Distributed parameter modelling for sediment yield estimation from Hamp watershed in upper Mahanadi basin

Abstract

Hydrologic and water quality investigations are fundamental to any watershed management programme. Surface hydrologic modelling of watershed mainly includes processes like runoff and transport of sediment as well as pollutants from the watershed. Mahanadi is one of the major inter-state east flowing perennial rivers in peninsular India. Hamp watershed of Seonath Sub-basin of upper Mahanadi basin was considered in this study to estimate the sediment yield, and identification of critical agricultural sub-watershed using Soil and Water Assessment Tool (SWAT) interfaced with GIS i.e. ArcSWAT. The study area was subdivided into 14 sub-watersheds considering topographical parameters derived from DEM and drainage network. The land cover, soil layers, and DEM were used to generate 207 Hydrological Response Units (HRU) for analysis of daily and monthly sediment yield for 2004- 2008 (calibration period) and 2010-2013 (validation period). Adequately calibrated and validated ArcSWAT model was used to estimate the soil loss for development of effective watershed management plan of the upper Mahanadi River basin. Based on the annual soil loss and runoff, the most critical sub-watershed was identified as WS4 with runoff (245.97 mm) and sediment yield (18.18 t/ha).