National Institute of Hydrology (NIH)

In this study, HEC 2 programme has been implemented on river Digaru to compute flow regime or the water surface profile for various discharge conditions. In this reach, two bridges have been considered to compute water surface elevations, critical water surface elevations, energy grade elevations & slope, velocity in the channel, flow area, top width and Froude Number.

The report presents the groundwater balance for the Southern Channel command area of the Pennar delta canal system as a part of the conjunctive use studies in the area. In a hydrological system, surface water flows, low or high, do not necessarily coincide with the low or high levels in groundwater, because of the sluggishness of the groundwater flow compared to surface water flow.

The study deals with dam break analysis of Barna dam located in the state of Madhya Pradesh carried out using the popular National Weather Service Dam Break Flood Forecasting (NWS DAMBRK) model to assess the likely maximum flood discharge and elevation to be attained in Bareli township, 22 km downstream of the dam.

The study deals with flow computation in Saptamukhi river estuary in Sunderbans delta of West Bengal using finite element method. Complex interactions between physical, chemical and biological processes are present in coastal areas. Water circulation is one of the most important factors controlling these processes. The study of the real hydrodynamic regime and proper management of estuaries, lagoons and coastal regions due to high tides, peak flows erosion, sedimentation and pollutant load discharges is vital.

The report presents flood plain mapping of Phulbari area within the flood plains of Brahmaputra basin in the States of Assam and Meghalaya using satellite data. Flood is a natural calamity in which most parts of the north-eastern region are ravaged. Management of the problem in these disastrous flood affected areas often requires flood plain mapping for protection and resource development. This has mostly being done in real time on the basis of time consuming and often hazardous ground based surveys.

The report deals with estimation of evaporation losses from water surface in Tawa reservoir in Hoshangabad district of Madhya Pradesh. The study is third in the series of evaporation studies to assess the adaptability of different methods for estimation of evaporation from free water surfaces in semi-arid areas. The estimates of evaporation from free water surface obtained by four methods namely Penman, Kohler, Van Bavel and Morton are compared with observed pan values on monthly, seasonal and annual basis.

The report deals with Geographical Information Systems (GIS) based rainfall-runoff modeling using Topography Model (TOPMODEL) for the Hemavathy catchment of Cauvery basin in Western Ghats of Karnataka. The TOPMODEL is a variable contribution area model in which the predominant factors determining the formation of runoff are represented by the topography of the basin and a negative exponential law linking the transmissivity of the soil with the vertical distance from the ground level.

The study deals with the analysis of surface and groundwater flow process in Dakshina Kannada district in Western Ghats of Karnataka. The area receives over 4000 mm rainfall annually but is still faced with acute shortage of freshwater during summer months. The study attempts to identify the surface and sub-surface flow process through geohydrological and geomorphological investigations in the Sithanadhi and Netravathi basins.

The report presents the hydrologic information and news available from print media and various government agencies mostly for the year 1999-2000 compiled problem-wise and basin-wise for the whole country.

The study attempted to estimate the actual crop evapotranspiration from minimum weather data of Tavanur, Kerala and resulted in an Artificial Neural Network (ANN) model, which makes use of average temperature data to estimate the actual evapotranspiration. The effectiveness of this model was evaluated using various statistical indices. The results of this model were compared with various existing techniques. The analysis led to the conclusion that the ANN models were performing better than all existing techniques for computing the actual evapotranspiration. However, the study was based on a single season lysimeter data and more research work may be required to reinforce this conclusion.