Forest Vegetation Cover Change And The Relationship With Climate Factors In Mojiang County Based On EVI In Recent Ten Years

As an essential ecological factor, vegetation is not only influenced by global climate change, but also responds to the global climate change. So the research of vegetation coverage change in Mojiang county and it response to climate factoes under global climate change background is of important practical significance to local management of ecological environment.Vegetation coverage can be represented by EVI. Based on 2005-2015 MODIS/EVI time series, this article explores the trend of vegetation change in Mojiang county and the relationship of it and climate change(mainly drought). The research findings are as below:(1) Forest vegetation in Mojiang county is influenced by Xinan drought event. So the annual average EVI in 2010 decreased to the lowest during the research period. But The monthly average forest EVI on early September 2009,2013 and August 2010,2014 was outlier, which was lower than other EVI in the same period. Vegetation coverage has space differentiation. There are lush vegetation in north and south, sparse vegetation in middle parts.(2) Precipitation in Mojiang county decreases to the lowest from 2008 to 2010. And precipitation in Yunnan province increases from north to south, east to west. So does to Mojiang county.(3) On an interannual scale, the correlation coefficient between forest yearly mean EVI and yearly mean precipitation, temperature were lower than the correlation coefficient on an monthly scale.(4) The correlation coefficient between forest monthly mean EVI and monthly mean precipitation, temperature were positive and high. It showed the increase of precipitation and temperature benefits vegetation growth. And precipitation has the stronger influence than temperature.(5) There was one month lag phase of EVI and precipitation and two months lag phase of EVI and temperature.(6) This paper has established the optimum multiple linear mixed regression model between EVI and precipitation, temperature.This thesis can support the research of the relationship of climate change and vegetation by forest remote sensing. Meanwhile the response of vegetation change to climate change is important to the research of the effect of extreme climatic event, such as drought, on vegetation.