Abstract:

Based on CASA model, net primary production (NPP) of Tianjin area was estimated using NOAA/AVHRR 1B data and climate data. The influence of vegetation types on light utility efficiency and albedo on net radiance were considered. The NPP simulated result of Tianjin area showed that total of NPP of Tianjin in 2007 was 3.86×109gC/a and average NPP was 335gC/m2/a. The top three NPP area of Tianjin were Jixian, Ninghe and Baodi. And the contribution of NPP of Tianjin for summer in all year was 62%, and for autumn was 21%, and for spring was 16% and for winter was 1%, separately. For the influence of different phenology law and weather factors, NPP of Tianjin had distinct annual variation. And annual NPP could be simulated by annual average NDVI and the simulated equation was .