基于 RS的昆明市植被覆盖度变化动态分析

摘要

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。%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 .