Vegetation Water Monitoring Based On Modis Data And Applied Research

The vegetation water content contains compounded and dissociative water inside vegetation cells. Water is basic material for photosynthesis, it plays an important role in the growth of vegetation. Besides, research on vegetation water content will do favor for monitoring biomass burning, drought and zoology protection.With the progress of satellite and sensor technology, the theories and methods of estimating vegetation water content have a fast development at the same time. After the newest MODIS data has been available, performing a long-term monitoring of vegetation water content will be possible. The purpose of this paper focuses on estimating vegetation water content from MODIS data.The paper reviewed the history of research on vegetation water content, compared several methods, found that the GVMI model is the best method in estimating vegetation water content because the difference of vegetation species has no effect on the model result. In my research, the model was adapted for MODIS data. Using this method, vegetation water content of China from April to July, 2003 was computed. Research on the result, we find that vegetation water content was affected by the location and climate. The distributing of vegetation water content in China presents an increasing trend from North-West to South-East.Combined with precipitation synchronization and the average precipitation data from 1951 to 2000, We also find that the acute change of precipitation will not affect vegetation water content a lot, because vegetation needs time to absorb water and vegetation exhibition a good self-adjust ability when there is a lack of water supply. Without big abnormity in climate and artificial action, vegetation water content takes a good relationship with average precipitation. They are consistent in changing trends. Because vegetation water content come from soil water content, and rainfall is a main supporter for soil water content. Based on vegetation water content, we can know drought condition.Now, the achievement of this research has been applied in the grassland fire forecast system. Research on estimating vegetation water content needs a far development.