Les observatoires du ruissellement : comprendre les processus pour améliorer les modélisations

Grangeon, Thomas; Landemaine, Valentin; Vandromme, Rosalie; Desprats, Jean‐François; Salvador‐Blanes, Sébastien; Vanhooydonck, Pierre; Gaillot, Arthur; Manière, Louis; Pene-Galland, Isabelle; Evrard, Olivier; Foucher, Anthony; Ledieu, Lauriane; Simonneau, Anaëlle; Ouvry, Jean-François; Pak, Lai Ting

doi:10.1051/lhb/2020056

Cited by 3 publications

(1 citation statement)

References 22 publications

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“…The 'Data type in EUSEDcollab' refers to the temporal structure of the time series data as it is made publicly available. 'Event -variable timestep' signifies event data with a variable timestep within each event Eventaggregated (Richet et al, 2020;Ouvry and et al, 2018;Grangeon et al, 2022;Pak and et al, 2018;Grangeon et al, 2020) In this study, we utilised four catchment datasets with measurements taken in ephemeral stream channels activated during rainfall-runoff events (Fig. 1 & 2).…”

Section: Catchment Data Subsamples From the Eusedcollab Databasementioning

confidence: 99%

On the potential of a low-complexity model to decompose the temporal dynamics of soil erosion and sediment delivery

Matthews,

Panagos,

Fendrich

et al. 2023

Preprint

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Abstract. Testing and improving the capacity of soil erosion and sediment delivery models to simulate the intra-annual dynamics climatic drivers and disturbances (e.g. vegetation clearcutting, tillage events, wildfires) is critical to understand the drivers of the system variability. In seasonally changing agricultural catchments, explicit temporal dynamics are typically neglected within many soil erosion modelling approaches, in favour of a focus on the long-term annual average as the predictive target. Here, we approach the trade-off between the need for model simplicity and temporally-dynamic predictions by testing the ability of a low-complexity, spatially distributed model (WaTEM/SEDEM), to decompose the 15-day dynamics of soil erosion and sediment yield. A standardised parameterisation and implementation routine was applied to four well-studied catchments in North-West Europe with open-access validation data. Through the testing of several alternative model spatial and connectivity structures, including the addition of an empirical runoff coefficient, we show that a temporally-static calibration of transport capacity cannot adequately replicate the relative seasonal decoupling of gross (on-site) soil erosion and sediment delivery. Instead, embedding seasonality into the calibration routine significantly improved the model performance, revealing a negative relationship between gross (pixel-scale soil displacement) and net erosion (stream channel sediment load) throughout the year. By incorporating temporal dynamics, the relative net effect is a reduction in the magnitudes of the spatially-distributed sediment fluxes at aggregated timescales, compared to a temporally-lumped approach. Published catchment observations infer that the efficacy of sediment delivery via overland flow is strongly reduced in the summer by abundant vegetative boundaries and increased in the winter via soil crusting and its promotion of runoff. Models operating at temporally-aggregated timescales should account for the possibility of decoupling in time and space between gross erosion and sediment delivery in arable catchment systems, related to alternations between transport- and detachment-limited sediment transport capacity states. Despite the complexities involved in the temporal downscaling of WaTEM/SEDEM, we show the utility of this approach to: 1) identify key missing information components requiring attention to reduce error in gross erosion predictions (e.g. more consideration of antecedent soil conditions), 2) form a basis for strategically adding physical process-representation, with a focus on maintaining low model complexity while improving predictive skill, and 3) better understand the spatial and temporal interdependencies within soil erosion models when undertaking upscaling exercises.

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Section: Catchment Data Subsamples From the Eusedcollab Databasementioning

confidence: 99%

On the potential of a low-complexity model to decompose the temporal dynamics of soil erosion and sediment delivery

Matthews,

Panagos,

Fendrich

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

EUSEDcollab: a network of data from European catchments to monitor net soil erosion by water

et al. 2023

Self Cite

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As a network of researchers we release an open-access database (EUSEDcollab) of water discharge and suspended sediment yield time series records collected in small to medium sized catchments in Europe. EUSEDcollab is compiled to overcome the scarcity of open-access data at relevant spatial scales for studies on runoff, soil loss by water erosion and sediment delivery. Multi-source measurement data from numerous researchers and institutions were harmonised into a common time series and metadata structure. Data reuse is facilitated through accompanying metadata descriptors providing background technical information for each monitoring station setup. Across ten European countries, EUSEDcollab covers over 1600 catchment years of data from 245 catchments at event (11 catchments), daily (22 catchments) and monthly (212 catchments) temporal resolution, and is unique in its focus on small to medium catchment drainage areas (median = 43 km2, min = 0.04 km2, max = 817 km2) with applicability for soil erosion research. We release this database with the aim of uniting people, knowledge and data through the European Union Soil Observatory (EUSO).

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Uncontrolled deforestation and population growth threaten a tropical island’s water and land resources in only 10 years

Foucher,

Evrard,

Rabiet

et al. 2024

Sci. Adv.

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Rapid demographic growth in tropical islands can exacerbate conflicts and pressures on natural resources, as illustrated by the French island of Mayotte where resources are limited. In only 10 years, uncontrolled migration and population growth (+80% of population between 2002 and 2021) have led to a pronounced 3600% increase in deforestation rates (2010–2014) and an intensification of agricultural practices, escalating conflicts over limited land, water, and biodiversity resources. Implementing an original multi-proxy approach to sediment cores, our study reveals a staggering 300% acceleration in erosion during the first wave of migration (2011–2015), followed by a further 190% increase (2019–2021) under sustained migratory and demographic pressures. Sedimentary DNA analysis provided insights into increased connectivity and community changes. By 2050, the population of this region will increase by 74 and 103%, in Comoros and Madagascar islands, respectively. Urgent conservation measures are needed to avoid major socio-environmental crises and to protect resources for future generations.

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Les observatoires du ruissellement : comprendre les processus pour améliorer les modélisations

Cited by 3 publications

References 22 publications

On the potential of a low-complexity model to decompose the temporal dynamics of soil erosion and sediment delivery

On the potential of a low-complexity model to decompose the temporal dynamics of soil erosion and sediment delivery

EUSEDcollab: a network of data from European catchments to monitor net soil erosion by water

Uncontrolled deforestation and population growth threaten a tropical island’s water and land resources in only 10 years

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