Climate-induced changes in crop water balance during 1960–2001 in Northwest China

Climate change affects regional agricultural development, but a quantitative assessment of large-scale impacts remains difficult. Northwest China has experienced considerable climate change during the last 40 years, and this study uses GIS technology to evaluate the impacts of that change on the agricultural water balance. Results show that over the last 40 years the climate has transitioned from a warm-dry to a warm-wet pattern in the northwestern area of Northwest China, while exhibiting a pattern of increasing aridity in other parts of the region since the 1980s. Through analysis of the spatio-temporal distribution of agricultural water balance using water cycle models that include climatic, crop and cropland layers, we found that the climate warming in the northwestern area of the region has led to a notable reduction in the agricultural water deficit. This reduction, however, still cannot significantly alleviate the water deficit. Finally, we argue that to make agricultural development sustainable in this area, both hard and soft approaches are needed to bring about efficient use of the limited water resources.