Past and future climate evolution and its impact on aquifers of Recife

03/09/15 PAST AND FUTURE CLIMATE EVOLUTION AND ITS IMPACT ON
AQUIFERS OF RECIFE (BRAZIL)
Ricardo Hirata1, Melissa Franzen2, Suzana Montenegro3, Emmanuelle Petelet4
CEPAS | USP – Groundwater Research Center | University São Paulo
CPRM - Geological Survey of Brazil
3 UFPE - Federal University of Pernambuco
4 BRGM - Bureau de Recherches Géologiques et Minières
1
2
THIS PRESENTATION IS PART OF COQUEIRAL PROJECT
Challenge Of water Quality in Urban Environmental Issue: Recife Aquifers and Land use. How
to face groundwater salinization and contamination under global environmental change in its
societal context.
CONSORTIUM OF COQUEIRAL PROJECT
COQUEIRAL is a Franco-Brazilian research project funded by ANR (ANR-11-CEPL-012) / FACEPE
(APQ-0077-3.07/11) / FAPESP (2011/50553-0) under the Global Environmental Changes and Societies (GEC&S)
Program PARTNER
S
FUNDERS
CPRM - Serviço Geológico do Brasil
COORDINATOR
S
INPE - Instituto Nacional de Pesquisas Espaciais
APAC - Agência Pernambucana de Águas e Clima
UFPE - Universidade Federal de Pernambuco
CEPAS | USP
Universidade de São Paulo
BRGM - Bureau de Recherches
Géologiques et Minières
CeRIES - Université de Lille 3
OSUR - Université de Rennes 1
GÉO-HYD
1 03/09/15 TASKS OF
COQUEIRA
L PROJECT
/ CPRM
/ BRGM
- USP
STUDY
AREA
General
view of the
estuary and
mangroves
• 
• 
• 
Northeast
of Brazil
Plain of
Recife
The fourth
largest
Brazilian
metropolis
2 03/09/15 URBANIZATIO
N
1970 1930 Today 1950 RECIFE: A CITY DEPENDENT ON GROUNDWATER
•  The city of Recife has been facing intense groundwater exploitation problems, resulting in
lowering of potentiometric levels (< 90mbsl) and salinity in several wells.
INCREASING OF WELLS
•  Frequent droughts (2009, 2012) causing many
water rationing.
•  And a strong deficiency in sanitation
infrastructure have caused the drilling of many
water wells.
•  It is estimated around 13,000 private wells,
mostly of them illegal.
V RH 20150831 8h00 3 03/09/15 REGIONAL AND LOCAL GEOLOGY
Metropolitan Region of Recife
Fonte: Lima Filho (2014)
Residual Gravimetric Map
(2003)
Geological Map
Source: CPRM
SEISMIC PROFILES OF PERNAMBUCO AND PARAIBA
BASINS
Source: Barbosa e Lima Filho (2005)
4 03/09/15 SCHEMATIC PROFILES IN CONTINENTAL AREA
•  PARAÍBA BASIN In con8nental area shows a homocline conforma8on and a b s e n c e o f t e c t o n i c 8 l 8 n g , characteris8c of marginal basins. •  PERNAMBUCO BASIN Displays intense tectonic 8l8ng followed by clas8c sedimenta8on of conglomerates of basin border, and the events of magma8c intrusion and volcanism. Source: Barbosa (2004)
HYDROGEOLOGY OF RECIFE There are five principals aquifers:
1. 
2. 
3. 
4. 
5. 
Fissural
Cabo
Beberibe
Barreiras
Boa Viagem (include the Quaternary deposits)
5 03/09/15 WELLS FOR AQUIFER
Beberibe
Cabo
Boa Viagem
Barreiras
Fissural
Yield - 18 m3/h
Public water supply
Yield - 5 m3/h
Highest density wells
Yield - 17 m3/h
Overlap deep aquifers
Yield - 14 m3/h
Private water supply
Yield - 6 m3/h
Source: Arouet
(2012).
POTENCIOMETRIC
LEVEL
IN BEBERIBE AQUIFER
The potentiometric level dropped
until 50 mbsl in the north of the
region
Source: CPRM
(2015).
6 03/09/15 POTENCIOMETRIC
LEVEL
IN CABO AQUIFER
The potentiometric level dropped
until 90 mbsl in the south of the
region
Source: CPRM
(2015).
ELECTRIC CONDUCTIVITY OF WATER OF
DEEP WELLS
Beberibe
Aquifer
Cabo Aquifer
7 03/09/15 ELECTRIC CONDUCTIVITY OF WATER
IN UNCONFINED BOA VIAGEM
AQUIFER
Data /
Source:
CPRM
(2014).
Data: Hidrorec II (2002)
Source: Arouet (2012).
Cabo and Beberibe are naturally protected aquifers Recife is located in a complex hydrogeological context, which conforms two different Cretaceous confined aquifers: Cabo System and Beberibe, covered by two Cenozoic unconfined aquifers: Barreiras and Boa Viagem. •  The Precambrian basement consists of gneiss and metamorphic rocks. • 
(Cary et al 2015) 8 03/09/15 Cabo and Beberibe are naturally protected aquifers • 
The water age of the Cabo and Beberibe aquifers is >18000 years (14C esFmaFon), ( ChaYon 2014) CAS&BA 14C water age (Cary et al 2015) Cabo and Beberibe are naturally protected aquifers • 
• 
The water age of the Cabo and Beberibe aquifers is >18000 years (14C esFmaFon). Aquifers were recharged when the atmospheric temperature was 10°C lower than the current one (noble gases es8ma8on) associated to the Last Glacial Maximum (LGM). Current Recife air temperature = 25oC -­‐10oC CAS&BA 14C water age 9 03/09/15 Cabo and Beberibe are naturally protected aquifers • 
Stute et al (1995) have observed similar results in the state of Piaui (North) – Brazil and other countries -­‐10oC Cabo and Beberibe are naturally protected aquifers • 
The Cabo and Beberibe aquifers resisted to the marine transgression (seawater level up to 5 m higher than current level) that occurred in the area from 6k – 3k years BP •  There is a geochemical evidence (refreshing) that 123k years ago marine transgression had salinized the whole Cabo and Beberibe aquifers CAS&BA 14C water age 10 03/09/15 Cabo and Beberibe are naturally protected aquifers • 
• 
• 
Beberibe and Cabo aquifers are confined with low groundwater flow velocity (0.001 m/year), controlled by limited discharge into the sea, blocked by a structural barrier boundary located 4 km from the coast. The residual gravimetric survey detected this structure along the cost BA and CAS recharge is located in the basement outcrop area in the west of Recife (Hirata et al unplublished) (Barbosa et al 2014) But affected by a very intense exploita8on • 
Although there is a very intense exploita8on (density up to 330 wells/km2), the saliniza8on in Beberibe & Cabo aquifers is s8ll restricted •  The confinement explains why the intense aquifer exploita8on -­‐ that creates poten8ometric levels lower than 50m (N)-­‐90m (S) below sea level -­‐ is not affecFng the water quality by salinizaFon or even contaminaFon from the shallower unconfined and locally contaminated Boa Viagem Aquifer. 11 03/09/15 But the intense exploita8on + climate change will affect these aquifers • 
• 
• 
Climate change scenarios for year 2100: i) increase seawater level +0.8m above current level, impac8ng the shallow aquifers; ii) rainfall -­‐20% and the droughts will be more frequent and intense, impac8ng the recharge and reducing the surface water offer Seawater level un8l 2100; based on the tendency observed on the Brazilian coast 0.28+0.02 cm/year Joseph Harari IO/USP But the intense exploita8on + climate change will affect these aquifers • 
• 
• 
> 23 Climate change scenarios for year 2100 (Global Model HadGEM – ES, INPE Model): i) increase seawater level +0.8m above current level, impac8ng the shallow aquifers; ii) reduce the rainfall -­‐20% and the droughts will be more frequent and intense, impac8ng the recharge and reducing the surface water offer (Lincoln Alves -­‐ INPE) 2011-­‐2040 2041-­‐2070 2071-­‐2100 Representa8ve concentra8on Sea level up to 2100 pathway RCP 4.5 Representa8ve concentra8on pathway RCP 8.5 12 03/09/15 With inauspicious future … •  The ModFlow+Seawat model has predicted that maintaining the current pumping rate: i)  saltwater intrusion into Cabo+Beberibe aquifers through the aquitard; and ii)  saliniza/on of the unconfined Boa Viagem and Barreiras aquifers due to rising seawater level and decreasing natural and anthropogenic (reducFon of mains leakages) recharges sea Seawater intrusion reaching the Cabo aquifer in 2100 C C' In conclusion •  Cabo and Beberibe are very important to public and private water supply of Recife Metropolitan Region •  Due to infrastructure sanita8on problems, Recife could not do without Cabo Aquifer to the addi8onal supply to the public system •  Cabo and Beberibe are confined systems that are s8ll protected from intense exploita8on (14k wells, most of them illegal) •  The intense exploita8on has been changing completely the groundwater flow that in long term will result in the saliniza8on of Cabo and Beberibe aquifers •  The increase of seawater level and reduc8on of natural and induced recharge will create condi8on to saliniza8on of part of Boa Viagem aquifer 13 03/09/15 Melissa Franzen
Researcher Brazilian Geological Survey (CPRM)
Superintendência Regional de Recife
Av. Sul, 2291
CEP 50770-010
Recife PE Brazil
E-mail: [email protected]
www.cprm.gov.br
Ricardo Hirata
Vice-Diretor Groundwater Research Center - CEPAS | USP
University of São Paulo (USP)
Rua do Lago, 565
CEP 05508
São Paulo SP Brazil
E-mail: [email protected]
www.igc.usp.br/cepas
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