基于NDVI的贵州省植被覆盖时空特征分析

An NDVI-based Analysis of the Temporal and Spatial Characteristics of Vegetation Coverage in Guizhou Province

  • 摘要: 利用2001—2018年的500 m分辨率的MOD13A1数据,计算每个像元的NDVI的变化趋势,并采用线性趋势分析法和相关性分析法,分析贵州省植被覆盖面积在18年间的时空变化特征;结合2001—2018年植被的降水利用效率与2010、2017年2期土地覆盖数据,研究不同土地覆盖类型的NDVI的特征. 研究结果表明:(1) 2001—2018年,贵州省的植被覆盖面积总体呈增加趋势,表明生态环境得以明显改善,以毕节、六盘水市最为显著;(2)从植被覆盖面积变化趋势来看,贵州省的植被改善区域大于退化区域,植被退化区主要集中在城镇扩张区;(3)贵州省的整体植被降水利用效率与植被覆盖面积的变化趋势不具有一致性;(4)贵州省的NDVI与同期降雨量、气温均呈现良好的相关性,而植被生长对气温变化不存在明显滞后性、对降雨量变化的滞后期为1个月,即植被生长对气温的敏感性高于降雨量;(5)在植被生长季,不同土地覆盖类型的NDVI具有不同的特征: NDVI(林地)>NDVI(耕地)>NDVI(草地)>NDVI(建设用地)>NDVI(水体).

     

    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).

     

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