县域耕地数量变化及其影响因素分析

耕地是土地的精华，是维护中国粮食安全的重要保障。笔者针对当前中国学者对耕地数量变化研究中存在的不足之处，以重庆市荣昌县1996—2004年耕地数量变化为例作了深入分析，研究结果表明：(1)1996—2004年全县耕地数量减少较快，平均每年净减少率为0.99%；(2)耕地变化区域性差异明显，且耕地相对减少较快的乡镇并不是经济发展较快的乡镇；(3)生态退耕是全县耕地减少的主导因素；建设占用耕地并不是耕地减少的主要原因；(4)当年建设占用耕地面积与社会经济发展各因素间的相关性不大，而累计建设占用耕地面积与各因素之间的相关性较强，且建设占用耕地与社会经济发展存在时间上的错位性，即经济和社会发展滞后于对耕地资源的占用。

Analysis on County Change of Cultivated Land and Its Causes

Cultivated land is the core of land, and is an important factor to ensure food security. In allusion to the disadvantage in the former research, the paper, taking Rong chang County of Chong qing as an example, analyzed the change of cultivated land area and its causes from 1996 to 2004,and the results shows that; (1)Area of cultivated land has changed a lot, the total area of cultivated land and per capita cultivated land has been reduced year and year;(2)There are great regional differences in cultivated land change, and the cause is different;(3)Conversion of cultivated land for ecological use is the main cause of county reduction in the recent 8 years, and meanwhile conversion from cultivated land into construction land can realize requisition and compensation balance of arable land through land consolidation;(4)Reduction of cultivated land for construction land every year has been ill correlated to the development of economy and society since 1996,but accumulated reduction of cultivated land for construction has been well correlated to these factors.