Development of cost effective technology for treatment of torrents in Shivalik hills, India

Abstract

In NorthWestern Himalayan region, Shivalik hills occupy an area of 2.14 mha and this area is perhaps the most degraded and fragile ecosystem in India. The present study was conducted to develop the cost effective technologies for treatment of seasonal torrents in mid hill of Shivalik. There was an urgent need to develop water resource for mitigation and adaptation to minimize the impacts of climate change in the region. Through cost effective technology, the torrent bank was stabilized against erosion. The stream flow was channelized and land reclamation of adjoining area was achieved through bio-engineering measures i.e. by applying mechanical barriers in conjunction with vegetative measures. Low density polyethylene (LDPE) lined farm ponds were also constructed for rain water harvesting Farm pond is an ideal proposition for the hill farmers having small and fragmented land holdings for resource generation The cost effective technology was evaluated using a database of hydrological, geomorphologic and land use. In the catchment, the gullies were small to medium in size which were treated with gully plugging by constructing loose boulder check dams and erecting with different species of plants. Attracting and deflecting type of spurs were constructed with vegetative reinforcement for channelization of stream flow. Agroforestry plant species in combination of engineering measures were found effective for stabilizing the nala bank which reduced soil erosion and runoff. The sediments deposited in first year at downstream was recorded 0.09-14 t and in second year it was reduced up to 0.07-8 t. Similarly, upstream sediment deposition was recorded 1.0-21.0 and 0.37-12 t in two consecutive years, respectively. Thus, the bio-engineering measures were found effective in channelizing the torrent flow stabilizing the stream beds and banks.