Since 2013, hundreds of thousands of refugees have migrated southward to Jordan to escape the Syrian civil war. The migration has put major stress on Jordan’s water resources, a heavy burden for a country ranked among the most water-poor in the world, even prior to the influx of refugees. However, the refugee crisis also coincided with an unexpected, rapid increase in flow in the Yarmouk River—from Syria to the Al-Wehda reservoir on the Syria-Jordan border. This flow provided a small supplement to Jordan’s agricultural irrigation supply, that although beneficial was modest compared to both the actual freshwater needs of the refugees and the transboundary flow from Syria long anticipated by Jordan.
Graduate Student - Department of Earth System Science, Stanford University
Post-doctoral Fellow - Jordan Water Project, Stanford University
Cyrus Fisher Tolman Professor - School of Earth, Energy, and Environmental Sciences, Stanford University
Senior Fellow - Stanford Woods Institute for the Environment
How to assess water resources in a war zone
Reliable summer daytime land cultivation maps and urbanization maps (based on night-light images), as well as hydrological data, are essential to investigate the potential relationship between civil conflict, land use, and water consumption, but obtaining on-the-ground data in a war zone is next to impossible. To solve this problem, we turned to remote sensing data. Using spatial and statistical analyses of satellite imagery, we were able to provide evidence of rapid changes in land use, water use, and water management in the southern Syrian Yarmouk-Jordan River watershed.
The migration has put major stress on Jordan’s water resources, a heavy burden for a country ranked among the most water-poor in the world, even prior to the influx of refugees.
In order to test the causal effect of the refugee crisis on land and water resources, we compared changes observed in Syria with corresponding changes observed in nearby regions where irrigation and dam management were unaffected by the refugee crisis: the Jordanian side of the Yarmouk basin to assess changes in irrigated agricultural land use and the Israeli-controlled Golan Heights to evaluate changes in water reservoir management. The causal effect of migration on irrigated land areas and reservoir storage volumes was evaluated statistically by relating pre-migration and post-migration changes in Syria to changes in the control regions over the same periods.
Effect of Syrian migration on land use
To evaluate the effect of refugee migration on Syrian land use, we generated maps of irrigated crop areas for the Jordanian and Syrian portions of the Yarmouk basin between 2000 and 2015. We found that irrigated areas increased in both countries between 2000 and 2006, followed by an abrupt reduction during the following years, which corresponded to a regional drought. However, in Syria irrigated area declined considerably after 2012, coinciding with the flight of Syrian refugees.
Notably, the post-2012 drop was much greater in Syria than in Jordan, suggesting that conflict and the flight of refugees caused a major reduction in farming and associated reduction in irrigation water use in Syria. Using temporal changes in irrigated area in Jordan as a counterfactual, we found that there was a 47 percent decrease in irrigated land in southern Syria caused by the recent mass migration of refugees that started in 2013.
Effect of the Syrian crisis on reservoir levels
Effects on the watershed
Finally, we evaluated the impacts of refugee migration along with associated land-use and reservoir storage changes on the hydrological response of the watershed. Coinciding with the refugee crisis of 2013-15, measured inflows into the Al-Wehda reservoir on the Jordan border reveal a three-fold increase in annual flow compared to the 2006-12 period. The imagery showed that Syrian dams retained considerably less wet-season runoff during the refugee migration period compared with prior years. The decreased retention of wet-season flows during the refugee migration period accounts for almost half of the flow increase reaching Jordan.
Armed conflict resulted in significant changes to land use and water management in Syria, and ultimately, in an unanticipated increase in transboundary flow to downstream Jordan.
The refugee crisis also caused a significant decrease in irrigation demand, which likely increased the portion of reservoir releases making it back from irrigation canals to the stream during the summer. We found that about half of the stream flow increase between 2006-12 and 2013-15 is attributable to the rapid migration of Syrian refugees and subsequent abandonment of irrigated agriculture in southern Syria.
Conflict and the implications for water users
Our analysis suggests that the Syrian conflict and subsequent refugee migration caused downstream flow to increase primarily by the reduction in irrigation demand and changes in reservoir management practices. The abnormal recent decrease in Syrian water retention detected on satellite imagery is consistent with reports from the field, which point to the underuse or decommissioning of dams due to targeted military operations and poor operational management.
Acknowledgments: This work was supported by the National Science Foundation (NSF) under Grant GEO/OAD-1342869 (to Stanford University). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF.
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[On the security risks of climate change] The classic definition [of state security] has been around conflict—threats to human life from armed aggression—which includes intrastate components such as dissident groups and civil war, and then, of course, when states go to war with each other.... [But climate change may induce conflict] to happen in places that are already living on the edge.