Vegetation Coverage Change and Its Relationship with Climate Factors in Liaohe River Watershed
LI Yi-ming;SU Fang-li;LI Hai-fu;ZHAO Guang-hui;College of Water Conservancy, Shenyang Agricultural University;Liaoning Shuangtai Estuary Wetland Ecosystem Research Station;
In order to reveal the vegetation coverage changes of time and space of Liaohe River Watershedand its response to climatic factors, taking the period of 1999-2013 as a time scale, through ArcGIS spatial analysis module and mathematical statistics,we analyzed the interannual dynamics, the monthly variation in the year and the spatial change between NDVI andtemperature withprecipitation. The NDVI of Liaohe River Watershed was overall in upward trend in 1999-2013, whichrespectively reached0.339, 0.405 and 0.409 in 2000, 2004 and 2008. The eological environment improvement area of Liaohe River Watershed accounted for 26.91% of the total area of the basin,and theecological environment that had a good representation in Zhangwu,Kangping and Fuxin. The effects of temperature and precipitation on the annual NDVI were significant,and the response of NDVI to temperature was higher than that of precipitation,and the response of NDVI to precipitation decreased from northeast to southwest. The growth rate of NDVI in the basin respectively reached 7.7% in summer, 3.4% in autumn, 1.5% in spring, 1.4%in winter, and the NDVI change trend in summer and autumn was the same as that in a full year.The correlation analysis showed that the NDVI had a significant correlation with temperature in 72.01% catchment area, which indicated that temperature was the main climate factor that influednced the annual vegetation coverage changes of Liaohe River Watershed, and that the response of vegetation cover to precipitation had a certain lag,which took mainly the winter snowmelt and spring precipitation as the form of expression.