Research on Net Primary Productivity and Its Spatio-temporal Characteristics in the Three Gorges Reservoir Area ( Chongqing Section) During 1998 to 2007
Based on the CASA model, we report a remote sensing estimation of net primary productivity [NPP) during 1998 to 2007, using SPOT/VGT NDVI data, vegetation-type coverage, as well as meteorological and other data, and we analyze its spatio-temporal characteristics. Results show that; 1) the volatility of NPP during 1998 to 2007 drops on the whole. 2) Seasonal variation of iVPP during 1998 to 2007 shows the following regularity: summer (675.705 gC · m-2} > spring (368.2 gC · m-2) > autumn (207.944 gC·m-2) > winter (49.495 gC ·m-2). In summer, the maximum value of WPP (1 022.173 gC · m-2) occurred in 2000; the minimum value of NPP (318.321 gC · m-2) occurred in 2006. 3) NPP values in the research region varied between 184.8 and 515.548 gC · m-2 during 1998 to 2007. High values were mainly distributed in northeast Chongqing, such as Wuxi, Wusnan, Fengjie, and in south east Chongqing, such as Shizhu, Wulong and others. Low values were distributed in Zhongxian, Fuling and most of the main urban areas. 4) The highest productivity per unit area was found in regions of broad-leaved forests. Productivity was progressively lower in the following vegetation classifications: bush fallow and irrigated grass vegetation, coniferous forest vegetation, grassy marshland, aquatic vegetation, and wider area.
Three Gorges Reservoir area (Chongqing section)NPPspatio-temporal characteristics
NETL
NSTL
万方数据
