Rivers

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.

In this study, a Hydrologic Simulation Model (HYSIM) is applied to the Rushikuliya river basin in Orissa to model the daily flows of the river at Purushottampur. The model used in the study is a menu-driven PC based version and contains modes both for optimization and production runs.

In the study, Soil Conservation Services Curve Number (SCS-CN) method is used to predict runoff volume from the Bewas basin at a dam site meant to augment municipal drinking water supply to Sagar city. The SCS-CN model involves relationship between land use, land cover, hydrologic soil class, and runoff Curve Number of hydrologic soil cover complex, which in turn is a function of soil type, land cover and antecedent moisture condition.

The study attempts to apply the Shuffled Complex Evolution Algorithm (SCE-UA) of Duan et al for the calibration of a Conceptual Rainfall Runoff (CRR) model. CRR modeling lies intermediate between physically based models and black box models. 

The study has been conducted to develop a data simulation model and irrigation schedules for the eastern Godavari delta irrigation system, Andhra Pradesh. It aims at analysis of various factors that influence the irrigation operations and development of appropriate mathematical models and associated computer programs.

The study attempts to undertake surface modeling to simulate the water levels in the mouth portion of Vasishta-Godavari by taking the tidal effect during a flood season, by using the Finite Element Surface Water Modeling System (FESMWS) developed by United States Geological Survey (USGS) to model the reach. The objective is to simulate the surface water flow for a flood discharge of 2.35 lakh cusecs, under the effect of diurnal tide at the bay end.

The surface water levels of a river, especially at the mouth are required for planning and managing flood alleviation schemes and river engineering works. In the lower reaches of many rivers, flood plain inundation may result from very high tide or a very high flood or a combination of both. Also the extent of landward intrusion of saline water into a river at mouth varies with the relative strength of freshwater discharge and the co-oscillating tidal flow resulting from the dynamical interaction of the adjacent coastal waters.

In the study, the hydrogeomorphological parameters of Myntdu basin have been estimated from a digitized basin map where basic map data could be retrieved and manipulated quickly and accurately. The estimated geomorphological parameters of the basin covering linear, areal and relief aspects will be helpful in estimating and modeling the flow process in the basin.

The study applies TOPMODEL (Topography Model) to the Malaprabha catchment of Krishna river basin in Karnataka to simulate the daily flows at Khanapur site. The catchment area of Malaprabha up to discharge measuring site Khanapur is 520 sqkm. The model uses topographic index for the formation of runoff through development of a Digital Elevation Model (DEM) by interpolating the contours in the basin at 300 m grid size.

The report describes the results of the study of arsenic pollution in groundwater in Nadia as well as the hydro-chemical study of the river Hoogly in West Bengal. The alluvial tract along the river Hoogly covering a stretch of around 470 km encompassing eight districts is affected by arsenic pollution of ground water, the source being geogenic.

The report describes a software developed by the National Institute of Hydrology (NIH) for reservoir analysis in view of the importance of reservoir operation problem in the Indian context and the non-availability of generalized software for reservoir analysis.