Abstract:

Aquifer of basaltic fracture is the most productive formation for not only Buon Me Thuot-Dak Lak but also Central Highland area. Previous studies show this aquifer with complex and alternating structure between the high permeability, large fissured network areas, and low permeability areas. In area with large fissure network, water from surface percolate and recharge to aquifer very quickly thus water quality is very sensitive to be contaminated. Therefore, vulnerability assessment and mapping for this aquifer is required and indispensable. By using Disco method (Discontinuite - Couverture Protectrice) which developed by Hydrogeology Centre, Neuchatel University (Swiss) and with help of ArcGIS, a vulnerability assessment map has been done for basaltic facture aquifer in Buon Me Thuot, Dak Lak area. This method is based on three basic characteristics: (1) the discontinuous factor (Discontinue-DIS); (2) characteristic of covering layers-Couverture Protectrice (CO); (3) the characteristics of surface runoff (Ruiselement). The study shows that the aquifer with a high self-protection level spread over the study area (over 90%), while the rest of the aquifer has an average protective level