Impact of climate change on water resources in Spanish Mediterranean basins Teodoro Estrela Júcar River Basin Authority Research Institute of Water and Environmental Engineering (IIAMA), Technical University of Valencia, Miguel Ángel Pérez-Martín Research Institute of Water and Environmental Engineering (IIAMA), Technical University of Valencia,
Contents The climate change in the Mediterranean Region Climate Change impact on water resources in Spain: climate scenarios and methodologies. Impacts on Mediterranean Spanish River Basins Impacts on the Júcar River Basin District Main conclusions
Climate change in the Mediterranean Region
Climate Change in the Mediterranean Region Water is a strategic resource which can be threatened by climate change. The European Environment Agency (2010) states that the Mediterranean basin has experienced decreased precipitation and increased temperature over past decades, a trend projected to worsen. Changes in precipitation and temperature can lead to important changes in water resources in Mediterranean region.
Climate Change in the Mediterranean Region Percentage of variation for mean annual runoff in the period 2090-2099 respect to the period 1980-1999 Grated areas: more than 90% in the concordance of the models in the sign of change Source: Climate Change and Water, IPCC Technical Paper VI. IPPC, june 2008
Climate Change in the Mediterranean Region Climate change impacts can be aggravated in regions that already face frequent droughts in combination with low water resources levels and therefore imbalances between water demand and available resources.
Climate Change in the Mediterranean Region The European Mediterranean region is very vulnerable to possible climate changes because of the low available resources in this region for which higher temperature increases and precipitation decreases are projected (European Commission, 2009). Water Exploitation Index in the EU (expected for 2030). Source: European Environment Agency
Project Ensembles 2009 Application of 7 global models with A1B climate change scenarios. Application of regional models regional from medium-term (2030-2050) to long-term (2080-2100) Increases in temperature referred to the 1980-1999 period Fuente: IPCC Fourth Assessment Report (AR4): WGI: Climate Change 2007: The Physical Science Basis
Climate Change Scenarios Scenario A1B: Increased concentration from the current 400 ppm up to 900 ppm 2100 values (predictable scenario). It implies growth in emissions up to 2050 and gradual reduction of intermediate stage between A2 and B1.
Ensembles 2009 results Regional models with A1B scenario Increase temperature air referred to 1961-1990 Scenario A1B Mean results of RCM models Period 2021-2050 Precipitation variation referred to 1961-1990 Scenario A1B Mean results of RCM models Period 2021-2050
Ensembles 2009 results Regional models with A1B scenario Increase temperature air referred to 1961-1990 Scenario A1B Mean results of RCM models Period 2071-2100 Precipitation variation referred to 1961-1990 Scenario A1B Mean results of RCM models Period 2071-2100
Impact of Climate Change on water resources in Spain: climate scenarios and methodologies.
Preliminary assessments of Climate Change impacts in Spain Preliminary assessment reports on climate change impacts in Spain show: Decreases in mean values for water resources are expected. For a decrease of 5% in mean annual precipitation and an increase of 1ºC in mean annual temperature, a decrease between 9 and 25% in runoff is expected depending on the river basin districts. The most critical Spanish areas are arid and semiarid ones where water scarcity and drought problems are greater.
Impact on water resources Reduction of the total runoff in scenario: increase of 1 º C of temperature Reduction of the total runoff in scenario: increase of 1 C of temperature and decrease of 5% of precipitation Source: Water in Spain, Ministry of Environment (2000)
Impact on water resources and vulnerability Impact on runoff reduction for a decrease of 5% in mean annual precipitation and an increase of 1ºC in mean annual temperature (year 2030) Vulnerability: Water Exploitation Index (quotient between water demand and water resources) in Spanish water resource systems Source: Water in Spain, Ministry of Environment (2000)
Spanish National Plan of Adaptation to Climate Change Spanish National Adaptation Plan on Climate Change Aim: Integration of adaptation to climate change into the planning strategy of the different socio-economic sectors in Spain The Spanish Center for Hydrographic Studies of CEDEX - a research and experimentation center for water issues has been commissioned by the Ministry of Agriculture, Food and Environment in the framework of National Adaptation Plan on Climate Change to make an assessment of the climate change impact on water resources sector: Natural water resources(cedex, 2010), Water demands (irrigation, public water supply and industry), Available resources in water resources systems Ecological status of water bodies
Climate Change scenarios of the Spanish National Plan of Adaptation to Climate Change The climatic data used are the climate scenarios regionalised by the Spanish State Meteorological Agency (AEMET, 2008). It combines the results of global circulation models made by various international organisations with regionalisation techniques at the local level. The selected emission scenarios (A2 and B2) are part of the set of greenhouse gas emission scenarios established by the IPCC in 2000.
AEMET, 2008 Climate Change scenarios of the Spanish National Plan of Adaptation to Climate Change
Climate change and water resources in Spain The main variables of the hydrological cycle (soil moisture, recharge to the aquifers, runoff, ) have been simulated using the SIMPA distributed hydrological model (Ruiz, 1998). Monthly runoff maps Monthly precipitation and potential evapotranspiration maps
Climate change and water resources in Spanish River Basins Percentage of water resources decrease at long term: 2041-2070 for scenario A2 (taken from Estrela et al, 2012). Source of data. CEDEX(2010)
Impact on water resources in Mediterranean Spanish river basins
Climate change and water resources in Mediterranean Spanish river basins River Basin District Period Scenario A2 Scenario B2 The impact of climate change on water resources in all the Mediterranean basins (except for the Internal river basins in Catalonia) is greater than the mean values for the whole of Spain. The impact is greater in the basins located in the southern part of the country. Internal river basins in Cataluña mean annual runoff mean annual runoff 2011-2040 0-7 2041-2070 -4-9 2071-2100 -21-16 Ebro 2011-2040 -9-9 2041-2070 -14-13 2071-2100 -28-16 Balearic Islands 2011-2040 -4-15 2041-2070 -15-20 2071-2100 -31-23 Júcar 2011-2040 -5-12 2041-2070 -18-13 2071-2100 -32-24 Segura 2011-2040 -10-13 2041-2070 -21-14 2071-2100 -33-21 Internal river basins in Andalusia 2011-2040 -12-16 2041-2070 -30-15 2071-2100 -41-27 Spain 2011-2040 -8-8 2041-2070 -16-11 2071-2100 -28-14 Variation of runoff (%) for Mediterranean Spanish river basin districts in the periods 2011-2040, 2041-2070 and 2071-2100 with regard to the control period of 1961-1990. Source of data: CEDEX (2010)
Water Exploitation Index in Spanish River Basins River Basin Water resources (hm 3 /year) Total demand (hm3 /year) Current Water Exploitation Index (WEI) Water resources change Scenario A2 Water Exploitation Index (WEI) 2041-2070 MIÑO-SIL 11,918 581 4.9% -12% 5.5% GALICIA-COSTA 12,077 783 6.5% -12% 7.4% CUENCAS INTERNAS PAIS VASCO 1,637 310 18.9% -16% 22.5% CANTABRICO 16,143 717 4.4% -16% 5.3% DUERO 13,179 3,830 29.1% -17% 35.0% TAJO 10,075 2,667 26.5% -19% 32.7% GUADIANA 4,473 2,333 52.2% -27% 71.5% GUADALQUIVIR 7,087 3,368 47.5% -28% 66.0% CUENCA MEDITERRANEA ANDALUZA 2,330 1,343 57.6% -30% 82.3% GUADALETE Y BARBATE 1,475 383 26.0% -30% 37.1% TINTO, ODIEL Y PIEDRAS 692 181 26.3% -30% 37.5% SEGURA 762 1,807 237.2% -21% 300.3% JUCAR 3,357 2,949 87.8% -18% 107.1% EBRO 16,202 7,034 43.4% -14% 50.5% CUENCAS INTERNAS DE CATALUÑA 2,603 1,346 51.7% -4% 53.9% ISLAS BALEARES 639 285 44.7% -15% 52.5% ISLAS CANARIAS 420 414 98.5% -32% 144.9% España 105,076 30,334 28.9% -17% 34.8%
Water Exploitation Index in Spanish River Basins Current Water Exploitation Index (WEI) Water Exploitation Index (WEI) 2041-2070 Scenario A2
Water Exploitation Index in Spanish River Basins Major WEI percentage increases take place in the river basins with the greatest current WEI. As a consequence the most stressed river basins will aggravate its situation.
Impact on water resources in the Júcar River Basin District
Climate Change Impacts in Júcar RBD Location of Jucar River Basin District 900 800 700 600 500 400 300 200 100 0 Mean annual precipitation in Jucar River Basin District Variation of precipitation in period 1980/81-2008/09 respect to Precipitación (mm) en la DHJ precipitation in period 1940/01-2008/09 1940-41 1942-43 1944-45 1946-47 1948-49 1950-51 1952-53 1954-55 1956-57 1958-59 1960-61 1962-63 1964-65 1966-67 1968-69 1970-71 1972-73 1974-75 1976-77 1978-79 1980-81 1982-83 1984-85 1986-87 1988-89 1990-91 1992-93 1994-95 1996-97 1998-99 2000-01 2002-03 2004-05 2006-07 2008-09 mm Año Precipitación anual Media 1940/41 2008/09 Media 1980/81 2008/09
Climate Change impacts in Júcar RBD 1000 900 Precipitation Mean (1940-2007) Mean (1980-2007) Mean (1940-1979) 14 Temperature Mean (1940-2007) Mean (1980-2007) Precipitation (mm) 800 700 600 500 400 300 200 100 0 1940 1950 1960 1970 1980 1990 2000 Year Temperature (ºC) 13 12 11 10 1940 1950 1960 1970 1980 1990 2000 Year 2000 1800 St reamflow Mean (1940-2007) Mean (1980-2007) 1600 Streamflow (hm3) 1400 1200 1000 800 600 400 200 0 1940 1950 1960 1970 1980 1990 2000 Year CC impacts in the upper river basins draining to Alarcon and Contreras reservoirs
Climate Change Impacts in Júcar RBD Future climate using AR4 scenarios has been characterised in the Júcar RBD by Chirivella (2010) in Technical University of Valencia, showing that: the scenarios AR3 collected in AEMET (2008) reproduce correctly the temperature in the Júcar River Basin District for the control period (1961-1990) but not the precipitation. Additionally, Chirivella (2010) performs a climatic regionalisation obtained with dynamic downscaling in two stages (first for the whole Iberian Peninsula and second, using these results above as boundary conditions on the Júcar RBD territory), observing a clear improvement:
Climatic regional model RegCM3 Emission Scenario: A1B Global model downscaling: ECHAM5 Regional model: RegCM3 Historic control period: 1990 2000 Simulation period: 2010-2040 Coarse grid Nested grid
Climate Change Impacts in Júcar RBD The predicted impact on water resources in the Júcar River Basin District means a reduction of 21% for the period 2010-2040 over the control period 1990-2000. This reduction is significantly higher than that obtained with the AEMET(2008) scenarios used by CEDEX (2010): 5% with A2 and 12% with B2 over the control period 1961-1990. These differences can have its explanation in the combination of two facts: different CC scenarios (A1B) and use of the dynamic downscaling to represent the climate variables.
Conclusions
Main conclusions The Mediterranean region is one of the most affected regions in the world by the climate change impact on water resources. The impact on water resources is greater in the river basin districts located in the southern part of the Spain which are the most stressed ones, what will aggravate their current situation. The values of the reductions of water resources depend on the climate change scenarios and the global and regional models used. The predicted impact on water resources with the latest studies in the Mediterranean Júcar River Basin District, means a reduction of 21% for the period 2010-2040.