Global Water Scarcity Assessment Incorporating Green Water in Crop Production

Over the past decades, water scarcity has become prevalent in many regions of world. Previous assessments largely considered “blue water” (surface and groundwater) overlooked “green (soil moisture), despite its key role supporting crop production. Moreover, long-term evolution remains unclear. Here, we propose an agricultural index (WSIAW) that explicitly combines green blue water. The WSIAW measures degree to which both availabilities can satisfy requirement. directly indicate rainfed irrigated areas, cannot be captured by alone. Using WSIAW, assessed across world during 1971–2010 at a spatial resolution 0.5 arc degree. We found 22% 228 river basins with >1 presented much broader geographical coverage compared estimates based on only (8% total basins). also exhibited clear trend increasing severity over study period, particularly major regions. Expanding cropland increasing/competing withdrawals other sectors were main reasons for intensification scarcity, was pronounced some Asian African basins. proposed applied different various scales is important addressing global issues.