基于GIS的重庆市丘陵山地耕地质量评价与比较

Cultivated land quality evaluation among hills and mountains of Chongqing City based on GIS

利用农用地分等自然质量等指数模型,结合分模块控制的方法实现区域间等指数可比,对重庆市丘陵山地4个代表县耕地质量进行了评价。利用MapGIS采用多图层叠加确定评价单元并获取单元属性数据;建立省内2级区间可比的自然质量分综合评判模型;通过采用同能量标准化产量和引入光温协调系数,改进对光温潜力指数的加和。结果表明:丘陵区大足、低山丘陵区梁平以中高等地为主,低中山区彭水以中低等地为主,中山区巫溪以低中等地为主,地势起伏对丘陵山地耕地总体质量具有重要的影响。评价方法能实现跨区域和跨耕作制度间等指数的可比性,提高耕地质量评价的精度。

Natural quality grade index model of agricultural land classification, coupled with module-control method, was adopted to evaluate the cultivated land quality in 4 counties located in hills and mountains, in Chongqing, in order to acquire accurate evaluation results inter-districts. Firstly, with the aid of MapGIS, the multi-map superimposition method was used to define evaluation units and to extract unit attribute data. Second- ly, comprehensive evaluation model of natural quality of agricultural land classification was built up which was comparable in 4 secondary districts in Chongqing. Thirdly, additional method of photo-thermal productivity index was ameliorated by adopting ratio of energy to standardize yield, and introducing harmonizing photo-thermal productivity coefficient. The results indicate that cultivated land quality gives priority to middling and high quality grade in Dazu located in hills region and Liangping located in low mountains and hills region, to middling and low quality grade in Pengshui located in low and medium mountains region, and to low and middling quality grade in Wuxi located in medium mountains region, which shows low or high hypsography gives significant effects on total quality of cultivated land in hills and mountains region. The evaluation method can acquire accurate evaluation results inter-districts and inter-farming systems.