Developing a hydrogeological model for Aruwakkalu limestone mine, Puttalam

Abstract

A hydrogeological model has been developed for the Aruwakkalu limestone mine to study the behaviour of groundwater flow, associate with specific problems within the mine, in this research. Groundwater flow model was constructed using Visual MODFLOW 3D Finite difference method. Five distinct types of material layers were identified for material property designation in the study area of the mine by using the borehole data report, which was completed in year 2008. The mine is mainly bounded by two water bodies; Puttalam lagoon and Kala Oya. Existing hydrogeology related data and the results of several field tests were used to develop the groundwater model initially with a conceptual model. Utilizing hydrogeological data gained from field works; specially the aquifer parameters gained from pumping tests, the model was developed and calibrated for steady state conditions. According to the model simulation, groundwater flow is mainly towards the west direction and it simulates sea water intrusions in some locations. Dewatering feasibility and cost associated with groundwater movement of the mine can be evaluated using the developed model by conducting predictive simulations.