National Institute of Hydrology

The study attempts to determine the useful life of the Bargi reservoir and assesses the sedimentation rate in it using satellite data. Periodical surveys are essential to provide a correct understanding of the sedimentation process going on in a reservoir, so that remedial measures can be undertaken well in advance and reservoir operation schedule planned for optimum utilization of water.

The study attempts to develop a conjunctive use model involving judicious use of surface and groundwater for the Habibpur region of Gandak command in Bihar. The area is characterized by insufficient surface water during rabi and summer seasons and excess surface water in the kharif season.

The report deals with the field testing of weighing rain gauge. Reliable and accurate measurement of rainfall is an essential requirement in hydrological studies. For automated recording of rainfall data, tipping bucket rain gauges are generally used.

The report emphasizes the necessity of Computer Aided Learning and presents a Learning Package on Hydrology covering various important elements of hydrology including the definitions and figures in a simple and straight forward language.

In this study, a model has been developed considering surface flow component and subsurface flow component along with the evapotranspiration from the crop as the sink term for the Lokapavani area of KR Sagar command of Karnataka. The surface flow component is represented using one-dimensional St-Venant equations and the subsurface flow component is represented using one-dimensional Richards equation with the sink term for the evapotranspiration from crop.

The report attempts asymptomatic estimation of runoff curve number for small hard rock watersheds from rainfall-runoff data.One of the major activities in Applied Hydrology is the estimation of storm event runoff from ungauged small watersheds. Such estimates are often required in the design of small hydraulic structures and in formulation of watershed management strategies.

The report attempts to do a comparison of single and multiple flow direction algorithms for computing topographic parameters in TOPMODEL. Topography is an important factor that influences the physical phenomenon of rainfall-runoff. Undeniably, it plays a primary role in the gravity drainage within a basin. In the last decade, ever-developing computer techniques associated with the greater availability of terrain data in digital form has favored the production of physically based models, which have spatial variability of topography built into their structure.

The report deals with the estimation of geomorphology parameters for small catchments using Geographical Information Systems (GIS). Stream channel morphology is literally the study of stream channel form and structure, but generally it is taken to mean their form and structures regarded as a whole or their collective morphology features. Systematic analysis of morphometry of any drainage basin and its stream system is of great importance in understanding the hydrological behavior of the basin.

The report presents the seasonal mapping of water bodies along the Andhra coast using satellite data to analyze the pre-monsoon and post-monsoon variations in the reservoirs. Water resources development be it construction of reservoir, anicut or irrigation canal, calls for mapping of the various water bodies to throw light on its behavior in different seasons in order to plan a judicious water management scheme.

Remote sensing methods are considered to be more appropriate than conventional methods for collection of such information owing to their capability to provide broad synoptic and repetitive coverage of the area in a multi-spectral mode.

The study focuses attention on the use of inverse modeling technique for estimation of rainfall-recharge in a coastal aquifer. MODINV (Modular Inverse Model), which is software for parameter optimization of 3-D groundwater flow model, MODFLOW is applied to the Central Godavari delta in Andhra Pradesh to estimate the distributed rainfall-recharge during monsoon season.