基于土地类型的西峡县农用地适宜性评价

目的 土地类型反映了自然地理特征的同质性。为做好农用地保护工作,贯彻落实党中央、国务院及自然资源部关于“宜耕则耕”“宜园则园”“宜林则林”等要求,有必要开展以土地类型为单元的农用地适宜性评价研究。方法 文章首先,在构建的西峡县土地类型的三级分类框架的基础上,采用自上而下的叠置法与自下而上的合并法划分土地类型。其次,以土地类型的最小单元为评价单元,综合自然条件、社会经济和生态环境因素,分别建立了针对耕地、园地和林地的适宜性评价体系。最后,运用层次分析法和加权求和法相结合的方法评价西峡县各类农用地的适宜性。结果 （1）西峡县的土地类型有3个等级,包括14个土地类、299个土地亚类和570个土地单元。（2）西峡县86%以上的区域为林地适宜区,约47%的区域适宜园地,而只有13%的区域适宜耕地。（3）各类农用地的高度适宜区（S1）主要分布于研究区南部河流谷地地带。各类农用地的勉强适宜区（S3）在空间分布不均匀,且研究区北部的大部分山地区域均不适宜（N）作为耕地。结论 基于土地类型的适宜性评价可以识别潜在适宜作为农业利用的土地,并可为农用地的布局优化提供参考。

SUITABILITY EVALUATION OF AGRICULTURAL LAND BASED ON LAND TYPE IN THE XIXIA COUNTY

Agricultural land is the key resource and environmental factor for human survival and development, with the core function of ensuring human livelihood and food safety. Land types reflect the homogeneity of physical geographical features. To protect agricultural land and implement the requirements of "farming should be cultivated when the land is appropriate". It is necessary to conduct the suitability evaluation of agricultural land, optimize the agricultural land layout, and gradually realize the transformation from grain security to food security. Firstly, based on the three-level classification framework of land types in Xixia county, land types were divided by the top-down superposition method and bottom-up consolidation method. Secondly, taking the smallest unit of land type as the evaluation unit, the suitability evaluation system integrating natural conditions, socioeconomic factors, and ecological indicators for cultivated land, garden land, and woodland was established respectively. Finally, the AHP method and the weighted summation method were used to evaluate the suitability of various agricultural land in Xixia county. The results showed that there were three levels of land types in Xixia county, including 14 land classes, 299 land subclasses, and 570 land units. More than 86% of Xixia county was suitable for woodland, about 47% was suitable for garden land, and only 13% was suitable for arable land. The highly suitable areas (S1) of all kinds of agricultural land were mainly distributed in the southern river valley area of the study area. The barely suitable areas (S3) of all kinds of agricultural land were not evenly distributed in space, and most of the mountainous regions of the northern part of the study area were not suitable (N) for cultivated land. Therefeore, suitability evaluation based on land type can identify potentially suitable land for agricultural use and provide references for agricultural land layout optimization. It also plays an important role in the realization of regional food security from the perspective of the "big food view", and can be promoted at the county level.