Remotely Sensed Inversion Of Forest Biomass And Its Temporal And Spatial Distribution Patterns Dynamics In Beijing

Forest biomass plays important role in the global climate change, regional or global sustainable development,which is entire forest ecosystem's energy and nutrient sources and base of biological productivity,the net productivity and the carbon cycling.Remotely sensed estimation of forest biomass in Beijing area and analysis of its temporal and spatial distribution patterns is the main object of this research. Based on the different conditions of study area and the ground survey information, using the remote sensing images of 1999,2002 in Beijing, the estimation model of Biomass =13.007×(NDVI)2+203.74×(NDVI)+10.859 was built, by which the biomass of 1999,2002 was estimated; Then the temporal-spatial dynamics of biomass and the relations with the environmental factors was analyzed; Also a biomass prediction model was built based on Markov model and changing matrix of first, second-ordem, by which the biomass of 2005,2008 has been predicted, and the 3-D simulation of forest biomass has been performed.This paper include following content and results:(1) Compared the correlation of biomass with NDVI,RVI,DVI,SAVI,MASVI, TM3, TM4, TM5, TM3+4+5, slope, aspect, slope position, elevation, etc.variables, using the survey data of permanent and temporary sample plots and TM remotely sensed images, we selected NDVI,RVI,DVI,SAVI and MASVI to establish the inversion models which has high coefficient with ground biomass. Through error analysis and accuracy matching, it showed that Biomass=13.007×(NDVI)2+203.74×(NDVI)+10.859 has high correlation coefficient.(2) By estimating the biomass of 1999, 2002 of Beijing area, the temporal and spatial biomass dynamics was analyzed. For temporal dynamics, forest biomass of 2002 is more than 1999's,, because of conversion of cropland and waste land to forest land. For spatial dynamics, the biomass increases with elevation ascending and starts to gradually decrease at a top value both in 1999 and 2002; Although the 1999's biomass distribution by slope is similar to the 2002's, the biomass has different change at respective slope gradient. For aspect, the biomass of 2002 and 1999 has the same distribution; At last the biomass of 2002 has greatly change.,especially the valley position's biomass ,which sharply decreases from 39.59t to 10.66t.The reason is that forest vegetation of valley position has been destroyed for increasing demand of wood .(3) The forest biomass in 2005 and 2008 was predicted based on Markov model and changing matrix of first,second-order. The result showed that the total biomass will increase from 1999 to 2008. Although the third biomass's area will decrease significantly, the fifth biomss's area will raise in this period.