Impacts Of Climate Change On Crop Yield And Virtual Water Content Of China

China is water-scare country with a large population of1/5of the world. Water shortage in China is a key factor that limits its grain production and economic development. Food and water demand in China is always increasing caused by population growth, economy development and consumption pattern change. The increasing temperature and changing precipitation caused by climate change has become big challenges to water and food security of China. By analyzing the impacts of climate change on yield and virtual water content (VWC) of the four major crops (maize, wheat, soybean and rice) in China, climate change, water resources and agriculture has been linked.The GIS-based Environmental Policy Integrated Climate (GEPIC) model was used to simulate the yield and VWC of the crops in three climate change scenarios and two different management conditions (rainfed and irrigated). The result shows:The C4crop (maize) has relative lower VWC (about0.8m3kg-1) than the C3crops, while rice has the largest VWC. The VWC of a same crop is lower in southern China than that in western China. VWC of aggregated crops shows a high-low-high trend from south to the north. The increasing of CO2concentration could increase crop yield and water productivity significantly. Ignoring carbon fertilization, crop yield often shows a first increase then decrease trend, while VWC would first increase then decrease or increase steady.In the future, the increasing precipitation would be helpful for rainfed crops by increasing crop yield and decreasing VWC in northern China. The increasing temperature would make the plateau or high-latitude area become suitable for agriculture. However, too high temperature increasing would have negative effect on crop yield and water productivity (especially for wheat and rice). Agriculture of China would benefit from climate change by taking carbon fertilization, temperature and precipitation change into consideration together. Ignoring CO2fertilization, wheat and rice would be adversely affected by climate change. Climate change would lead an increasing water use demand of agriculture for China in the future, and water demand would be even higher when CO2fertilization was considered, making it hard to guarantee food security and food security.There are huge uncertainties about the impacts of climate change on agriculture and water resources, so China has to think and take action carefully to guarantee its food and water security.