ZHANG Beibei1, CAI Hong1, TIAN Pengju2, HUANG Linfeng2, LIAO Yao2, LIAO Shubing1, LI Yiping1
(1. Mining College, Guizhou University, Guiyang 550003, China;
2. Guiyang Ecological Meteorology and Satellite Remote Sensing Center, Guiyang 550002, China)
Abstract: Based on MODIS/NDVI data and regional meteorological observations in the past 18 years, this study analyzed the responses of spatiotemporal variation characteristics of vegetation coverages in Guizhou to regional change direction and rate of meteorological factors. The results were shown as follows: (1) The comparison of NDVI images showed that vegetation coverages in Guizhou increased significantly at a rate of about 0.004/a from 2000 to 2017. The highest NDVI values happened in summer and the largest increase trend happened in winter. Spatially, vegetation coverages were higher in south and east regions and lower in north and west regions of Guizhou. In terms of the change trend, the area of improved or degraded vegetation coverage occupied 94.97% or 5.03% of the total area of Guizhou, respectively. (2) The climate of Guizhou can be characterized by the uneven precipitation, which concentrates in the period of from May to August, and the insignificant seasonal temperature variation, however, during the period of 2000 to 2017, the precipitation and temperature of Guizhou showed an overall trend of increase, for example, areas with increasing temperature and precipitation were about 98.4% and 60.46% of the total area of Guizhou, respectively, indicating that, in the context of global warming and humidification, the most region of Guizhou had experienced the increases of both temperature and precipitation. (3) Generally, NDVI of Guizhou showed a better correlation with temperature than with precipitation and a higher hysteresis with precipitation than with temperature, the time-lag between vegetation and precipitation was strongest in autumn then in summer. (4) The effects of different climatic factors on the vegetation growth varied spatially in Guizhou, NDVI values in 98.4% study area showed a positive correlation with temperature but precipitation in the same year, whereas NDVI values in 82.63% study area showed a positive correlation with precipitation of the previous year. Construction land and bare land dominated the areas whose NDVI values correlated negatively with precipitation. Hence, the role of human activities in vegetation changes cannot be ignored.
Key words: vegetation coverage; climate change; time-lag; spatiotemporal variation characteristics; Guizhou province
EARTH AND ENVIRONMENT Vol.48, No.4, Tot No.336, 2020, Page 461-470