Evaluation of accumulation process of total nitrogen in the forested watershed by using the satellite remote sensing data and the vegetation database

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The relationship between the total nitrogen (TN) balance and the vegetation characteristics in a few forested mountain areas was investigated by field observations and GIS analysis of the forest lists and the satellite remote sensing data. The results were summarized as follows.1. A mathematical model of TN balance in the atmosphere was developed to evaluate the supplied TN from the atmosphere into the forested mountain area through the rainwater. The governing factors of the accumulation process of TN in the atmosphere were advection of TN in the atmosphere and the removal of TN by the precipitation, and the seasonal variation of TN concentration in the rainwater, which were obtained during the longer measurement period, could be estimated well.2. TN loading in the stream water was generally small and the assimilation of nitrogen in trees become active in the forest watershed in which the growth rate corresponding to the vegetation activity and the stem volume of tree corresponding to the biomass were large. Seasonal variations of TN in the stream water were not large because the runoff process of TN was very slow.3. A new method to estimate the distributions of vegetation characteristics related to the biomass and vegetation activities is proposed by using multiple probability distributions of remotely sensed data. The applicability was investigated by using Landsat/TM data and the forest, and it was better than the ISODATA method.4. A sound water environment must be created by the keeping continuity on the material circulation system and the control of the forest management and the human activities preventing the continuity becomes the watershed management. To keep the continuous material circulation it becomes important for residence to establish the monitoring system in the watershed and for organizations of administrations or research institutes to collect Various water environmental data.