基于GIS的安塞县土壤水分制图及其数量分析  

Mapping and quantitative analysis of soil moisture of Ansai county based on GIS techniques

作　　者：焦峰[1] 温仲明[1] 陈云明[1] 杨勤科[1] 李锐[1] 

机构地区：[1]中国科学院水利部水土保持研究所

出　　处：《中国水土保持科学》2006年第1期75-80,共6页Science of Soil and Water Conservation

基　　金：国家自然科学基金项目(403010290);中国科学院"西部之光"人才培养计划项目(B22012900);中国科学院水土保持所领域前沿项目(SW04101)

摘　　要：以空间图形和数据库为基础，利用GIS安塞县的土壤水分样点数据与地理数据结合起来，建立不同利用类型-土地类型-坡度分级的浮点型土壤含水率字段，对安塞县域尺度土壤水分制图及其定量化方法进行研究和探讨，对安塞县不同土层土壤水分状态和分布进行定量分析。结果表明：从土壤水分结构看，安塞县土壤水分总体上处于较低水平，0～500cm土层平均土壤含水量在含水量为8．6％。10．8％的分布面积占到总土地面积的75．34％，在含水量〈6．4％和6．4％～8．6％的分布面积占到总土地面积的19．36％，其中含水率〈6．4％的土壤干层面积占到总土地面积的9．23％，其在上层分布面积大于下层，分布在一般（≥10．8％）以上水平的面积仅占总土地面积的5．31％。安塞县每^2的土壤水库蓄水量在0～120cm土层仅有0．06～0．07m^3，而其他土层都在0．15m^3以下。说明安塞县土壤水分环境极差，土壤水库的调节作用对于林木生长极其有限，大面积植树造林超越了安塞县土壤水库的供水和调水能力，是不适宜的；因此，在以适地适树原则适应土壤水分环境的同时，应加强土壤水分环境的改善。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 300 cm 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 120 cm deep is only 0.06 -0.07 m^3/m^2, and were less than 0.15 m^3/m^2 in other layers. This indicated that the ＂Soil moisture reservoir＂ hadconsumption 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.

关 键 词：GIS 土壤水分 土壤水库 定量评价 

分 类 号：S152.7[农业科学—土壤学] TU411.7[农业科学—农业基础科学]