基于MODIS NDVI的文山州植被覆盖度及景观格局分析

以文山壮族苗族自治州为例，利用2001-2020年的MODIS数据，采用像元二分模型、一元线性回归分析方法，分析文山州的植被时空变化规律，在此基础上对其变异系数进行计算，观察全州20 a间的植被变化波动情况，最后对其景观格局进行综合分析。结果表明，2001-2020年文山州植被覆盖度在时间序列上整体呈增长趋势。在空间上，植被较低覆盖度区和高覆盖度区呈上升趋势，增幅达44.2%、103.6%;中覆盖度区和较高覆盖区呈下降趋势，降幅分别为59.2%、46.2%。全州有84.9%的像元处于稳定程度，整体呈平稳型。文山州在20 a间整体景观破碎度呈先减少后增加再减少最终趋于稳定，较高、高植被覆盖度为整个区域的优势区域类型；景观多样性指标在2011年达到峰值，说明景观类型在此年最为丰富；聚集度指标在2020年最大，说明2020年各景观连通性最好；同时，景观类型优势区域也由较高覆盖度区向高覆盖度区转变。

Analysis of Vegetation Covering and Landscape Pattern in Wenshan Based on MODIS NDVI

MODIS NDVI,as a technique to measure temporal changes of vegetation,can well study the temporal and spatial evolution of regional vegetation coverage.Taking Wenshan Zhuang and Miao Autonomous Prefecture as an example,the temporal and spatial variation of vegetation in the prefecture was analyzed by using MODIS data from 2001 to 2020 and by adopting the binary pixel model and unitary linear regression analysis method.Then the variation coefficient was calculated to observe the fluctuation of vegetation in the prefecture during the past 20 years.Finally,the landscape pattern was analyzed comprehensively.The results showed that the FVC of the prefecture showed an overall increasing trend in time series from 2001 to 2020.Spatially,the low vegetation coverage and high vegetation coverage increased by 44.2% and 103.6%,respectively.The middle coverage area and the high coverage areas decreased by 59.2% and 46.2%,respectively.In the whole prefecture,84.9% of pixels were stable.The landscape fragmentation decreased firstly,then increased,then decreased,and finally became stable.Higher and high vegetation coverage was the dominant type in the whole region.The index of landscape diversity reached its peak value in 2011,indicating that landscape types were the most abundant in 2011.The aggregation index was the highest in 2020,indicating that the connectivity of all landscapes was the best in 2020.At the same time,the dominant area of landscape type also changed from high coverage area to high coverage area.