Another fluxing procedure that will work for steep areas, where the flow is entirely driven by the gradient. We assume that fluxes are defined by the amount of water available in the donor cell. All the water available or a fixed proportion of it, determined by the flux_parm is moved downhill. However this time the water can travel over several cells before it reaches the recipient cell. The travel path is defined by the gradient. The travel length is a function of the amount of available water in the donor cell. The more water is available the further downhill it will travel. Currently we use a version of the hyperbolic function to define the travel length:
n = MAXDRUN*w0*wo/(w0*w0+HSHEAD),
where w0 is the available water in donor cell, MAXDRUN is the maximal travel length (number of cells), HSEAD - is the half-saturation coefficient (m), which is the squared water stage that corresponds to a travel path equal to MAXDRUN/2.
First, for each cell in the StudyArea we calculate the amount of water that is to be moved. Then we update the Surface Water variable in each cell, adding water to the recipient cells and subtracting water from donor cells. Also move 'Stuff' together with water, in proportion to the amount of water moved. 'Stuff' can be dissolved (nutrients), or suspended (detritus, sediment). It has to be uniformly distributed in the cell volume, so that its flux can be assumed proportional to water transport.
E-mail to Alexey Voinov
Another fluxing procedure that will work for steep areas, where the flow is entirely driven by the gradient. We assume that fluxes are defined by the amount of water available in the donor cell. All the water available or a fixed proportion of it, determined by the flux_parm is moved downhill. However this time the water can travel over several cells before it reaches the recipient cell. The travel path is defined by the gradient. The travel length is a function of the amount of available water in the donor cell. The more water is available the further downhill it will travel. Currently we use a version of the hyperbolic function to define the travel length: