This section calculates the darcy flow of groundwater. [insert_php] if (isset($_POST[‘submit’])) { $k = $_POST[‘k’]; $ar = $_POST[‘ar’]; $g = $_POST[‘g’]; echo “Darcy Flow: ” . $k*$ar*$g; } [/insert_php] Hydraulic Conductivity (m/s): X-sectional Area of Flow (m2) : Hydraulic Gradient (-):