应用因子分析研究塔里木河下游生态环境的退化

采用SPSS分析软件，对塔里木河下游沿河道布设的39个样地进行了环境退化的因子分析。通过数学变换，9个观测指标被转换为2个综合指标(主分量)。根据本地区的实际，对2个综合指标进行了环境解释。依据这2个主分量的贡献率计算了塔里木河下游39个样地的因子得分，并据此进行了环境退化程度(荒漠化)的评价。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予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，与本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。

Study on the Degeneration of Ecological Environment in the Lower Reaches of the Tarim River by Using Factor Analysis

The previous studies reveal that the climate change in the lower reaches of the Tarim River is not soobvious since recent decades,and the formation and development of land desertification in the region are closelyrelated to the vulnerable ecological environment and the extensive exploitation and utilization of water and landresources. In this paper,the degeneration of ecological environment in the lower reaches of the Tarim River isanalyzed by monitoring 39 plots and using the factor analysis,which is supported by the software of StatisticalPackage for the Social Science (SPSS). Through mathematic transform,the 9 observational indexes aretransformed into 2 synthetic indexes. According to the actuality and the data invested in the region,theenvironmental degeneration is explained with the 2 synthetic indexes. Based on the cumulated varianceexplained,the factor scores of the 39 plots are calculated,and the desertification is evaluated by using the factorscores. Viewing from the consequence,the desertification in the lower reaches of the Tarim River becomes moreserious with the increase of distance away from the Daxihaizi Reservoir,which is mainly caused by shortage ofwater resources,salt accumulation in topsoil and degeneration of the natural vegetation. The study results accordbasically with the actuality in the region.