The spatial and temporal dynamics of NDVI and its relation with climatic factors in Loess Plateau
XU Qian1， REN Zhi-yuan1*， YANG Ren2,3
(1 College of Tourism and Environment, Shaanxi Normal University, Xi′an 710062, Shaanxi, China；2 Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China；3 Graduate University of Chinese Academy of Sciences, Beijing 100049, China)
Abstract:
Based on SPOT NDVI and GIMMS NDVI data, combined RS and GIS techniques of geostatistical spatial analysis, the spatial and temporal differences of vegetation cover conditions in Loess Plateau area from 1998 to 2007 and the relationship between NDVI and main climatic factors (monthly average temperature, precipitation) were analyzed from 1991 to 2000. The results show that obvious regional difference of the NDVI value is displayed (the average value in July and August), which presents the increasing tendency from north to south. The value in south, east and southwest are high, while in north and northeast they are low. Wave ascending trend is showed by NDVI value through the overall period from 1999 to 2007. And NDVI value is affected by different land-use types, the value in woodland was the maximum and it was the minimum in desert. The status of the low NDVI in Loess Plateau will be achieved by the optimization of land-use structure. The temperature and precipitation are the main climate factors determined the vegetation growth status in the Loess Plateau area, which have high positive correlation with NDVI value.
KeyWords:
normalized difference vegetation index (NDVI); Loess Plateau; temperature; precipitation
