Oceans and Coasts

This initiative is an attempt to provide daily updates on Flood Situations and related events/news to water enthusiasts, professionals and citizens concerned about flood in Odisha. News and information collected from Odia news papers, English media (internet editions) and web site of Department of Water Resources, Govt of Odisha are put together at one place to provide an overview of flood in Odisha on a daily basis.

Salinity in coastal groundwater is a widespread problem and may be caused by individual or combined effects of inherent salinity, tidal effect, irrigation by saltwater and by seawater intrusion due to extensive pumping.

The report deals with the modeling of the Cochin estuary along Kerala coast using two- dimensional finite element model. The basic equations for modeling of any surface water problems are the three dimensional hydrodynamic equations arising from consideration of mass and momentum conservation. In vertically well mixed shallow water bodies, the horizontal components of flow quantities are normally much more significant than vertical components.

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.

In this study, a two dimensional numerical model in the vertical plane for simulating miscible transport of saltwater in a coastal aquifer has been developed. In order to simulate the variable density flow, the governing partial differential equation of flow and solute transport has been written in terms of pressure and concentration respectively.

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. 

ABSTRACT

In the study saltwater intrusion processes in a hypothetical homogenous and multi-layered coastal aquifer system are simulated using the United States Geological Survey (USGS) finite element model for saturated-unsaturated fluid density-dependent groundwater flow with energy transport of chemically reactive single species solute transport (SUTRA) for different boundary conditions and aquifer parameters.

The saltwater intrusion profiles for steady-state or transient conditions are obtained and analyzed. The effects of changes in the permeabilities of aquifers and aquitards, changes in the influx at the boundary, and changes in dispersivities in medium on the saltwater intrusion process are investigated.

The study presents the spatial analysis of groundwater levels and its quality for the year 1998 for Kakinada town in coastal Andhra Pradesh. The Deltaic Regional Centre of NIH has been monitoring groundwater levels and its quality in and around Kakinada town since 1994. Groundwater samples have been analyzed for physical and chemical parameters. The variation in each parameter is discussed in the report.

A total of 164 samples were collected from 41 observation wells during the months of February, May, August and November 1998. The area covered by these observation wells is around 82 sqkms. The groundwater table contours were plotted for pre-monsoon (May 98) and post monsoon (November 98) periods and the approximate flow direction had been demarcated.