Some of my current research Modeling sediment delivery

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 Aims Study area Methodology Results Conclusions Outlook Background (1) • 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 Aims Study area Methodology Results Conclusions Outlook 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 (20 -200 km 2) – 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-modellerscientist

Background Aims Study area Methodology Results Conclusions Outlook Research aim (2) • • Landscape evolution model LAPSUS (Schoorl, 2002) (Landsc. Ape Proces. S modelling at m. Ulti-dimensions and Scales) LAPSUS 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 Mediterranean Israel up till now. • Upper Nysa Szalona: • South western Poland: Temperate climate, • 23 km 2

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

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

Background Aims Study area Methodology Results Conclusions Outlook Changes to LAPSUS • 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

Background Aims Study area Methodology Results Conclusions Outlook Current status of model development Time step 1 Time step 2 Precipitation Interception by vegetation Precipitation Surface storage Infiltration Run on Maximum storage capacity Maximum infiltration rate Surface runoff Infiltration Groundwater Darcy: slope of groundwater level Multiple flow: slope of surface Surface 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

Background Aims Study area Methodology Results Conclusions Outlook Methodology: calibration in Poland • 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

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

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

Background Aims Study area Methodology Results Conclusions Outlook 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 (20 -200 km 2) 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

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