基于GIS的县级耕地地力评价及土壤障碍因素分析

目的]以沙湾县为例,研究新疆县级耕地生产潜力及耕地土壤障碍因素,为分区改良利用提供依据和对策.方法]在GIS支持下,充分应用第二次土壤普查资料及成果,利用新疆沙湾县土壤图、土地利用现状图叠置划分法确定评价单元4 002个,采用模糊评价、特尔斐法、层次分析法等,选取了土壤管理、物理及剖面性状、化学性状等3个方面12个影响因子,建立耕地地力评价体系及其模型,采用综合指数法对沙湾县耕地地力进行评价.结果]全县的78 060 hm2耕地中,一至五等地分别占耕地的10.55;、37.80;、37.57;、9.10;和1.93;.耕地土壤障碍因素有:(1)土壤部分大量元素和微量元素处于不同程度缺乏状况；(2)土壤结构存在不同的土壤障碍层次；(3)部分土壤存在盐渍化障碍.结论]评价结果符合当地实际,将沙湾县分为三个改良利用片并提出改良利用方向及措施.

Evaluation of Soil Fertilities of Farmland at County Level Based on GIS and Analysis of Obstacle Factors

【Objective】 The fertility of farmland and obstacle factors were researched in this project in order to provide countermeasures for regionalization by taking Shawan County as an example.【Method】This study,based on the geographic information system(GIS),the statistics and result of the second soil census and the Shawan County soil map,overlaid the current landuse map with the basic farmland protection map and the soil map,forming 4002 patches,which are used as the basic management and evaluation cells.And also,this research built up the evaluation system and model of farmland fertility by selecting twelve affected factors from three aspects of soil nutrient content,profile situation and land management.The grade of arable land productivity was formed according to the theory of Fuzzy Mathematics,Telphi Principle and Analytic Hierarchy Program.Comprehensive indexes were applied in this study to evaluate the farmland fertility of Shawan County and analyze its space distribution.【Result】The results suggest that among the 78 060 hm2 farmlands,the fertility of grade from the first to the fifth respectively account for 10.55%,37.80%,37.57%,9.10%,and 1.93%.Obstacle factors in soil are:(1) Nutrient deficiency of soils;(2)Different obstructed horizons;(3) Soil salinization.【Conclusion】The results were well in line with the local situation,thus three regions of regionalization will adopt different technical improving measures in Shawan.