苏贝淖流域植被覆盖时空变化及影响因素分析

Spatial-temporal changes of vegetation cover and its influencing factors in the Subei Lake basin

利用Landsat TM影像数据,结合乌审召气象站的气象资料,分析了苏贝淖流域植被覆盖变化以及可能的影响因素,在小尺度流域层面上探讨了干旱半干旱地区地下水系统排泄区湖淖流域植被变化与气候因子、人类活动的关系。结果表明:1)时间尺度上,2000-2007年间苏贝淖流域年均NDVI呈增长趋势;2)空间尺度上,植被覆盖在2000-2007年里整体改善、局部恶化,退化区主要分布在可能受到工业活动开采地下水影响的苏贝淖、奎生淖、乌审旗碱厂附近,但之后的2009-2011年间植被覆盖由局部退化发展为整体退化,水体面积也逐渐缩减,佐证了地下水开采对植被覆盖产生一定程度负面影响的论点;3)NDVI在月份尺度上与气温、降水存在显著的相关性,且与气温的相关性大于降水。

In this study,spatial- temporal variation of vegetation cover and its potential influencing factors in Subei Lake basin were analyzed by utilizing TM data in combination with the meteorological data from Wushenzhao weather station. The primary goal was to explore the relationship between vegetation cover change and climate factors,human activities in lake basins located in groundwater discharge area of semi- arid and arid regions.The results showed that：（ 1） temporally,the annual average NDVI of Subei Lake basin was on the rise during the period from 2000 to 2007,（ 2） Spatially,vegetation cover situation had been overall improved,but locally deteriorated from 2000 to 2007,vegetation degradation areas were mainly distributed in Subei Lake,Kuisheng Lake and Wushen soda plant,these degraded areas were very likely to be subjected to groundwater intensive exploitation caused by industrial activities,but vegetation cover situation had been changed from locally deteriorated to overall degraded and the areas of water bodies were gradually reduced from 2009 to 2011,which confirmed the fact that groundwater exploitation had exerted negative impact on vegetation cover to a certain degree,（ 3）The temperature and precipitation showed a significant correlation with NDVI in the monthly scale,as well as the correlation between NDVI and temperature was more significant than the correlation between NDVI and precipitation.