基于混合像元分解的毛乌素沙地红碱淖面积提取及变化监测

Extraction and Monitoring of Hongjiannao Lake Area in Mu Us Sandy Land based on Mixed Pixel Decomposition of Remote Sensing Data

基于混合像元分解法,利用Landsat卫星遥感数据提取红碱淖湖面面积,监测36 a来红碱淖湖面面积的动态变化。结果表明,1973—2009年红碱淖湖面面积总体减小19.7 km2,变化率为-34%。20世纪70年代,湖面面积较大且变化率较小,1974年湖面面积最大,为59.97 km2;80年代湖面面积开始大幅减小,变化率为-12.4%;90年代湖面面积缩小变慢,变化率为-10.6%;21世纪初,湖面面积萎缩迅速加快,变化率达-16.6%,2009年湖面面积仅为38.33 km2。2001—2002年内湖面面积变化情况监测表明,3—5月湖面面积较大,6—11月湖面面积逐渐缩小。2001年11月到2002年3月,湖面面积处于增大期,变化率为+2.2%;2001年5—11月、2002年3—11月面积缩小,变化率分别为-4.4%、-4.1%。

Based on the mixed pixel decomposition of remote sensing data, the Hongjiannao Lake area is extracted by making use of Landsat data. The Hongjiannao Lake area shrank by 19.7 km^2 during 1973-2009, and the change rate was 34%. In the 1970s, the lake area was bigger and showed little change, and the largest was 59.97 km^2 in 1974; It reduced rapidly in the 1980s, and the change rate was -12.4% ; In the 1990s, the change rate became smaller, it was--10.6 % ; The lake area reduced faster in the 2000s, and the change rate reduced to --16.6%, and the lake area was only 38.33 km^2 in 2009. As for its monthly change, the lake area was relatively bigger from March to May in 2001 ; from May 2001 to November 2001, the lake area reduced continuously and the change rate was --4.4% ; from November 2001 to March 2002, the lake area increased again and the change rate was ＋2.2%; from March 2002 to November 2002, the lake area reduced lastly and the change rate was -4.1%.