基于LMDI模型的黄淮海地区县域粮食生产影响因素分解

Influencing factor decomposition of grain production at county level in Huang-Huai-Hai region based on LMDI

实现粮食的持续稳定增长是保障区域粮食安全的关键。分解各因素对粮食生产的作用及影响强度,识别其主导因素,对提升粮食产量具有积极意义。该文运用对数平均迪氏分解方法(logarithmic mean weigh division index method,LMDI)建立因素分解模型,定量评价并对比分析1980-2010年间黄淮海地区县域粮食生产变动的区域因素。结果表明,1)1980-2010年间,黄淮海地区粮食产量增加了1.01亿t,县域粮食产量"南高北低"的空间分异格局明显,苏北、皖北、豫东和鲁西地区的粮食增产显著;2)4个因素中,粮食单产对粮食产量变化起到显著的正向促进作用,复种指数次之,而粮作比例和耕地面积在较大程度上抑制了黄淮海地区粮食产量的增加;3)县域粮食生产因素分解结果表明,县域之间在耕地面积、复种指数、粮作比例和粮食单产效应方面存在明显差异。总体而言,粮食单产效应叠加上复种指数效应使苏北、皖北和豫东多数县域粮食总产量显著增加;而粮作比例效应、复种指数效应和粮食单产效应的叠加使鲁西县域的粮食总产量增加明显。

Sustained and stable growth of grain production is very important for national food security in China.As one of the most important production bases and commodity grain bases in China, Huang-Huai-Hai Region plays an important role in ensuring national grain security. It is of positive significance to enhance food production by decomposing the impact of each factor on grain production and identifying the dominant factors.Taking 347 counties as sampling units in Huang-Huai-Hai region, and adopting the logarithmic mean weight divisive method（LMDI）, the grain production was decomposed into four effects, i.e., cultivated land area,multiple cropping index, grain farming index, and grain yield per hectare. On the basis of the LMDI model, effect and accumulated effect of each factor were explored.First, the grain production increased by 1.01 ×108t from 1980 to 2010 in Huang-Huai-Hai Region, accounting for nearly 45% of the increased grain yield in China, and the pattern ＂high in the southern while low in the northern and central＂ of grain yield is very evident. The counties with higher grain yield are gathered in North Jiangsu,North Anhui, Eastern Henan, and Western Shandong. Secondly, the accumulated effects of cultivated land area,multiple cropping index, grain farming index, and grain yield per hectare are 57×104t, 1457×104t,-991×104t, and9 626×104t, respectively. Among the four factors, grain yield per hectare was confirmed as the dominant contributor to the growth in grain production, and the increase of grain production by the effect of grain yield per hectare was more than 45.0×104 in most of counties in North Jiangsu, North Anhui, Eastern Henan, and Western Shandong; the multiple cropping index was the second important contributor to the growth in grain production,and the positive accumulated effect of multiple cropping index was more obvious in North Anhui, Eastern Henan,and Western Shandong. The grain farming index played an important role in the decline in grain production, and the accumulated effects of the grain farming index in 233 counties were negative. The accumulated effect of the cultivated land area was non-significant, but with obviously spatial difference, and the negative effect was more obvious in counties with a superior location and an abundant economic basis. Thirdly, there are obvious differences among the four factor effects at the county level in the Huang-Huai-Hai region. Overall, multiple cropping index and grain yield per hectare prompted a significant increase of grain production in northern Jiangsu,northern Anhui, and eastern Henan; superposition of the grain farming index, multiple cropping index, and grain yield per hectare showed a significant increase of total grain production in western Shandong.In view of the spatio-temporal variation of grain production and regional difference of the four factors, some work such as technological progress, cultivated land balance, and the optimization of regional planting structure should be enhanced to maintain the growth trend of grain production in the Huang-Huai-Hai region.