STUDY ON SNOWMELT RUNOFF PREDICTION USING WEEKLY WEATHER FORECAST

This paper presents an attempt to apply weekly weather forecast data f or snowmelt runoff prediction. The basin surveyed for this study is 1. 0 km(2) in area and ranges from 390 to 800 m above sea level. The snow melt model makes use of digital terrain data with a 20-m grid spacing. Energy balance components are calculated for each grid element taking topographic variables of solar radiation into account. In order to us e the snowmelt model in the forecast situation, it is necessary to pre dict the meteorological data for any future time period. In this study : 1) the insolation is calculated by the forecasted percentage of suns hine, which is classified into 15 weather conditions, and 2) the tempe rature is calculated as a function of time elapsed. A one week forecas t of snowmelt runoff using weekly weather forecast data is sufficientl y accurate for practical purposes.