生态学报2018，Vol.38Issue(6)：2128-2138,11.DOI:10.5846/stxb201703050361
黄土高原植被覆盖与土壤湿度的时滞关联及时空特征分析
Analysis of temporal and spatial characteristics of time lag correlation between the vegetation cover and soil moisture in the Loess Plateau
摘要
Abstract
Based on the MODIS-NDVI and MODIS-LST data from 2001 to 2014,we have estimated the soil moisture using temperature vegetation dryness index,analyzed the spatiotemporal seasonal variation of the vegetation cover and soil moisture and their interrelationship in the Loess Plateau.The findings suggest the following:(1) There are obvious time-lag effect for vegetation growth relative to soil moisture in the Loess Plateau.The vegetation cover and vegetation phenology is closely related to soil moisture change.(2) The intense affected area of soil moisture to vegetation cover located mainly in the mountains and hills of the northem agriculture and grassland biome,which the vegetation cover has slow response.The intense affected area of vegetation cover to soil moisture spread over the western alpine region,which the response time of soil moisture is relatively shortest.The second one distributes across the upper and middle reaches of the rivers in the northern agriculture and grassland biome,and the soil moisture respond slowly.The response speed gradually increase from east to west and from north to south.(3) From vegetation types,there are relatively strong negative correlations between vegetation cover and soil moisture of vegetation I that the response degree of vegetation growth to soil moisture change weakens successively,and their response rate is relatively slow and speed up.A weak correlations were found between vegetation cover and soil moisture of vegetation Ⅱ,and their lag time are close to 0 day,which reflects vegetation cover and soil moisture change simultaneously.The soil moisture changes lag behind vegetation cover change of vegetation Ⅲ (xerophytic/psammophytic vegetation),and the degree that vegetation cover positive impacts on soil moisture increase consequently,but time effects extend.The positive impact of alpine vegetation (vegetation V) to soil moisture is strong which has better response speed.(4) There is close relationship between the annual variance of vegetation growth and soil moisture in the Loess Plateau.The vegetation phenology is a good fit to the peak and valley of soil moisture changes over the years which can be used as an important evidence for the extraction of vegetation phenological information.关键词
土壤湿度/植被覆盖/Whittaker平滑/时滞关联/黄土高原Key words
soil moisture/vegetation cover/Whittaker smooth/time lag correlation/the Loess Plateau引用本文复制引用
张翀,雷田旺,宋佃星..黄土高原植被覆盖与土壤湿度的时滞关联及时空特征分析[J].生态学报,2018,38(6):2128-2138,11.基金项目
宝鸡文理学院校级重点项目(ZK16064) （ZK16064）
陕西省社会科学基金项目(2016G013) （2016G013）
