Présentations Colloques

Oral Presentation
5.01
Session 5.01: Groundwater resources in a world facing climate change
Saadé-sbeih Myriam Zwahlen François
Irrigation and war, the drivers of change in the Orontes River basin
The Orontes River (Nahr Al Asi) basin, shared between Lebanon, Syria and Turkey, is a representative example of the global changes in water use that impacted surface and groundwater systems in the eastern parts of the Mediterranean basin during the last century. Since the 1950s and especially in the 1990s, the area witnessed an intensive surface and groundwater development, mostly for irrigation purposes. It led to a sharp decrease of the Orontes river discharge in its middle course+ the drying up of numerous springs and local overexploitation of groundwater in several areas. After 2011, the basin became one of the most conflict-affected regions in Syria- it witnessed a drastic spatial redistribution of the water consumption and thus a radical reconfiguration of surface and groundwater flows. As a consequence of the decrease of water consumption in its middle reach, the Orontes River discharge of the basin increased by two-fold at the Syrian-Turkish border in 2014. **This presentation aims to analyze the drivers of long term and radical changes in the Orontes River basin. The interdisciplinary approach consisted of assessing the human-hydrosystem coevolution to determine these drivers through a historical water balance calculation for the Lebanese and Syrian parts of the basin. The lack of accurate and comprehensive long term datasets, the absence of current data – because of the destruction of hydrometric monitoring systems but also because of they are very sensitive – are tackled by confronting different estimation methods of historical and present surface and groundwater flows- literature reviews, historical records, statistical analysis, expert interviews, maps and satellite images analysis to assess land use changes. **This study is based on the results of the Orontes River Basin Research Program conducted at the Graduate Institute of International and Development Studies (Geneva) between 2012 and 2016, with the support of the Swiss Development and Cooperation Agency. The Orontes Program aimed to provide baseline elements to support emergency interventions and post-conflict planning in Syria and to contribute and coordinate a sustainable management, at long term, of the shared water resources of the Orontes River basin
Switzerland