Abstract:
This dissertation describes a hydrological study of the Vanathavillu Limestone aquifer using the Electrical Resister Analogue Techniques. Vanathavillu is situated about 18 km, north of Puttalam covering an area of about 80 km2. It is considered to be an isolated basin with the boundaries in the north at Kalaoya delta and the other boundaries being impermeable due to faults on the west and the south and an outcrop of basement in the east. The basin consists of two main water bearing strata namely, the upper Moongil Aru formation of quaternary age and a lower Limestone aquifer of Miocene age. Some observations had been carried out during the past two decade with reference to the geology and the hydrogeology of the area. The aquifer parameters and hydrological factors such as recharge and abstraction have been estimated with some degree of uncertainty. The application of the Electrical Analog Technique in the present study is to obtain refined estimates of these parameters and thereby predict the maximum usefulness of the aquifer. In using the Analog method, more weightage was given to some data such as piezometric head contours already established so that the uncertain data could be checked for their validity. Based on the numerical values of the aquifer parameters that were established and the recharge quantities that were evaluated, an overall evaluation of the aquifer as a source of water supply is carried out.
