ENVIRONMENTAL FLOW ASSESSMENT OF EASTERN RAMGANGA RIVER

Abstract

Generally rivers or streams perform important functions for the welfare of human society. They specify the social and economical needs of people. They also provide the consistency in life for aquatic species and plants under water. Since evolution, people have been using their waters for domestic, irrigation, industrial purposes rampantly without any conservation. Therefore, the quantity and quality of water in rivers or streams have reached a questionable mark these days. As these are the major sources for storage of water, these primarily affect the development of water resources. Uttarakhand is a State which is situated in the northern part of India. In this State many rivers have undergone various EF experiments. The State is blessed with many riversthe Ganga, Bhagirathi, Alakananda, Yamuna, Kali, Sarju are a few among many others. The river Eastern Ramganga is an important tributary of Sarju River. It rises from the Ramganga glacier in Northern Himalayas. The river flows south in its upper course and gradually turns towards west to meet with the River Sarju at Rameswar Ghat in Pithoragarh district. In some recent years the health of the river has been degrading continuously. People have used its water indiscriminately for various purposs, such as from domestic use to industrial use. There are many small hydropower stations (<25MW) present on the river course. These stations do not get sufficient flow in the non-monsoon period. Also the survival of aquatic species has entered the questionable zone. To get relief from these obstacles and to understand various problems on river health, EF assessment must be investigated on that basin. In this study, land use/cover classification was carried out to detect the changes in Eastern Ramganga River basin. Six major land use classes namely-snow, water body, forest land, agricultural land, barren land and built-up areas were identified. Further, assessment of EF in the Eastern Ramganga River has been carried out using different hydrologic approaches: Tennant Method, Modified Tennant Method, Hughes and Münster Method, 7Q10 Method, and Seasonal Methodology. Based on these assessments, recommendations have been made for the study basin