基于GIS的喀斯特山区农用地适宜性评价——以贵州省黔西县为例

Study on agricultural land suitability evaluation in Karst mountain area based on GIS——Case on Qianxi county,Guizhou province

为高效准确地进行土地适宜性评价,以MAPGIS 6.7为软件平台,以Visual C++6.0为二次开发工具,构建一个GIS与模糊综合评判法结合的土地适宜性评价模型。以贵州省黔西县为例,选择坡度、海拔、土层厚度、耕层厚度、土壤质地、有机质含量、全氮、速效磷、速效钾、pH值、复种指数、交通条件、石漠化程度等指标为参评因子,对该县的农用地进行宜耕、宜园、宜林、宜牧评价。由评价结果可见,区域内高度适宜的用地比例较小,均不到30%,其中耕地仅为9.54%;而中度适宜和勉强适宜用地面积则较大,超过70%;用地限制多表现为坡度大,土层薄,土壤质地差,裸岩比例高,土壤侵蚀严重;宜耕地资源紧缺,后备耕地面积较少且质量不高;林地和牧草地相对宽裕,后备资源较多。

In order to evaluate the land suitability efficiently and accurately, a model of land suitability evaluation is built based on GIS and fuzzy comprehensive judgment, with MAPGIS Professional 6. 7 as the platform and Visual C ＋ ＋ 6. 0 as the developing tool. A case study was carried at Qianxi county, Guizhou province, indicators such as slope, elevation, soil thickness, cultivated thickness, soil texture, organic material content, total nitrogen, available Phosphorus, avail Potassium, pH, multiple crop index, traffic, stone desertification degree ere, were chosen as the evaluation factors. The suitability of agricultural land for agricultural use was evaluated. The results show that： there is more than 70% medially and marginally suitable land but less than 30% highly suitable land of the total area, especially only 9.54% of farm land use. The landuse limitations include steep slope, thin soil layer, poor soil texture, high bare rock ratio,seriously soil erosion etc. Less and lower quality farm land are in support, relatively more land resources for forest and grassland are in the study area.