Some of my current research: Modeling sediment delivery on a daily basis for meso-scale catchments: a new tool: LAPSUS-D By: Saskia Keesstra and Arnaud Temme Wageningen University (Netherlands) with many thanks to: Agnieszka Czajka (University of Silesia)

Background (1) Background Aims Study area Methodology Results Conclusions Outlook For management purposes important to assess sediment yield of a catchment. Currently: models designed for estimating sediment yield either: –give very detailed storm-based information –or yearly averages.

Background (2) 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. Background Aims Study area Methodology Results Conclusions Outlook

Background (3) BUT: yearly averages models: ignore lot of other detailed information like: – daily discharge –precipitation data. Currently no models that model sediment yield –On temporal scale of one day –On spatial scale of a meso-scale catchment, without making use of very detailed input data. Background Aims Study area Methodology Results Conclusions Outlook

Research aim (1) Make a model that can: –Model erosion in a meso-scale catchment ( 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 Background Aims Study area Methodology Results Conclusions Outlook

Research aim (2) Landscape evolution model LAPSUS (Schoorl, 2002) (LandscApe ProcesS modelling at mUlti-dimensions and Scales) LAPSUS model models water and sediment routing Background Aims Study area Methodology Results Conclusions Outlook

Research aim (3) 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. Background Aims Study area Methodology Results Conclusions Outlook

Study area (1) 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 Background Aims Study area Methodology Results Conclusions Outlook

Study area (2) Nahal Oren: Mediterranean climate Carmel mountains 20 km2 Background Aims Study area Methodology Results Conclusions Outlook

J.M. Schoorl Laboratory of Soil Science & Geology Modelling framework Rainfall Erodibility Infiltration Landuse Geology Soil type Soil depth DEM Scenarios Erosion Deposition changed DEM LAPSUS model Run-on Run-off

Changes to LAPSUS Background Aims Study area Methodology Results Conclusions Outlook 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

Current status of model development Background Aims Study area Methodology Results Conclusions Outlook Precipitation Interception by vegetation Surface storage Time step 1Time step 2 Infiltration Maximum infiltration rate Maximum storage capacitySurface runoff Groundwater Darcy: slope of groundwater level Multiple flow: slope of surface Run on InfiltrationSurface runoff Run on Explain water stocks, flows and losses: Stocks: Surface storage Storage in unsaturated zone. Flows: Infiltration Hortonian overland flow Saturated overland flow Groundwater to surface flow Groundwater to groundwater Losses: Soil evaporation Interception Repetition of processes in time step 1 Precipitation

Methodology: calibration in Poland Background Aims Study area Methodology Results Conclusions Outlook With limited input no full hydrological simulation Specially baseflow not well simulated. BUT: only peak discharge is important for sediment transport Therefore focus on peak discharge

Results of calibration in Poland Background Aims Study area Methodology Results Conclusions Outlook

Results of calibration Background Aims Study area Methodology Results Conclusions Outlook Our set calibration tool gave satifactory results as: Peak height and peak duration and peak volume was modelled with good accuracy

Calibration in Israel No base flow But due to geology: deep drainage which is not accounted for in model With few adaptations, which need to be refined: –Peak duration and peak volume modelled with good accuracy Sediment calibration: good results Now looking for longer record for validation Background Aims Study area Methodology Results Conclusions Outlook

Summary LAPSUS-D Meso-scale catchment ( 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: good indication of possible sediment transport Background Aims Study area Methodology Results Conclusions Outlook

Thanks! Questions?