Estimating Net Primary Production in Xinjiang Through Remote Sensing

Land cover components of photosynthetic vegetation (PV) and non-photosynthetic vegetation (NPV) were analyzed with satellite remote sensing technology and knowledge of the typical climate-vegetation characteristics of the arid region of Xinjiang in western China. The objective was to develop a Net Primary Productivity-Geography Processing Ecology Model (NPP-GPEM) of solar energy utilization efficiency based on remote sensing and ecological processes that would fit the arid region with reference to such remote sensing-ecological models as the Global Production Efficiency Model (GLO-PEM), Carbon Exchange between Vegetation, Soil, and Atmosphere (CEVSA), and Carnegie-Ames-Stanford Approach (CASA). The terrestrial ecosystem of Xinjiang was taken as an example for this study. Supported by NOAA/AVHRR (Advanced Very High Resolution Radiometer) meteorological satellite remote sensing data and climate data, the annual NPP of Xinjiang's mountain-oasis-desert ecosystem from 1981 to 2000 was estimated at I kin spatial resolution. Detection and analysis of spatio-temporal change also was performed. The results showed there were great differences in NPP spatial-temporal patterns in various regions. NPP increased in most parts of Xinjiang from the 1980s to the 1990s. The west part of the piedmont plain on the north slope of the Tian Shan Mountains had the largest increase in NPP in north Xinjiang, and Kashi-Shache Delta had the largest increase in south Xinjiang. The spatial distribution of NPP was characterized by a general decrease from north to south and from cast to west.