Snow and glacier melt contribution in the Beas River at Pandoh Dam, Himachal Pradesh, India

The water balance approach was used to estimate the average contribution of snow- and glacier-melt runoff in the annual flow of the Beas River at Pandoh Dam. About 45% of the basin area is covered by snow during winter and about 15% remains covered by perpetual snow and glaciers. Snowand glacier-melt contribution was estimated by computing the other components, i.e. rainfall, runoff and losses through evaporation, of the water balance equation. The total water budget of the basin was calculated for a period of 15 years (1990–2004). Total rainfall input to the basin was computed using available records of rainfall. The total volume of flow for the above-mentioned period was computed using measured discharge data of the Beas River at Pandoh Dam. Evapotranspiration losses from the basin were estimated only from the snow-free area, considering evaporation losses from the snowcovered area as negligible. The results of the analysis show that the snow- and glacier-melt runoff contributes about 35% to the annual flow of the Beas River at Pandoh Dam.