干旱区农业土地生产力增进中人类活动要素定量研究——以塔里木河流域1980～2000年县域为例

A quantitative study on human factors in the increasing ofland agricultural productivity in arid area ——A case study of Tarim River basin

采用探索性数据分析技术——投影寻踪回归(PPR)模型,定量研究了干旱区农业土地生产力影响因素问题。以塔里木河流域40个县市作为研究单元,以近20a(分5个研究时段)的农业土地生产力(粮食产量)作为因变量,人类活动的5个因素(引水量、耕地、人力、化肥和机械力)作为自变量,通过建立PPR模型,研究了这一区域农业土地生产力增进中人类活动因素的贡献度。研究结果表明,耕地、引水量等资源性因素虽然在20世纪90年代后有一定程度的下降,但仍是这一区域生产力增进的主要因素,化肥增进作用显著。结果也表明,PPR模型适合于这类研究。

The projection pursuit regression (PPR), a new exploratory data analysis method, was used to make a quantitative evaluation on human factors in the increase of land agricultural productivity (LAP) in arid area. Taking the 40 counties in Tarim River basin as samples, using food output as dependent variable, and 5 factors of human activities (water, cultivated land, agricultural labor forces, fertilizer, mechanical power) as independent variables, 5 PPR models were set up at 5 time phases (1980,1985,1990,1995,2000) so as to study the contributing degrees of the factors of human activities in the LAP increasing. The computing results show that the contributing degrees of resource factors (water and land) have appeared some descend since 1990's but is still the dominant factors in LAP increasing. The increasing role of fertilizer is obvious. The results also prove that PPR is a practicable method for the similar studies.