民勤1988～1997年间土地荒漠化社会经济驱动力分析

以甘肃民勤县为例,建立民勤5个区域1988~1997年三个时段的荒漠化指数和其变化率,采用相关分析、多元逐步回归分析方法,利用对应年份和各区域乡镇的标准化社会经济统计资料,建立民勤荒漠化的社会经济驱动力模型,对1988-1997年民勤区域荒漠化社会经济驱动力进行分析。民勤的牧业区和新开发的昌宁与环河灌区受人类影响小,其区域荒漠化指数大小主要取决于自然因素,但两区域荒漠化指数变化率分别与单位面积载羊量和人口密度变化率线性相关。对坝区、泉山区和湖区老灌区,区域荒漠化指数大小取决于区域的社会经济因素和自然因素的综合作用,社会经济结构已经影响了区域荒漠化指数的大小,各区域荒漠化指数变化率分别与单位面积的粮食播种面积、单位面积人均纯收入和单位面积的大牲畜变化率线性相关。

Analysis of socio-economic driving forces on land desertification at Minqin county in Gansu Province in 1988～1997

Taking the Minqin oasis as an example, the socioeconomic driving force model for Minqin land (desertification) was established. First, the three-period desertification index and its change rate were established, belonging to 5 different regions at Minqin county during the periods of 1988~1997. Second, the correlation (analysis) was conducted to discover the relationship between desertification index and its change rate with socio (economic) factors and their change rates, then stepwise multi-variables regression method was adopted to and the linear equation of those variables. According to the equation, the causes and results were analyzed. On the (pasture) region and the Changning & Huanhe River irrigation agriculture region which was newly explored, their regional and desertification indexes mainly depend on natural conditions because of the relatively less influence of people, but their change rates of land desertification index are affected by economical conditions. On the pasture region, the relationship between the change rate of land desertification index and the change rate of sheep numbers per hectare is linear, the higher change rate of sheep numbers per hectare, the higher change rate of land (desertification). For Changning & Huanhe River irrigation agriculture region, the relationship between the change rate of land desertification index and the population density is linear too. For the zones with long agriculture development history, food-economic planting structure, has impacts on the regional land desertification. When the regional land desertification become less, the planting area of the economic crop will rise. On the opposite, when the regional land desertification deteriorates, the planting area of food crop will arise through more land exploited, which induces more land desertification.