Subcatchment Extraction and Runoff Simulation Utilizing Remote Sensing Data

摘要

In the fields of flood hazard prediction and water resource management, subcatchments and their parameters play veiy important roles because they are needed for almost all analyses and simulations related to rivers. However, they are prepared by field surveys in usual cases, so they have not yet been prepared for mountainous or deep forest areas difficult to survey, or they are not so accurate although they have been already prepared for those areas. In addition, such kinds of field surveys spend much time and costs, so it seems stalled to prepare subcatchments and their parameters with high accuracy in those areas. In this research, we developed the methods to extract subcatchments and their parameters from satellite remote sensing data. Our method to extract subcatchments needs only DEM obtained by satellite remote sensing, without any field surveys, so we can extract subcatchments anywhere if only DEM exists for there. Topographical parameters of extracted subcatchments are calculated also only from DEM. Using surface data obtained by multi band optical sensor, landcover is determined. These methods will enhance the preparation of subcatchments' parameters for mountainous or deep forest area. As a practical way to use of those extracted parameters, we developed a runoff simulation program too. It simulates draining discharges, using the extracted parameters above and some other parameters. By the simulation for past runoff, with fitting algorithm, it can correct parameters into more suitable.