Evolution of coastal sandy aquifer system in Kalpitiya peninsula,Sri Lanka: sedimentological and geochemical approach     

Pathmakumara Jayasingha  A. Pitawala  H. A. Dharmagunawardhane 《Environmental Earth Sciences》2014,71(11):4925-4937

The study on the evolution of groundwater sources has arisen because of growing concern about deterioration of groundwater resources due to overexploitation. The chemical nature of a coastal aquifer depends on the initial composition of aquifer media, internal geochemical processes and external chemical inputs. Therefore, geochemical characteristics of an aquifer can be used as indicative components on elaborating the origin of aquifer media and its evolutionary processes. This study was aimed at understanding the evolution of Quaternary coastal aquifers of the Kalpitya area, Sri Lanka, by studying groundwater quality and aquifer media. The textural, mineralogical and chemical characteristics of aquifer media and chemical nature of groundwater of the area imply that the aquifer media may not have been derived from marine processes and paleo coastal formations of the western coast but are indicative of a fluvial origin due to past strong fluvial processes. Fluviatile sand depositions had taken place initially and with the gradual sea level rise, deposits were transported, sorted and then re-deposited to form barrier islands parallel to the coast. These have evolved to the present state during the Quaternary period. Intermittent climatic changes caused several changes in the depositional pattern of the aquifer material and the chemical nature of the aquifer. Present day groundwater geochemistry indicates an evolution of a fresh water aquifer with relics of ionic constituents showing paleo geochemical processes that were active during the evolution. In addition, anthropogenic activities have also significantly altered the geochemical nature of groundwater in the present aquifer system.  相似文献