Theme 1-3-Role of storage characteristics of glaciers in the regulation of streamflow

Abstract

There are more than 5000 glaciers in the high altitude region of the Himalayas and make a significant contribution to the annual flows of the rivers originating from the Himalayas. Melt water storage and drainage characteristics of a glacier regulate the streamflow emerging out from the glacier. The diurnal variation in the melt water runoff is controlled by these characteristics of the glacier. In order to understand these characteristics of the glacier, continuos monitoring of the meteorological and hydrological information is required. In the present paper, storage and drainage characteristics of the Dokriani glacier located in the Garhwal Himalayas have been studied. Total area of this glacier is about 10 km2. Required data were collected for a period of 4 years for the Dokriani glacier by establishing a meteorological observatory and discharge gauging site with the provision of automatic water level recorder near the snout of the glacier. Observation of discharge round the clock for the summer period shows the availability of considerable amount of runoff during the night period due to these characteristics. Movement of snowline over the glacier due to depletion of snow from the glacier surface results in exposition of glacier ice surface and reduction in storage capacity of glacier. Such variations in physical condition of a glacier attribute to the reduction in the melt water storage of a glacier. The effect of reduction in storage characteristics on the hydrologic response of the basin has also been studied by analysing clear weather hydrographs. The response of the basin becomes faster with advancement of melt season.