基于GIS的重庆市耕地质量评价模型建立与检验

Build-up & Checkout of Evaluation Model of Cultivated Land of Chongqing, Baced on GIS

借助GIS空间数据获取、分析与管理能力,基于农用地分等方法的应用和改进,建立了包括自然质量等和利用等指数模型的重庆市耕地质量评价模型。评价对象为2003年末39个区县更新调查的耕地,总面积2347627.48hm2,通过各区县1:5万土地利用现状图共获取142319个评价单元。评价模型通过分功能模块从机理上实现评价质量控制,以实现指标区之间和标准耕作制度间指数的可比性。就光温/气候潜力指数加和算法,采用以能值为基础确定标准产量折算系数β,引入光温潜力协调系数γ;就自然质量分模型,指标区之间因素-分级-分值进行了统一,但保留了因素权重的区域差异性,体现了指标区间共性和个性的统一。采用2004-2005年重庆市分区县统计平均粮食播面单产对平均自然质量等和利用等进行独立检验,线性相关系数分别达83%和87%,相关性极显著。研究得出结论,评价模型有效实现了重庆市跨区域耕地质量评价指数的可比性。

With the aid of MapGIS capability in obtaining, analyzing and managing space data, based on the methodology of Agricultural Land Classification applied and ameliorated, Cultivated Land Quality Evaluation Model of Chongqing was built up, which included Physical Quality Grade Index model and Use Grade Index model. The object evaluated was the Cultivated Land or counties of Chongqing, which total acreage was 2,347,627.48 obtained based on 1：50,000 land use maps of every boroughs updated to end of 2003 in 39 boroughs hm^2, including 142,319 evaluated units or counties. Evaluation Model realized control of evaluation quality from mechanism by differential function module, so as to reach comparability of index among factor districts or among standard farming systems. （1）To addition of Photo-Thermal Productivity Index, converting standard yield coefficient βwas determined based on energy value, and harmonizing Photo-Thermal Productivity coefficients/was introduced. （2） To Physical Quality Cent Model, factor-grading-value of cultivated land quality evaluation among factor districts was unified, but otherness of factors＇ weight was kept among factor districts, which embodied the unification of commonness and individuality among districts, statistical average crop yield of per unit of seed-acreage of boroughs or counties in Chongqing from 2004 to 2005, was adopted to checkout average Physical Quality Grade and Use Grade. Result shows, linear correlative coefficients are respectively 83% and 87%, that is, both correlativities are very inarked, and correlativity of Use Grade is appreciably higher than that of Physical Quality Grade. Drawn is Conclusion： the Evaluation Model effectively realizes the comparability of Index of cultivated land quality evaluation among inner regions in Chongqing.