Soil erosion models get more sophisticated Models more physically based and suitable for different kinds of situations. Price: model require large amounts of input data - very temporally dense data (like 10 minute rainfall data)
- difficult to obtain soil data such as the saturated conductivity.
If such data are unavailable: sediment yield models producing yearly averages.
BUT: yearly averages models: ignore lot of other detailed information like: BUT: yearly averages models: ignore lot of other detailed information like: Currently no models that model sediment yield
Make a model that can: Make a model that can: - Model erosion in a meso-scale catchment (20-200 km2)
- Is based on physical processes
- Has a significant hydrological component
- Can be run for daily time-step
- Requires input data readily available for most catchments
Eventually: A GIS- model that can be used by catchment managers and non-modeller-scientist
Landscape evolution model LAPSUS (Schoorl, 2002) (LandscApe ProcesS modelling at mUlti-dimensions and Scales) Landscape evolution model LAPSUS (Schoorl, 2002) (LandscApe ProcesS modelling at mUlti-dimensions and Scales)
LAPSUS has water balance as a base. LAPSUS has water balance as a base. has been adapted to model sediment yield on a daily basis: LAPSUS-D: - Calibrated with daily precipitation and discharges.
- gives good indication of possible sediment transport.
This new version of LAPSUS was tested on both a catchment in SW Poland and Mediterranean Israel up till now. This new version of LAPSUS was tested on both a catchment in SW Poland and Mediterranean Israel up till now. Upper Nysa Szalona: South western Poland: Temperate climate, 23 km2
Nahal Oren: Nahal Oren: Mediterranean climate 20 km2
Because of smaller time step of 1 day: Because of smaller time step of 1 day: Basic assumption of all water leaving the catchment in 1 time step no longer valid: Therefore: Cut rainfall-runoff in two parts: - Surface runoff leaves catchment in 1 day
- Subsurface runoff moves with 1 cell/day
No base flow No base flow With few adaptations, which need to be refined: - Peak duration and peak volume modelled with good accuracy
Now looking for longer record for validation
Meso-scale catchment (20-200 km2) Meso-scale catchment (20-200 km2) Hydrological component Daily time-step Calibration with the discharge at the outlet - Using only:
- DEM (10 to 30 m pixel size)
- soil map
- land use map
- daily discharge and precipitation data
- A general idea of the soil depths in the catchment.
With this: calibration for water flow part:
Thanks!
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