1.Institute of Soil and Water Conservation,Chinese Academia of Sciences and Ministry of Water Resources;2.Northwest Sci-Tech University of Agriculture and Forestry: 712100,Yangling,Shaanxi;3.Graduate School of Chinese Academy of Sciences,100039,Beijing: China
Abstract：Soil moisture is crucial to plant growth and plays a vital role in vegetation restoration.Based on spatial pictures and databases,combined with sample soil moisture data and geographic data of Ansai by GIS,a method was developed to define the sample soil moisture ratio according to different combinations of land use type,land type and slope grade.Using GIS technique and maps were made for indicating the spatial variation of soil moisture in different soil layers.Using these maps,the amount and distribution of average soil moisture content in different soil layers in Ansai county were calculated.Quantitative analysis of the soil moisture structure demonstrated that soil moisture content in Ansai County was at a very low level as a whole.The soil layer from 0 to 500cm with soil water content between 8.6% and 10.8% accounted for 75.34% of total land area,and the area with soil moisture less than 8.6% accounted for 19.36% of the total land area,of which the area with soil moisture less than 6.4%（dry layer） accounted for 9.23%.The distribution of soil moisture content in soil profile showed that dry layer was mainly concentrated in a upper layer from 0 to 300cm depth.The area with soil moisture more than 10.8% just accounted for 5.31% of the total area.The amount of soil moisture content,or so called "Soil moisture reservoir capacity" in the layer from 0 to 120cm deep is only 0.060.07?m3/m2,and were less than 0.15m3/m2 in other layers.This indicated that the "Soil moisture reservoir" had limited capability to adjust for forest growth,and a large scale of planting was not suitable because its water consumption exceeded the supply of water from "Soil moisture reservoir".These findings showed that soil moisture environment was rather serverse in Ansai County,and could not provide much water for vegetation restoration.Therefore,more efforts should be laid on the improvement of soil water environment while following the principle of "selecting suitable tree species for sites" in planting.
焦峰1,2,3；温仲明1；陈云明1；杨勤科1；李锐1. 基于GIS的安塞县土壤水分制图及其数量分析[J]. 中国水土保持科学, 2006, 4(1): 75-80.
JIAO Feng-；Wen-Zhong-Meng-；Chen-Yun-Meng-；Yang-Qi-Ke-；Li-Dui. Mapping and quantitative analysis of soil moisture of Ansai county based on GIS techniques. SSWCC, 2006, 4(1): 75-80.
2006, Vol. 4 
