塔里木河下游环境退化的因子分析

 为了研究土地荒漠化及其影响因子,对塔里木河下游沿河道布设的39个样地,进行环境退化因子分析。通过数学变换,8个观测指标被转换为3个综合指标(水分指标、沙化指标、盐化指标)。根据本地区的实际,对3个综合指标进行环境解释。依据这3个主分量的贡献率,计算塔里木河下游39个样地的因子得分,并据此进行环境退化程度(荒漠化)的分类。从因子得分结果看,塔里木河下游地区呈明显的随距大西海子水库距离的增加荒漠化程度加重的特点,引起这一结果的主要原因,是水、盐条件逐渐恶化带来的植被衰败。从分类的结果看,与该地区的实际基本相符合。这说明因子分析的方法综合了多指标的综合影响,划分的结果更加客观。

Factor analysis in environmental degradation at the lower reaches of Tarim river

The environmental degraded degree of 39 monitoring sites built along the Tarim river in the lower reaches were analyzed by using the factor analysis method, which is provided by the software of Statistical Package for the Social Science(SPSS). Through mathematic transform, the 8 observed indexes are transformed into 3 synthetic indexes. According to the fact and data invested in this area, environmental context of these synthetic indexes was given. Based on the contribution rate, the factor scores of the 39 sites are calculated, and the desertification degree is classified by its factor scores. Viewing from the consequence, the more distant from the Daxihaizi Reservoir the worse the desertification degree in the lower reaches of Tarim river. Analysis results showed that the vegetation is deteriorated with the water deficit and salt accumulated. Due to the result is suit for the fact, the method is accurate, scientific and practical for reason that it synthesizes the affect of every index.