土地适宜性评价是近20年来国内外土地资源研究的主要内容之一，可为分析土地利用的现状、修编土地利用的规划以及合理开发利用土地资源提供科学可靠的基础依据。本文以黄土丘陵沟壑区典型县域陕西省榆林市米脂县的农用地作为研究对象，基于土地适宜性评价相关理论和方法，研究并总结了米脂县农用地各个土地单元的限制性因素及对土地适宜性的影响程度，充分利用GIS的空间分析技术对研究区从坡度、坡向、地貌、土壤分布、土地利用现状等方面进行多角度的土地适宜性评价，并采用了评价因子权重确定方法中的“调试法”确定了各个评价因子的权重，进而得出米脂县土地适宜性评价各指标的综合指数值，最终确定土地评价单元的适宜性，结合米脂县实际情况，提出了该县土地利用的主要问题以及适用性较强的治理和改造措施，为米脂县实现对农用地的科学管理、合理利用以及土地规划提供了科学依据。 本文以榆林市米脂县作为研究区，以构建合理的适合研究区的土地利用适应性评价方法为研究主线，主要研究内容如下： 1）以统计资料为基础建立研究区土地利用适应性评价的指标体系，对研究区进行土地利用适宜性综合评价； 2）在GIS技术支持下，运用空间叠加分析方法，评价研究区内不同土地类型的适宜性程度，并对适宜性评价结果进行分等定级，构建土地利用适宜性评价结果的空间数据库，实现土地利用适宜性评价的空间化和属性可查； 3）综合统计分析结果和区域实际调研成果，对空间分析结果进行修正和验证，获取科学合理的分析评价结果，为实现土地资源的可持续管理提供建议，为土地利用规划的修编工作提供技术支持。

Land suitability evaluation is in the past twenty years, one of the main content of the land resources research at home and abroad for the analysis of land use present situation, the revision of land use planning and rational development and utilization of land resources to provide scientific and reliable basis. Based MiZhi county with northern shaanxi geomorphic characteristics of agricultural land as the research object, based on land suitability theory research, studies and sums up the MiZhi county agricultural land unit types of restrictive factors and influence degree, make full use of GIS spatial analysis technology from MiZhi county land slope, slope direction, landform, soil, land use status, etc for multiple perspectives in the study area has carried on the comprehensive evaluation of land suitability, and adopt the evaluation factors weight method for determining the "debugging method" to determine the weight of each factor in the evaluation, then draws MiZhi county the index synthetical index of land suitability evaluation, finally determine the suitability of land evaluation unit, in combination with the practical situation of MiZhi county, puts forward the main problems of the county land use as well as the applicability of strong governance and reform measures for MiZhi county implementation of scientific management, reasonable utilization of agricultural land and land planning provides a theoretical basis. Based on MiZhi county of YuLin city as study area, this paper to construct a reasonable suitable for in the study area land use suitability evaluation method. The main research content is as follows: 1) based on the statistical data to establish the research area land use suitability evaluation index system, and using the analytic hierarchy process (ahp) to the study area of land use suitability evaluation; 2) under the GIS support, using spatial overlay analysis method, the evaluation of different types of land suitability degree of study area, and the suitability of the evaluation results of classification and grading, spatial database of land use suitability evaluation results, the implementation of land use suitability evaluation of the spatial and attribute can be checked; 3) comprehensive statistical analysis of results and research area actual results, modification and verification the result of the spatial analysis, access to scientific and reasonable analysis and evaluation results, in order to achieve the sustainable management of land resources to provide advice, to provide technical support for the land use planning revision work.