SIMULATION OF GROUNDWATER FLOW SYSTEM IN ALLUVIUM AND FRACTURED WEATHERED BEDROCK ZONE;SAND LICK WATERSHED,BOONE COUNTY, WEST VIRGINIA, USA

Determining the hydraulic properties of aquifers and aquitards (Hydraulic conductivity, transmissivity, and storage coefficient) is very important in hydrogeologic studies. These parameters can be approximated by methods such as laboratory permeability and borehole hydraulic response tests, or by inverse numerical modeling. The Appalachian Plateau (where our study is located) is characterized by relatively flat-laying but intensely eroded bedrock, comprising cyclical sequences of Pennsylvanian age sedimentary bedrock dominated by sandstone, siltstone, shale, coal, claystone and occasionally limestone. Fractured/weathered sandstone is potentially the main bedrock groundwater transmitting zone and the main groundwater flow occurs from within the intergranular pore space through fractures and along bedding planes of the bedrock. Conventional field or laboratory methods of estimating the hydraulic properties in selected points within such fractured and weathered bedrock groundwater transmitting zones are seldom representative or feasible because of their physical characteristics, heterogeneity and irregular geometry. Therefore, the objectives of the following study, is to determine the hydraulic properties of a weathered/fractured zone in a valley located within the Appalachian Plateau Geomorphic Province as well as recharge and evapotranspiration rates by applying inverse numerical simulation of groundwater flow.