Seepage

SeepageWhen water flows underground through a porous medium, flow rate can be computed using Darcy Law if the individual term in eth equation can be evaluated. But in many instances, the flow of water through soil is not in one direction only, nor is it uniform over the entire area perpendicular to the flow. The use of equation q=kiA becomes difficult. In such cases, the groundwater flow is generally calculated by use of graphs referred to as Flow Net. The concept of flow net is based on the Laplace Equation of Continuity which governs the steady flow condition for a given point in the soil mass. This continuity principle states that there can be no net change in eth soil mass of a fluid contained in a small volume of porous media. Any changes in the mass flow into the small volume of the porous media must be balanced by the corresponding change in the mass flux out of the volume or a change in the mass stored in the volume or both.