2001-2018年西南地区NDVI变化特征及影响因素  

NDVI Changes and Driving Factors in Southwest China from 2001 to 2018

作　　者：杨艳蓉 侯召朕[1,2] 张增信 Yang Yanrong;Hou Zhaozhen;Zhang Zengxin(Nanjing Forestry University, College of Biology and the Environment, Nanjing, Jiangsu 210037, China;Co-innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China;Nanjing Forestry University, College of Forestry, Nanjing, Jiangsu 210037, China)

机构地区：[1]南京林业大学生物与环境学院,江苏南京210037 [2]南京林业大学南方现代林业协同创新中心,江苏南京210037 [3]南京林业大学林学院,江苏南京210037

出　　处：《水土保持通报》2021年第2期337-344,共8页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“基于云地闪分析的我国西南天然林雷击火起火点范围预警研究”(31971670)。

摘　　要：[目的]研究西南地区人为和自然因素影响下的NDVI动态特征,为该区天然林保护政策的科学实施提供依据。[方法]利用2001—2018年MODIS NDVI数据、土地利用数据、气候数据,结合Theil-Sen中值趋势分析、Mann-Kendall趋势检验等,探讨人为和自然因素下西南地区植被动态变化。[结果]①各类型植被NDVI均逐年递增,增速最快的是农用地和稀树草原。岷江—乌蒙山以东是NDVI高值区和显著改善趋势区;加上云贵高原南缘,显著改善趋势区占总面积的67.09%。②天然林保护、退耕还林/还草的林业政策促使低NDVI植被向高NDVI植被转变是西南地区NDVI增加的原因之一。其中贡献度最大的是稀树草原类型向森林类型的转化,2001—2018年转化面积达73693 km^(2),净转化率逐年提高,主要分布在岷江—乌蒙山以东。③气温与不同植被NDVI的正相关性大于年降水量,在岷江—乌蒙山以东,NDVI与气象要素的正相关性都较高。在气温上升、降水量增加的条件下,41.8%的NDVI增长与气温和降水有关,二者的贡献率分别为32.35%和14.54%。[结论]随着20世纪末以来的天然林保护政策实施以及暖、湿化区域气候变化等人为和自然因素影响,2001—2018年西南地区NDVI持续增加,这种增加特征在岷江—乌蒙山东、西两侧表现差异,东侧森林增加面积、NDVI改善趋势普遍高于西侧。[Objective]The dynamic changes of NDVI under the influence of human and natural factors in Southwest China were studied in order to provide a basis for the scientific implementation of natural forest protection policies in this region.[Methods]Based on MODIS NDVI,land use data and climate data from 2001 to 2018,combined with Theil-Sen median trend analysis and Mann-Kendall trend test,the dynamic changes of vegetation under human and natural factors in the Southwest China were investigated.[Results]①NDVI of all types of vegetation increased year by year,with the fastest growth in agricultural land and savanna.The east of Minjiang and Wumeng Mountains was the region with high NDVI value and significant improvement trend;Combined with the southern margin of the Yunnan-Guizhou Plateau,the trend area of significant improvement accounted for 67.09%of the total area.②One of the reasons for the increase of NDVI in Southwest China was that the natural forest protection and the forestry policy of returning farmland to forest/grassland promoted the transformation of low NDVI vegetation to high NDVI vegetation.The largest contribution was the conversion of woody savanna and savanna to forests.From 2001 to 2018,the conversion area reached 73693 km^(2),and the net conversion rate increased year by year,mainly distributed in the east part of the boundary of Minjiang River and Wumeng Mountain.③The positive correlation between temperature and NDVI was greater than that of annual precipitation.In the east of Minjiang River and Wumeng Mountains,the positive correlation between NDVI and meteorological elements was high.Under the condition of warming and getting wetter,41.8%of NDVI growth was related to temperature and precipitation,and their contribution rates were 32.35%and 14.54%respectively.[Conclusion]With the implementation of natural forest protection policy and the warming and humidifying regional climate change in the last 20 years,the NDVI in the Southwest China continued to increase from 2001 to 2018.Based on the bou

关 键 词：NDVI 天然林保护工程 退耕还林/还草工程 区域气候 西南地区 

分 类 号：S157.2[农业科学—土壤学] X87[农业科学—农业基础科学]