round table 1 climate variability assessment and … · (blue) have the highest recharge change,...

The Fourth Inter-Celtic Colloquium onHydrology and Management of Water Resources NASNAS Water in Celtic Countries:

Quantity, Quality and Climate variabilityUniversidade do Minho, Guimarães

July 11-13, 2005

ROUND TABLE 1 ROUND TABLE 1 "CLIMATE VARIABILITY ASSESSMENT AND"CLIMATE VARIABILITY ASSESSMENT AND RELEVANCE“RELEVANCE“

On methodologies for the assessment of On methodologies for the assessment of climate change impacts on groundwater resources climate change impacts on groundwater resources

João Paulo Lobo Ferreira [email protected]

Maria Emília Novo [email protected]

Manuel Mendes Oliveira [email protected]

Catarina Diamantino [email protected]

mailto:[email protected]




Climate variability assessment Climate variability assessment and relevance:and relevance:

On methodologies for the On methodologies for the assessment of climate change assessment of climate change

impacts on groundwater resourcesimpacts on groundwater resources

MARIA EMÍLIA NOVO



July 11-13, 2005

Models to predict the impact of the Models to predict the impact of the climate changes on aquifer rechargeclimate changes on aquifer recharge

[email protected] Mendes Oliveira1

Maria Emília Novo2 [email protected]

João Paulo Lobo Ferreira1 [email protected]

1 Laboratório Nacional de Engenharia Civil (LNEC) Hydraulics and Environment Department (DHA), Groundwater Division (NAS)

Av. do Brasil, 101, 1700-066 Lisboa, PortugalInternet: http://www.dha.lnec.pt/nas/

2 Parque Natural do Douro Internacional, Largo do Outeiro, n.º 6, 5810-118 Freixo de Espada à Cinta, Portugal




http://www.dha.lnec.pt/nas/

The Fourth Inter-Celtic Colloquium onHydrology and Management of Water Resources

NASNASWater in Celtic Countries:


July 11-13, 2005

Climate change, seawater rise and saltwater Climate change, seawater rise and saltwater vulnerability assessment in coastal aquifersvulnerability assessment in coastal aquifers

Catarina Diamantino [email protected]. J. Henriques [email protected] M. Oliveira [email protected]ão Paulo Lobo Ferreira [email protected]

Laboratório Nacional de Engenharia Civil (LNEC) Hydraulics and Environment Department (DHA), Groundwater Division (NAS) Av. do Brasil, 101, 1700-066 Lisboa, PORTUGALInternet: http://www.dha.lnec.pt/nas/








July 11-13, 2005

Methods to predict Groundwater RechargeMethods to predict Groundwater Recharge

Water mass balance above the saturated zone – predictive methods

Sequential daily water balanceSequential daily water balance modelmodel ––the the BALSEQBALSEQ modelmodel (Lobo Ferreira, 1981)(Lobo Ferreira, 1981)

day = day + 1

P > 5080 / NC - 50.8 ? No Sr = 0

Yes

Is = P - SrHl = Al + Is

Hl > AGUT ?

Yes

Dp = Hl - AGUTAl = AGUT

Dp = 0Al = Hl

Start

read Pread ETP

Last day?

Yes

End

( )8/8004.25/

2/2004.25/4.25 2

−++−

=NCP

NCPSr

Hl > PET ?

Yes

No RET = Hl

RET = PET

Hl = Hl - RET

No

No

Soil

Vadose zone below soil

Saturated zone

Surface water

∆Al

Sr

D

groundwater level

RET

Is

Dp

P

XR

P = precipitationSr = surface runoffIs = surface infiltration∆Al = difference of water stored in the soil in the end of the day and in the beginning of that dayRET = evapotranspirationDp = deep percolationR = rechargeD = groundwater discharge

R = Dp = P - RET - ∆Al – Sr



July 11-13, 2005


Water mass balance in the saturated zone – response methods

Soil (l)

Vadose Zone below the soil

(v)

Saturated zone (b)

Hbs

Surface water (p)

R

∆AbEbe Ebs

Hbe

D

groundwater level

Eb2e Eb2s

Spring discharge method

Flow quantification in aquifer sections

Water level change

Surface flow hydrograph separation method

Time

Tota

l flo

w

Precipi-tation

end of direct runoff

direct runoff

base flow



July 11-13, 2005


Water mass balance in the saturated zone – response methods

17L01-Ponte PanascoF = 0.6984P - 310.74

R2 = 0.9517

Fd = 0.2823P - 131.06R2 = 0.8445

Fb = 0.4161P - 179.68R2 = 0.8961

0

100

200

300

400

500

600

500 600 700 800 900 1000 1100

Precipitation (mm/a)

Flow

(mm

/a)

Total flow Direct runoff Base flowLinear (Total flow) Linear (Direct runoff) Linear (Base flow)

Avg Prec80 % Avg Prec

Avg Recharge

Recharge (80 % Avg Prec)



July 11-13, 2005

Climate Change ScenariosClimate Change Scenarios

reliable climate models are required

projections of socio-economic developments and responses to climate change

define anthropogenic emissions of greenhouse gases and aerosols

emission’s scenarios

outputs from the climate models: precipitation and temperature average values



July 11-13, 2005

ApplicationApplication

Carta Geológica de PortugalEscala 1:5000 000 (IGM, 1992)

Ponte VelhaCapitão5 km

NC = 80AGUT = 100 mmhi = 0 mm

9 yearsAvg P = 715 mm/yr

Sequential daily water balanceSequential daily water balance model model ––the the BALSEQBALSEQ modelmodel (Lobo Ferreira, 1981)(Lobo Ferreira, 1981)

day = day + 1

P > 5080 / NC - 50.8 ? No Sr = 0

Yes

Is = P - SrHl = Al + Is

Hl > AGUT ?

Yes

Dp = Hl - AGUTAl = AGUT

Dp = 0Al = Hl

Start

read Pread ETP

Last day?

Yes

End

( )8/8004.25/

2/2004.25/4.25 2

−++−

=NCP

NCPSr

Hl > PET ?

Yes

No RET = Hl

RET = PET

Hl = Hl - RET

No

No

Ponte Algalé-19N02

Monte Pisão-19N01

Rasa-17M01Moinho Novo-18I01

Ponte Barnabé-19C02

Penedos de Alenquer-19C01

Couto de Andreiros-18L01Pavia-20I04

Ponte Canha-21F01

Ponte Panasco-17L01

Herdade das Pancas-22G02

Entradas-27I01

Monte dos Pachecos-30G01

Ponte Velha Capitão-06P01

Ponte Junqueira-05E01

Aspra-03D01

Impacts on Groundwater – case study (Terceira island: Azores)

Pattern change in temperature/precipitation– Affects: (1) Recharge; (2) Evapotranspiration; (3)

Runoff; and possibly (4) Groundwater qualitySea level change: – Affects: (1) Saline intrusion; in coastal island

aquifers (2) The areal extent of these aquifers.We will deal with recharge, evapotranspirationand runoff.

Impacts on groundwaterPattern change in temperature/precipitation – In this Azores case study, a series of precipitation and evapotranspiration was changed in accordance with the trends given by RGM’s; these modified data series were used to calculate aquifer recharge in a well known aquifer: Cabrito (at Terceira island). The scenarios considered were:– precipitation increase– precipitation decrease– evapotranspiration increase– evapotranspiration decrease– precipitation + evapotranspiration increase

Impacts on groundwaterFrom the results of the recharge models, the response of different soil type/vegetation cover sets to changes in precipitation and evapotranspiration, reflected in changes in aquifer recharge and surface runoff (henceforth named simply as runoff) was studied. Correlation trends were obtained for precipitation/recharge and evapotranspiration/recharge for these soil/vegetation cover sets.The soil type/vegetation cover sets were the larger and the smaller changes in recharge occurred were identified.

Precipitation change scenarios- 0,3mm/d

- 0,5mm/d

- 1mm/d

- 15%anual

- 20%anual

Scenar.30 (1)

Scenar.40 (2)

Scenar.50 (3)

Scenar. 60 (4)

AGUT/NC

Soilmoist.

Recharge change for changed precipitation series (%)

185 -5,7 -9,2 -17,6 -17,2 -23,3 -17,1 -32,8 -7,8 -23,0186/91100 -5,8 -9,4 -18,0 -17,6 -23,9 -17,4 -33,5 -8,0 -23,5181 -3,9 -6,2 -11,8 -18,0 -24,2 -17,3 -31,9 -6,8 -20,8182/75100 -3,9 -6,2 -11,9 -18,2 -24,5 -17,5 -32,2 -6,9 -21,1

105/56 100 -3,1 -5,0 -9,8 -18,7 -25,0 -17,9 -32,1 -6,3 -20,1105/1 100 -3,0 -4,8 -9,4 -19,9 -26,5 -19,6 -33,9 -7,1 -21,099/83 100 -3,9 -6,2 -11,9 -16,0 -21,5 -15,4 -29,3 -6,2 -19,697/61 100 -3,2 -5,1 -9,9 -18,2 -24,4 -17,4 -31,5 -6,1 -19,8

100 -2,8 -4,5 -8,8 -18,9 -25,2 -24,4 -32,2 -6,4 -19,956/3855 -2,8 -4,5 -8,8 -19,0 -25,3 -18,4 -32,3 -6,5 -20,0100 -3,5 -5,6 -10,9 -12,5 -16,9 -12,2 -24,0 -5,1 -16,518/9017 -3,5 -5,7 -11,1 -12,7 -17,2 -12,4 -24,3 -5,2 -16,7

Average -3,7 -6,0 -11,7 -17,2 -23,1 -17,2 -30,8 -6,5 -20,2(1) Spring precipitation = –30%, Summer precipitation = -15%, Autumn precipitation = -35%, Winterprecipitation = +20%; average anual precipitation = –14,9%(2) Spring precipitation = –30%. Summer precipitation = -15%, Autumn precipitation = -60%, Winterprecipitation = +20%; average anual precipitation = –25,3%(3) Spring precipitation = –30%, Summer precipitation = -15%, Autumn precipitation = -35%, Winterprecipitation = +50%; average anual precipitation = – 5,8%(4) Spring precipitation = –30%, Summer precipitation = -15%, Autumn precipitation = -60%, Winterprecipitation = +50%; average anual precipitation = = – 15,9%

Impacts on groundwaterPrecipitation change scenarios

- 15% year - 20% year Scenar. 30(-14,9%)

Scenar. 20(-25,3%)

Scenar. 50(-5,8%)

Scenar. 60(-15,9%)

AGUT/NC Multiplication factor between precipitation decrease and recharge decrease186/91 1.17 1.20 1.17 1.32 1.38 1.48182/75 1.21 1.23 1.17 1.27 1.19 1.33105/56 1.25 1.25 1.20 1.27 1.09 1.26105/1 1.33 1.33 1.32 1.34 1.22 1.3299/83 1.07 1.08 1.03 1.16 1.07 1.2397/61 1.21 1.22 1.17 1.25 1.05 1.2556/38 1.26 1.26 1.64 1.27 1.10 1.2518/90 1.17 0.85 0.82 0.95 0.88 1.04

Impacts on groundwaterSoils with high infiltration capacity and tree cover (blue) have the highest recharge change, and so the highest recharge losses. Largest losses occur for large precipitation reductions in Autumn.Largest recharge losses occur in low permeability soils(high NC):– For grass cover (green), these losses follow in a very narrow way

the percipitation reductions.– For tree cover (reddish) the losses are clearly above the

precipitation reductions, being notorious for large precipitationreductions in Autumn, even if Winter precipitation increase.

Impacts on groundwaterSoils of average infiltration capacity (yellow) have a similar recharge reduction either for tree cover or for grass cover.

Impacts on groundwaterPrecipitation change scenarios

+ 6% + 10% + 15% + 20% + 25% + 30% Scenario 1(1)

AGUT/NC

Soilmoist.

Recharge change for changed precipitation series (%)

185 +5,3 +9,9 +13,4 +19,2 +23,9 +28,6 +10,8186/91100 +5,4 +10,1 +13,8 +19,6 +24,5 +29,3 +11,0181 +6,4 +10,6 +15,7 +22,3 +27,8 +33,2 +12,3182/75100 +6,5 +11,8 +15,9 +22,6 +28,1 +33,6 +12,4

105/56 100 +6,9 +12,4 +16,7 +23,8 +29,8 +35,7 +13,6105/1 100 +7,6 +13,7 +18,4 +26,5 +33,2 +40,0 +15,099/83 100 +5,5 +9,9 +13,3 +19,0 +23,5 +28,1 +11,197/61 100 +6,7 +12,0 +16,2 +23,1 +28,8 +34,5 +13,2

100 +7,0 +12,6 +19,8 +24,5 +30,6 +36,9 +13,956/3855 +7,0 +12,7 +17,1 +24,6 +30,8 +37,0 +14,0100 +3,4 +6,8 +9,5 +13,7 +17,1 +20,6 +7,718/9017 +3,5 +7,0 +9,6 +14,0 +17,4 +20,9 +7,9

Average +5,9 +10,9 +14,9 +21,1 +26,3 +31,5 +11,9(1) Wet season precipitation = +15%; no change in Summer

Precipitation change scenarios+ 6% + 10% + 15% + 20% + 25% + 30% Scenario 1

(+7,5%)AGUT/NC Multiplication factor between precipitation increase and recharge increase186/91 0.90 1.01 0.92 0.98 0.98 0.98 1.47182/75 1.08 1.18 1.06 1.13 1.12 1.12 1.65105/56 1.15 1.24 1.11 1.19 1.19 1.19 1.81105/1 1.27 1.37 1.23 1.33 1.33 1.33 2.0099/83 0.92 0.99 0.89 0.95 0.94 0.94 1.4897/61 1.12 1.20 1.08 1.16 1.15 1.15 1.7656/38 1.17 1.26 1.32 1.23 1.22 1.23 1.8518/90 0.57 0.68 0.63 0.69 0.68 0.69 1.03(1) Wet season precipitation = +15%; no change in Summer

Impacts on groundwater

Impacts on groundwaterIn soils of average infiltration - green - (medium NC) recharge change for tree cover and for brush-grass has a similar evolution.In soils of high infiltration capacity and tree cover (blue) recharge is almost always the highest; the largest recharge increase occurs for seasonal Wet period precipitation increase.In soils with high runoff potential (yellow) recharge increase is almost always inferior to average precipitation increase and can be the lowest in grass cover.

RAQ change for precipitation change - Eapotranspiration as in 1990

01020304050

186/

91/1

85

182/

75/1

81

105/

56/1

00

99/8

3/10

0

56/3

8/55

18/9

0/17

AGUT/NC/Soil moisture

RA

Q c

hang

e (%

)

pp +6%pp +10%pp +15%pp +25%pp +30%cenário 1

RAQ change for precipitation increase, on distinct AGUT (soil cover)/NC (soil type) sets

y = 92,752x + 1,1986R2 = 0,9744

y = 105,85x + 1,5201R2 = 0,9786

y = 111,85x + 1,7156R2 = 0,9731

y = 125,88x + 1,6592R2 = 0,9731

y = 87,158x + 1,6222R2 = 0,9689

y = 107,91x + 1,7145R2 = 0,9729

y = 116,42x + 1,5854R2 = 0,9722

y = 66,896x + 0,6031R2 = 0,9683

01020304050

0% 10% 20% 30% 40%

Precipitation change (%)

RA

Q c

han

ge

(%)

186/91/100 182/75/100 105/56/100105/1/100 99/83/100 97/61/10056/38/100 18/90/100 Linear (186/91/100)Linear (182/75/100) Linear (105/56/100) Linear (105/1/100)Linear (99/83/100) Linear (97/61/100) Linear (56/38/100)

RAQ change for Precipitation decrease,on distinct AGUT (soil cover)/NC (soil type) sets

y = 0,8238x - 8,4217R2 = 0,7507

y = 0,9653x - 5,2363R2 = 0,9093

y = 1,0759x - 3,224R2 = 0,9332

y = 1,1172x - 3,8815R2 = 0,9594

y = 0,8359x - 5,2773R2 = 0,8734

y = 1,0018x - 4,08R2 = 0,9366

y = 1,07x - 3,555R2 = 0,9586

y = 0,6521x - 4,9375R2 = 0,818

-40-35-30-25-20-15-10-50

-30 -25 -20 -15 -10 -5 0


RA

Q c

han

ge

(%)

186/91/100 182/75/100 105/56/100105/1/100 99/83/100 97/61/10056/38/100 18/90/100 Linear (186/91/100)Linear (182/75/100) Linear (105/56/100) Linear (105/1/100)Linear (99/83/100) Linear (97/61/100) Linear (56/38/100)Linear (18/90/100)

Recharge variation vs precipitation change

30,0

Cenar io 40

-20,0Cenár io 60

-15,0Cenár io 30

-1 mm

Cenár io 50-0.5 mm-0.3 mm

10,0

Cenár io 1

6,015,0

20,0 25,0

y = 13.758x + 1181R2 = 0.9987; erro = 7.0

0200400600800

10001200140016001800

-30,0 -20,0 -10,0 0,0 10,0 20,0 30,0 40,0


Ave

rag

e R

ech

arg

e(m

m)


Set AGUT/NC = 105/1 - shows the highest change in recharge concerning precipitation change (highest increase in recharge for precipitation increase and highest recharge decrease for precipitation decrease)Set AGUT/NC = 18/90 - shows the lowest recharge change for precipitation variation.

Evapotranspiration change scenarios+1,5% + 5% + 10% + 15% + 20% + 25% + 30% + 40% + 50%

AGUT/NC

Soilmoist

Recharge change for changed evapotranspiration series (%)

185 -1,2 -3,8 -7,6 -11,1 -14,1 -16,5 -18,7 -22,9 -26,9186/91100 -1,2 -3,9 -7,8 -11,4 -14,5 -16,9 -19,1 -23,4 -27,5181 -0,8 -2,3 -4,3 -6,3 -8,2 -10,0 -11,8 -15,4 -18,4182/75100 -0,8 -2,3 -4,4 -6,3 -8,2 -10,1 -11,9 -15,5 -18,6

105/56 100 -0,5 -1,6 -3,1 -4,5 -5,9 -7,3 -8,6 -10,9 -13,2105/1 100 -0,5 -1,5 -2,9 -4,2 -5,5 -6,8 -8,1 -10,4 -12,699/83 100 -0,7 -2,1 -4,0 -5,8 -5,7 -8,9 -10,4 -13,4 -16,397/61 100 -0,5 -1,6 -3,1 -4,5 -5,9 -7,3 -8,5 -10,8 -13,1

100 -0,4 -1,2 -2,3 -3,5 -4,5 -5,6 -6,6 -8,5 -10,456/3855 -0,4 -1,2 -2,4 -3,5 -4,6 -5,6 -6,6 -8,6 -10,5100 -0,5 -1,6 -3,1 -4,6 -6,0 -7,5 -8,9 -11,7 -14,318/9017 -0,5 -1,6 -3,1 -4,6 -6,1 -7,6 -9,1 -11,9 -14,5

Average -0,6 -2,1 -4,0 -5,9 -7,4 -9,2 -10,7 -13,6 -16,4


Impacts on groundwater Evapotranspiration change scenarios

+1,5% +5% +10% +15% +20% +25% +30% 40% +50% AGUT/NC Multiplication factor between evapotranspiration increase and recharge

decrease 186/91 -0.80 -0.78 -0.78 -0.76 -0.73 -0.68 -0.64 -0.59 -0.55 182/75 -0.53 -0.46 -0.44 -0.42 -0.41 -0.40 -0.40 -0.39 -0.37 105/56 -0.33 -0.32 -0.31 -0.30 -0.30 -0.29 -0.29 -0.27 -0.26 105/1 -0.33 -0.30 -0.29 -0.28 -0.28 -0.27 -0.27 -0.26 -0.25 99/83 -0.47 -0.42 -0.40 -0.39 -0.29 -0.36 -0.35 -0.34 -0.33 97/61 -0.33 -0.32 -0.31 -0.30 -0.30 -0.29 -0.28 -0.27 -0.26 56/38 -0.27 -0.24 -0.23 -0.23 -0.23 -0.22 -0.22 -0.21 -0.21 18/90 -0.33 -0.32 -0.31 -0.31 -0.30 -0.30 -0.30 -0.29 -0.29

Impacts on groundwaterRecharge decreases with evapotranspiration increase. Maximum reductions occur for low permeability soils(high NC) and tree cover (reddish).Lowest decrease occurs for medium-high permeabilitysoils and grass cover (blue).For medium permeability soils and tree cover the recharge change can be similar, which might hint that in medium permeability conditions, soil cover is the most effective control factor for recharge (yellow).For grass cover (green) in soils with distinct permeabilities, the recharge change is higher for low permeability soils, and lower for medium-high permeability soils.

Impacts on groundwaterEvapotranspiration change scenarios

- 5% - 10% - 15% - 20% - 25% - 30%AGUT/NC

Soilmoist

Recharge change for changed evapotranspiration series (%)

185 +4,0 +8,4 +13,3 +18,5 +23,6 +28,8186/91100 +4,1 +8,6 +13,7 +18,9 +24,2 +29,4181 +2,7 +5,3 +7,9 +10,6 +13,2 +15,9182/75100 +2,7 +5,4 +8,0 +10,7 +13,4 +16,1

105/56 100 +1,6 +3,3 +4,9 +6,5 +8,2 +10,2105/1 100 +1,5 +3,1 +4,6 +6,1 +7,7 +9,699/83 100 +2,2 +4,3 +6,5 +8,8 +11,2 +13,797/61 100 +1,7 +3,4 +5,0 +6,7 +8,4 +10,2

100 +1,2 +2,5 +3,8 +5,1 +6,6 +8,156/3855 +1,3 +2,5 +3,8 +5,2 +6,6 +8,1100 +1,6 +3,2 +4,8 +6,5 +8,4 +10,218/9017 +1,6 +3,2 +4,9 +6,7 +8,5 +10,4

Average +2,2 +4,4 +6,8 +9,2 +11,7 +14,2

Impacts on groundwaterEvapotranspiration change scenarios

- 5% - 10% - 15% - 20% - 25% - 30% AGUT/NC Multiplication factor between evapotranspiration decrease and recharge

increase 186/91 -0.82 -0.86 -0.91 -0.95 -0.97 -0.98 182/75 -0.54 -0.54 -0.53 -0.54 -0.97 -0.54 105/56 -0.32 -0.33 -0.33 -0.33 -0.97 -0.34 105/1 -0.30 -0.31 -0.31 -0.31 -0.97 -0.32 99/83 -0.44 -0.43 -0.43 -0.44 -0.97 -0.46 97/61 -0.34 -0.34 -0.33 -0.34 -0.97 -0.34 56/38 -0.24 -0.25 -0.25 -0.26 -0.97 -0.27 18/90 -0.32 -0.32 -0.32 -0.33 -0.97 -0.34

Impacts on groundwaterRecharge increases if evapotranspiration decrease. Highest recharge increase occur for tree cover and low permeability soil (reddish).Lowest recharge increase occur in medium-high permeability soils and grass soil cover (blue).Tree cover in medium to high permeability cover (yellow) and grass cover in low permeability soil do have a similar recharge change with evapotranspirationchange.Grass cover (green) have distinct recharge changes according to the soil permeability, hinting that in such type of cover, soil permeability might be the main controlling factor for recharge.

Impacts on groundwaterEvapotranspiration and precipitation change

scenarioScenario 1

AGUT/NC

Soilmoist

Recharge change for changedevapotranspiration/percipitation series (%)

185 4.1186/91100 4.2181 5.6182/75100 5.7

105/56 100 6.4105/1 100 7.199/83 100 4.997/61 100 6.3

100 6.656/3855 6.7100 2.918/9017 3.0

Average 5.3

Scenario 1 – Average percipitation rises = 6%; evapotranspiration rises = 1,5%; according Brito eGonçalves (2002)

RAQ change for evapotranspiration change - Precipitation as 1990

05

101520253035

186/

91/1

85

186/

91/1

00

182/

75/1

81

182/

75/1

00

105/

56/1

00

105/

1/10

0

99/8

3/10

0

97/6

1/10

0

56/3

8/55

56/3

8/10

0

18/9

0/17

18/9

0/10

0AGUT/NC/Soil moisture

RA

Q c

ha

ng

e (

%)

evr -5%evr -10%evr -15%ever -20%ever -25%evr -30%

RAQ change for evapotranspiration decrease, on distinct AGUT (soil cover)/NC (soil type) sets y = -102x - 1,3667

R2 = 0,9994y = -53,543x + 0,0133

R2 = 1y = -33,886x - 0,1467

R2 = 0,9986

y = -31,886x - 0,1467R2 = 0,9984

y = -46x - 0,2667R2 = 0,999y = -33,829x - 0,02

R2 = 0,9997y = -27,257x - 0,1867

R2 = 0,9986

y = -35,257x - 0,2867R2 = 0,9992

05101520253035

-35% -30% -25% -20% -15% -10% -5% 0%

Evapotranspiration change (%)

RA

Q c

ha

ng

e

(%)


RAQ change for evapotranspiration increase, on distinct AGUT (soil cover)/NC (soil type) sets

y = -53,876x - 2,1703R2 = 0,9803

y = -36,872x - 0,6274R2 = 0,998

y = -26,249x - 0,4467R2 = 0,9965

y = -25,06x - 0,3619R2 = 0,998

y = -32,04x - 0,4825R2 = 0,99

y = -25,988x - 0,4704R2 = 0,9962y = -20,821x - 0,2763

R2 = 0,9984

y = -29,065x - 0,2097R2 = 0,9992

-35-30-25-20-15-10-500,00% 10,00% 20,00% 30,00% 40,00% 50,00% 60,00%


RA

Q c

ha

ng

e (

%)


Recharge variation vs evapotranspiration change

50,0

-30.0%

-25.0% -15.0%

-20.0%

-5.0%

-10.0% 1.5%

5.0% 15.0%

20.0%10,0

25,0

30,0

40,0

y = -4.1407x + 1202.2R2 = 0.9905; erro = 7.92

0200400600800

1000120014001600

-40,0 -20,0 0,0 20,0 40,0 60,0


Aver

age

Rec

harg

e(m

m)


Evapotranspiration change:– Set AGUT/NC = 186/91 - largest recharge

change, inverse trend from that of evapotranspiration change. It is the tree cover who shows the largest decrease for an increase in evapotranspiration.

– Set AGUT/NC = 56/38 - lowest recharge change, inverse trend from that of evapotranspirationchange.

Impacts on groundwaterRunoff – from the water budget outputs, the response of different soil type/vegetation cover sets to runoff changes triggered by precipitation changes was studied, and identified the soil type/vegetation cover sets were these changes were larger.


(1)AGUT/NC Multiplication factor between precipitation increase and runoff increase186/91 1.58 1.67 1.49 1.61 1.62 1.63 2.43182/75 2.20 2.35 2.11 2.31 2.35 2.39 3.41105/56 3.03 3.29 2.99 3.33 3.43 3.53 4.8399/83 1.90 2.02 1.81 1.97 1.99 2.01 2.9397/61 2.78 2.99 2.71 3.01 3.08 3.16 4.3956/38 4.87 5.45 5.02 5.78 6.10 6.41 8.4018/90 1.62 1.72 1.53 1.66 1.67 1.68 2.49(1) precipitation change at +15% in wet season and no change in Summer season

Runoff change vs precipitation change - precipitation decrease

0,0100,0200,0300,0400,0500,0600,0700,0800,0900,0

1000,0

pp =

-0.

3 m

m/d

pp =

-0.

5 m

m/d

pp =

-1

mm

/d

pp =

- 1

5% a

nual

pp =

- 2

0% a

nual

Cen

ário

30

Cen

ário

40

Cen

ário

50

Cen

ário

60

Precipitation change scenarios

Ave

rage

runo

ff (m

m/y

ear)

AGUT/NC = 186/91AGUT/NC = 182/75AGUT/NC = 105/56AGUT/NC = 105/1AGUT/NC = 99/83AGUT/NC = 97/61AGUT/NC = 56/38AGUT/NC = 18/90Média

Impacts on groundwaterSurface runoff increases with increased precipitation,

being the vegetation areas with lowest radiculardimensions (AGUT) those worstly affected.

Soil areas with medium runoff potential (intermediate NC) are those with larger runoff rises.

Soil areas with high runoff potential (high NC) suffer the lower runoff variations.

Vegetation controls runoff, as can be seen for sets of equal NC and distinct vegetation cover (AGUT); although this control can be minor in high runoff conditions (high NC).

Precipitation change scenarios- 15%year

- 20%year

Scenar. 30(-14,9%)

Scenar. 40(-25,3%)

Scenar. 50(-5,8%)

Scenar. 60(-15,9%)

AGUT/NC Multiplication factor between precipitation decrease and runoff decrease186/91 1.52 1.50 1.50 1.43 1.28 1.31182/75 2.00 1.95 2.10 1.84 1.81 1.61105/56 2.57 2.47 3.07 2.43 3.41 2.2399/83 1.77 1.74 1.79 1.64 1.47 1.4597/61 2.41 2.32 2.76 2.23 2.83 2.0156/38 3.59 3.31 4.97 3.34 7.50 3.3918/90 1.55 1.54 1.54 1.46 1.29 1.33

Remark: -15% year and –20% year means that the series was affected by a day reductionrespectively 15 and 20%

In areas with lower radicular dimensions (low AGUT) runoffchange is largest (see yellow).

For soils with high runoff potential (high NC) infiltrationcapacity seems to be the main controling factor on runoff, onceeither for tree cover (green) or herbaceus cover (yellow lower) runoff variations are similar.

Runoff change vs precipitation change - precipitation increase

0

500

1000

1500

186/9

118

2/75

105/5

610

5/199

/8397

/6156

/3818

/90Méd

ia

AGUT/NC Scenarios

Ave

rag

e r

un

off

(m

m/y

ea

r)

pp = +6%

pp = +10%

pp = +15%

pp = +20%

pp = +25%

pp = +30%

pp =Cenário 1

pp =CenárioBrito

Cenários de Variação da Evapotranspiração e PrecipitaçãoCenário 1

AGUT/NC Factor de multiplicação entre o valor de subida da precipitação e o de subida doescoamento superficial

186/91 1.58182/75 2.20105/56 3.03105/1 0.0099/83 1.9097/61 2.7856/38 1.4018/90 1.62


Surface runoff increases and, with the sets AGUT/NC = 56/38 e 18/90 exceptions, the rate change are similar to those odprecipitation increase scenario = 6% + no evapotranspirationchange.

Impacts on groundwaterRecharge change impacts on spring discharge – the relation recharge/spring discharge was calculated for each of the precipitation/evapotranspiration changed scenarios, assuming the proportion recharge/spring discharge remains constant regardless of the scenarios considered (this was assumed simply due to lack of information on recharge spring discharge variation for distinct evapotranspiration-rainfall conditions), so obtaining a spring discharge change -when compared to the actual annual average values - for each scenario.

Precipitation change scenarios- 0,3mm/d

- 0,5mm/d

- 1mm/d

- 15%year

- 20%year

Scen.30

Scen.40

Scen.50

Scen.60

∆ Average RAQ (%) -3,7 -6,0 -11,7 -17,2 -23,1 -17,2 -30,8 -6,5 -20,2New RAQ (hm3/year) 11,75 11,47 10,77 10,10 9,38 10,10 8,44 11,41 9,74Storage+Seeping 4,50 4,50 4,50 4,50 4,50 4,50 4,50 4,50 4,50New spring discharge(hm3/year) 7,25 6,97 6,27 5,60 4,88 5,60 3,94 6,91 5,24Ratio discharge/RAQ(%) 61,70 60,76 58,23 55,45 52,03 55,45 46,70 60,55 53,78∆ Spring discharge (%) -5,86 -9,51 -18,54 -27,25 -36,60 -27,25 -48,80 -10,30 -32,01


∆ Average RAQ (%) +5,9 +10,9 +14,9 +21,1 +26,3 +31,5 +11,9New RAQ (hm3/year) 12,92 13,53 14,02 14,77 15,41 16,04 13,65Storage+ Seeping 4,50 4,50 4,50 4,50 4,50 4,50 4,50New spring discharge(hm3/year) 8,42 9,03 9,52 10,27 10,91 11,54 9,15Ratio discharge/RAQ(%) 12,92 13,53 14,02 14,77 15,41 16,04 13,65∆ Spring discharge (%) 9,35 17,27 23,61 33,43 41,67 49,91 18,85

RAQ = Recharge

Evapotranspiration change scenarios+1,5% + 5% + 10% + 15% + 20% + 25% + 30% + 40% + 50%

∆ Average RAQ(%)

-0,6 -2,1 -4,0 -5,9 -7,4 -9,2 -10,7 -13,6 -16,4

New RAQ(hm3/year) 12,13 11,94 11,71 11,48 11,30 11,08 10,89 10,54 10,20Storage+Seeping 4,50 4,50 4,50 4,50 4,50 4,50 4,50 4,50 4,50New springdischarge (hm3/year) 7,63 7,44 7,21 6,98 6,80 6,58 6,39 6,04 5,70Ratiodischarge/RAQ (%) 62,89 62,32 61,58 60,80 60,17 59,38 58,70 57,31 55,88∆ Spring discharge(%) -0,95 -3,33 -6,34 -9,35 -11,72 -14,58 -16,95 -21,55 -25,98

Evapotranspiration change scenarios- 5% - 10% - 15% - 20% - 25% - 30%

∆ Average RAQ(%)

+2,2 +4,4 +6,8 +9,2 +11,7 +14,2

New RAQ(hm3/year) 12,47 12,74 13,03 13,32 13,63 13,93Storage+Seeping 4,50 4,50 4,50 4,50 4,50 4,50New springdischarge (hm3/year) 7,97 8,24 8,53 8,82 9,13 9,43Ratiodischarge/RAQ (%) 63,91 64,67 65,46 66,22 66,98 67,70∆ Spring discharge(%) 3,49 6,97 10,77 14,58 18,54 22,50


Evapotranspiratio + precipitation changeScenario 1

∆ Average RAQ (%) 5,3New RAQ (hm3/year) 12,85Storage+Seeping 4,50New spring discharge(hm3/year) 8,35Ratio discharge/RAQ (%) 64,97∆ Spring discharge (%) 8,40


C lim ate change”scenarios

R ecargechange (% )

Spring d ischargechange (% )

N ew R echarge(hm 3)

N ew spr ingdischarge(hm 3)

R atio spr ing d ischarge-recharge (% )

A ctua l 0 0 193 18 9 ,33PP = - 0,3 m m /d - 3 ,7 -5 ,86 185 ,86 16 ,94 9 ,12PP = - 0,5 m m /d - 6 ,0 -9 ,51 181 ,42 16 ,29 8 ,98PP = - 1 m m /d - 11,7 -18 ,54 170 ,42 14 ,66 8 ,60

PP = - 15% - 17,2 -27 ,25 159 ,80 13 ,09 8 ,19PP = - 20% - 23,1 -36 ,60 148 ,42 11 ,41 7 ,69Scen ar io 30 - 17,2 -27 ,25 159 ,80 13 ,09 8 ,19Scen ar io 20 - 30,8 -48 ,80 133 ,56 9 ,22 6 ,90Scen ar io 50 - 6 ,5 -10 ,30 180 ,46 16 ,15 8 ,95Scen ar io 60 - 20,2 -32 ,01 154 ,01 12 ,24 7 ,95PP = + 6% + 5,9 + 9,35 204 ,39 19 ,68 9 ,63

PP = + 10% + 10,9 + 17,27 214 ,04 21 ,11 9 ,86PP = + 15% + 14,9 + 23,61 221 ,76 22 ,25 10 ,03PP = + 20% + 21,1 + 33,43 233 ,72 24 ,02 10 ,28PP = + 25% + 26,3 + 41,67 243 ,76 25 ,50 10 ,46PP = + 30% + 31,5 + 49,91 253 ,80 26 ,98 10 ,63Scen ar io 1 + 11,9 + 18,85 215 ,97 21 ,39 9 ,91

E V R = + 1,5% -0 ,60 -0 ,95 191 ,84 17 ,83 9 ,29E V R = + 5% -2,10 -3 ,33 188 ,95 17 ,40 9 ,21

E V R = + 10% -4,00 -6 ,34 185 ,28 16 ,86 9 ,10E V R = + 15% -5,90 -9 ,35 181 ,61 16 ,32 8 ,98E V R = + 20% -7,40 -11 ,72 178 ,72 15 ,89 8 ,89E V R = + 25% -9,20 -14 ,58 175 ,24 15 ,38 8 ,77E V R = + 30% -10,70 -16 ,95 172 ,35 14 ,95 8 ,67E V R = + 40% -13,60 -21 ,55 166 ,75 14 ,12 8 ,47E V R = + 50% -16,40 -25 ,98 161 ,35 13 ,32 8 ,26E V R = - 5% + 2,20 + 3,49 197 ,25 18 ,63 9 ,44

E V R = - 10% + 4,40 + 6,97 201 ,49 19 ,25 9 ,56E V R = - 15% + 6,80 + 10,77 206 ,12 19 ,94 9 ,67E V R = - 20% + 9,20 + 14,58 210 ,76 20 ,62 9 ,79E V R = - 25% + 11,70 + 18,54 215 ,58 21 ,34 9 ,90E V R = -30% + 14,20 + 22,50 220 ,41 22 ,05 10 ,00

cen ar io 1 = + 6%PP, +1 ,5% E V R

+ 5,3 + 8,40% 203,23 19 ,51 9 ,60




July 11-13, 2005

Climate change, seawater rise and saltwater vulnerability Climate change, seawater rise and saltwater vulnerability assessment in coastal aquifersassessment in coastal aquifers

PROBLEM DEFINITIONPROBLEM DEFINITION• Continued human interference with the coastal hydrologic system has led to pollution of coastal groundwater aquifers by salt water.

• Change in groundwater levels with respect to mean sea elevation along the coast largely influences the extent of seawater intrusion in the fresh water aquifers.

• The smaller the drop in groundwater levels, the lesser the sea water intrusion in the aquifers. In other words, the magnitude of change in sea level would have the identical effect on seawater intrusion if the groundwater levels were held constant.

• In the geological pastgeological past, sea levels have changed with changes in natural climatic conditions several times, during the glacial and interglacial periods.

• However, in the geological presentgeological present, the climate is largely influenced by human interference in the form of air and water pollution and this has led to an imbalance in atmospheric heat. The effect of this thermal imbalance is seen in the melting of polar ice caps leading to a rise in sea level. Coastal infrastructures, tourism, and other economic activities are also at risk in costal areas.




July 11-13, 2005

SALTWATER INTRUSIONSALTWATER INTRUSION

Artificial recharge with freshwater injection in a coastal aquifer

http://biology.queensu.ca/~bio111/pdf%20files/lect16-waterquality.PDFFreshwater - Saltwater interface with or without pumping

http://pangea.stanford.edu/research/hydro/research/sw_intrus/sw_content.htm#Abstract

http://pangea.stanford.edu/research/hydro/research/sw_intrus/sw_content.htm#Abstract

http://biology.queensu.ca/~bio111/pdf files/lect16-waterquality.PDF




July 11-13, 2005

Assessing aquifer vulnerability to seawater Assessing aquifer vulnerability to seawater intrusion using GALDIT method:intrusion using GALDIT method:

Part 1 Part 1 –– Application to the Portuguese Aquifer of Application to the Portuguese Aquifer of Monte GordoMonte Gordo

João Paulo Lobo Ferreira1 [email protected]. G. Chachadi2 [email protected] Diamantino3 [email protected]. J. Henriques4 [email protected]

1,3,4 Laboratório Nacional de Engenharia Civil (LNEC) Hydraulics and Environment Department (DHA), Groundwater Division (NAS) Av. do Brasil, 101, 1700-066 Lisboa, PORTUGALInternet: http://www.dha.lnec.pt/nas/

2 Goa University, Dept. of Earth Science, Goa – 403 206 INDIA









July 11-13, 2005

Assessing aquifer vulnerability to seawater intrusion using GALDAssessing aquifer vulnerability to seawater intrusion using GALDIT method: IT method: Part 1 Part 1 –– Application to the Portuguese Aquifer of Monte GordoApplication to the Portuguese Aquifer of Monte Gordo

PROBLEMPROBLEM DEFINITIONDEFINITION• The aim of the present investigation is to study the impacts of sea level risesea level rise on the extent of surface inundation along the coastsurface inundation along the coast and sea water intrusionsea water intrusion into the coastal aquifers in Southern Portugal´s Algarve coastal zone, using the GALDIT methodGALDIT method developed by CHACHADI and LOBO-FERREIRA (2001);

• Comparing this results with the ones given by the study developed for North Goa coast, presented in CHACHADI and LOBO-FERREIRA (2005).




July 11-13, 2005


DEFINITION OF GROUNDWATER VULNERABILITY TO SEA WATER INTRUSIONDEFINITION OF GROUNDWATER VULNERABILITY TO SEA WATER INTRUSION

• Following the basics concepts presented in LOBO-FERREIRA and CABRAL (1991) for the definition of groundwater vulnerability to pollutiongroundwater vulnerability to pollution, we believe that the most useful definition of vulnerability to seawater intrusion is one that refers to the intrinsic intrinsic characteristicscharacteristics of the aquifer, which are relatively static and mostly beyond human control.

• Groundwater vulnerability to sea water intrusionGroundwater vulnerability to sea water intrusion can to be defined as:

“the sensitivity of groundwater quality to an imposed groundwate“the sensitivity of groundwater quality to an imposed groundwater r pumpagepumpage or or sea level rise or both in the coastal belt, which is determined sea level rise or both in the coastal belt, which is determined by theby theintrinsic characteristics of the aquifer”intrinsic characteristics of the aquifer”




July 11-13, 2005


SUGGESTED SYSTEM OF VULNERABILITY EVALUATION AND RANKING SUGGESTED SYSTEM OF VULNERABILITY EVALUATION AND RANKING --GALDIT INDEXGALDIT INDEX

Most important mapable factors that control the seawater intrusion:• Groundwater Occurrence (aquifer type; unconfined, confined and leaky confined).• Aquifer Hydraulic Conductivity.• Height of Groundwater Level above Sea Level.• Distance from the Shore (distance inland perpendicular from shoreline).• Impact of existing status of seawater intrusion in the area.• Thickness of the aquifer, which is being mapped.

The acronym GALDITGALDIT is formed from the highlighted and underlined letters of the parameters.




July 11-13, 2005


GALDITGALDIT APLICATION TO THE AQUIFER SYSTEM OF MONTE GORDOAPLICATION TO THE AQUIFER SYSTEM OF MONTE GORDO

AquiferAquifer systemsystem of Monte Gordoof Monte Gordo• is extending from Vila Real de Santo António, in Southern Portugal’s Algarve region, to Praia Verde;• total area of approximately 10 km2 (extension of about 5 km long by 2 km as average width);

LithologicalLithological formationsformations (SILVA, 1984):

• sands, located along the coast line in a narrow strip of sands dune - this is an environment protected area occupied by pine trees. • sands of different grain sizes with important argillaceous and organic components to the North of this region, corresponding to old dune systems and alluvial materials.




July 11-13, 2005


GALDIT APLICATION TO THE AQUIFER SYSTEM OF MONTE GORDOGALDIT APLICATION TO THE AQUIFER SYSTEM OF MONTE GORDO

Parameter L

Parameter G

Parameter D

Parameter I

Parameter A

Parameter T

GALDIT index for the GALDIT index for the first scenariofirst scenario

(today’s sea level)(today’s sea level)

GALDIT INDEX for today´sGALDIT INDEX for today´s seasea levellevel




July 11-13, 2005



GALDIT index for the GALDIT index for the second scenariosecond scenario

(sea level rises 0.25 m)(sea level rises 0.25 m)

Parameter L

Parameter G

Parameter D

Parameter I

Parameter A

Parameter T

Parameter LParameter L

GALDIT INDEX for seaGALDIT INDEX for sea levellevel rises 0,25 mrises 0,25 m




July 11-13, 2005



Parameter L

Parameter G

Parameter D

Parameter I

Parameter A

Parameter T

GALDIT index for the GALDIT index for the third scenariothird scenario


Parameter LParameter L

GALDIT INDEX for seaGALDIT INDEX for sea levellevel rises 0,50 mrises 0,50 m




July 11-13, 2005



Comparison of the three scenarios

GALDIT index for the GALDIT index for the third scenariothird scenario


GALDIT INDEX for today´sGALDIT INDEX for today´s seasea levellevelGALDIT INDEX for seaGALDIT INDEX for sea levellevel rises 0,25 mrises 0,25 mGALDIT INDEX for seaGALDIT INDEX for sea levellevel rises 0,50 mrises 0,50 m




July 11-13, 2005


CONCLUSIONS:CONCLUSIONS:

The three scenarios application regarding the parameter L - Height of Groundwater Level above Sea Level, show how important it is to assess on due time the impact of sea water level rise do to climate changesimpact of sea water level rise do to climate changes. These figures are also important to observe the negative effects of overexploitation of aquifers, which affects regional groundwater level, causing in coastal zone salt water intrusion.

To complement this reasoning, on the effects of sea water rise in aquifers, the values presented before for Monte Gordo aquifer can be compared with those computed for the Bardez aquifer in Goa, India, presented in Part 2 of this paper (also included in the Proceedings of this 4th Interceltic Colloquium), i.e. in CHACHADI and LOBO-FERREIRA (2005).




July 11-13, 2005

Artificial groundwater rechargeArtificial groundwater rechargeassessment techniquesassessment techniques

A Ph.D Thesis under development at LNEC and theA Ph.D Thesis under development at LNEC and the

Univ. Univ. LisboaLisboa / FCUL/ FCUL

byby

CatarinaCatarina DiamantinoDiamantino [email protected]

Laboratório Nacional de Engenharia Civil (LNEC) Hydraulics and Environment Department (DHA), Groundwater Division (NAS) Av. do Brasil, 101, 1700-066 Lisboa, PORTUGALInternet: http://www.dha.lnec.pt/nas/






July 11-13, 2005

Examples of artificial groundwater recharge techniquesExamples of artificial groundwater recharge techniques

AVRA VALLEY RECHARGE PROJECT projectado para armazenar subterraneamente água do rio Colorado

http://www.nerc-wallingford.ac.uk/gwf/gwoha/gwf020.jpgAGUA FRIA RECHARGE PROJECT

http://www.cap-az.com//recharge/index.cfm?action=aqua&subSection=70

http://www.nerc-wallingford.ac.uk/gwf/gwoha/gwf020.jpg






July 11-13, 2005

EXAMPLES OF ARTIFICIAL GROUNDWATER RECHARGEEXAMPLES OF ARTIFICIAL GROUNDWATER RECHARGE

Adapted from Gale et al. (2002)“The effectiveness of Artificial Recharge of groundwater: “The effectiveness of Artificial Recharge of groundwater:

a review (AGRAR)” a review (AGRAR)” -- ÍNDIAÍNDIA




July 11-13, 2005

EXAMPLES OF ARTIFICIAL GROUNDWATER RECHARGEEXAMPLES OF ARTIFICIAL GROUNDWATER RECHARGE

AquíferoAquífero de de JáveaJáveaSanjas no Rio GorgosSanjas no Rio Gorgos

http://www.terralia.com/revista15/pagina42.htm

Recarga artificial no aquífero de ORBA Dique de vaso permeável construído no Barranco de Fontilles

http://aguas.igme.es/igme/publica/libro36/lib36.htm

round table 1 climate variability assessment and … · (blue) have the highest recharge change,...

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