Abstract:
The MOD13A1 data with 500 m resolution from 2001 to 2018 was used to calculate the NDVI change trend of each pixel. Linear trend analysis and correlation analysis were used to analyze the spatiotemporal variation characteristics of vegetation coverage in Guizhou Province. Combining the precipitation use efficiency of vegetation from 2001 to 2018 with the land cover data of 2010 and 2017, the NDVI characteristics of different land cover types were studied. The results are as follows. First, from 2001 to 2018, the vegetation cover area in Guizhou Province has shown an overall increasing trend, and the ecological environment has been significantly improved, especially in Bijie and Liupanshui areas. Second, overall, the change trend of vegetation cover area shows that the improvement area in Guizhou Province is larger than the degradation area, and degradation concentrates in the urban expansion area. Third, the overall efficiency of precipitation utilization by vegetation in Guizhou Province is not consistent with the change trend of vegetation cover. Fourth, the NDVI of Guizhou Province showed a good correlation with rainfall and air temperature in the same period. However, vegetation growth did not lag behind the change of air temperature, and the lag period of rainfall was 1 month. In other words, the sensitivity of vegetation growth to air temperature was higher than that of rainfall. Finally, the NDVI values of different land cover types in the vegetation growing season have different characteristics: NDVI(woodland)>NDVI(arable land)>NDVI(grassland)>NDVI(construction land)>NDVI (water body).