基于RS的昆明市植被覆盖度变化动态分析

植被覆盖度是反映植被状况的重要因素，以1988、1996、2000、2006和2010年5个时相的TM和ETM＋影像数据，利用像元二分法模型计算了昆明市植被覆盖度并分析其时空变化。结果表明，1988～2010年的22年间，昆明市的植被覆盖度变化明显，平均植被覆盖度从56．2％下降到50．7％，降幅达5．5％；特别是官渡区和呈贡新区变化幅度最为显著，降幅分别为12．3％和6％。按时段分析结果，1988～2000年昆明市整体植被覆盖度呈下降趋势，2000～2010年呈增长趋势。分析认为，城市的发展与扩建导致植被覆盖度减少；应注重城市绿化建设，新建公园与广场，使城市植被得到恢复。

Dynamic Analysis of Vegetation Region based on Coverage Change in Kunming Remote Sensing

Vegetation coverage is an important factor reflected vegetation condition. Vegetation coverage of Kunming was calculated based on RS images （TM images and ETM ＋ ） of 1988, 1996, 2000, 2006 and 2010 by using dimidiate pixel model. The results showed that vegetation coverage obviously changed during 1998-2010, the area of average vegetation coverage decreased from 56.2% to 50.7% and the re- duction was up to 5.5 % ; In particular, the vegetation fraction of Guandu district and Xishan district are obviously reduced by 12.3% and 6%. Results of the analysis by time period of 1988 to 2000, the vege- tation coverage showed downward trend, from 2000 to 2010, the vegetation coverage showed upward trend. The development and expansion of urban leaded to vegetation coverage reduction, so we should fo- cus on urban greening, new parks and squares built for the vegetation recover.