巴丹吉林沙漠湖泊遥感信息提取及动态变化趋势

 结合巴丹吉林沙漠的地物光谱特征，提出了改进的MDLWI 水体指数法。该方法增加了水体与植被以及水体与干湖盆的区分度，提高了提取沙漠中水体的效率和精度。利用MDLWI 水体指数法，分析了巴丹吉林沙漠1990-2010 这20 年间夏季（1991，1995，2000，2005，2010）和秋季（1990，1996，2000，2006，2010）两个系列湖泊面积的年际变化趋势。结果表明，夏季湖泊面积平均值为19.11 km²，秋季湖泊面积平均值为17.74 km²，秋季湖泊面积明显小于夏季；20 年来秋季湖泊面积年际变化呈缓慢减少趋势，而夏季湖泊面积变化呈先减少后增大再减少趋势，且变化幅度相对较大；降雨不是湖泊补给的主要来源，湖泊面积的变化主要受地下水补给变化的影响，夏季地下水补给量大于秋季。

Extraction of Remote Sensing Information of Lakes in Badan Jaran Desert and Trend of Their Dynamic Changes

Based on analysis of the spectral characteristics of ground objects in Badan Jaran Desert, modified index for desert lake water identification was put forward in this paper. This new water index effectively increased the discrimination of water body from the information of vegetation and dry lakes, improving the extraction efficiency and precision. Using TM/ETM+ remote sensing images (eight remote sensing image totally), this study analyzed the variation of lake area in summer and autumn from 1990 to 2010 using the method of MDLWI. The results showed that the average lake area is 19.11 km² in summer and 17.74 km² in autumn, which is significantly smaller than that in summer. The lake area has been slowly decreasing in the 20 years, while in summer the lake area shows a decrease-increase-decrease trend and the change is relatively large. Combined with changes of precipitation and evaporation, the analysis showed that underground water recharge is the main source for desert lake recharge instead of precipitation, the amount of which is more in summer than in autumn.