山岳地融雪解析における人工衛星リモートセンシングデータの応用に関する基礎的研究

抄録

Prediction of the runoff from a mountainous snow covered area is one of the most important problem in the hydrology field in order to make good use of water resources. In recent years, satellite remote sensing data by LANDSAT or NOAA have become available. If the data could provide information of the fallen snow in a wider area, they would remarkably increase computational accuracy of the snowmelt-runoff. The present paper, using a real basin as an example, deals with co-relations among the information such as reflectance of the snow in a snow-covered area obtained from LANDSAT/ MSS data, the thermal distributing on the snow-covered surface of the Earth obtained from NOAA/AVHRR data, and the condition of snow melting. The following properties become evident after examing the result of analysis.
(1) It is shown that the reflectance of the snow-covered surface decreases in proportional as the average incidence angle of solar rays.
(2) Along as contour line, the reflectance of the snow surface does not keep in uniform condition.
(3) It is shown that the reflectance of snow decreases with seasonal change. Also, the decreasing ratio varies with topographical feature.
(4) It is shown that the pattern of temperature distribution depends upon both the wind direction and the direction of the solar rays against the snow-covered surface influence.