Dynamic of soil water, groundwater and water balance in Hetao irrigation area
河套灌区土壤水和地下水动态变化及水平衡研究

In order to explore the dynamics of soil moisture and groundwater under different crops and irrigation patterns, four experimental plots of 2 Mu in the Hetao irrigation area were selected. The regional dominant crops, spring wheat, corn and sunflower were cultivated in three plots respectively and the other plot acted as the control cell without any crop. The soil and groundwater were sampled from April to November, 2009. The results showed that different soil moisture contents among crops were mainly in the grown period of May to September. The soil moisture content generally decreased during the summer irrigation because of evaporation and transpiration. In the fall irrigation period, the soil moisture change was due to infiltration recharge, different from that of the summer irrigation. Mean monthly groundwater depth of four fields showed little difference. The response of groundwater was sensitive to irrigation and rainfall due to the preferential flow. This study quantified the variation of regional soil moisture and groundwater, and revealed the mutual exchange between the water balances. The conclusion provided a theoretical basis for the scientific and rational management of water resources in the irrigation area.