Simulating effects of climate change on evapotranspiration of major crops in China

Simulations were conducted to quantify the influence of climate change on three crops in China using a Soil-Vegetation-Atmosphere Transfer (SVAT) model. The model reflected dynamic connections of canopy temperature, leaf moisture potential and soil temperature to environmental factors. When environmental and physiological changes were given to the model, responses of evapotranspiration of cropland were estimated. Six factors were taken into consideration: air temperature, radiation, air humidity, wind velocity, leaf area index and stomatal resistance. Climate changes were simulated by altering air temperature by 3°C, radiation by 10%, air humidity by 5%, wind velocity by 10%, leaf area index by 15% and stomatal conductivity by 22%. Scenarios of single- and multiple-factor change produced different responses in evapotranspiration, ranging from -14% to 27%. Crop water consumption in China may increase by 0.7, 2.4 or 2.2 billion m 3 for cotton, corn or rice, totally 5.3 billion m 3 .