Rivers

The study uses Water Erosion Prediction Project (WEPP) model of the United States Department of Agriculture (USDA) to simulate the flow and erosion processes in Sallopat watershed of Mahi river basin in Banswara, Rajasthan. The WEPP model is a distributed, continuous, small agricultural watershed erosion model. It can simulate the effects of management practices and land use changes on the spatial and temporal variability of the erosion processes within a watershed system. The major features of this model are the ability to –

• Delineate areas of detachment and deposition on a hill slope or along a channel reach
• Account for the effects of management and land use changes on the erosion process
• Account for the effects of backwater on detachment, transport and deposition processes within channels

The study develops a regional hydrological model for estimating flow characteristics at ungauged sites of Narmada basin using climatological, hydrological and morphological variables. The term low flow is broadly used to describe stream flows that are significantly below average or below normal flow levels.

The study deals with adsorption of lead and zinc ions on the bed sediments of river Kali in western Uttar Pradesh. Adsorption is one of the most important processes in water quality control, which influences the transport of pollutants in aquatic environment.

The study demonstrates Geographic Information Systems (GIS) based methodology for identification of sediment source areas and prediction of storm sediment yield for small watersheds. The Nagwa watershed in Bihar was discretized in to 50m grid cells using Integrated Land and Water Information Systems (ILWIS) GIS package, and unique drainage directions were obtained using GIS analysis. Also, a threshold channel network was generated from Digital Elevation Model (DEM) of the watershed. Actual observed drainage and generated drainage networks were superimposed and were found identical.

The study carries out sediment yield estimation for the Shakkar catchment of the Narmada river in Madhya Pradesh and successfully implements a methodology for prioritization using Geographical Information Systems (GIS) and image processing on ERDAS and ILWIS software.

The study deals with the estimation of hydrological soil parameters of the doab between Sher, Umar river and Bargi left bank canal in Narsinghpur district of Madhya Pradesh. The soil properties determined are soil texture, soil moisture characteristic curves and saturated hydraulic conductivity.

In this study, a spatially distributed unit hydrograph was developed for the Kolar basin in Madhya Pradesh using Arc Info GIS package. The one-hour distributed hydrograph was determined for the basin using S hydrograph technique from the time-area diagram of the basin.

The study attempts to do a space-time distribution of rainstorms associated with the tropical cyclones in the Bay of Bengal over a period of 20 years from 1976 to 1996.

The magnitude of peak flood and shape of the flood hydrograph depends not only on the magnitude of the total storm rainfall but also on its distribution in space and time. Improvements of the accuracy and timeliness of hydrological forecasting would thus largely depend on the prediction of rainfall distribution in space and time.

In this study, NASMO model, a rainfall-runoff method, which uses the SCS method to determine effective rainfall, the linear reservoir method to route the runoff over land and the modified Puls method to route the runoff in the stream have been applied for hydrological modeling of the Malaprabha catchment in Karnataka. Geographical Information Systems (GIS) has been applied to derive the catchment characteristics like shape, size, slope and land use pattern.

The report is the first of a two-part study on water availability for the Ken river system and attempts to evaluate the direct surface runoff in the smaller basins, where gauging sites are not available. In this study on water availability in Ken river basin, rainfall-runoff modeling in the Sonar, Bearma and Bebas river basins, which are the sub-basins of the Ken river system, have been carried out using the Soil Conservation Services Curve Number (SCS-CN) model.

This is a widely used hydrological model for calculating the runoff using rainfall and Curve Number (CN). The SCS-CN is a quantitative descriptor of the land use, land cover and soil complex characteristics of a watershed. The CN is an index that represents the watershed runoff potential.