20-Streamflow measurements in the mountainous areas

Abstract

For the development of water resources in the mountainous regions, a realistic assessment of the available water resources is necessary for their proper utilization and management. Installation of mini and micro-hydel schemes in the hilly areas is expected to generate substantial electricity to meet the demands of the local population. For estimating the design capacity of these mini/micro-hydel schemes dependable flows are needed for which discharge data are required. For this purpose, establishment of gauging sites at high altitudes (above 2000m) and their monitoring has to be carried out. The general features of these streams include very high velocity of flow due to steep slopes, sediment and boulders in the streams and low water temperature. In the present chapter, problems experienced in selection and establishment of gauging sites including measuring and monitoring of flow at high altitudes in different parts of the Himalayas are highlighted. Based on field experiences, suggestions are made to modify, design and develop the instruments to suit the requirements. Flow measurement techniques based on local conditions of the streams has been suggested.