Precipitation and run-off
A top layer system is protects the final landfill cap against the destructive influence of the sun.
Such system traditionally consists of:
- a drainage layer at the bottom to collect the run-off water
- a soil layer to prevent erosion of the drainage layer
The impermeability of the final capping can generate big amounts of run-off water to be collected in short periods of time.
Drainage systems at the top, in slopes and at the bottom should be adequately designed and constructed to prevent local instability of the top layers.
Specific software can simulate local blockages in the drainage system leading to unstability of the final soil cap.