Investigation the implications of climate change on crop water requirements in Western Nile Delta, Egypt

Egypt is grappling with water shortage, with agriculture using about 80% of its water consumption. Climate change is only going to further complicate water availability and water consumption. This study investigates the potential impacts of climate change on irrigation demands in the Western Nile Delta of Egypt, focusing on both coastal region, Mahmodia, (Ma) and interior region, Nubaria, (Nu). An ensemble of 40 Global Circulation Models (GCM) was utilized to project climate conditions under two representative concentration pathways, RCP4.5 and RCP8.5, based on the Intergovernmental Panel on Climate Change (IPCC) and the Fifth Assessment Report. The CROPWAT model was used to calculate the reference evapotranspiration (ET0) and the crop water requirements (CWR) for key crops in the Western Nile Delta. This included summer crops (sugar beet, cotton, summer maize, summer tomato, watermelon and sweet melon), winter crops (wheat, alfalfa, winter potato, winter squash and broad bean), and permanent crops (orange, apple, grape, and olives). The assessments considered both historical and projected climate data extending until 2100. According to RCP8.5 scenario, the findings indicate a projected rise in CWR rates in Nubaria, with an increase of 1.03%, 1.15%, and 0.94% per decade until the end of the century for summer, winter, and permanent crops, respectively. Similarly, Mahmodia is expected to experience a rise in CWR rates by 1.1%, 1.16%, and 1.08% per decade for the same crop categories until 2100. These projections underscore the urgent necessity to integrate climate change considerations into water resource management strategies to enhance the efficiency of these strategies.