Li-Zhi-An, LIU Chu-Zhen, ZHANG Jian-Guo, ZHANG Li-Xin
(1.Monitoring Center of Soil and Water Conservation, Ministry of Water Resource,100053,Beijing; 2.Institute of Mountain Hazards and
Environment, CAS, 610041, Chengdu; 3.School of Geography, Nantong University, 226007, Nantong, Jiangsu; 4.School of Geography, Beijing Normal University, 100875,Beijing;5.State Key Laboratory of Remote Sensing Science, Beijing Normal University and Institute of Remote Sensing Applications, CAS, 100875, Beijing:China)
Abstract:Freeze-thaw erosion is the third largest soil erosion type after water erosion and wind erosion, and it is also the main type of soil erosion need to be surveyed in census of water and soil conservation situation, Chinese first-ever nationwide water resources survey. The survey method formulation and correctly applying have important influence on survey results of freeze-thaw erosion. The survey method and technique process of freeze-thaw erosion were introduced clearly in this paper in order to let more workers in water and soil conservation field to know the survey method of freeze-thaw erosion. Firstly, the method for defining the freeze-thaw erosion area in China and the assessment method of freeze-thaw erosion intensity were introduced. Then, the calculation procedure, criterion and weight of six indices for assessment freeze-thaw erosion were formulated. The six indices include the annual freeze-thaw cycle days, phase transition water content in freeze-thaw process, annual precipitation, slope, aspect, vegetation coverage. Finally, the quality measures in survey process were introduced. The survey method introduced in this paper is very important for freeze-thaw erosion survey, and for scientifically evaluating present state, forecasting development trend.