Modelling of stream run-off and sediment output for erosion hazard assessment in Lesser Himalaya: need for sustainable land use plan using remote sensing and GIS: a case study

Abstract

Assessment and inventory on soil erosion hazard are essential for the formulation of successful hazard mitigation plans and sustainable development. The objective of this study was to assess and map soil erosion hazard in Lesser Himalaya with a case study. The Dabka watershed constitutes a part of the Kosi Basin in the Lesser Himalaya, India, in district Nainital has been selected for the case illustration. The average rate of erosion hazard is 0.68 mm/year or 224 tons/km 2 /year. Anthropogenic and geo-environmental factors have together significantly accelerated the rate of erosion. This reconnaissance study estimates the erosion rate over the period of 3 years (2006-2008) as 1.21 mm/year (398 tons/km 2 /year) in the barren land having geological background of diamictite, siltstone and shale rocks, 0.92 mm/year (302 tons/km 2 /year) in the agricultural land with lithology of diamictite, slates, siltstone, limestone rocks, while in the forest land, it varies between 0.20 mm/year (66 tons/km 2 /year) under dense forest land having the geology of quartzwacke and quartrenite rocks and 0.40 mm/year (132 tons/km 2 /year) under open forest/shrubs land having geological setup of shale, dolomite and gypsum rocks. Compared to the intensity of erosion in the least disturbed dense forest, the erosion rate is about 5-6 times higher in the most disturbed agricultural land and barren land, respectively. The erosion hazard zones delineated following scalogram modelling approach. Integrated scalogram modelling approach resulted in severe classes of soil erosion hazard in the study area with numerical values of Erosion Hazard Index (EHI) ranging between 01 (very low hazard) and 5 (very high hazard).

Impacts of climate change and hydrological hazards on monsoon crop patterns in the Lesser Himalaya: A watershed based study

“…Intensive rainfall triggers several hydrological hazards, including flash floods, river-line floods, soil erosion, and non-seismic landslides in monsoon periods. During flash floods especially in the monsoon season, tremendous amounts of erosion occur on the banks of rivers and streams and the floods wash away crops and productive land and later deposit sediments over other agricultural fields and settlements (Rawat et al 2012). River-line floods erode valley sides and induce landslides and slope instability, which destroy agricultural lands and lead to reduced crop production.…”

“…But the present study argues that food security problems are also caused by productivity loss of agricultural land through hydrological hazards accelerated by climate change. Climate change triggers hydrological hazards such as high runoff, flash floods, river-line floods, and non-seismic landslides, which cause community food availability risks in mountainous terrains (Ives 1989;Valdiya and Bartarya 1989;Cruz 1992;Jain, Kumar, and Varghese 1994;Sing 2006;Rawat et al 2012). Although climate change and hydrological hazards affect all four key dimensions of food security-availability, stability, access, and utilization, the present study focuses only on the availability aspect of food for the local communities.…”

Ecological-Economic (Eco-Eco) Modelling in the River Basins of Mountainous Regions: Impact of Land Cover Changes on Sediment Yield in the Velicka Rijeka, Montenegro

“…Since it is difficult to accurately measure soil erosion in the field, also the performance assessment of soil erosion models is difficult (Conoscenti et al, 2008, Rawat et al, 2011. By contrast, sediment yield models are easier to apply and to be tested, because the data for these models can be measured at the watershed outlet (Kinnell and Riss 1998;Erskine et al, 2002;Kinnell, 2010).…”

Efficiency of Intero Model to Predict Soil Erosion Intensity and Sediment Yield in Khamsan Representative Watershed (West of Iran)

“…The models use and modeling processes modeling, especially watersheds of without hydrometric stations, are the useful and essential tools to evaluate the amount of sediment and soil erosion Smith, 1965, 1978) for this purpose the various models have been developed (Zhang et al, 1996). Evaluation of the applicability of soil erosion models to a watershed is not easy, as it is difficult to accurately measure soil erosion in the field (Conoscenti et al 2008, Rawat et al 2011. In contrast, sediment yield models are easier to apply, because the data for these models can be measured at the watershed outlet (Kinnell and Riss 1998;Erskine et al 2002;Kinnell, 2010).…”