Calculation time (Water Overlay)
Aspects which impact calculation time
The following aspects can negatively impact the calculation time of the Water Overlay:
Simulation time
The simulation of the Water Overlay requires that the movement of water is computed in small enough steps that the natural flow of water can be accurately simulated. This means that for any given simulation time, the total simulation time is divided into calculation timesteps of less than a second. For each timestep, all grid cells must undergo a calculation. The longer the simulation time, the more individual timesteps must be computed, and therefor the longer it takes to fully calculate the entire duration of the intended simulation.
Ensure the duration of the simulation is set to a timespan suitable for the intended use-case, but not longer than neccesary.
Grid cell size
The more cells requiring calculation, the more time is requires to perform the neccesary calculations for every cell in the project area. The Tygron Platform can run many calculations as such in parallel, but with large enough quantities more cells means it may take multiple passes to compute them all. A smaller grid cell size means a quadratic increase in the amount of cells. Halving a cell's size means 4 times as many cells to compute.
In addition, smaller grid cells means that to properly calculate the flow of water, the amount of time per computational timestep is reduced. This is because water with the same impulse can travel just as quickly, but must not be allowed to overshoot any cells in between.
Ensure the grid cell size is set small enough that any significant waterways in the Project area are at least 4 grid cells in width, and water is allowed to flow through any other significant routes. But do not reduce the grid cell size significantly beyond that size.
Geographical spread of water
Amount of applicable models
Aspects which do not impact calculation time
Timeframes
