Projecting rice water footprint for different shared socioeconomic pathways under arid climate conditions

Climate change would intensify water and food scarcity in arid regions. As a main cereal crop, projecting rice water consumption and yield responses to climate change is crucial for improving water management and ensuring food security. This study projected the effect of climate change on rice yield (Y), evapotranspiration (ET), and total water footprint (WFT) in Damietta, Egypt, under two Shared Socioeconomic Pathways (SSPs): 2–4.5 and 5–8.5. First, five global climate models (GCMs) were evaluated for their accuracy in capturing the baseline temperatures (T) and precipitation (Pr) under the SSPs scenarios. Then, AquaCrop-GIS, integrated with ensemble downscaled GCMs data, was used to project the future climate change impacts on rice Y, ET, and WFT under a 3-day irrigation frequency regime (3IF) and two SSPs and CO2 emission scenarios during 2021–2099. Results indicated that GCMs accurately predicted climate variables during the baseline. Without CO2 effect, Y would slightly increase (1.07%–3.03%) during the 2030s and 2050s but significantly decline (4.55%–18.94%) during the 2070s and 2090s under the SSPs scenarios. However, with CO2 effect, Y would significantly increase (14.19%–28.31%) during 2021–2099. Projected ET would decline (1.42%–18.98%) under the SSPs and CO2 scenarios over time. Meanwhile, without CO2 effect, the WFT would increase by 2.88% to 17.13% during the 2070s and 2090s. However, with CO2 effect, the WFT would decrease significantly (15.45%–34.50%) under the SSPs scenarios during the future periods. The findings help growers and policymakers develop effective water management strategies for agricultural sustainability in arid regions.