groundwater management in iberian river basins - csic · groundwater management in iberian river...

SCARCE 1st annual conference

Groundwater management in Iberian River Basins

Emilio CUSTODIO, Dr.I.E., Emilio CUSTODIO, Dr.I.E., Royal Acad. Sciences, SpainRoyal Acad. Sciences, SpainDept. GeoDept. Geo––Eng., Technical University Catalonia (UPC)Eng., Technical University Catalonia (UPC)Foundation Intern. Centre on Groundwater HydrologyFoundation Intern. Centre on Groundwater Hydrology

SCARCESCARCE––ECEC––11

Understanding the effects of global change on water quantity and qualityin river basins

02nd/03rd December 2010, Girona, Spain

Contents: • The hydrological cycle• Climate and global change• Effects on water resources

* planetary, in Europe, in Spain* in the Ebre Basins, in Catalonia

• Influence on groundwater management

Inside project CICYTREDESAC (CGL2009–12910–C03–01)

The hydrological cycle


Schematic hydrological cycle

• Forward • air humidity transport• precipitation

• Backward Fast branch = surface waterSlow branch = groundwater

Water balance in the soilGeneration of aquifer recharge

Wanted resultsrunoff generationgroundwater recharge

Interconnected

The hydrological cycle


Surface water • from direct runoff soil [rare]

• rainfall on open continental water bodies• as interflow• as GROUND WATER DISCHARGE (BASE FLOW)

Groundwater • rainfall recharge

• river infiltration important in

diffusethrough fissuresconcentrated

on saturatedon frozen Fast renovation rate

Slow to very slow renovation rateReserves >> Resources

Important • to ecology• to river flow persistence• a resource for human needs

Relatively recent intensive useEasy appropriation by users

Aquifer recharge in peninsular

SpainR R/PRCV

arid areaspiedmontsintensively exploited aquifers

Climate change


IPCC definition

A statiscally significant variation in the state variables that define the climate of a region (e.g. T, P) or in their variability,persistent over an extended)period of time (≥ decades)

There are: • Stable periods or a smooth trend• Periods of fast change

• positive feedback reinforcementa flip–flop like system

Large scale, planetary–wide effect producing changes in

* Forcings• solar radiation smooth trends• atmosphere greenhouse effect due to gases

CO2, CH4, NOX, … smooth trendsH2O (vapour droplets) highly variable

* linked to atmospheric situation* a major cause of uncertainty

• dust ( wind, volcanic, anthropogenic)* Ocean smooth to fast trends• circulation• temperature• mean level

* Continent smooth trends• surface area• distribution• relief effect• albedo• ice extension


Reference pre–industrial value: 270 ppm vol.Current value: 387 ppm vol. (Mauna Loa)

From Antartic ice cores

EEA, 2008

years before 2005IPCC, 2007

Rad

iativ

e fo

rcin

g, W

m–2

NO

2 in

10–

9vo

l.C

H4

in 1

0–9

vol.

CO

2 in

10–

6vo

l.

Historical changes in atmospheric gas contents


Temperature change in the last millennium

Reference point: average 1995 – 2004 for 01–01–2000Natural variations: up to 0,5ºC for 1–4 decades

Result: 20th century warming is overimposed on centuries of considerable lower temperatures

After Chapman D.S. and Davis, M.G. (2010), EOS 91 (37)NRC (2006), IPCC(2007)

Memory of past temperature in deep boreholes

ΔTºC of last years still in upper m

tree ringscoressedimentsice coresglacier length changessubsurface temp. in boreholes

Proxi estimates

Instrumental: from 1850

Δ Population, 109 Condition Results ΔTºC*A2A1B

B1C3

6 12

6 8.7 76 8.7 7

no agreements bussiness as usualefficiency and 50%

non–fossilcontrolCO2 at 2000 level

4*

~2.52

0.5

* Global averages. Up to 3 times in high latitudes

ipcc future scenarios 2000–2010

150100

0

150500

Global change


global ≠ planetary = all processes

Combination at local level of:

Climate change

Anthropogenic effects

• on land cover • forest• cropland due to changes in • urban area

• on water • use and demand• consumption• quality

• on quality of the environment

surface areadensitymanagementalbedo

due to

urbanizationpopulation growthpollutionmore water demanding habits

Climate and global change


Climate is the result from complex systems

with important feedbacks positive reinforcement and amplificationnegative trend to stability

Understanding simplify actual processesQuantification must consider relevant influencesneed numerical models

Large uncertainties involved due to:• complexity understand complexity• positive feedbacks chaotic behaviour• insufficient understanding improve• need to introduce simplifications reproduce what is important• insufficient monitoring increase

Reduce uncertainty through:• improved general models• better downscaling methods• ability to reproduce past events

use proxi variables of climate variables

historicalpalaeoevents

But there is always a irreductive degree of uncertainty


Future climatic change effectsPrimary effects

• Temperature increase. Reasonable predictions

• Precipitation changes in quite uncertain

• Planetary fluctuation changes e.g. El Niño / La Niña phenomenaocean thermohaline circulation

• Sea level rise

annual valuesregime

Results

Increased evapotranspiration

Decreased runoff through

Change in runoff regime due to

Possible increased frequency of extensive events

Water quality changes

Ecological changes

Modified water resources

in potential values clearactual values unclear

less interflowless aquifer recharge base flowincreased phreatophyte uptake in dry areas

seasonal interflow variationinterannual early snow melt

droughts especially in dry areasfloods especially in flat landsin surface water

in lakesin groundwater

in ecosystems

in biodiversity

surface arealiving specieshydroperiod

management to adaptmitigation

Modelling is needed

probable but uncertainuncertainuncertain

Effects of climate change on water resources


Changes:• river runoff

• river flow regime rainfall regimeice melt time

decreasedecrease

more irregularearlier

Expected in Spain

This means:• Different of dam reservoirs

• capacity to hold floods• reserve for droughts• evaporation losses• hydroelectric power generation• water quality and silting up rate

• Changed aquifer–river relationships• Problems associated to sealevel rise• Modified water demand

• for urban uses • for agriculture• for environment

• ecological (maintenance) flows• dilution flows• wetland surface area

more emphasis in availability

lowerlowerincreaseddecreasedimpairedlower baseflowmoderate

less waterless waterimpaired

behaviourmanagement rules

quantityquality

• aquifer recharge

Effects of climate change on groundwater resources


Aquifer recharge complex, non linear function of rainfallthe more the dryer is the area

subject to change● per event● progressive

Future effects difficult to forecast small experiencevery uncertainhighly dependent on land use changesa function of surface water/impounded water management

In Mediterranean and Central Spain / Archipelagos● probable less diffuse recharge● possible increase in localized recharge

if streams, creeks, flooding areas are not modified

subject to management


Change in water demand due to increased temperatureIn crop land Increased crop evapotranspiration expected

Modified crop behaviour• faster maturity expected• enhanced double cropping possible• crop yield changes due to CO2 increase expected• longer growing seasons possible

• shift in crop possibole

In forest areas Water availability decreases as forest:• expands• is less managed increased interception and detention• temperature increases

In Nature• wetland evaporation

• river water for

In human use• for cooling• for sanitation• for recreation

typesvarieties

wild lifewaste digestion

Annual river flow reduction due to forest growth, in hm3/km2 forested (or m), versus local precipitation (after Zhang et al., 2001,

WRR 37: 701–708)

But many unknowns remain ● fog trapping in forest● environmental humidity

Climate change modelling


Global (planetary) circulation models GCM• Several models

• ∼ coincide for the historial period• for the same future scenarios their results

* are close for the next decades* may diverge for late the 21st century

• Coarse grid• insufficient data availability• limited computing capacity• simplification of

– continent–sea interaction– orography– land cover

But they are being improved progressively

Regional circulation models RCM

Downscalling from GCM● statistical using pre–established relationships● dynamical (nested in RCM) (eg. PROMES)

Typical GCM grid on peninsular SpainShortcuts

Models are needed

Observed recent temperature changes


Average annual temperatures (Hulme & Sheard, 1999)= 1.6ºC; 2.0ºC in summer; 1.4ºC in winter

∆T in the 20th century +0.7ºC

Planetary

Calendar year

Planetary

In the Iberian Peninsula

CRU, 2003

IPCC, 2007

ΔT

Forecasted planetary temperature changes

SCARCESCARCE––ECEC––1515Increase from 2000 to 2071–2100 in scenario A2.

Green Paper, European Commission 2007

Projections for mean planetary temperature change in different scenarios∆T = 1.8ºC to 4ºC (extreme 6.4ºC) in year 2100(IPCC, 2007)

Uncertainty in

To produce comparable forecasts• start from a base situation (eg. 1970–1999)• refer to a given future period• construct probable scenarios

calculationforecasting There is an irreductible

uncertainty

IPCC, 2007


Forecasted temperature changes in the Iberian PeninsulaReference 1961–1990

Model UCLM–PROMES, nested in HadAM3. 2071–2100Gaertner, 2005, PRUDENCE Project

Seasonal ∆T in the centre of the Iberian Peninsula (MMA, 2005)

TΔ 2–3ºC/30 years in summer1–2ºC/30 years in winter in Spain. Harley Center, A2; B2

∆T, º

C

winter

spring

summer

autumm

Changes in precipitation and water resources


Circumstances to be considered

• Recording stations may suffer from local effects (land use, urbanization)

• Water resources are affected by

• Environmental pollution influences water availability

• Important local effects downscalling

• Values may increase or decrease

consider

hydrological processesabstractions, land usemanagement

average yearly valuesintensityannual regime

duration of

important consequences

Observed values Forecasted values Comments on past behaviourTemperatureRainfallRunoffGroundwater rechargeWater resources

Rather lowRather largeRather largeRather largeLarge

ModerateQuite largeQuite largeQuite largeVery large

Good records and proxisShort recordsShort, inaccurate recordsComplex calculation and anthropic effectsLarge influence of management and water works

Uncertainty in

droughtswet periods

Trends in precipitation in the Iberian Peninsula


Accumulated deviated precipitation

In Sevilla–Tabladas extended by the Sevilla–Iglesia de la Encarnación

station

In Madrid (CH Tajo)

In general no clear trends

World forecasted changes in rainfall


Percentage of world runoff change using 12 climate models

Forecasted precipitation changes in Europe


Increase 2000 to 2071–2100 in scenario A2

Green Paper, European Commission

Source: EEA, 2005Water availability in Europe

Scenario A2/SRES

Increase 2000 to 2071–2100

IPCC, 2007

Forecasted precipitation changes in the Iberian Peninsula


Reference 1961–1990

Seasonal ∆P (mm/d) in the centre of the Iberian Peninsula (MMA, 2005) Model UCLM–PROMES, nested in HadAM3. 2071–2100

Gaertner, 2005, PRUDENCE Project

∆P, m

m/d

Observed river flow changes in the Ebre River Basinand in Madrid Basin


black: measured flowblue: simulated flowEbre river in Tortosa (MIMAM, 2000)

Water availability in the river basins contributing to the Madrid area (Bolarque).

Heavy line: annual inflow, hm3/year (Iglesias et al., 2010, Water Policy in Spain,

CRC: 67)

Time evolution of irrigation water use and other consumptions not explained by climate change or

irrigation. Ebre basin (after Armengol)

hm3/ahm3/a

hm3/a

River flow changes in Catalan river basins


Llobregat river basin headwatersArea upstream La Baells reservoirRiver close–to–the–river flow piezometric levels(from Water Change project (LIFE), CETaqua–CRAHI)

expansiondensification

Ter river basin headwaters (after Gallart)Contribution to Sau reservoirNo conspicuous land–use changes

excet for forest in 30% of basin

year

Ann

ual i

nflo

w re

lativ

e to

Sa

u re

serv

oir c

apac

ity

Average inflow change to Catalan InnerBasins surface water reservoirs in

%/year (after Armengol)RESERVOIR Boadella Sau La Baells Siurana

ObservedDue to climateOther*

–0.070.37–1.14

–0.980.05–0.67

–1.020.18–0.66

–3.350.08–2.17

* after correcting for known water use changes

m3/s

mm/a

m

m

inflow

Forecasted water resources decrease in peninsular Spain

SCARCESCARCE––ECEC––2424Current water shortage areas

Water resources decrease, % OECC, 2006

Runoff reduction in 2030For ∆T = +1ºc; decrease –5%

CEDEX, 2008

PΔ

Scenario Year ∆T ºC ∆P%ABCD

2030203020302060

+1ºC+1

+2,5

0–5%

0–8%

PROMES

A B C DLow use

Circumstantial Shortage

Structural Shortage

0%

1‐10 %

11 ‐ 25 %

26 ‐ 50 %

51 ‐ 75 %

76 ‐ 100 %

Scenario

Trends of change in Catalonia


Average yearly seawater temperature at the surface and three depths.

Mediterranean Sea

Tem

pera

ture

ºC%

pre

cipi

tatio

nA

nom

alie

s re

lativ

e to

196

1–19

90

year

–20 m

Surface

Tem

pera

ture

ºC

–50 m

–80 m

year

yearyear

Ave

rage

tem

pera

ture

ºC

Sau reservoir Ter river basin (Gallart)

Climate change results for the Ebro/Ebre basin


Alvares, 2010

Coupled Global Climate Change Model (Canada) CGCM3

IPCC, Escenarios AIB A2 B1 Commit (attainement of CO2 control goals)

Forecasted average change for the basin (Alvares, 2010)Variable 2010–39 2040–69 2070–99

Temperature, ∆T ºCPrecipitation, ∆P mm/yrSurface runoff, ∆SRInterflow, ∆INTGW flow, ∆GWFActual evap., ∆AETTotal flow, ∆Q

1.25–7 (–1.2%)

–10.3%–11.3%

–9.4%

2.23–51 (–8.6%)

–20.9%–24.2%

–22%

2.28–47 (–7.9%)

–2.2%–21.1%–22%

small (*)–20.2%

* PET increases (increased temperature); soil water reserve decreases

Alvares, 2010

Changes in hydrological terms affecting aquifer recharge in the Ebro river basin (Alvares, 2010)


Interception, mm/yr

PET, mm/yr

AET, mm/yr

Surface runoff, mm/yr

Interflow, mm/yr

Groundwater flow, mm/yr

Effects of climate and global change in water resources


Results and conclusions

In forthcoming years demand will increase for

In many areas they will dominate over temperature increase

This conditions effective mitigation results

environmentagriculture and foresturbanpopulation

Depending on the area, yearly average water resources mayincreasenot changedecrease

This means

existing water works effectiveness will changecurrent water use has to be reassessedimproved integrated water resources usewide–scope approaches are needed, eg. virtual water tradewater value has to be taken into accountthe water footprint of human activities has to be known

But there are possible changes in

annual regime

droughts

intensity of extense eventscoastal flooding

durationfrequency floods

erosion rate

managementadaptation

Forecasting means


● Improved monitoring of

● More accurate scenarios

● Linked models for:– local precipitation– runoff generation– aquifer recharge– integrated water resources management– socio–economic evaluation– decision making

● Improved ● coupling of models● data base sharing

surface watergroundwatercoastal aquifers

Mitigation means for global and climate change


Results and conclusions

• Improved use of groundwater storage

• Change of existing water works operation rules

• Better territorial connectivity for water resources, including virtual water transfer

• New resources have to be considered and integrated

• Effort on water quality protection and restoration

• Increased water use efficiency less use with improved

This needs flexible but enforced

• Social aspects have to be improved • markets• institutions• users participation and co–responsability• long–term policies instead of short–term politics• clear and flexible water rights• ethical and moral behaviour

quality is a key issue with increasing future importance

Mitigation needs considering

naturalartificial

used water reclamation for reuse

desalinization of brackish waterseawater

economic resultsemploymentNaturesocial satisfaction and equitynorms

prioritiesincentives

adequate knowledgeadequate monitoringmanpower and collaborationresearchlong–term vision

Groundwater role will increase

quantityquality

Groundwater plays a key role, especially in Spain

groundwater management in iberian river basins - csic · groundwater management in iberian river...

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