改进耕地资源优势度模型在半湿润区的应用——以陕西省长武县为例

Application of improved development dominance ratio model of cultivated land resources in sub-humid areas——A case study of Changwu County

针对以往耕地资源开发优势度模型在计算耕地生产潜力时存在的不足,结合长武县农业耕作的具体特点对该模型在半湿润区适用的科学依据及机理进行了分析,提出了改进耕地资源开发优势度模型,计算了该县耕地资源优势度,并做了进一步分析验证。结果表明:1990、2008年该县耕地资源优势度分别为0.886和0.836;耕地面积从1990年的2.234万hm2减少至2008年的1.146万hm2,18年间共减少了1.088万hm2,减少量达到1990年总面积的49%;粮食播种面积比例从1990的81%上升到了2008年的84%;耕地面积的减少和粮食播种面积比率的提高导致了该县耕地资源优势度的下降。改进后的耕地资源开发优势度模型较好地拟合了实际耕地面积和粮食作物播种面积比重的变化情况。

In connection with the deficiencies of the development dominance ratio model of cultivated land resources on calculating productive potentiality and combining the specific features of agricultural farming in Changwu County,this paper proposes an improved development dominance ratio model of cultivated land recourses,then calculates the dominance ratio of cultivated land recourses in Changwu County and conducts further verification and analysis.The results indicate that the dominance ratios of cultivated land recourses in Changwu County are 0.886 and 0.836 in the year 1990 and 2008 respectively.It leads to the decrease in the dominance ratio of cultivated land recourses in Changwu County that the size of cultivated land decreases from 22 344.47 hm2 in 1990 to 11 464 hm2 in 2008,by 10 880 hm2 in 18 years,accounting for 49% of the size of cultivated land in 1990 and the proportion of cultivation area for grain crops rises from 81% in 1990 to 84% in 2008.The analysis indicates that the improved development dominance ratio model of cultivated land resources fits the changes of the actual size of cultivated land and the proportion of cultivation area for grain crops well.