@phdthesis{discovery10192241,
            year = {2024},
           title = {The hydrological effects of the Eurasian beaver (Castor fiber) in a UK headwater catchment},
           pages = {1--615},
           month = {May},
            note = {Copyright {\copyright} The Author 2024.  Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/).  Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms.  Access may initially be restricted at the author's request.},
          school = {UCL (University College London)},
          author = {Van Biervliet, Oliver Robin Malcolm},
             url = {https://discovery.ucl.ac.uk/id/eprint/10192241/},
        abstract = {Beavers (Genus: Castor) are ecosystem engineers that build dams, impounding
water and causing a cascade of interacting changes to water fluxes and storage.
Few studies have quantified site-scale effects of beaver dams on the water
balance. The effect of beaver dams on low-flows and high-flows have been
reported but results are sometimes contradictory and underlying mechanisms
remain unresolved. Little consideration has been given to the effects on average
flows. Numerical modelling could help to fill such knowledge gaps, but an
appropriately validated approach for representing beaver dams is currently
lacking. This thesis investigates the hydrological effects of beaver dams using
25-months of monitoring data from adjacent catchments in eastern Scotland, one
with 28 beaver dams (165ha) and another without beaver dams (58ha). Field data
were used to build, calibrate and validate coupled hydrological/hydraulic models
(MIKE SHE/MIKE 11) representing a 418m stream reach and 12.3ha of
associated floodplain containing five beaver dams. Model simulations
demonstrated that fluxes of stream water, mainly to floodplain soils, reduced
stream discharges downstream of beaver dams causing average-flow reductions
of approximately 29\% and a median peak-flow reduction of 3\% (range: +4\% to -
11\%). Beaver dams appeared to augment downstream discharges when they fell
below the leakage rate through the dams (estimated to be 0.5-2.0Ls-1
), but
reduced low flows above this threshold. Subsequent model scenarios
demonstrated that soil permeability modulated the effect of beaver dams with
many of the hydrological effects of the dams decreasing in magnitude with
reduced soil permeability. Additionally, a commonly employed device used to

control beaver pond water levels was shown to substantially reduce beaver dam-
induced floodplain water levels. By changing the behaviour of artificially incised

streams from draining floodplains to partially irrigating them, beaver dams could
help to restore wetlands well beyond beaver ponds themselves.}
}