Study On Estimation Of Arid Oasis-Desert Ecosystem Biomass-Taking Fukang Oasis In Xinjiang As An Example

Doing dynamic change of oasis ecosystem vegetation biomass and making out exact monitoring. Thereby, it is not only directly connected with development of territory agriculture economy, scale and stability of oasis, but also indirectly affects sustainable development of economy and society of minority territory. Moreover research of oasis ecosystem vegetation biomass has important direction significance in the research of structure function evolvement of ecology system, depressing desert ecology system depravation and promoting oasis ecology system development. Main content in this thesis:1．Discussing relationship model of remote sensing vegetation index and oasis ecology system vegetation biomass on the former research basis, comparing and analyzing application range of different vegetation index, supplying basic proof for setting up oasis vegetation biomass remote sensing monitor model.2．Doing correlation analysis to some familiar vegetation index and vegetation biomass, then resulting: the correlation of normalized difference vegetation index and oasis ecology system vegetation biomass is strongest . Furthermore we come to the conclusion that NDVI is fittest test of goodness of fit in every regression model.3．Establishing the regression model of remote sensing vegetation index and vegetation biomass, through repetitive analysis and reasoning, we believe that non-linear regression model is more according with actual biomass, and through analyzing vegetation index and actual biomass in different non-linear regression model, we conclude this cubic equation: (Y=-5593.3NDVI3+7509.7NDVI2-1269.8NDVI+191) is the fittest regression model of Fukang oasis ecosystem vegetation biomass (Dry weight). 4．Analyzed from the result of biomass estimate, vegetation biomass has ascending tendency, especially prominent to crop field inside oasis ecology system, but isn't conspicuous to desert vegetation biomass inside or outside oasis ecology system though a little addition of biomass. It can be seen that the whole of vegetation biomass begins to ascend from April, till reach peak between July and August, and then descend. Vegetation biomass shows non-synchronization of ascending and descending in different months and location farther shows distinctive spatial distribution phenomena, because of desert vegetation's different life circle and physical character.