Subsurface runoff

Lateral subsurface runoff via macropores

Flow velocities of fast subsurface flow via macropores \(v_{mp}(j)\) (m \(h^{-1}\), [Steinbrich2016]):

Potential lateral subsurface flow via macropores \(SSF_{mp-pot}\) (\(m^3 h^{-1}\)):

\[SSF_{mp-pot}=\sum_{j=1}^8 z_{sat}(j) \cdot v_{mp}(i) \cdot \rho_{mph} \cdot A_{mp}\]

with \(i\) slope (\(m m^{-1}\)), \(j\) horizon, \(z_{sat}(j)\) saturated thickness of the jth horizon (m), \(v_{mp}(i)\)rho_{mph}` density of slope parallel macropores (\(m^{-2}\)) and \(A_{mp}\) cross-sectional area of one macropore (\(m^2\))

Lateral subsurface runoff via soil matrix

Potential lateral subsurface flow via macropores \(SSF_{mp-pot}\) (\(m^3 h^{-1}\)):

\[SSF_{mat-pot}= z_{sat} \cdot k_s \cdot i \cdot w\]

with \(w\) width of the flow (m), \(z_{sat}\) saturated thickness (m) and \(k_s\) saturated hydraulic conductivity (\(m h^{-1}\)).