Patio?Temporal Variation Of NDVI And Its Relationship With Environmental Factors In Jiangxi Province

As the substrate of terrestrial ecosystem,vegetation NDVI reflects the quality of surface cover and its growth,which is of great significance to the description of ecosystem function and environmental processes.In this paper,the MODIS~NDVI images were selected from 2000 to 2015 in Jiangxi Province,and its spatial variability and temporal characteristics at the annual,quarterly and monthly time scales were analyzed by descriptive statistics and one-way regression.Based on the weather stations,DEMs and latitude and longitude data,the response of NDVI and environmental factors were explained by the co rrelation analysis and RDA variance decomposition method,and the temporal and spatial multi-scale characteristics of NDVI were described by wavelet analysis.Draw the following conclusions:At the scale of inter annual,the NDVI of Jiangxi Province increased from 0.733 to 0.789,and the annual rate of change was 0.0016 / a.On the seasonal scale,NDVI seasonal variation was obvious,the rule was summer> autumn Spring and summer.In the summer and autumn,NDVI in January to June gradually increased,9~12 months The photosynthetic efficiency of vegetation was the most active in 7~8 months,and NDVI reached the peak value.The NDVI in Jiangxi Province distributed in the eastern,southern and western provinces border areas and the south~central mountainous areas,and its increase from the Poyang Lake and river waters to the surrounding plains,hills,mountains,the NDVI show some spatial variability.The coefficient of variation is consistent with the distribution of NDV.The spatial and temporal variability of NDVI is the result of multidimensional factors such as climate,topography and geographical location.Quantitative separation shows that the degree of each dimension is: terrain factor(34.90%)<climatic factor(31.8%)<geospatial location factor(18.9 %),Terrain factor is the dominant factor of NDVI variability,climate and geographical factors play a role in this basis.The influence of single environmental factors is slope> elevation> rainfall> latitude> temperature> longitude.The variance of the NDVI shows that the vegetation scale of NDVI in Jiangxi Province is 4,12 in the seasonal and monthly time scales,which is consistent with the inter annual phenology during the year of vegetation growth.The typical feature scale of NDVI in the warp and weft directions is 35 km,and the elevation scale window is 17 m,and the NDVI is closely related to the environmental factors of the response at different scales.