基于GIS的三都县农业用地适宜性评价

Suitability Assessment of Agricultural Land Based on GIS in Sandu County

[目的]将传统的土地适应性评价方法与现代GIS技术相结合,对三都县农业用地适宜性进行评价。[方法]以贵州省三都县农业用地(耕地、园地、天然草地)为研究对象,结合当地实际情况,选取地形坡度、表层土壤、土壤有机质含量、土壤p H、交通条件、灌溉条件6个评价因子作为农业用地适宜性的评价体系;运用GIS空间分析技术,对土地利用现状数据库、高程数字模型图(DEM)、坡度分级图、耕地质量等级评价数据库作缓冲区进行空间叠加,建立农业用地适宜性评价数据库,采用综合指数评价模型对研究区农业用地进行了适宜性等级评价。[结果]三都县农业用地适宜区面积为620.65 hm^2,占总研究区农业用地面积的0.88%;较适宜区面积为17 595.82 hm^2,占总研究农业用地面积的24.87%;中等适宜区面积为42 077.62 hm^2,占总研究区农业用地面积的59.48%,不适宜区面积为10 443.63 hm^2,占总研究区农业用地面积的14.76%。[结论]该研究结果为调整和优化土地利用结构,制定不同适宜性等级的农业用地利用对策提供了参考。

[Objective] The aim was to combine the traditional land suitability assessment method with the modern GIS technology,and evaluate the suitability of agricultural land in Sandu County. [Method] Taking the agricultural land（ such as plow land,garden land and natural grassland） of Sandu County in Guizhou Province as the research object,according to the actual situation,we chose six factors such as slope gradient,surface soil,soil organic matter content,soil pH,traffic condition and irrigation condition to form the system of suitability assessment. We used GIS spatial analysis techniques to lay over the current land use status database,elevation digital model diagram,slope grading spatial and the quality database of plow land,and established the database of suitability assessment. We evaluated agricultural land suitability by using comprehensive index assessment model. [Result] The suitable area of agricultural land was 620. 65 hm^2,accounting for 0. 88% of agricultural land; the less suitable of agricultural land was 17 595. 82 hm^2,accounting for 24. 87% of agricultural land; the medium suitable area of agricultural land was 42 077. 62 hm^2,accounting for 59. 48% of agricultural land; the unsuitable of agricultural land was 10 443. 63 hm^2,accounting for 14. 76% of agricultural land. [Conclusion]The result provides reference for adjust and optimize the structure of land use and formulate agricultural land use countermeasures of different suitability grades.