Isohypses and equipotential lines

• equipotential lines: visualisation of spatial variations in hydraulic heads
• isohypses: lines connecting points with equal groundwater levels

  • type of equipotential line
• flow lines: path water droplets take to travel from high hydraulic heads to low hydraulic heads

  • if soil is isotropic, flow lines are perpendicular to equipotential lines because water droplets follow steepest decrease in hydraulic head
• flow path/tube: area between two flow lines
• flow net: network of equipotential lines and flow lines
• curvilinear square flow net: equipotential lines result of hydraulic head measurements at many locations
• upward and downward seepage vary in space and time

  • spatial variability is result of differences in elevation and soil composition
  • temporal variability is result of wet and dry periods
• Dupuit assumption: flow in aquifers can be simplified to horizontal flow and flow through aquitards can be simplified to vertical flow