Surface Water

In this study, a two-dimensional overland flow model has been developed considering random roughness coefficients and irregular land surface for the analysis of surface flow component. The one-dimensional Richards equation for subsurface flow component has been used for calculating the infiltration from the pervious area.

The report presents the status of risk based hydrologic designs that have been reported in literature and based on these, identifies a computational procedure for developing hydrologic design bases for dams and spillways. Some illustrative examples are presented in order to demonstrate the impact of risk based analysis on current design practices.

This report describes the study of regional flood frequency analysis using peak flood series data of gauging stations of Krishna basin based on at site and regional data combined using the following methods: (a) Index-Flood method (b) PWM based EVI distribution (c) PWM based GEV distribution and (d) PWM based Wakeby distribution.

The report deals with the hydrological aspects of watershed development and describes watershed components and watershed models. It gives an account of the various watershed models in details including data requirement, input, output, various physical processes and governing equation. The suitability of a particular model to Indian condition is also highlighted in the report.

The study attempts to do flood inundation and flood plain feature mapping as well as undertake river planform measurements for a part of the river reach of Satluj. The river is a part of the Indus system and faces flood during monsoon months in spite of various flood control measures that have been adopted. The vast expanse of land adjoining the river course is inundated by large floods.

The report attempts to compile all the published works on the Sagar lake in one place. This includes brief description of the historical and the geographical background of the lake, details of water quality analysis carried out in various years, present position of the lake and various schemes proposed and implemented for the improvement of the condition of the lake. 

The report is set in the context of the growing application of computers in the field of hydrology, and the consequent development of large number of softwares for hydrological and allied applications. The report is structured as a Directory and presents brief details about softwares for hydrological and general purpose application available with the National Institute of Hydrology.

The study undertakes hydrological land use mapping in Narmada basin from Jabalpur to Hoshangabad by using various methods right from empirical formulae to Soil Conservation Services Curve Number (SCS-CN) method for design discharge computations and continuous runoff modeling. The SCS Curve Number method is used to derive an empirical relationship of the catchment hydrological variables and based on this the dimensional unit hydrograph is prepared and continuous runoff modeling done.

The study uses GIS techniques for spatial discretization of the Karso catchment into time-area segments to be used in numerical solutions of the governing differential equations for rainfall-runoff-erosion process. Various thematic layers such as soil, land use, slope, flow direction and Digital Elevation Model (DEM) were generated for the catchment using various tools available in GIS. These thematic layers were further utilized to generate attribute information such as Manning’s n, USLE K and C parameters for use in the rainfall-runoff-soil erosion model.

The study, which is a part of the representative basin studies, attempts to do a morphometric analysis of the Suddagedda basin of Andhra Pradesh. The linear, areal and relief aspects pertaining to morphology are studied. In ungauged basins and basins with very little hydrological data, the study of geomorphologic characteristics is important as these can be related with the hydrological characteristics of the basin and thus provide a simple way to understand the hydrologic behavior of various basins.