Oceans and Coasts

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.

The report presents a literature review on the status of research related to saltwater intrusion and groundwater management in coastal and deltaic environments in the east coast of South India. The area is typically characterized by highly productive and alluvial aquifers and high use of both surface as well as groundwater. Seawater intrusion into the freshwater aquifers is extensive due to increased pumpages.

A quantitative understanding of the patterns of movement and mixing between freshwater and saline water and the factors that influence these processes is stressed in the report. It presents the mechanics of saltwater intrusion through studies by Ghyben and Herzberg and later on by Hubbert. A comprehensive review of studies by Reilly and Goodman relating to saltwater intrusion is discussed. Later advances in understanding saltwater-freshwater relationship through numerical models like sharp interface model and miscible flow model are described.

The study is based on investigations and collection of necessary information on the super cyclone in Orissa in October 1999. It examines cyclonic phenomenon in the country in general and Orissa in particular, and stresses the need for preparing a comprehensive plan for dealing with such disasters.

Please have a look at the Demonstration video about clearing oil spills in oceans or any other water body.

http://video.godlikeproductions.com/video/CWRoberts_Presentation_2wmv

It is a simple and effective method.

Food Distribution in K-Plot on Feb 17th

In face of the dire situation in Aila Affected areas, AID EB approved Rs. 1,50,000 for distribution of food in the remote island of K-plot and Nagenabad area of Moipith island. AID has been working with Baikanthapur Tarun Sangh (BTS) since Aila, on relief/rehabilitation and the revival of agriculture in the area.

The earth is currently warming rapidly. And this warming is bringing about massive changes. Our glaciers are melting rapidly. The artic ice-shelf is breaking apart into pieces and threatens to modify the salinity of the oceans.