Study On The Spatiotemporal Change And Driving Force Vegetation Cover In Fuhe Watershed

Vegetation is a key component of terrestrial ecosystems.By monitoring the spatiotemporal changes of vegetation,we can not only understand the advantages and disadvantages of the regional ecological environment,but also reflect the impact of climate and human factors on the ecological environment.RS and GIS technology can solve the problem of monitoring the spatial and temporal dynamic changes of vegetation,and provide some scientific theoretical guidance and technical support for the ecological environment and ecological civilization construction in Fuhe watershed.This article is based on MODIS-NDVI time series data from 2000 to 2018.The climate data for the same period mainly includes monthly temperature,precipitation data,digital elevation model DEM data of 10 meteorological stations in the Fuhe watershed,and Landsat series remote sensing image data for 2010 and 2017.With the help of calculation software such as MRT,ENVI + IDL,Arc GIS,and SPSS,the mean value method,trend analysis method,and correlation analysis method were used to analyze the temporal and spatial characteristics of temperature,precipitation,and vegetation coverage in the Fuhe watershed over the past 19 years.And explore the impact of three factors,climate change,topographical factors,and land use changes on vegetation NDVI.the result shows:The overall vegetation NDVI in Fuhe watershed from 2000 to 2018 showed a fluctuating upward trend,and the average annual NDVI value was between 0.52 and 0.64,the vegetation status was best in summer and autumn.The spatial distribution of NDVI is high in the south and low in the north.The low values are mainly concentrated near towns.The annual average temperature of Fuhe watershed is 20.3 ?,and the vegetation NDVI has a significant positive correlation with temperature.The annual accumulated precipitation is 1768.5mm,and there is no significant positive correlation between vegetation NDVI and precipitation.NDVI in the growing season has significant lags with temperature and precipitation in the first and second months.Spatial changes in average temperature and precipitation were not significant.According to the distribution of NDVI and topographical factors in the Fuhe watershed,it is known that the lower the vegetation NDVI in the lower altitude area,the stronger the fluctuation,and the less stable the vegetation stability in the gentle area is.The effects of human factors on the increase of vegetation cover in the Fuhe Watershed are stronger than those of the climate.Land use and ecological construction measures have some intervention effects on vegetation NDVI.The transfer of a large amount of forest land,land conversion to forestry,and ecological civilization construction in the land use of the Fuhe watershed have led to an overall upward trend in vegetation.