoir with capacity to fulfill small-to-medium-size demands and work as a complementary water source. The storage and flow of the water occur through physical discontinuities such as fractures, faults, and interflow surfaces, which constitute a heterogeneous, anisotropic, and discontinuous media (Rebouças, 1978). The fracture systems are related to tectonic stresses and also to cooling processes generating subvertical and subhorizontal fractures, respectively (Campos, 2004; Lastoria et al., 2006). Water extraction is done through wells with 100–200-m depth, which allow yields varying from 100 m3/h (when intercepting productive fracture systems) to null, a situation that may happen very often. The relationship between water yield and lineament density proved to be weak according to studies carried out by DAEE (2005). The explanation given is that subhorizontal surfaces such as lava spill contacts do have an important influence controlling water flow, but are not detectable by remote-sensing techniques. The water from the SASG is mainly calcium bicarbonate and secondarily calcium–magnesium bicarbonate and sodium bicarbonate with saline contents less than 250 mg/L (Campos, 2004). According to the classification scheme adopted, these aquifers fall between class 2, in clearly confined scenarios, and 6 due to their topo-graphic setting.

3.4.4.4  Bauru Aquifer System (SAB)

The Bauru Aquifer System comprehends a succession of Cretaceous sedimentary rocks that were deposited over 370,000 km2 of the center-setentrional part of the Paraná basin covering the basalt floods of the Serra Geral formation. Its mean thickness is 100 m, but it may reach 300 m in certain sectors of the basin. Due to the fact that it is a superficial aquifer, well drilling gets easier and exploitation costs are low. On the other hand, it shows high vulnerability toward inorganic and organic contaminant leakages (DAEE, 1976, 1979). The SAB is a multilayered hydroestratigraphic system composed of the Marília, Adamantina, Birigui, Santo Anastácio, and Caiuá aquifers and the aquitards Araçatuba and Pirapozinho (Paula and Silva, 2003, 2005). The sedimentation environments of these aquifers are mainly fluviatile with eolic interactions. The aquitards relate to pelites developed at lacustrine environment (Paula and Silva, 2005). Their hydrodynamic behavior is heterogeneous according to their lithological framework in which sediments with different porosities and permeabilities share lateral and vertical contact relationships. Consequently, the registered yields in these aquitards are variable (Paula and Silva, 2003). The SAB is considered to have moderate permeability according to its clay and silt contents and to the presence of less permeable and impervious layers along the profile (DAEE, 1976). The conductivities in the SAB range from 2.31 × 10−8 to 4.24 × 10−5 m/s whereas the transmissivities vary from 1.62 × 10−6 to 3.8 × 10−3 m2/s. Values lower than 50 m2/day are very often the case (DAEE, 2005). In areas where sedimentation is predominantly eolic, clearly sandy, the transmissivities reach far beyond 200 m2/day (Iritani et al., 2000). The effective porosities are about 5% in clayish sandstones and between 10% and 20% in sandstones with less clay (DAEE, 1979). These hydraulic characteristics set up exploitable yields that start at 10 m3/h and reach up to 120 m3/h. Discharges more than 80 m3/h, however, are not recommended (DAEE, 2005). Multilayered aquifer systems or single confined aquifer units, such as the SAB, may exhibit more than one potentiometric surface, which reflects the equilibrium among different aquifer unit hydraulic charges. So, at one single place, one can recognize an uncon-fined potentiomentric surface, at shallow depths, and a deeper confined one (Paula and Silva, 2005). The aquifer unconfined potentiometric surface is ruled by the groundwater flow within the watershed. The water from the SAB is calcium to calcium–magnesium bicarbonate and more rarely sodium bicarbonates (Coelho, 1996; Celligoi and Duarte, 2002; Barison, 2003). Stradioto (2007a,b) has also found the presence of calcium chloride–sulfate and sodium chloride–sul-fate water. Generally, the SAB presents lower saline concentration with dry residue showing values rarely higher than 300 mg/L (DAEE, 2005).

3.5  Mesozoic and Meso-Cenozoic Sedimentary Basin

In respect to their strategic importance for the semi-arid region in Brazil, among all the Mesozoic and Meso-Cenozoic basins, only the ones situated in the northeast area of the country are going to be emphasized (Figure 3.1).

3.5.1  Potiguar Basin

This basin is located in the north coast of the state of Rio Grande do Norte and southeast of Ceará state. Its entire extension comprises an area that can vary between 41,000 and 60,000 km2, including its outcrop-ping and subsurface portions. The main aquifers are represented by the Jandaíra and Açu formations. The aquifer Açu, whose thickness varies between 400 and 700 m, corresponds to the inferior portion of the Açu formation and is constituted by sandstones and conglomerate at the lower portion of the sequence evolving gradually to fine sandstones at the upper part of the sequence. It is perceived as the most important groundwater storage system within the Potiguar Basin.

The outcropping areas are situated along a marginal belt whose widths vary from 5 km at the eastern side to 20 km at the western corner. The first deep well drilled in this aquifer was in 1967 and has revealed artesianism conditions, discharging about 80 m3/h of excellent water quality. This favorable scenario was followed by an intense economic development of the region and increase of the water demand due to agro-industrial plants based on irrigation schemes. The Açu aquifer exploitation has been accelerated since the 1970s, reaching overall discharge rates of about 42 hm3/year generating expressive drawdowns of more than 160 m in the most critical areas. Despite the fact that there is a vertical drainage from the limestone above, studies are still not conclusive thus far. The incontestable fact is that the discharge increase has triggered the deepening of the groundwater levels depleting the storage capacity of the aquifer. Meanwhile admitting that the CAERN (Water and Sewage Company of the State of Rio Grande do Norte) has slowed down the use of this aquifer for domestic purposes and that irrigation plants have started to use water from the Jandaíra Aquifer, the potentiometric depression tends to recover. However, the Açu aquifer will always play an important and strategic role in providing low cost solutions. It normally shows high magnitudes of yield allowing it to be classified as productivity class 1. Mean hydrodynamic parameters are T = 2.3 × 10−4 m2/s, K = 7.5 × 10−6 m/s, and S = 1 × 10−4. The Jandaíra aquifer must be addressed in the limestone.

3.5.2  Araripe Basin

The Araripe basin is situated in the states of Ceará, Pernambuco, and Piauí and covers an area of about 11,000 km2. It can be divided into two different sectors: Araripe Highlands and Cariri Valley. Almost the entire groundwater exploitation takes place inside the valleys with few water wells on the highlands. The most important aquifers are the Mauriti and the Batateira/Abaiara/MissãoVelha system. The Mauriti aquifer is constituted by a uniform sequence of coarse-grained sandstones, generally silicified, contributing to significant losses of primary porosity. In this case, groundwater flow is controlled by the secondary porosity (fractures and faults). In general, they show only a moderate potential with thickness about 100 m. Discharge from wells is low (<5 m3/h), excepting fault zones, where yields tend to be much higher. The Rio da Batateira/Abaiara/MissãoVelha system is constituted by course to fine size sandstones with siltstones, clay-stones, and shales, at the intermediate to upper part of the sequence reaching 500 m of thickness. Actually, it is the most used aquifer in the region with wells yielding up to 300 m3/h. Recent studies carried out by the CPRM and the Federal University of Ceará had proposed for the Cariri valley (including the both aquifers) the following estimates: 360 million/m3 of renewable resources, 14 billion/m3 of permanent resources, 450 million/m3/year of exploitable resources, and availability of 54 million/m3/year.

3.5.3  Interior Basins

3.5.3.1  Iguatu/Malhada Vermelha/Lima/Campos Icó Basins

At the southeast of the Ceará state, there is a group of small basins situated between the Iguatu and Icó cities, occupying an area of approximately 1000 km2. The sedimentation within these basins is mainly clastic with pelite intercalations composing the following aquifer unities: Icó, Malhada Vermelha, and Lima Campos. On top of them, there are some unconsolidated clastic formations that may exhibit groundwater storing capacity. Well drilling is done intercepting all these aquifers at depths lower than 100 m. However, the exploitation in this region is still small due to the large hydric availability imposed by the Orós Lake. There is no well deeper than 100 m and underground information has been generated by geophysical assessments. The aquifers show a small hydrogeological potential delivering yields of about 3 m3/h. The greatest potential remains in the banks of the Jaguaribe River where reservoirs may have 25 m of thickness and 500 m of width. The high conductivities shown by these alluvial bars allow expressive groundwater extraction fulfilling water demands of Iguatu City.

3.5.3.2  Lavras da Mangabeira Basin

This represents a group of small basins situated in the southeast region of the Ceará state covering an area of about 60 km2. The Serrote, Limoeira, and Iborepi formations show groundwater potential. Assessments carried out by the CPRM and the Federal University of Ceará (CPRM/UFC, 2008b) indicates 4.6 million/m3/year of potential and an installed availability of 1 million/m3/year. The greatest part of this volume is used by the state-owned water company CAGECE for public supply.

3.5.3.3  Coronel João Pessoa/Marrecas and Pau dos Ferros Basins

These small basins with total area of 16, 27, and 65 km2, respectively, are situated in the west side of the state of Rio Grande do Norte. They are constituted by fine-to-coarse-grained sandstones, siltstones, and claystones from the Antenor Navarro formation. Despite the inexistence of data, through an analogy with other similar sequences, one may estimate that they bear reasonable groundwater potential at their sand-rich zones.

3.5.3.4  Rio do Peixe Basin

This basin is located at the far northwest side of the Paraíba State covering an area of 1300 km2. Sedimentary filling comprises the coarse-to-fine sandstones of the Antenor formation, the siltstones, shale, and calciferous sandstones of the Souza formation, and the fine sandstones and conglomerates of the Rio Piranhas formation. This stratigraphic profile conditions the existence of two major aquifers, namely, the Rio Piranhas and the Antenor Navarro, separated by the Souza aquitard. Recent studies developed by the Brazilian Geological Survey in partnership with the Federal University of Campina Grande (CPRM/UFCG, 2008) led to significant advances in the understanding of the groundwater flow network within the basin. The reserves estimates had not been calculated because there are still some incongruences concerning aquifer geometry. Both aquifers show a small potential with yields of about 10 m3/h.

3.5.3.5  Cedro Basin

This basin is situated at the northwest corner of the state of Pernambuco and has an area of 168 km2. The most important aquifer is represented by the Mauriti formation, whose hydrogeological behavior was already described. Detailed information is still missing but expectations converge to moderate groundwater potential.

3.5.3.6  São José do Belmonte Basin

It is situated at the center–north of the Pernambuco state and has an area of 755 km2. The predominant aquifer is the Tacaratu formation composed of heterogeneous medium-size-to-coarse sandstones with kaolinite levels and strong diagenesis. It shows a very heterogeneous hydrodynamic behavior, where secondary porosity prevails over the primary one. As a consequence of that, a wide discharge magnitude variation occurs (starting at 1 m3/h to more than 50 m3/h). Besides the existence of more than 1000 wells registered by the CPRM, the knowledge on the aquifer is still very incipient.

3.5.3.7  Mirandiba/Carnaubeira/Betânia and Fátima Basins

These basins are located in the center portion of the state of Pernambuco and present the following dimensions: 143, 136, 280, and 270 km2, respectively. Their hydro-geological potential is given by the Tacaratu formation, which is constituted by medium-to-coarse heterogeneous sandstones with kaolinite levels and strong dia-genesis as well. In the outcropping areas, groundwater behavior is similar to the Mauriti aquifer. The knowledge is still very incipient, but potential is expected to be moderate to low. Tubular wells completed by the Brazilian Geological Survey in the Fátima basin with depths starting at 300–420 m delivered yields of 30 and 100 m3/h, respectively.

3.5.3.8  Recôncavo/Tucano/Jatobá Basins

The sedimentary basins of the Recôncavo and Tucano cover an area of about 50,000 km2 across the coastal areas of the Bahia State and Pernambuco. In these two basins there are three major aquifer systems: (i) the upper aquifer represented by the Marizal and São Sebastião formations; (ii) the intermediate aquifer represented by the Ilhas Group and Candeias formation; and (iii) the lower aquifer represented by the Sergi and Aliança formation. The upper aquifer system is the most exploited one and the São Sebastião formation is the most productive unit with wells reaching up to 100 m3/h and thickness of 3000 m. This aquifer is responsible for the water supply of the Camaçari petrochemical plant, where a strict water-quality monitoring control is taking place. There is no consistent data on stored volumes, mainly in the intermediate and lower aquifers. In general, one can assume a moderate to high hydrogeological potential with wells having a specific capacity of 3 m3/h/m. Until 800 m the water is considered to be of good quality. The Jatobá basin is situated in the central region of the Pernambuco and northeast of the Alagoas state, covering 5941 km2. It shows an excellent hydrogeological potential represented by the Inajá/Tacaratu aquifer system. This system is constituted by a sequence of coarse-grained sandstones with pelite intercalations at the base (Tacaratu formation) and fine, ferruginous sandstones with siltstones intercalations at the upper part (Inajá formation). Thickness estimates reach about 500 m for the entire sedimentary sequence, whereas 350 m refers to the Tacaratu formation and 150 m to the Inajá formation. Studies carried out by the Brazilian Geological Survey together with the Pernambuco Federal University revealed reserves of about 6.192 hm3 (only for the areas under unconfined behavior regime), renewable resources in order of 3.1 hm3/year, potential about 12.4 hm3/year, installed availability of 0.7 hm3/year, and exploitable resources of about 9.3 hm3/year for the next 50 years (CPRM/UFPE, 2008). The groundwater resources are being used for the supply of the surrounding cities (Sertânia and Arcoverde in Pernambuco state).

3.5.3.9  Sanfranciscana Basin/Urucuia Aquifer

The Urucuia Aquifer, in the context of the Sanfranciscana basin, covers territories of six different states of Brazil (Bahia, Tocantins, Minas Gerais, Piauí, Maranhão, and Goiás) and occupies an area estimated as 120,000 km2. The greatest area, 90,000 km2 occurs in the western side of the Bahia State. For a long time, due to the lack of information, the Urucuia Aquifer has been considered a low hydrogeological potential unit. However, recent studies have shown that wells with 250–300-m depths delivering up to 500 m3/h and bearing specific capacity higher than 10 m3/h/m are frequent. From a lithological point of view, they are represented by a succession of friable fine-to-coarse-size kaolinite sandstones with conglomerate levels reaching thickness of 600 m. It acts as the watershed boundaries between the São Francisco river at the east, the Tocantins river at the west, and the head of the Parnaíba river at the north. Under such conditions, it is expected that the aquifer exerts an important role keeping basal flow in those rivers, a scenario where the integrated water resources management concepts are crucial. In the last few years, the aquifer exploitation has risen vertiginously following the accentuated expansion of irrigated agriculture. Aquifer knowledge is still insufficient and restricted to pilot areas after studies carried out by the Brazilian Geological Survey, the Water Resources Secretary of the Bahia State, and universities. The unconfined characteristics of the Urucuia Aquifer make it the largest groundwater reservoir in the Bahia State and one of the largest within the entire country. Gaspar (2006) has estimated permanent and renewable reserves in 3 × 1012 m3 and 3 × 1010 m3/year, respectively. The exploitable reserves were estimated to be 4 × 1011 m3.

3.6  Limestone

Karstic limestone formations are always or nearly always present in all Brazilian sedimentary basins with varying degrees of economic interest both as groundwater reservoirs and as raw material for the cement industry. The most extensive water-bearing limestone formations occur, nevertheless, in Neo-Proterozoic terrains, in the states of Bahia and Minas Gerais, within the drainage basin of the São Francisco River. Overall, four major hydrogeologic karstic provinces may be recognized in Brazil, at the current stage of knowledge. These are (1) Jandaira Aquifer, in the Cretaceous Potiguar Basin, state of Rio Grande do Norte, northeast Brazil; (2) Pirabas Aquifer of Tertiary age, in the sedimentary coast basin of the state of Pará, north Brazil; (3) the Una Group of Neoproterozoic age, in the north of the state of Bahia; and (4) the Bambuí Group of Neoproterozoic age, in the west of the states of Bahia and Minas Gerais.

3.6.1  Jandaira Aquifer

The Jandaira Formation is a sedimentary marine deposit made mostly of carbonate rocks whose thickness may attain 600 m in some places of the Potiguar Basin, such as the valley of the Mossoró River. The formation traces back the widespread marine transgression which closed the Cretaceous sedimentary history of the Potiguar Basin in the north coast of the state of Rio Grande do Norte (Figure 3.8). Karst structures such as solution channels, caves, and sinkholes developed in the upper 80 m of the formation, giving place to the so-called Jandaira Aquifer. Although occurring all over the Potiguar Basin, this aquifer shows its uppermost expression in the region west of the Apodi River known geologically as Platform of Aracati. There, since the early decade of 1990, the Jandaira Aquifer has been giving extensive support to fruit crops such as melon, pineapple, papaya, and others, mainly for exportation to Europe and the United States. Recent studies carried out by the Brazilian government counted about 2000 wells in the Platform of Aracati, with depths in the range of 60–120 m, and discharges commonly vary from 10 to 70 m3/h. Discharges from 70 to 250 m3/h also occur although less frequently. The groundwater storage, namely, the water table, is very sensitive to the recurring droughts that affect the region, which may cause serious water crises, when a great number of wells can go dry. In the year 2002, the fruit crops, which are the basis of the economy of the region, were impacted strongly by such a crisis. Nevertheless, the typical karstic landscape with sinkholes densely scattered all over the surface area greatly improves the response of the water table to infiltration in years when precipitation is above the annual mean value of 700 mm. On occasion, one or two very generous rainy seasons may provide the replenishment of the reservoir to what its reserves were prior to the draught period. In this way, the water table of the Jandaira Aquifer, as well as its reserves, seems to undergo a long-term fluctuation whose behavior is to be better understood for the sake of groundwater management in the region. In the year 2010, 244 hm3/year were being extracted, which represented 41% of the renewable resources, estimated as 591 hm3/year with a 50% chance (Oliveira et al., 2012).

3.6.2  Pirabas Aquifer

The Potiguar Basin and the Platform of Aracati. (Modified from Feitosa, E. C. and J. G.

Figure 3.8   The Potiguar Basin and the Platform of Aracati. (Modified from Feitosa, E. C. and J. G. Melo. 1998. Estudos de Base—Caracterização Hidrogeológica dos Aquíferos do Rio Grande do Norte. In: Hidroservice, Plano estadual de recursoshídricos do Rio Grande do Norte.)

Although present all over the coastal region of the Pará State, the main area of occurrence of the Pirabas Formation is the region west of Belém City. This area measures about 24,000 km2 and is known geologically as the Bragantina Platform (Figure 3.9). The Pirabas Formation, of Tertiary age, shows two distinct sections.

The upper section is made up of limestone and marls with intercalations of black and greenish-gray shale and carbonate sandstones. Light-gray sandstones dominate in the lower section. The Upper Pirabas Aquifer developed in the upper section of Pirabas Formation, in depths between 70 and 180 m. Wells can yield up to 200 m3/h being, nevertheless, very expensive, which makes drilling accessible only to government or big industries (Matta, 2002). Quite preliminary studies suggest groundwater storage of about 400,000 hm3. The discharge being recovered is something around 100 hm3/year corresponding to 0.03% of the groundwater storage. No data are available yet on renewable resources. The Lower Pirabas Aquifer developed in the lower section of Pirabas Formation, in depths within the range of 180–280 m. Wells may produce as much as 600 m3/h of excellent potable water (Matta, 2002). Due to excessive costs of drilling, though, this aquifer is little exploited.

3.6.3  Salitre Aquifer

The Salitre Formation, of the Neo-Proterozoic age, is the most important formation in the Una Group, in the state of Bahia. It spreads itself over an area of about 38,000 km2 forming four separate bodies. The most important of them is the so-called Basin of Irecê. The dominant lithology is black-to-gray limestone exhibiting a certain degree of metamorphism. Tectonic style goes from near-horizontal layers, in the region along the rims of the basin, to folded layers striking E–W and dipping near vertically in the central regions. The Una Group is physically separated from the Bambuí Group by high ridges sculptured in Proterozoic quartzites. The Salitre Aquifer corresponds to karst structures which are widely developed in the Salitre Formation to depths up to 80 m. About 20,000 wells this deep are reported to exist in the Irecê Basin giving support both to agriculture and public supply. As with the Jandaira Aquifer, climate hazards affect seriously on occasion the economy of the region. Nowadays the Brazilian Water Agency is undertaking hydrogeologic studies in the karst provinces of the São Francisco Basin, aiming at the knowledge of the amount of water being withdrawn from the aquifer and being recharged to it. The main goal of the studies is to establish a groundwater budget in order to assess the sustainability of groundwater exploitation in the near future.

3.6.4  Bambuí Aquifer

Main area of occurrence of the Pirabas Formation.

Figure 3.9   Main area of occurrence of the Pirabas Formation.

The Bambuí Group, of Proterozoic age, is composed of five geological formations (Três Marias Formation, Serra da Saudade Formation, Lagoa do Jacaré Formation, Santa Helena Formation, and Sete Lagoas Formation), which occur in the states of Bahia, Minas Gerais, Goiás, and Tocantins, spreading itself over an area of about 120,000,00 km2 (Figure 3.10). Excepting the uppermost Três Marias Formation, all the other formations of the Bambuí Group include carbonate rocks in greater or lesser amounts. The term Bambuí Aquifer, therefore, applies to the water-bearing karst structures developed in the various formations of the Bambuí Group. The formations Sete Lagoas and Lagoa do Jacaré, particularly, are the ones mostly made up of limestone. In this way, these formations are the most susceptible to development of karst structures. Due to the variation in the carbonate content of the formations of the Bambuí Group, groundwater storage and availability in the Bambuí Aquifer varies widely throughout its domain of occurrence. The Bambuí Aquifer has become of utmost importance in providing support to irrigation and public supply in the states of Bahia and Minas Gerais, mainly in times of droughts. Prolonged droughts, however, such as the one the region is undergoing, impact the economy and public supply in exactly the same way as with the Jandaíra Aquifer. The lack of knowledge concerning withdrawals and recharge brings about incertitude as to sustainability of ground-water exploitation in the future. The Brazilian Water Agency is carrying out extensive studies to provide better knowledge on the matter.

Una and Bambuí Groups in the basin of the São Francisco River.

Figure 3.10   Una and Bambuí Groups in the basin of the São Francisco River.

3.7  Pre-Cambrian Crystalline Basement

In the crystalline region of the Brazilian semiarid, where there is practically no weathering cover, the groundwater flows through interconnected rock fracture and discontinuity systems, building up reservoirs with limited extension. Considering a certain control volume of rock, which is representative of the whole rock mass of the basement region, there are “n” discontinuity systems, independent among themselves, but with the ability to store and transmit water. Manoel Filho (1996) introduced the concept of hydraulic conductor (HC), in order to define the interconnected fracture systems that are associated with a certain well and that represent the water storage and production at crystalline rocks. Therefore, the fissured aquifer would be the sum of all existing HCs within an area, being represented as

i = i n CH i ( X,Y,Z )

where X and Y are location coordinates and Z is the depth of the well.

At crystalline rock terrains, the water prospection approaches still miss deeper technical affirmation. A great number of unsuccessful drillings or wells bearing saline water are still taking place. There are no conceptual models strong enough to fully sustain well location and exploitation and the variables conditioning groundwater quality and quantity. The utilization of these water sources is always associated with risk components to the extent that the groundwater-sustainable yields and overall reserves cannot be safely estimated still. Despite this, since the early 20th century, in the entire northeast region, there is a great number of water wells discharging uninterruptedly. In many cases, unconfined aquifer characteristics and the high hydraulic conductivities associated with fracture systems allow a direct and prompt recharge that keeps permanent exploitation conditions which, in turn, are only disturbed under long periods of drought. The major restrictive factor, for instance, for the use of ground-water resources within this region, is the quality. In general, waters are sodium chlorinated and show total dissolved solids above potable limits. The issue regarding the high heterogeneity and anisotropy of the fractured media depends directly on the assessment scale. At a punctual scale, practically, every single well may represent a single aquifer, which may differ from other ones. The differences in quantity and quality between neighboring wells, which intercept distinct HCs, are surprising. Regionalization approaches, dealing with fractured aquifer data sets, therefore, are not consistent. However, for smaller scales (≥ 1:1,000,000) it may be possible to establish some zones showing similar tendencies regarding determined variables. Figure 3.11 shows 18,600 determinations of electrical conductivity of the groundwater found in fractured aquifers in the states of Ceará, Rio Grande do Norte, Paraíba, and Pernambuco. Each source is classified according to conductivity values, chosen for expressing water quality in terms of salinity: freshwater (CE ≤ 500 μS/cm), brackish water (1000 μS/cm < CE ≤ 2500 μS/cm), and salt water (CE > 2500 μS/cm).

It can be clearly seen that there are zones with different water qualities.

Water classified as brackish appears in the form of contour belts between fresh and salt water. A generic assessment suggests that there are four large zones: Zone 1—predominantly freshwater (southeast coastal area); Zone 2—predominantly salt water (a northeast– southwest range); Zone 3—predominantly freshwater (midwest); and Zone 4—predominantly salt water (north–northwest). Regarding quantity issues, every attempt at reserve evaluation would be mere speculation. However, it is believed that the quantities that can be extracted from fractured aquifers are enough to supply great parts of the diffuse-located population within the semiarid region of Brazil. The occurrence area of the basement rocks in the northeast region is about 750,000 km2 and alone in the region called the drought polygon, the area would be 600,000 km2. Considering the hypothesis of the existence of one single working tubular well in each 5-km2 cell, there would be a total number of 120,000 wells exploiting groundwater resources within this region. The average depths of the wells are 60 m and the mean yields are situated between 1 and 3 m3/h. Statistically, yield distribution assumes a lognormal model, with median oscillating around 1 and 2 m3/h. Möbus et al. (1998) found the value of 1.7 m3/h for the yield of tubular wells at crystalline regions of the state of Ceará. Adopting the lower value found for the median, that is, 1 m3/h, and admitting a pumping regime of 6/24 h (considered low), the daily quantity of water delivered would be 720 million L/day, supplying 3.6-million inhabitants at a daily consumption rate of 200 L/inhabitant/day. However, according to the assessment done by the Brazilian Geological Service, the percentage of freshwater within this region is about 20%–30%, reducing the production of freshwater drastically. The most important factor that hinders groundwater use within this region is given by quality constraints. At the southeast area, the existing water boreholes tend to have depths between 100 and 150 m due to the occur-rence of thick-weathering covers. The yields are higher than in the northeast, averaging about 5–10 m3/h and delivering water of good physical and chemical quality (Feitosa and Feitosa, 2011).

Groundwater quality in the domain of crystalline rocks in the northeast region. (From Feitosa, F. A. C. 2008. Compartimentação qualitativa das águas subterrâneas das rochas cristalinas do Nordeste oriental. UFPE, Proposta de Tese de Doutoramento, Feitosa, F. A. C., Manoel Filho, J., Feitosa, E. C., and J. G. A. Demetrio. Hidrogeologia: conceitos e aplicações. 3

Figure 3.11   Groundwater quality in the domain of crystalline rocks in the northeast region. (From Feitosa, F. A. C. 2008. Compartimentação qualitativa das águas subterrâneas das rochas cristalinas do Nordeste oriental. UFPE, Proposta de Tese de Doutoramento, Feitosa, F. A. C., Manoel Filho, J., Feitosa, E. C., and J. G. A. Demetrio. Hidrogeologia: conceitos e aplicações. 3a Edição Revisada e Ampliada. Rio de Janeiro: CPRM, 2008.)

3.8  Use of Groundwater in Brazil

The urban and rural population growth together with an expressive expansion of agriculture and industrial activities experienced by the nation have led to a remarkable increase in the use of groundwater. There is a close spatial connection between population growth and quality and quantity availability. Groundwater potability can be analyzed after electrical conductivities values because that directly reproduces the dissolved salt content of samples for the whole country, as it was represented in the hydrogeological map of Brazil (Diniz et al., 2014). A great part of the Brazilian territory shows water of excellent quality (electrical conductivity <150 μS/cm), mainly at the north and midwest. Similar to this one, other regions, such as the south and the southeast and the northeast states of Maranhão and Piauí, do have good water quality (electrical conductivities between 150 and 500 μS/cm) suitable for all kinds of uses. These low saline content zones coincide with the major Paleozoic basins (Amazonas, Parecis, Paraná, and Parnaíba). Besides them, low electrical conductivity values are also found within the Urucuia Aquifer at the borders with the states of Bahia and Goiás, Tocantins and Maranhão, and Piauí. Areas with high saline contents are found at crystalline areas in the northeast region of the country. Waters bearing intermediate quality are found at the Recôncavo—Tucano-Jatoba Basin and Potiguar and Araripe Basin as well. Figure 3.12 illustrates the spatial distribution of the electrical conductivity values for the entire country. Analyzing Table 3.2 it is clear that in many areas of the northern and midwestern regions, despite the good groundwater quality, well density is very small due to the low urban density development and enormous superficial water availability. The northeast region of semiarid climate conditions, which encompasses large regional capitals such as Recife, Fortaleza, Natal, Joao Pessoa, and Maceió, some of them partially supplied with groundwater, present the greatest well density of the country—more than 50% of registered wells consuming 41% of the total volume of extracted groundwater in the entire country.

Although these waters are frequently saline, they still represent the only available water source. From a general overview, the largest groundwater exploitation takes place at the coastal areas, increasing toward the east and south, coherent with the main urbanization and industrialization axis of the country. The overall volumes according to each region in the country are found in Table 3.2.

Distribution of the electrical conductivity in Brazil. (Modified from Diniz, J. A. O. et al. 2014. de, Mapa hidrogeológico do Brasil ao milionésimo: Nota técnica. Recife: CPRM—Serviço Geológico do Brasil, Recife.)

Figure 3.12   Distribution of the electrical conductivity in Brazil. (Modified from Diniz, J. A. O. et al. 2014. de, Mapa hidrogeológico do Brasil ao milionésimo: Nota técnica. Recife: CPRM—Serviço Geológico do Brasil, Recife.)

Table 3.2   The Use of the Groundwater in Brazil

Geographic Region

State

Área (km2)

Number of Wells

Wells/10 0 km2

Brazil (%)

Annual Volume Exploited (m3)

Brazil (%)

Norte

Acre

164.123,04

647

0.39

0.27

15.742.165

0.17

 

Amazonas

1.559.159,15

7134

0.46

2.96

617.083.709

6.59

 

Amapá

142.828,52

105

0.07

0.04

11.400.410

0.12

 

Pará

1.247.954,67

6809

0.55

2.82

456.689.795

4.88

 

Rondonia

237.590,55

1794

0.76

0.74

96.057.123

1.03

 

Roraima

224.300,51

906

0.4

0.38

55.572.734

0.59

 

Tocantins

277.720,52

1211

0.44

0.5

68.539.787

0.73

Total Norte

 

3.853.676,96

18606

0.48

7.72

1.321.085.723

14.11

Ne

Alagoas

27.778,51

1211

4.36

0.5

33.149.230

0.35

 

Bahia

564.733,18

21943

3.89

9.1

833.999.175

8.91

 

Ceará

148.920,47

21098

14.17

8.75

345.643.058

3.69

 

Maranhão

331.937,45

11332

3.41

4.7

658.216.578

7.03

 

Paraíba

56.469,78

17781

31.49

7.37

207.294.650

2.21

 

Pernambuco

98.148,32

25416

25.9

10.54

536.515.417

5.73

 

Piauí

251.577,74

27721

11.02

11.5

776.444.593

8.3

 

R.G. Do Norte

52.811,05

9557

18.1

3.96

385.816.506

4.12

 

Sergipe

21.915,12

4956

22.61

2.06

67.658.849

0.72

Total Nordeste

 

1.554.291,62

141015

9.07

58.43

3.844.738.056

41.08

Centro Oeste

Distrito Federal

5.780,00

198

3.43

0.08

8.219.712

0.09

 

Goiás

340.111,78

3181

0.94

1.32

100.760.244

1.08

 

Mato Grosso

903.366,19

3535

0.39

1.47

183.807.837

1.96

 

Mato G. Do Sul

357.145,53

1377

0.39

0.57

185.152.320

1.98

Total C. Oeste

 

1.606.403,50

8291

0.52

3.44

477.940.113

5.11

Sudeste

Espírito Santo

46.095,58

1010

2.19

0.42

23.703.519

0.25

 

Minas Gerais

586.522,12

19316

3.29

8.01

712.075.045

7.61

 

Rio De Janeiro

43.780,17

488

1.11

0.2

13.054.442

0.14

 

São Paulo

248.222,80

18607

7.5

7.72

1.498.161.956

16.01

Total Sudeste

 

924.620,67

39421

4.26

16.35

2.246.994.962

24.01

Sul Paraná

199.307,92

12429

6.24

5.15

683.350.782

7.3

 

R.G. Do Sul

281.731,44

14670

5.21

6.08

581.358.666

6.21

 

Santa Catarina

95.737,00

7260

7.58

3.01

204.217.799

2.18

Total Sul

 

576.776,36

34359

5.96

14.24

1.468.927.247

15.69

Total Brazil

 

8.515.767,05

241.692

2.84

9.359.686.101

 

Source: Based on SIAGAS—Groundwater Information System—www.cprm.gov.br.

References

Almeida, F. F. M., B. B. Brito Neves, and Carneiro, C. D. R. 2000. The origin and evolution of the South American platform. Earth Science Reviews, 50:77–111.
Bahia, R. B. C. Evolução Tectonossedimentar da Bacia dos Parecis—Amazônia. 2007. 115 f. Tese (Doutoramento em Ciências Naturais)—Escola de Minas, Universidade Federal de Ouro Preto, Ouro Preto. 2007.
Barison, M. R. 2003. Estudo Hidroquímico da Porção Meridional do Sistema Aquífero Bauru no Estado de São Paulo. 2003, 153p. Tese (Doutorado em Geociências e Meio Ambiente)—Instituto de Geociência e Ciências Exatas, UNESP, Rio Claro—SP.
Bocardi, L. B., Rostirolla, S. P., Deguchi, M. G. F., and F. Mancini. 2008. História de soterramento e diagênese em arenitos do Grupo Itararé—implicações na qualidade de reservatórios. Rev. Bras. Geoc., 38:207–216.
Caetano-Chang, M. R. 1997. A Formação Pirambóia no centroleste do estado de São Paulo. 1997. Tese (Livre Docência em Geologia) Instituto de Geociências e Ciências Exatas—Rio Claro, Universidade Estadual Paulista (UNESP), Rio Claro.
Campos, H. C. S. 2004. Águas subterrâneas na Bacia do Paraná. Geosul, Florianópolis, 19(37): 47–65.
Celligoi, A. and U. Duarte. 2002. Hidrogeoquímica do Aquí fero Caiuá no Estado do Paraná. Boletim Paranaense de Geociências, n. 51, pp. 19–32, 2002. Editora UFPR.
Coelho, R. O. 1996. Estudo hidroquímico e isotópico do aquífero Bauru, Sudoeste do Estado de São Paulo. Dissertação (Mestrado em Recursos Minerais e Hidrogeologia)—Instituto de Geociências, Universidade de São Paulo, São Paulo.
CPRM—Serviço Geológico do Brasil. 2003. Geologia, tectônica e recursos minerais do Brasil: Texto, mapas & SIG. Organizadores: Bizzi, L. A., Schobbenhaus, C., Vidotti, R. M., and Gonçalves, J. H. Brasília.
CPRM—Serviço Geológico do Brasil. 2014. Mapa Hidrogeológico do Brasil ao Milionésimo. Organizadores: Diniz, J. A. O., Monteiro, A. B., De Paula, T. L. F., and Silva, R. C. Recife.
CPRM—Serviço Geológico do Brasil; Universidade Federal do Ceará—UFC. 2008a. Projeto Comportamento das Bacias Sedimentares da Região Semiárida do Nordeste Brasileiro/Hidrogeologia da Porção Oriental da Bacia Sedimentar do Araripe-Ceará. Fortaleza.
CPRM—Serviço Geológico do Brasil; Universidade Federal do Ceará—UFC. 2008b. Projeto Comportamento das Bacias Sedimentares da Região Semiárida do Nordeste Brasileiro/Hidrogeologia da Bacia Sedimentar de Lavras da Mangabeira-Ceará. Fortaleza.
CPRM—Serviço Geológico do Brasil; Universidade Federal de Campina Grande—UFCG. 2008. Projeto Comportamento das Bacias Sedimentares da Região Semiárida do Nordeste Brasileiro/Hidrogeologia da Bacia Sedimentar do Rio do Peixe-Paraíba. Fortaleza.
CPRM—Serviço Geológico do Brasil; Universidade Federal de Pernambuco—UFPE. 2008. Projeto Comportamento das Bacias Sedimentares da Região Semiárida do Nordeste Brasileiro/Hidrogeologia da Bacia de Jatobá—Sistema Aquífero Tacaratu/Inajá. Fortaleza.
DAEE—Departamento de Águas e Energia Elétrica do Estado de São Paulo. 1974. Estudo de águas subterrâneas—Região Administrativa 6—Ribeirão Preto. São Paulo: DAEE. 4 v.
DAEE—Departamento de Águas e Energia Elétrica do Estado de São Paulo. 1976. Estudo de Águas Subterrâneas—Regiões Administrativas 7, 8, 9—Bauru, São José do Rio Preto, Araçatuba. São Paulo: DAEE. v. 1 e 2.
DAEE—Departamento de Águas e Energia Elétrica do Estado de São Paulo. 1979. Estudo de Águas Subterrâneas—Regiões Administrativas 10 e 11—Presidente Prudente e Marília. São Paulo: DAEE, v.1 e 2.
DAEE—Departamento de Águas e Energia Elétrica do Estado de São Paulo. 1981. Estudo de Águas Subterrâneas—Região Administrativa 5—Campinas. São Paulo: DAEE. 2 v.
DAEE—Departamento de Águas e Energia Elétrica do Estado de São Paulo. 1982. Estudo de Águas Subterrâneas—Região Administrativa 4—Sorocaba. São Paulo: DAEE. 2 v.
DAEE—Departamento de Águas e Energia Elétrica do Estado de São Paulo. 1984. Caracterização dos recursos hídricos no Estado de São Paulo. DAEE, São Paulo.
DAEE—Departamento de Águas e Energia Elétrica: IG-Instituto Geológico: IPT-Instituto de Pesquisas Tecnológicas do Estado de São Paulo: CPRM-Serviço Geológico do Brasil, 2005. Mapa de águas subterrâneas do Estado de São Paulo. Escala 1:100.000. Coordenação Geral Gerôncio Rocha. São Paulo.
Diniz, J. A. O., Monteiro, A. B., Silva, R. de C. T. L. F., and Paula. 2014. de, Mapa hidrogeológico do Brasil ao milionésimo: Nota técnica. Recife: CPRM—Serviço Geológico do Brasil, Recife.
Diogo, A., Bertachini, A. C., Campos, H. C. N. S., and R. B. G. S. Rosa. 1981. Estudo preliminar das características hidráulicas e hidroquímicas do Grupo Tubarão no estado de São Paulo. In: SBG, Simp. Reg. Geol., 3, Curitiba, Atas, 1:359–368.
Eiras, J. F., Becker, C. R., Souza, E. M., Gonzaga, J. E. F., Silva, L. M., Daniel, L. M. F., Matsuda, N. S., and F. J. Feijó. 1994. Bacia do Solimões. Boletim de Geociências da PETROBRAS, Rio de Janeiro, 8(1): 17–45.
Eiras, J. F., Kinoshita, E. M., and F. J. Feijó. 1994a. Bacia do Tacutu. Boletim de Geociências da PETROBRAS, Rio de Janeiro, 8(1): 83–89.
Feitosa, E. C. and J. G. A. Demetrio. 2009. Os Aquíferos Cabeças e Serra Grande no vale do Gurguéia: síntese dos conhecimentos e perspectivas de explotação. LABHID/UFPE. Recife: Relatório Inédito.
Feitosa, E. C. and J. G. Melo. 1998. Estudos de Base—Caracterização Hidrogeológica dos Aquíferos do Rio Grande do Norte. In: Hidroservice, Plano estadual de recursoshídricos do Rio Grande do Norte.
Feitosa, F. A. C. and E. C. Feitosa. 2011. Realidade e perspectivas de uso racional de águas subterrâneas na região semi-árida do Brasil. In: Medeiros, S. S., Gheyi, H. R., Galvão, C. O. and V. P. S. Paz. Recursos Hídricos em Regiões Áridas e Semiáridas, Campina Grande, INSA, pp. 269–305.
Feitosa, F. A. C. 2008. Compartimentação qualitativa das águas subterrâneas das rochas cristalinas do Nordeste oriental. UFPE, Proposta de Tese de Doutoramento, Feitosa, F. A. C., Manoel Filho, J., Feitosa, E. C., and J. G. A. Demetrio. Hidrogeologia: conceitos e aplicações. 3a Edição Revisada e Ampliada. Rio de Janeiro: CPRM, 2008.
França, A. B., Araujo, L. M., Maynard, J. B., and P. E. Potter. 2003. Secondary porosity formed by deep meteoric leaching: Botucatu eolanite, southern South America. AAPG Bulletin, 87(7): 1073–1082.
França, A. B. and P. E. Potter. 1989. Estratigrafia, ambiente deposicional do Grupo Itararé (Permocarbonífero), Bacia do Paraná (Parte 2). Boletim Geociências Petrobrás, 3:17–28.
Gaspar, M. T. P. 2006. Sistema aquífero Urucuia: caracterização regional e propostas de gestão. Brasília: UNB. Tese de doutorado.
Gesicki, A. 2007. Evolução diagenética das Formações Pirambóia e Botucatu (Sistema Aquífero Guarani) no Estado de São Paulo. Tese de Doutorado. Instituto de Geociências—USP. São Paulo.
Góes, A. M. and F. J. Feijó. 1994. Bacia do Parnaíba. Boletim de Geociências da PETROBRAS. Rio de Janeiro, 8(1): 57–67.
IBGE—Instituto Brasileiro de Geografia e Estatística, 2010. Base cartográfica vetorial contínua do Brasil ao milionésimo—BCIM. Ver. 3. Rio de Janeiro.
Iritani, M. A., Oda, G. H., Kakazu, M. C., Campos, J. E., Ferreira, L. M. R., Silveira, E. L., and A. A. B. Azevedo. 2000. Zoneamento das características hidrodinâmicas (transmissividade e capacidade específica) do Sistema Aquífero Bauru no Estado de São Paulo—Brasil. In: Assessment of Groundwater Resources in Brazil Congresso Mundial Integrado de Águas Subterrâneas, 1 e (ABAS, 11 e ALHSUD, 5), Fortaleza—CE, Brasil, Boletim de Resumos. p. 147.
Lastoria, G., Sinelli, O., Chang, H. K., Hutcheon, I., Paranhos Filho, A. C., and D. Gastmans. 2006. Hidrogeologia da Formação Serra Geral no estado de Mato Grosso do Sul. Águas Subterrâneas, 20(1): 139–150.
LEBAC—Laboratório de Estudo de Bacias. 2008. Informe Final de Hidrogeologia Regional do SAG. In: Gastmans, D. and H. K. Chang (Coord.). Informe Técnico do Consórcio Guarani. Rio Claro.
Machado, J. L. F. 2005. Compartimentação Espacial e Arcabouço Hidroestratigráfico do Sistema Aquífero Guarani no Rio Grande do Sul. 2005, 238 p. Tese (Doutorado em Geologia).—Programa de Pós-Graduação em Geologia Sedimentar, Universidade do Vale do Rio dos Sinos (UNISINOS). São Leopoldo (RS).
Machado, J. L. F. and U. F. Faccini. 2004. Influência dos falhamentos regionais na estruturação do Sistema Aquífero Guarani no Estado do Rio Grande do Sul. In: ABAS, Congresso Brasileiro de Águas Subterrâneas, 13, Cuiabá, Anais CD-ROM, pp. 1–14.
Manoel, F. J. 1996. Modelo de dimensão fractal para avaliação de parâmetros hidráulicos em meio fissural. São Paulo: USP, Tese de Doutorado.
Matta, M. A. S. 2002. Fundamentos hidrogeológicos para a gestão integrada dos recursos hídricos da região de Belém/Ananindeua, Pará/Brasil. Tese de Doutoramento apresentada à Universidade Federal do Pará, Belém.
Milani, E. J. 2004. Comentários sobre a origem e a evolução tectônica da Bacia do Paraná. In: Montesso-Neto, V., Bartorelli, A., Carneiro, C. D. R., and B. B. Brito Neves. Geologia do Continente Sul-Americano—Evolução da obra de Fernando Flávio Marques de Almeida. Ed. Becca, pp. 265–279.
Milani, E. J., Melo, J. H. G., Souza, P. A., Fernandes, L. A., and A. B. França. 2007. Bacia do Paraná. Boletim de Geociências da Petrobras, 15(2): 265–287.
Milani, E. J. and P. V. Zalán. 1998. Brazilian Geology Part 1: the Geology of Paleozoic Cratonic Basins and Mesozoic Interior Rifts of Brazil. In: AAPG, International Conference and Exhibition, Rio de Janeiro, Brazil. Short Course Notes.
Möbus, G., Silva, C. M. S. V., and F. A. C. Feitosa. 1998. Perfil estatístico de poços no cristalino cearense. IIISimpósiodeHidrogeologiadoNordeste. Recife, Anais.
OEA—Organização dos Estados Americanos. 2009. Aquífero Guarani: programa estratégico de ação—PEA. OEA: Brasil; Argentina; Paraguai; Uruguai, 2009.
Oliveira, F. R., Cardoso, F. B. F., Manoel Filho, J., Kirchheim, R., Feitosa, E. C., Teixeira, H. R., Varella Neto, P. L., Gonçalves, M. V. C., and F. S. Nascimento. 2012. Gestão Compartilhada de Águas Subterrâneas na Chapada do Apodi, entre os Estados do Ceará e Rio Grande do Norte. XVII CongressoBrasileiro de ÁguasSubterrâneas, Bonito/MS.
Paula e Silva, F. 2003. Geologia de subsuperfície e hidroestratigrafia do Grupo Bauru no Estado de São Paulo. Tese de Doutorado, Instituto de Geociências e Ciências Exatas, Universidade Estadual Paulista (UNESP), Rio Claro.
Paula e Silva, F., Kiang, C. H., and M. R. Caetano-Chang. 2005. Hidroestratigrafia do Grupo Bauru (K) no Estado de São Paulo. Águas Subterrâneas, 19(2): 19–36.
Rebouças, A. C. 1978. Potencialidades hidrogeológicas dos basaltos da Bacia do Paraná no Brasil. In: Congresso Brasileiro De Geologia, 30, Recife, Anais, v. 6, Recife: SBG. pp. 2963–2976.
Rebouças, A. da C., Manoel Filho, J., and B. B. Brito Neves. 1969. de Inventário hidrogeológico básico do Nordeste— Programa e Normas Técnicas. Recife: SUDENE—Superintendência de Desenvolvimento do Nordeste. Divisão de Documentação.
SADC—Southern African Development Community. 2009. Folheto Explicativo do Mapa e Atlas Hidrogeológico da Comunidade para o Desenvolvimento da África Austral (SADC). [Lusaka, Zambia]: SADC, March 2009. (Projecto de Elaboração do Mapa Hidrogeológico da SADC).
Soares, A. P., Soares, P. C., and M. Holz. 2008. Heterogeneidades hidroestratigráficas no sistema Aquífero Guarani. Revista Brasileira de Geociências, 38(4): 600–619.
Souza de E. L., Galvão, P. H. F., and C. S. do Pinheiro. 2013. Síntese da hidrogeologia nas bacias sedimentares do Amazonas e do Solimões: Sistemas Aquíferos IçáSolimões e Alter do Chão. Geological USP, Sér. cient. 13(1), São Paulo mar.
Stradioto, M. R. 2007a. Hidroquímica e aspectos diagenéticos dos Sistema Aquífero Bauru na região sudoeste do estado de São Paulo. 103 f. Dissertação (Mestrado)— Curso de Geociências e Meio Ambiente, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro.
Stradioto, M. R. 2007b. Hidroquímica e aspectos diagenéticos do Sistema Aquífero Bauru na região sudeste do estado de São Paulo. Dissertação (Mestrado em Geociências e Meio Ambiente)—Instituto de Geociências e Ciências Exatas, Universidade Estadual Paulista. Rio Claro.
Struckmeier, W. F. and J. Margat. 1995. Hydrogeological Maps: A Guide and a Standard Legend. International Association of Hydrogeologists—Hannover (International) Contributions to Hydrogeology; Vol. 17).
Tancredi, A. C. F. N. S. 1996. Recursos hídricos subterrâneos de Santarém: fundamentos para uso e proteção. 154 p. Tese (Doutorado)—Curso de Pós-Graduação em Geologia e Geoquímica, Centro de Geociências, Universidade Federal do Pará, Belém.
UNESCO—United Nations Educational, Scientific and Cultural Organization, 1970. International Legend for Hydrogeological Maps. Paris, published by Cook, Hammond & Kell Ltd, England, 101 pp.
Vidal, A. C. 2002. Estudo Hidrogeológico do Aquífero Tubarão na Área de Afloramento da Porção Central do Estado de São Paulo. IGCE/UNESP, Rio Claro SP. 109 p. (Tese de Doutorado).
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