Hannah Runeckles

Channel realignment and floodplain reconnection are increasingly used as nature-based solutions for flood management, yet their hydraulic effects remain poorly quantified in field settings. This study examines the impact of such interventions on hydraulic response in a headwater catchment, Goldrill Beck, Cumbria, UK. Here, 1-km of a historically engineered and confined single-thread channel was restored to a more geomorphically complex system. Using a combination of hydrological observational data spanning pre- and post-realignment conditions and two-dimensional hydraulic modeling (LISFLOOD-FP), changes in key hydraulic metrics (flood wave transmission and celerity, reach-scale hysteresis, and peak flow attenuation) were assessed. Results indicate that realignment increased flood wave travel time (median transmission time increased from 15 to 40 min), reduced flow celerity, and altered hysteresis patterns, suggesting enhanced in-channel and floodplain storage under low to intermediate flow conditions. Realignment also improved the diversity of flow biotopes and aquatic habitats, whilst increasing the wetted area by 47%. However, during more extreme events, transmission times decreased, and peak discharge was slightly elevated, highlighting limitations in attenuation potential for large floods. The findings contribute to the evidence base for renaturalisation of watercourses for flood mitigation, emphasizing the role of valley morphometry, channel morphology, and floodplain roughness in influencing hydraulic responses.

River sand and gravel are mined worldwide at volumes that now rival their natural replenishment, yet quantitative knowledge of this mining activity and its consequences lags far behind many other global environmental pressures. We synthesize 411 peer‐reviewed studies published since 1974 within a new Driver‐to‐Management Pathway for Sustainable Sand and Gravel Mining framework that links socio‐economic demand, spatial‐temporal extent of extraction, hydrogeomorphic change, socio‐ecological disruption, and management response. Evidence shows a pronounced scale mismatch: regional‐to‐global drivers fuel largely unreported local extraction, while impacts propagate well beyond mining sites. In most documented cases, annual removal exceeds bed‐material supply several‐fold, producing channel incision, bank collapse, declining groundwater tables, deteriorating water quality, and inland migration of saline water in coastal areas. These physical changes cascade into habitat loss, infrastructure damage, and livelihood insecurity, especially across rapidly developing regions of Asia and Africa. Despite the proliferation of impact studies (69% of the literature), research is dominated by hydrogeomorphic perspectives, with ecological and socio‐economic impacts far more often treated as secondary or co‐occurring components rather than primary foci; meanwhile, only 27% of studies quantify extraction extent and 24% analyze demand drivers, hampering the design of effective interventions. Together, these findings highlight the need for basin‐scale monitoring, cross‐boundary governance, and demand‐side interventions that explicitly link extraction limits to sediment budgets.

Channel realignment and floodplain reconnection are increasingly used as nature‐based solutions for flood management, yet their hydraulic effects remain poorly quantified in field settings of moderate‐gradient, small order channels. This study examines the impact of such interventions on hydraulic response in a headwater catchment, Goldrill Beck, Cumbria, UK. Here, 1‐km of a historically engineered and confined single‐thread channel was restored to a more geomorphically complex configuration. Using a combination of hydrological observational data spanning pre‐ and post‐realignment conditions and two‐dimensional hydraulic modeling (LISFLOOD‐FP), changes in key hydraulic metrics (flood wave transmission and celerity, reach‐scale hysteresis, and peak flow attenuation) were assessed. Results indicate that realignment increased flood wave travel time (median transmission time increased from 15 to 40 min), reduced flow celerity, and altered hysteresis patterns, suggesting enhanced in‐channel and floodplain storage under low to intermediate flow conditions. Realignment also improved the diversity of hydraulic biotopes and aquatic habitats, whilst increasing the wetted area by 47%. However, during more extreme events, transmission times decreased, and peak discharge was slightly elevated, highlighting limitations in attenuation potential for large floods. The findings contribute to the evidence base for renaturalization of watercourses for flood mitigation and habitat enhancement, emphasizing the role of valley morphometry, channel morphology, and floodplain roughness in influencing hydraulic responses.

Recent years have witnessed growing calls for more emphasis on justice in climate change education (CCE). Sund and Öhman (2025, 2) describe this as ‘the most significant development over the last d...