关键词: 特大暴雨, 特大暴雨, 水汽收支, 冷空气, 相对风暴螺旋度

Abstract: Vegetation coverage change and its response to climatic factors is a long-term and complicated dynamic process. This research is based on the MODIS NDVI data and temperature and precipitation data of 11 meteorological stations of Baoji Meteorological Bureau, the relationship between the spatial and temporal variation of vegetation cover and annual mean temperature and precipitation in Baoji area in recent 13 years is analyzed by the trend and correlation analysis method. The results showed that: (1) the average annual NDVI in Baoji area increased at a rate of 0.025/10 a in recent 13 years, which was faster than that of vegetation cover from 1982 to 2006 in the Three-north Forest Protection, and there were two high recovery periods in 2001- 2002 and 2003-2004; (2) high value areas of NDVI for years were concentrated in the southern Taibai County between the Taibai River and the Xu River; areas along the Qianhe River and the“ribbon”area in Baoji section of Weihe River basin including Baoji City, Baoji County, Fengxiang, Qishan had the lowest vegetation cover; (3) vegetation cover in the whole area was positively correlated with temperature and precipitation, the picture elements significantly and positively correlated with temperature accounted for 15.016% (P<0.05), and the picture elements significantly and positively correlated with precipitation accounted for 16.872% (P<0.05).