Progress in research on soil water redistribution
JIN Shijie;FEI Liangjun;FU Yuliang;Institutes of Water Resources,Xi'an University of Technology;
Soil water redistribution has significant effects on local ecosystem and agriculture in arid and semi-arid farmlands in the Loess Plateau. In a redistribution process,soil water moves in unsaturated soil under the potential gradient. The theories and models in soil water redistribution achived in home and abroad from point of view of both physics and biology were reviewed and summarized. It is found out that the progress is mainly affected by cultivation measures,rainfall intensity,initial moisture content and irrigation method from point of view of physics. The developed mathematical models based on soil water characteristic curve and its hysteresis,soil water flux method,and soil water motion equations are clarified. It is also identified that the soil water redistribution can effectively regulate soil moisture condition in root layer and enrich community structure and improve soil nutrient; but the process can be influenced by soil moisture,species and soil properties. Through the review of past research in this field,we clarify the research present situation and also propose some constructive opinions for the further study of the theory.