基于LMDI模型的我国省域粮食生产变化影响因素分析

Analysis of influence factors on crop production change in China at provincial level based on LMDI model

从耕地利用角度对影响粮食生产变化的因素在时间和空间上产生的影响进行科学分析;应用对数平均迪氏分解法(Logarithmic mean weigh division,LMDI)将影响1980—2010年我国省域粮食生产变化的因素分为粮食单产、复种指数、耕地面积和粮作比例;对粮食生产及其分解因素的统计指标在省级层面进行分析。结果表明:1980—2010年我国粮食产量增加22 592.3万t,粮食生产格局重心由南重北轻逐渐演变为北重南轻;4个因素中粮食单产对粮食产量变化起到最显著的促进作用,但增产作用逐年降低,并被复种指数和粮作比例所替代;耕地面积减少在一定程度上限制了我国粮食产量的持续增加;全国各省域之间粮食生产变化的分解因素效应有比较显著的空间差异,河北、湖北、新疆等14个区域的粮食单产和复种指数效应的叠加效应使得其粮食生产增加显著,而上海、浙江、福建等复种指数与粮作比例的叠加效应对粮食增产的影响最大。粮食单产效应的逐渐减小与耕地面积累积效应起负面作用表明我国粮食生产增加主要是粮食单产作用,且正逼于其上限,耕地利用中要严格保护数量,提升耕地质量。

From the perspective of cultivated land use, spatial-temporal analyses was conducted to investigate the factors affecting the change of grain production. In this paper, Logarithmic mean weigh division （LMDI） was applied and the provincial crop production change from 1980 to 2010 was decomposed into four factors;Per unit area yield of grain, multiple crop index, the cultivated land area and grain proportion. And the statistical indicators of food production and its decomposition factors at the provincial level were analyzed in detail. Results indicate that： 1 ） China＇s grain production increased 225. 923 million tons between 1980 and 2010;Food production pattern was transferred from more important in the South than in the North to more important in the North than in the South,2） Per unit area yield of grain in the four factors played the most significant role in promoting production, but promoting effect was weakened year by year and replaced by the multiple crop index and grain percentages3） The cultivated land was decreased to some extent,which limited the increase of China＇s grain production ;4） Among the provinces, domain decomposition effect on the change of grain production factors had significant spatial difference. In Fourteen areas including Hebei, Hubei and Xinjiang,per unit area yield of grain and the superposition of multiple crop index effect increased production significantly. In Shanghai, Zhejiang and Fujian,the effect of crop proportion and multiple cropping index on grain production was the largest. The decreasing of per unit area yield of grain effect with negative correlation of the cultivated land area indicated that the food production in China has been forced to the frontline. Protecting farmland use number and improving its quality is the keys.