Assessing the Impact of Climate Change on Soil water Balance in the Loess Plateau of China

Soil water balance has response to climate change and evaluation of soil water change is one of the most important items of climate change impact assessment. GCM outputs under three scenarios were statistically downscaled during 2010~2039 to simulate the potential change of soil water balance in Wangdonggou watershed on the Loess Plateau with WEPP model. GCM predicted a 1.8 to 17.5% increase in annual precipitation, 0.5 to 0.9 °C rises in maximum temperature, 2.0 to 2.3 °C rise in minimum temperature for the region. Plant transpiration will mainly change from April to June and soil evaporation mainly changed during July to September. Percent increases under climate changes, as averaged for each emissions scenario and slope, ranged from -5 to19% for crop transpiration, -4 to 4% for soil moisture, -7 to 7% for soil evaporation, 6.5 to 44.1% for wheat grain yield, 26.3 to 41.7% for maize yield. Climate change will affect soil water balance significantly and some countermeasures are necessary.