National Institute of Hydrology (NIH)

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, groundwater quality monitoring and evaluation of Greater Guwahati is presented based on the physico-chemical characteristics of thirty samples collected on grid pattern. The various parameters analyzed include pH, electrical conductivity, temperature, Dissolved Oxygen (DO), Total Dissolved Solids (TDS), alkalinity, hardness, Na⁺, K⁺, CA⁺⁺, Mg⁺⁺, NO₃^-, SO4^--, Cl^- and F^-. The results were compared with water quality standards prescribed by BIS and WHO.

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.

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 this study, the modified version of the Soil Conservation Services-Curve Number (SCS-CN) by Mishra and Singh (1998a) was employed to the data of 14 watersheds falling in the arid (Rajasthan) and 2 watersheds in the sub-humid (Madhya Pradesh and Uttar Pradesh) regions of India and the results were compared with those of the existing SCS-CN method. The modified version is found to perform better than the existing SCS-CN method in all applications to the data of 16 watersheds.

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.