SR-6/98-99 : Status and problems related with mountain hydrology

Abstract

This report discusses about the status and progress of studies of various hydrological problems related to mountainous areas experiencing rain or snow or both. The principal issues related to mountain hydrology on the local and regional scales are discussed. And highlighted. The status the hydrological studies carried out for the mountainous basins shows that understanding of basic hydrological variables like, precipitation, temperature and evaporation is poor for the mountainous basins. Spatial and temporal distribution of these hydrological variables is not well understood. Perhaps non-availability of hydrometeorological data at higher altitude for long duarion is the main reason for lacking in understanding of distribution of variables. There is urgent need to improve network design in the mountainous area in particular for high altitude region. For a better understanding of different hydrological variables, a long-term operation of a few multidisciplinary experimental research basins is required in different regions of mountain areas. Distribution of precipitation and temperature with altitude in a high altitude basin becomes important to compute melt runoff from snow and ice.

Application of remote sensing techniques has a tremendous potential to determine extent of snow and glacier covered areas on the basin scale. Year to year variation in snow covered area should be studied. Snow and glacier contribution in annual flows of Himalayan rivers is to be estimated. There is need to develop a hydrological model which can take into account the melting of snow and ice from high altitude part and contribution of rain from the lower part of the Himalayan basins. Impact of climate change on different hydrological parameters is to be studied for the snow and glacier fed rivers. High altitude lakes in the Himalayan region are also lacking for hydrological study. An accurate assessment of sediment transported by the Mountainous river is required for the planning of water resources in such regions.