1982-2015年西南岩溶区NDVI时空变化及未来变化趋势

Spatial-temporal variation of NDVI in the southwest karst areas from 1982 to 2015 and future trend

基于1982—2015年GIMMS NDVI 3g数据,运用趋势分析、Mann-Kendall检验及R/S分析方法,探究了西南岩溶区植被覆盖的时空变化及未来趋势,以期为该区生态的治理提供决策依据。结果表明:(1)时间上,1982—2015年西南岩溶区年际及季节NDVImean整体呈波动上升趋势,季节变化差异显著。(2)空间上,植被覆盖总体较好;NDVImean季节分布差异明显,NDVImean>0.8的区域随季节变化,呈现出鄂西山地往云南临沧一带转移趋势。(3)年尺度上,从趋势分析来看,占80.31%的区域NDVImax呈增加趋势,集中分布在云贵高原附近;NDVImax随季节变化差异明显,植被覆盖退化区表现出沿横断山脉—四川盆地、贵州—湖南及广东—云贵高原的轨迹变化。(4)未来植被覆盖均呈持续性增加或减少变化,年际、季节尺度植被覆盖呈持续改善的区域均大于73.30%。

Based on GIMMS NDVI3g data from 1982 to 2015,by trend analysis,Mann-Kendall test and R/S analysis,the temporal and spatial variation and future trend research of vegetation cover in the southwest karst area of China was studied.The results could provide a basis for ecology in this area.(1)In term of temporal variation of NDVI,annual and seasonal NDVI increased in fluctuant trends from 1982 to 2015.The annual and seasonal NDVI showed an overall trend of fluctuation and increase from 1982 to 2015,and the seasonal NDVI significantly increased.(2)In terms of the spatial distribution of NDVI,the vegetation cover was relatively better during the study period.The vegetation cover showed obvious spatial heterogeneity on the seasonal scale.The areas of NDVI≥0.8 changed with the seasons in a trend of transferring from the western mountains of Hubei to Lincang of Yunnan.(3)The annual NDVI showed an increasing trend during the study period,up to 80.31%and mainly in the vicinity of Yunnan-Guizhou Plateau.The variation of NDVI had significantly heterogeneity on the seasonal scale.The degradation of vegetation area changed along the Hengduan Mountains-Sichuan Basin,Guizhou-Hunan and Guangdong-Yunnan-Guizhou plateau.(4)In the future,the vegetation cover will show a continuous change.Vegetation area improvement will be 73.30%on the annual and seasonal scales.