Key to the management of the Western Himalayan Hillstreams in relation to

A key to the management of hillstreams in relation to Fish Species Richness (FSR) and Shannon and Weaver Diversity Index (H′) (Shannon and Weaver, 1949. The Mathematical Theory of Communications. Urbana, University of Illinois Press, IL, USA) using a multitude of factors such as altitude, water source, bed gradient, dominant channel materials and habitat type has been proposed on the basis of 10 study sites, belonging to three north Indian rivers namely; Ghaggar, Yamuna and Ganga. The selected streams are located between the altitudes ranging from 380 to 1524 m. It has been observed that high altitude streams having steep gradient, boulder dominated substrate with rapids as the main habitat type had lower FSR (3–4) and H′ (0.55–0.99) as compared to hillstreams located in the lower altitudes having gentle gradient, cobble dominated substrate with pools, riffles, runs, rapids and cascades as the main habitats and have high FSR (6–14) and H′ (1.67–2.35). Types – A, B and F hillstreams were encountered when the hillstreams are classified after Rosgen (Applied River Morphology, Wildland Hydrology, Co, USA).