袁 业， 宋晓丽　(海南大学政治与公共管理学院，海南海口 570228)



基于边际模型的城镇化对耕地影响极限研究
——以海口市为例

袁 业， 宋晓丽*(海南大学政治与公共管理学院，海南海口 570228)

摘要针对海口市城镇化进程引致耕地减少这一问题，首先采用扩展Kaya恒等式以及LMDI分解模型，测算2004～2014年海口市城镇化引致的耕地减少量；然后运用经济学边际效应模型、回归分析以及函数求导方法，构建边际耕地变化率测度模型；最后利用Excel软件，构造趋势线模型，测算城镇化进程对耕地影响最小的极限时刻。结果表明，海口市边际耕地变化率曲线为开口向下的抛物线，其极值点大约出现在2008年。该结果可为相关部门制定土地利用规划以及耕地保护政策提供参考。

关键词海口;城镇化；耕地；LMDI分解模型

Limit Research of the Influence of Urbanization on Cultivated Land Based on Marginal Model—A Case of Haikou City

YUAN Ye,SONG Xiao-li*

(School of Politics and Public Administration,Hainan University,Haikou,Hainan 570228)

AbstractAccording to the problem of cultivated land reduction induced by urbanization in Haikou City,extended Kaya identical equation and LMDI decomposition model were used to measure the cultivated land reduction induced by urbanization in Haikou City from 2004 to 2014.Then,marginal economics model,regression analysis and function derivative method were used to construct the change rate of marginal cultivated land.Finally,trend line model was constructed by Excel software.The time limit of the minimum effects of urbanization process on cultivated land was measured.Results showed that the change rate curve of marginal cultivated land was a parabola going downwards.Its extreme point appeared at about the year 2008.This research provided references for the policy making of cultivated land protection and land-use planning of relevant departments.

Key wordsHaikou; Urbanization; Cultivated land; LMDI model

城镇化是社会经济发展的必然趋势和要求，城镇的发展必然要占用一部分土地[1]，城镇化建设与土地利用变化息息相关。城镇化水平较低时，城市扩张以“摊大饼”式的粗放模式为主，占用耕地面积大；随着城镇化发展，城镇用地的需求变大，但城镇单位土地面积人口承载力也将提高，城镇土地利用方式会逐渐从粗放式向集约式转变，这一过程中，耕地的减少量将呈递减趋势。

为研究城镇化建设与耕地变化的关系，宋戈等[1]根据1952～2003年数据研究表明，随着我国城镇化水平的提高，耕地的减少量呈递减趋势；李丹等[2]分析了城镇化发展给耕地变动带来的正负面影响，得出我国自改革开放以来，城镇化对耕地的消耗呈现倒“U”型曲线变化规律；……