Temporal-spatial Distribution Of Npp In Jiangsu Province Based On Remote Sensing

Net Primary Production (NPP) is a key component of many important globe research programs; it keeps important position in global changing and global carbon cycle. This paper simulates The NPP of Jiangsu Province in2006-2010, based on CASA model, integrating with meteorological data and Remote Sensing data. Then building the Correction Model to correct2000-2006MODIS NPP product based on the accuracy assessment between MODIS NPP product and the result of CASA model in2006. Then analyzing the Temporal-Spatial Characteristics and factors influencing in the11years from2000-2010, with the corrected MODIS NPP product in2000-2006. This will be helpful for assessing the region ecological environment quality and its reasonable development and protection in Jiangsu Province.Firstly, this paper preprocesses the Remote Sensing data and meteorological data, including monthly average temperature, monthly average dew-point temperature difference. Then CASA model was built by GIS technology, choosing and calculating every parameter to simulate NPP data in2006-2010. After compared with the observed data, other modals’result, model precision can be proved reasonably. Then this paper uses the simulation result of CASA model in2006to correct MODIS NPP product.Secondly, according to the2000-2006corrected MODIS NPP product and the2007-2010CASA model result, the average NPP of Jiangsu Province in the2000-2010is615.38gc·m-2·a-1, the minimum value is519.5gc·m-2·a-1in2000year, and the max value is729.54gc·m-2·a-1in2008year. In the research period, average of NPP data rise slowly. The average NPP in the spring and summer is much higher than in the autumn and winter, so3-10month in every year is the mainly accumulation period of NPP, during this period the total NPP amounts higher than83.5%. Generally, the Temporal-Spatial trend in Jiangsu Province is average NPP decreases from southeast coastal area to northwest inland area, conforming to the national general rule NPP distribution.Finally, this paper analyzes the cause of the NPP value distribution rule in Jiangsu Province. The large scale changing of land cover and the destruction of the vegetation by human are the influential factors affecting NPP changing. Inter-annual temperature and precipitation doesn’t have good correlation with NPP generally, but on a monthly time scale, temperature and precipitation has positive relevance with monthly NPP.