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.
Since the Godavari at mouth is a uniformly enlarging shallow channel it is expected that the model may simulate the flows reasonably well. Unlike in an estuary, hydrodynamics may not be as dominant at the Godavari mouth because it drains an area more than half of the Deccan plateau.
The outcome of this two-dimensional depth averaged flow modeling study is to simulate the water level and velocity distribution in the study reach for different tide conditions during the flood scenario during which there is a lot of variation in river flows. The results arrived at on the water surface elevations may be useful in the design of embankments and the velocity vectors in the x and y directions will help in modeling sediment transport.
Download the report here: