Modelling the impact of climate change on irrigation area demand in the Jordan River Region

Changing climate conditions in the Jordan River Region are likely to have adverse effects on irrigated crop yields and, as a result, increase the demand for irrigation area. We apply a regional version of the dynamic land-use change model LandSHIFT to quantify the effect of climate change on the demand for irrigation area needed to maintain a constant production of irrigated crops. To evaluate uncertainties induced by climate projections, we use an ensemble of four regional climate datasets based on the IPCC emissions scenario A1B. In order to interpret the simulation results on additional irrigation area demands due to changing climate conditions, we compare them to the simulation results that were generated assuming socio-economic changes (increase in crop demand) under constant climate conditions. Our simulation results show that climate change may cause an expansion of irrigation area by about 25%, whereas different climate projections only lead to minor variability in the simulated irrigation area demands. By comparison, an increase in crop demand could result in an expansion of irrigation area by about 71%.