Water quality regulation functions under climate change in South … · 2018. 10. 15. · Water...

Water quality regulation functions under climate change in South-Western Europe catchments

Brussels, 19 Septembre 2018

Mélanie Raimonet, Roxelane Cakir, Sabine Sauvage, Magali Gerino, Robert Vautard, José Miguel Sánchez-Pérez

Climate change impacts on hydrology in Europe

IPCC AR5 (2014)

Donnelly et al. (2017)Climatic change

+3°C

Climate change impacts on hydrology in Europe

IPCC AR5 (2014)

↘ precipitation (<-0.25 mm/d)

Donnelly et al. (2017)Climatic change

↘ streamflow (<-0.15 mm/d)

Major impacts in the South of Europe :- ↘ water ressource- changes in hydrological regime- ↗ extreme events

+3°C

Water quality

Climate change impacts on biogeochemistry?

o Nutriento Sediment

o Sediment retentiono Nitrate removal

www.marlborough.govt.nz

Ecologicalfunctions

Export to the ocean

Water quality

Climate change impacts on biogeochemistry?

o Nutriento Sediment

o Sediment retentiono Nitrate removal

www.marlborough.govt.nz

Ecologicalfunctions

Export to the ocean

Ecological functions of water quality regulation

result from a group of physical / biological / biogeochemical processes

From Oraison et al. (2011), Peterson et al. (2001)

Ecological functions of water quality regulation

result from a group of physical / biological / biogeochemical processes

From Oraison et al. (2011), Peterson et al. (2001)

IN

OUTStream Solute Workshop (1990)

Net balance IN – OUT

o sediment retentiono nitrate removal

The AGUAMOD project

South-West of Europe

talk Dr. Sánchez-Pérez et al., session I1, Friday @12am

The AGUAMOD project

Environment

Economy

Society

South-West of Europe

talk Dr. Sánchez-Pérez et al., session I1, Friday @12am

The AGUAMOD project

Environment

Economy

Society

South-West of Europe

One objective: to evaluate impacts of global changes on ecological functions of water regulation

talk Dr. Sánchez-Pérez et al., session I1, Friday @12am

SWAT modelling

Calibration/Validation: past talk Ms. Cakir et al. today @2:40pm

• 263 subbasin ~ streames

• 12 834 HRUs

• 633 000 km²

Sampling stations - 19 hydrological- 28 physical-chemical

Human activities: - 44 dams- 44 urban releases

Climate Data

Soils

Land use

Digital Elevation

Model

Climate forcing

Europe(11 km x 11 km)Precip & Temp

1 set of reanalyses MESAN1989-2010

Climate forcing

Europe(11 km x 11 km)Precip & Temp

4 sets of projections BC-CORDEX1951-2100

1 set of reanalyses MESAN1989-2010

GCM (4)

RCM (4)

RCP (1)

Bias-correction (1)

RCP8.5

Climate forcing

Europe(11 km x 11 km)Precip & Temp

4 sets of projections BC-CORDEX1951-2100

1 set of reanalyses MESAN1989-2010

GCM (4)

RCM (4)

RCP (1)

Bias-correction (1)

RCP8.5

Trend = 1990/2059

Reference = 2000/10

Calibration/validation of hydrologywith MESAN reanalyses

2000/10

Garonne Ebro

Guadiana Jucar

Calibration: 2000/05Validation: 2006/10

Calibration/Validation: past talk Ms. Cakir et al. today @2:40pm

Validation of hydrology with climate models (BC-CORDEX)

Guadiana Alqueva 51

Tajo 3940_18

Turia

Duero Adour

2000/10

Trends of hydrological changes

Mann-Kendalltau

1990/2059

Trends of hydrological changes

Mann-Kendalltau

1990/2059

General annual streamflow decrease, more intense in the South

Trends of hydrological changes

Minho

1990/2059An

nual

river

dis

char

ge(m

3 /s)

Trends of hydrological changes

Minho Ebro

1990/2059An

nual

river

dis

char

ge(m

3 /s)

Trends of hydrological changes

Winter

Tau Mann-Kendall

1990/2059

Trends of hydrological changes

Winter

1990/2059

Tau Mann-Kendall

Trends of hydrological changes

FallSummer

Winter Spring

1990/2059

Tau Mann-Kendall

Trends of hydrological changes

FallSummer

Winter Spring

1990/2059

Tau Mann-Kendall

Trends of hydrological changes 1990/2059

Max average decrease in 70 yrs: -185 m3/s -98% summer streamflow

Summer

Tau Mann-Kendall

Trends of hydrological changes 1990/2059

Max average decrease in 70 yrs: -185 m3/s -98% summer streamflow

Summer

Extreme scenario(IPSL RCP 8.5)

Tau Mann-Kendall

Impacts of climate change on ecological functions

Ecological function = group of physical / biological / biogeochemicalprocesses (e.g. sediment retention, nitrate removal)

IN

OUTStream Solute Workshop (1990)

Net balance IN – OUT

Impacts of climate change on ecological functions

Ecological function = group of physical / biological / biogeochemicalprocesses (e.g. sediment retention, nitrate removal)

IN

OUTStream Solute Workshop (1990)

Net balance IN – OUT

Sediment releaseNitrate production+

Impacts of climate change on ecological functions

Sediment retentionNitrate removal

Ecological function = group of physical / biological / biogeochemicalprocesses (e.g. sediment retention, nitrate removal)

IN

OUTStream Solute Workshop (1990)

Net balance IN – OUT

Sediment releaseNitrate production

-+

Impacts of climate change on sediment retention

Net balance: IN - OUTDominance of sedimentretention in rivers of South-Western Europe

2000/10

<0 >0 -+

Impacts of climate change on sediment retention

Net balance: IN - OUT

Trend of net balance

Dominance of ↗ sediment retention

Dominance of sedimentretention in rivers of South-Western Europe

Tau Mann-Kendall

1990/2059

2000/10

<0 >0 -+

Impacts of climate change on nitrate removal

Dominance of nitrate removal in rivers of South-Western Europe, except large downstream rivers

2000/10

<0 >0 -+

Net balance: IN - OUT

Impacts of climate change on nitrate removal

Tau Mann-Kendall

↗ nitrate removal in main rivers↘ nitrate removal in smaller streams

Dominance of nitrate removal in rivers of South-Western Europe, except large downstream rivers

1990/2059

2000/10

<0 >0 -+

Net balance: IN - OUT

Trend of net balance

Explanatory factors Preliminary analysis

Spatial analysis

↗ NO3 removal

↘ NO3 removalnot significant

Explanatory factors Preliminary analysis

↗ NO3 removal

↘ NO3 removalnot significant

a b c

Trend Net balance NO3Spatial analysis

Explanatory factors Preliminary analysis

↗ NO3 removal

↘ NO3 removalnot significant

a b c a a a

a b c

a b b

Trend Net balance NO3 Trend Streamflow

Altitude

%agro-forestry (landuse)

Spatial analysis

Explanatory factors Preliminary analysis

↗ NO3 removal

↘ NO3 removalnot significant

a b c a a a

a b b

a b c

a b b

Trend Net balance NO3

Trend Net balance SED

Trend Streamflow

Altitude

%agro-forestry (landuse)

Spatial analysis

Explanatory factors Preliminary analysis

Hotspots of ‘nitrate removal increase’ :- downstream of large rivers- where %agro-forestry is high - where sediment retention also increases

↗ NO3 removal

↘ NO3 removalnot significant

a b c a a a

a b b

a b c

a b b

Trend Net balance NO3

Trend Net balance SED

Trend Streamflow

Altitude

%agro-forestry (landuse)

Spatial analysis

Conclusions and perspectives

Conclusions

o Effects of climate change in South-Western Europe (1990-2059):

Conclusions and perspectives

Conclusions

o Effects of climate change in South-Western Europe (1990-2059):

Explanatory factors : upstream/downstream

landuse

Conclusions and perspectives

Perspectives

o Investigate multiple factors explaining ecological functions variations

Conclusions

o Effects of climate change in South-Western Europe (1990-2059):

Explanatory factors : upstream/downstream

landuse

Conclusions and perspectives

Perspectives

o Investigate multiple factors explaining ecological functions variations

o Include more climate projections and combine climate scenarios

with changes in direct human pressures (e.g. population, landuse)

Conclusions

o Effects of climate change in South-Western Europe (1990-2059):

Explanatory factors : upstream/downstream

landuse

Conclusions and perspectives

Perspectives

o Investigate multiple factors explaining ecological functions variations

o Include more climate projections and combine climate scenarios

with changes in direct human pressures (e.g. population, landuse)

o Quantify impacts on export to the ocean

Conclusions

o Effects of climate change in South-Western Europe (1990-2059):

Explanatory factors : upstream/downstream

landuse

Thank you for your attention.