论文收集了102篇沙漠化、79篇水土流失和64篇盐渍化的案例研究(共245篇),运用总体分析方法,把造成3种生态环境问题的因素归结为四类原因(农业扩张、资源利用、基础设施建设和自然因素)和五类驱动因子(经济、制度、技术、文化和人口)。分析结果表明,生态环境问题绝大多数由多因子所引起;在原因层面上,对沙漠化、水土流失和盐渍化案例影响最频繁的因子分别是农业扩张因子(92%)、资源利用因子(90%)和自然因素(86%);从驱动因子的层面上看,对沙漠化、水土流失和盐渍化案例影响最频繁的都是经济因素,影响频率分别为86%、81%和89%;总体来看,在发生生态环境问题的区域中,往往以经济因素的影响最为常见(85%),其次为技术(69%)和人口因素(62%)。因此,不适当地发展经济是造成我国沙漠化、水土流失和盐渍化日益严重的重要原因。

Since the proposition of meta-analysis by psychologists,it has b een considered as a ve-ry useful method for synthesizing the research results and recently it has also been widely used in ecologic study.This paper consists of245cases,of which102cases on desertification,79cases on soil loss a nd64cases on salinization.Using meta-analysis method,four clusters of prox imate causes(namely,agricultural expansion,resource utilization,infrastructu re extension and natural factors)and five sorts of driving forces(namely,econ omic,policy&institutional,technolog-ical,cultural and demographic factors) are identified to be accountable for the three environment-al problems .As a result,the paper found out that most of the three problems were caused by mul tiple factors.At the proximate level,the most frequent causes were agricultu ral expansion for desertification(92%),resource utilization for soil loss (90%),and natural factors for salinization(86%),respectively.At th e underlying level,the most frequent factor was economic factor for all the th ree problems,the frequency was86%,81%and89%.On the whole,multiple f actors were omnipresent in the environmentally degraded area of China,with eco nomic factor being the most frequent factor(85%),following with technolog ical factor(69%)and demographic factor(62%).