Abstract
Egypt faces great challenges to manage its limited freshwater resources. Shortage in freshwater, due to expected stresses of climatic changes and upper Nile projects, will have major impacts on Egypt's water and food security. About 85% of the annual total freshwater resource is consumed by agriculture. The objective of this work is to assess the future water security situation of Kafr El-Sheikh governorate, Nile Delta, Egypt, under climate change and urbanization stresses, compared to the current situation. Main investigated water security elements for this study were the irrigation water requirements and agricultural land areas. Two different reference evapotranspiration equations were used to calculate the future irrigation water requirements under three different Representative Concentration Pathways (RCP) (2.6, 4.5 and 8.5 scenarios) for the period 2010–2100, based on the intergovernmental panel on climate change’s 5th assessment report. Remote sensing and Geographical Information System (GIS) were used to generate a land use classification map, which was used to estimate the losses in each land use category of the study area under 0.5 and 1.0 m relative sea level rise (SLR) estimates. Combined scenarios of future changes in irrigation water consumption and agricultural land area were analysed. The results show that the future water security situation of the governorate is highly sensitive to projected climatic changes. Moreover, most future scenarios revealed that the agricultural land area would decrease, which will cause serious food security problems. The maximum decrease by about 55.9% of the agricultural land area for year 2095 compared to year 2016 is estimated, due to the current annual decreasing rate of 0.4% and 1.0 m SLR, whatever the applied RCP scenario. While the maximum increase in the required irrigation water would be about 6% due to the RCP85 scenario, assuming no change in the irrigation land area, with a mixing ratio of 1.34 (freshwater): 1 (drainage water) which would affect the crop yield productivity. A regular assessment of water security elements for each of the Egyptian governorates should be managed and an urgent integrated plan for food security to adapt with the future climate change impacts is essential.
•Future climatic and land use changes should be combined to estimate future impacts.•Selection of evapotranspiration equations affects future projected values.•Future water security situation of the governorate is highly sensitive to projected climatic changes.•Expected shortage in agricultural land area due to urban sprawl and/or sea level rise will significantly affect the Egyptian food security.