Relative impact of irrigation techniques and climate change on hydroclimatic regimes in the Mediterranean region
- 1Eawag: Swiss Federal Institute of Aquatic Science and Technology , Department of Water Resources and Drinking Water, Dübendorf, Switzerland
- 2Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Systems Analysis, Integrated Assessment and Modelling, Überlandstrasse 133, 8600 Dübendorf, Switzerland
- 3Universitat Politècnica de València, Research Institute of Water and Environmental Engineering (IIAMA), Camí de Vera s/n, 46022 Valencia, Spain
- 4Universitat Politècnica de València, Valencian Center for Irrigation Studies, Camí de Vera s/n, 46022 Valencia, Spain
- 5University of Neuchâtel, Centre of Hydrogeology and Geothermics (CHYN), Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
- 6University of Basel, Department of Environmental Science, Bernoullistrasse 32, 4056 Basel, Switzerland
- 7ETH Zürich, Department of Civil, Environmental and Geomatic Engineering, Stefano-Franscini-Platz 5, 8093 Zürich, Switzerland
Irrigated agriculture is the major water consumer in the Mediterranean region. Improved irrigation techniques have been widely promoted to reduce water withdrawals and increase resilience to climate change impacts. In this study, we assess the impact of the ongoing transition from flood to drip irrigation on future hydroclimatic regimes in the agricultural areas of Valencia (Spain). The impact assessment is conducted for a control period (1971-2000), a near-term future (2020-2049) and a mid-term future (2045-2074) using a chain of models that includes five GCM-RCM combinations, two emission scenarios (RCP 4.5 and RCP 8.5), two irrigation scenarios (flood and drip irrigation), and twelve parameterizations of the hydrological model Tetis. Results of this modelling chain suggest considerable uncertainties regarding the magnitude and sign of future hydroclimatic changes. Yet, climate change could lead to a statistically significant decrease in future groundwater recharge of up -6.6% in flood irrigation and -9.3% in drip irrigation. Projected changes in actual evapotranspiration are as well statistically significant, but in the order of +1% in flood irrigation and -2.1% in drip irrigation under the assumption of business as usual irrigation schedules. The projected changes and the related uncertainties will pose a challenging context for future water management. However, our findings further indicate that the effect of the choice of irrigation technique may have a greater impact on hydroclimate than climate change alone. Explicitly considering irrigation techniques in climate change impact assessment might therefore be a way towards better informed decision-making.
This study has been supported by the IRRIWAM research project funded by the Coop Research Program of the ETH Zurich World Food System Center and the ETH Zurich Foundation, and by the ADAPTAMED (RTI2018-101483-B-I00) and TETISCHANGE (RTI2018-093717-B-I00) research projects funded by the Ministerio de Economia y Competitividad (MINECO) of Spain including EU FEDER funds.
How to cite: Pool, S., Francés, F., Garcia-Prats, A., Pulido-Velazquez, M., Sanichs-Ibor, C., Schirmer, M., Yang, H., and Jiménez-Martínez, J.: Relative impact of irrigation techniques and climate change on hydroclimatic regimes in the Mediterranean region, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2242, https://doi.org/10.5194/egusphere-egu21-2242, 2021.
