Hydrology, geomorphology and Rosgen classification of Doodhganga stream in Kashmir Himalaya, India

摘要

Hydrology and geomorphology of streams determine their physical state which in turn regulates the chemical and biological setup of these ecosystems. In the present study the hydrology and geomorphology of Doodhganga stream, which is one of the principle tributaries to the River Jhelum in the Valley of Kashmir (northern India), was worked out. Applicability of Rosgen stream classification, an important morphological classification of rivers, was tested so that consistent, reproducible and quantitative descriptions can be made. The flow velocity and discharge, worked out for the time period of January 2005 to December 2006 during base flow/low flow conditions, decreased downstream and there was an abnormal decrease in both these parameters in the middle stretches because of diversion of water for agricultural purposes and also because of extraction for drinking water facilities. On a temporal scale the spring (March to May) and summer (June to August) months maintained higher flow and discharge values while the autumn (September to November) and winter (December to February) months maintained low values for these parameters. The stream belongs to order 5 and has steep channel (0.0443 m/m) and basin (0.0423 m/m) slopes and moderate stream channel sinuosity (1.35 m/m). The different study reaches fell into different Rosgen stream classes and in general the Rosgen stream classification applied very suitably. At stretches where the predictions of the Rosgen classification were not followed, the anthropogenic influences were seen to be the major contributors for causing the deviations from the natural structure of the stream.