衛星リモートセンシングデータによる林地水保全機能の判読と降雨流出解析への応用

抄録

It is very important to obtain the information on soil physical properties and the growth condition of trees, when we make runoff analysis in forest land. But actual vegetation map is not including the growth condition of trees, and it is difficult to obtain the information on the soil. Therefore, it is thought that the usefulness of satellite data have to be verified in this aspect.
This paper aims at estimating the ratio of coarse pore, which relates to hydrologic cycle in forest using satellite data and applying it to flood-runoff analysis. In mountainous terrain, it is necessary to eliminate the terrain effect to radiometrical distortion for satellite data. Therefore, the radiometrical distortions of used LANDSAT/TM data were eliminated using digital terrain model (DTM). Many measurement points were selected in the area for survey of various physical soil properties and vegetation conditions of the forest.
In order to estimate the ratio of coarse pore from satellite data, we made linear multiple regression equation through multiple regression analyses on the relationship between the ratio of coarse pore and corrected LANDSAT/TM data to each of categorized three forest types. As the result, it was found that the ratio of coarse pore related to the band ratio of near-infrared/red. Further, we tried to apply the estimated ratio of coarse pore to runoff simulation model. It was found that this method was useful to estimate the ratio of coarse pore, because of the simulated hydrograph well coincide with the observed one.