贵阳市1990-2015年植被盖度时空变化特征分析

Temporal and spatial variation characteristics of vegetation coverage in Guiyang from 1990 to 2015

通过长时间序列较高空间分辨率植被盖度变化分析,揭示区域植被恢复与退化状况,为生态文明建设和可持续发展决策等提供参考。充分利用遥感和GIS手段,以Landsat 5TM、Landsat 7ETM+和Landsat 8OLI为数据源,在归一化植被指数值的基础上,利用像元二分模型反演得到贵阳市1990、2000、2015年植被盖度图及植被盖度变化图。进行贵阳市及各辖区内的植被盖度均值和植被盖度变化面积比例辩护特征分析。结果表明:1)贵阳市植被盖度总体呈北部较高而南部较低的分布格局。2)1990-2015年,贵阳市植被盖度均值增加了8%,呈逐渐增加的趋势,较低植被盖度等级面积比例减少,而较高植被盖度等级面积比例增加。3)植被盖度变化趋势表现为无明显变化占70%,正向变化占22%,负向变化仍占8%。4)贵阳市各辖区中,乌当区、开阳县、修文县、息烽县和清镇市多年平均植被盖度较高,小河区和南明区多年平均植被盖度较低。息烽县、小河区、乌当区和清镇市植被正向变化占面积比相对较大,观山湖区、白云区、开阳县负向变化占面积比相对较大。

Through analysis of long-time-series and high-spatial-resolution vegetation coverage change, we re- vealed the status of vegetation degeneration and recovery in target region, so as to provide reference for ecological civilization construction and sustainable development. Remote sensing and GIS technology adopted, with Landsat 5TM, Landsat 7ETM ＋ and Landsat 80LI as the data source, based on normalized vegetation index and dimidiate pixel model,we achieved the vegetation coverage map and the vegetation coverage change map of Guiyang in 1990, 2000 and 2015 ,Then the average vegetation coverage and vegetation coverage variation proportion in Guiyang and its districts were analyzed. The results showed that ： （ 1 ） The vegetation coverage in Guiyang was higher in the north and lower in the south; （2） From 1990 to 2015, the average vegetation coverage in Guiyang increased 8 % ,with the proportion of lower vegetation coverage area decreasing and the proportion of higher vegetation coverage area in- creasing ; （3） 70 % of the total vegetation coverage showed no obvious change,22 % showed positive change and 8% showed negative change; （4） The average vegetation coverage of Wudang District, Kaiyang County, Xiuwen County, Xifeng County and Qingzhen City was higher than that of Xiaohe District and Nanming District. The vegeta- tion coverage with positive change took a larger proportion in Xifeng County, Xiaohe District, Wudang District and Qingzhen City ,while the vegetation coverage with negative change took a larger proportion in Guanshanhu District, Baiyun District and Kaiyang County.