Published: July 24, 2024
Abstract. Flow regimes are increasingly impacted by more extreme natural hazards of droughts and floods as a result climate change, compounded anthropogenic influences in both urban intensively managed rural catchments. However, the characteristics sustainable flow that needed to maintain or restore hydrologic, biogeochemical ecological function under rapid global change remain unclear contested. We conducted an inter-comparison two streams Berlin-Brandenburg region NE Germany, which mesoscale sub-catchments River Spree; intermittent agricultural stream (the Demnitzer Millcreek) heavily anthropogenically Panke). Through tracer-based analyses using stable water isotopes, we identified dominant physical processes (runoff sources, flowpaths age characteristics) sustaining streamflow over multiple years (2018–2023), including three major drought (2018–20, 2021–22). In stream, low flows regulated through artificially increased baseflow from treated waste effluent (by up 80 %), whilst storm drainage drives rapid, transient high runoff responses (up %) intense convective summer rainfall. The groundwater-dominated experienced extended no-flow periods during (⁓ 60 % year), only moderate coefficients (<10 winter along near-surface paths after heavy streams, groundwater dominance with young influence prevails, ages despite significant runoff, higher ones (⁓15 %). Urban cover resulted mean transit time ⁓4 compared arable land ⁓3 years, highlighting interlinkages landuse catchment properties on times. Understanding seasonal interannual variability generation hydrological template, has potential for assessing impacts sustainability future management, wider quality implications across environments.
Language: Английский