Coastal Zones

Biography

Biography: Neetika Kumari Sahai

Abstract

The Fijian Government has identified 676 villagers to be relocated in the near future due to a rise in sea level in the region. This paper discusses a very such village from the 676, which will face the brink of increase in sea level rise and has already become a highly stressed area due to salt water intrusion. Contamination of freshwater bodies caused by saltwater intrusion is a global issue, affecting water quality, vegetation, and soil conditions along coastal lines of countries. The first relationship between seawater and freshwater was first established in the 1800’s by Bodon Ghyben and Herzberg who developed the relationship for static equilibrium conditions and latter observed the density variations between seawater and freshwater were also important (Perlmutter et al., 1959). Two ground water wells, located around less than 300meters from the high tide level in Madhuvani village have confirmed a significant change in salinity ratio in relation to salt water used as control through laboratory tests. Laboratory testing’s for two month on the site samples confirm that there is a certain increase in salt concentration. The site of study, Madhuvani, a sugar cane farming area is already under the threat of losing its coastal land area. But for now, the biggest issue faced by the sugar cane farmers is the poor quality of sugar production. With poor soil richness, production rate has reduced. Conductivity of well 1 920(μS/cm) and Salinity of 0.58ppt in contrast to well 2 conductivity of 460(μS/cm) and salinity of 0.46ppt demonstrate a rather clear picture of salt water intrusion. Moreover, interviewed villagers have stopped using the wells complaining about the salty taste in the well waters. As expected, villagers have confirmed that the well located further inland have a reduced saltiness in well water. The major causes of salt water intrusion could be the tidal activity intruding further inland creating a thicker interface that would occur without tidal effects and the configuration of the interface is radically changed when the tidal fluctuations are included (Ataie-Ashtiani et al., 1999). It also occurs naturally in many areas but can become problematic when groundwater is withdrawn (pumped) from the acquifer; this includes the hydraulic head in the aquifer, subsequently slowing or stopping the seaward (Khublaryan et al., 2008). The wells supplied water to 3 generations for 25 years. Furthermore, Over-abstraction is considered the main cause of saltwater intrusion where most of the water has been used. Moreover, climate change and sea level rise speed up saltwater intrusion (Abd-Elhamid and Javadi, 2011). Extreme whether events is also a highly contributing factor to saltwater intrusion. There are more reasons discussed in the paper. In the past, many communities who came across a saltwater intrusion problem simply set up new production wells further inland (Barlow, 2003). This only complicated the issue. Since then, various methods have been employed to help alleviate the concerns of saltwater intrusion. This paper looks into how this situation of salt water intrusion be managed.