National Institute of Hydrology (NIH)

The study evaluates the applicability of Artificial Neural Networks (ANN) in rainfall-runoff process modeling for the Ajay river basin, Jharkhand to predict the 6-hour ahead runoff at Sarath. Initially three flood events were considered for training, to find out the weights between different layers of the network. The back propagation algorithm has been used for optimization of weights. The developed ANN was validated for rest of the flood events.

In the present study, two different Artificial Neural Networks (ANN) were developed for Dharoi reservoir, Gujarat, one for flood control operation and another for conservation operation. In recent years, ANNs are increasingly being used to predict water resources variables particularly in the operation of reservoirs, the most important elements of complex water resources systems, constructed for spatial and temporal distribution of water.

The report presents guidelines for hydrological investigations in a small watershed. A watershed is an individual entity, and is a naturally occurring unit of the landscape, which contains a complex array of interlinked and interdependent resources and activities irrespective of political boundaries. In addition, it is logical unit having readily identifiable boundaries and characteristics of water movement, which helps in coordinated planning and management.

The report deals with expert systems for unit hydrograph analysis, an emerging technology, which may in years to come, revolutionize professional activities in the field of surface water analysis and modeling. The literature review on the topic revealed the potential of application of expert system for unit hydrograph analysis. A prototype expert system has been developed for the selection of the most appropriate model for unit hydrograph derivation of a given catchment.

The report presents development of a sensor system capable of automated measurement of soil-water status, using the four-electrode resistivity (VES) method, in a soil profile. In this method, by changing the separation between two electrodes (metallic rods) placed at the ground surface without digging any holes, the variation in moisture content in the sub-surface soil profile can be monitored.

The study attempts to develop a relationship between glacier melt runoff and meteorological parameters for the Dokriani glacier in Garhwal Himalayas. The discharge auto-correlation, correlation between discharge & temperature and between discharge & rainfall has been computed for each month of the summer season and for the melt season as a whole for different years.

The study provides an analysis of groundwater quality to identify probable pollution or contamination in coastal aquifers of Kakinada in Andhra Pradesh. Sampling surveys have been conducted in the months of May 99, August 99 and November 99 and about 186 water samples were collected from shallow wells, filter points, canal water and rainwater. The spatial and temporal variations of water quality parameters are presented in the report. 

The report presents a sedimentation study in which sedimentation rate and volume have been determined using remote sensing data in the Ukai reservoir constructed across the Tapti River in Gujarat.

The report deals with software developed by the National Institute of Hydrology with the purpose of preparation of hydrological data book in a form most valuable to the users. A menu driven, user friendly software has been developed to handle all types of hydrological and meteorological data.

The report presents a systematic procedure for the computation of evaporation from lakes. Water balance of a lake depends upon the relative importance of various inputs and outputs to and from the lake. In Indian conditions, evaporation loss constitutes one of the major outputs from a lake and as such, the water regime of a lake and yield are influenced by it. In order to conserve and use the water, there is an urgent need for a first hand reasonable accurate estimate of its water balance.