Spatial-temporal Variation of NPP in Nanning Metropolitan Based on Improved CASA Model
Based on CASA model and MODIS data, the paper had modified the three methods of the fraction absorbed of photosynthetically active radiation (FPAR) extraction, water stress coefficient calculation and the maximum energy conversion selection. The results showed that the average net primary productivity(NPP) of Nanning metropolitan reached 20.77 gC · m-2 · a-1 from 2000 to 2013; the spatial distribution of NPP was pronounced, among which the average NPP of the Liangqing District was maximun and the Xixiangtang District was minimum; in addition , NPP was mainly driven by precipitation in the study.