干旱区土地荒漠化的人为驱动作用分析——以塔里木河流域为例

Quantitative Analysis on Driving Role of Human Activity on the Land Desertification in Arid Area: The Case of Tarim River Basin

该文以典型干旱区塔里木河流域为例,分析了人类活动对土地荒漠化的主要影响因素,在此基础上结合以往工作,选择反映土地荒漠化发展的人类活动状态变量中的7个统计指标,即:人口数量、人口密度、耕地面积、粮食产量、人均粮食拥有量、牲畜存栏数和单位耕地牲畜承载量等,以及气温、降水量和径流量等自然因素状态变量,用因子分析法对人类因素贡献率进行了提取,分1949年～2000年和1985年～2002年2个研究时段对流域土地荒漠化发生发展过程中的人类因素进行了探讨。结果表明,1949年～2000年间,人类活动驱动力对土地荒漠化发展的贡献率占75%,1985年～2002年间的人类因素下降为69%,这表明技术进步等管理因素在一定程度上可部分抵消人类活动的负面影响。

Land desertification is one of the most prominent ecological and environment problems in arid area. The reasons of it occurring and developing especially distinguishing of natural and human factors are problems which researchers in this field devoted to solve. In this paper, taking the typical arid area-Tarim River Basin as an example, main influence factors of land desertification were analyzed. The 4 important roles of human activities in desertification were given: the increasing population will initiate and aggravate land desertification; human development causes cultivated land activity and provokes the land desertification; the advancing techniques reduce consumption of natural resources and increases income and thus inhibit desertification; policies and management can aggravate and inhibit desertification. On the base of this and the authors' past research work, 15 indices included natural and human factors were selected, 7 statistical indices of reflecting human activities variables (population, population density, cultivated land, grain crops, per capita out of grain, number of domestic animals, animals capacity of cultivated land) and 8 observed indices of natural variables which concluded climate (precipitation and temperature) and hydrology (water supplies of source streams in 6 hydrological stations). A calculation method of quantitative human driving role in the land desertification were designed by using factor analysis (FA).Human driving force on land desertification in this river were discussed using this method. And the researching period were divided into 2 periods:1949～2000 and 1985～2000. The results show that human driving force on land desertification was accounted for 75% in 1949～2000 and for 69% in 1985～2000. This indicates that technique advance and management can weaken the negative effect of human activities.