EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

How do Natural Water Retention Measures modify connectivity on agricultural hillslopes?

John Edward Perez1, Ronald Poeppl1, Laura Turnbull2, Shubham Tiwari2, and John Wainwright2
John Edward Perez et al.
  • 1Department of Geography and Regional Research, University of Vienna, Vienna, Austria
  • 2Department of Geography, Durham University, Durham, United Kingdom

Fine-sediment input into river networks presents one of the biggest environmental pressures in agricultural catchment systems due to accelerating soil erosion rates associated with agricultural practices. To understand and effectively manage this problem, it is essential to identify sediment source areas and the pattern of linkages between different landscape compartments along the sediment pathways that ultimately end up in the river channel. Sediment connectivity is an increasingly used concept to help assess both on-site and off-site impacts of soil erosion by describing the efficiency of fine-sediment transfer through these different zones. Natural Water Retention Measures (NWRM) that emulate natural processes to enhance or restore the water retention capacity of ecosystems, available to be applied at agricultural fields, can be understood within this framework as they modify connectivity and provide benefits that include erosion and sediment control. The aim of this study is to assess the differences in sediment connectivity associated with scenarios of different NWRM (e.g. buffer strips, strip cropping, terracing, mulching) in a selected hillslope of the Fugnitz Catchment (Austria). Using a process-based sediment-transport model (MAHLERAN; Wainwright et al., 2008), runoff and sediment transport were dynamically simulated. Simulation results of water and sediment fluxes were then translated into a graph representing the flow network, consisting of nodes and edges, where connectivity and network properties can be quantified using graph-theoretical metrics (e.g. betweenness centrality). The same workflow was used for other NWRM scenarios, modifying parameters of the sediment transport model to capture the NWRM conditions. The results show notable changes in connectivity between scenarios as well as varying patterns of hot spots where sediment delivery is high and where interventions may be targeted, thus providing options of agricultural practices that can be implemented to improve sustainability in agricultural catchments.

How to cite: Perez, J. E., Poeppl, R., Turnbull, L., Tiwari, S., and Wainwright, J.: How do Natural Water Retention Measures modify connectivity on agricultural hillslopes?, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12616,, 2023.