Chemical effects of a near-to-nature detention pond on a small urban headwater     

《Limnologica》2017

The near-to-nature approach has been established as best practice for stormwater management. However, pollutant mobility within such systems and its impact on small receiving waters are partly unexplained. The study takes place in an urbanised headwater catchment in south-western Germany with an area of 0.4 km². Runoff from roofs, roads, parking lots and gardens is collected in wells or trenches and stored in private and public dry detention basins. Accordingly, this study investigates pollutant input to a detention pond, removal efficiency and the associated effects on the receiving water.Grab samples with high temporal resolution of the receiving water (16 flood events with 315 samples and 41 baseflow samples), the three inflows of the detention basin and its outflow (four flood events with 64 samples) were taken. The outflow of the dry pond is recovered in the hydro- and chemographs of the receiving water. Runoff from roads with increased traffic volume caused the highest PAH inputs and runoff from the residential area showed the highest zinc concentrations, which partly infringe European Environmental Quality Standards. Yearly pollutant inputs (DOC, TSS, PAH, nutrients, metals) from the settlement into the tributary are reduced in the detention pond by up to 80%.  相似文献   

Metrics to assess how longitudinal channel network connectivity and in‐stream Atlantic salmon habitats are impacted by hydropower regulation          下载免费PDF全文

Willem B. Buddendorf  Iain A. Malcolm  Josie Geris  Mark E. Wilkinson  Chris Soulsby 《水文研究》2017,31(12):2132-2142

Habitat fragmentation in channel networks and riverine ecosystems is increasing globally due to the construction of barriers and river regulation. The resulting divergence from the natural state poses a threat to ecosystem integrity. Consequently, a trade‐off is required between the conservation of biodiversity in channel networks and socio‐economic factors including power generation, potable water supplies, fisheries, and tourism. Many of Scotland's rivers are regulated for hydropower generation but also support populations of Atlantic salmon (Salmo salar L.) that have high economic and conservation value. This paper investigates the use of connectivity metrics and weightings to assess the impact of river barriers (impoundments) associated with hydropower regulation on natural longitudinal channel connectivity for Atlantic salmon. We applied 2 different weighting approaches in the connectivity models that accounted for spatial variability in habitat quality for spawning and fry production and contrasted these models with a more traditional approach using wetted area. Assessments of habitat loss using the habitat quality weighted models contrasted with those using the less biologically relevant wetted area. This highlights the importance of including relevant ecological and hydrogeomorphic information in assessing regulation impacts on natural channel connectivity. Specifically, we highlight scenarios where losing a smaller area of productive habitat can have a larger impact on Atlantic salmon than losing a greater area of less suitable habitat. It is recommended that future channel connectivity assessments should attempt to include biologically relevant weightings, rather than relying on simpler metrics like wetted area which can produce misleading assessments of barrier impacts.  相似文献   

Glacial conditions that contribute to the regeneration of Fountain Glacier proglacial icing,Bylot Island,Canada          下载免费PDF全文

Pablo Wainstein  Brian Moorman  Ken Whitehead 《水文研究》2014,28(5):2749-2760

Proglacial icings are one of the most common forms of extrusive ice found in the Canadian Arctic. However, the icing adjacent to Fountain Glacier, Bylot Island, is unique due to its annual cycle of growth and decay, and perennial existence without involving freezing point depression of water due to chemical characteristics. Its regeneration depends on the availability of subglacial water and on the balance between ice accretion and hydro‐thermal erosion. The storage and conduction of the glacial meltwater involved in the accretion of the icing were analyzed by conducting topographic and ground penetrating radar surveys in addition to the modelling of the subglacial drainage network and the thermal characteristics of the glacier base. The reflection power analysis of the geophysical data shows that some areas of the lower ablation zone have a high accumulation of liquid water, particularly beneath the centre part of the glacier along the main supraglacial stream. A dielectric permittivity model of the glacier – sediment interface suggests that a considerable portion of the glacier is warm based; allowing water to flow through unfrozen subglacial sediments towards the proglacial outwash plain. All these glacier‐related characteristics contribute to the annual regeneration of the proglacial icing and allow for portions of the icing to be perennial. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Macropores as preferential flow paths in meander bends          下载免费PDF全文

Garrett T. Menichino  Adam S. Ward  Erich T. Hester 《水文研究》2014,28(3):482-495

Macropores are subsurface connected void spaces caused by processes such as fracture of soils, micro‐erosion, and fauna burrows. They are common near streams (e.g. hyporheic and riparian zones) and may act as preferential flow paths between surface and groundwaters, affecting hydrologic and biogeochemical processes. We tested the hydrologic function of macropores by constructing an artificial macropore within the saturated zone of a meander bend (open macropore, ‘OM’) and later filling its upstream end (partially filled macropore, ‘PFM’). For each treatment, we injected saline tracer at an upgradient monitoring well within the meander and monitored downgradient hydraulics and tracer transport. Pressure transducers in monitoring wells indicated hydraulic gradients within the meander were 32% higher perpendicular to and 6% higher parallel to the macropore for the OM than for the PFM. Additionally, hydraulic conductivities measured via falling head tests were 29 to 550 times higher along the macropore than in nearby sediment. We used electrical conductivity probes in wells and electrical resistivity imaging to track solute transport. Transport velocities through the meander were on average 9 and 21% higher (per temporal moment analysis and observed tracer peak, respectively) for the OM than for the PFM. Furthermore, temporal moments of tracer breakthrough analysis indicated downgradient longitudinal dispersion and breakthrough tracer curve tailing were on average 234% and 182% higher for the OM, respectively. This suggests the OM enabled solute transport at overall shorter timescales than the matrix but also increased tailing. Our results demonstrate the importance of macropores to meander bend hydrology and solute transport. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Ressi experimental catchment: Ecohydrological research in the Italian pre-Alps     

Giulia Zuecco  Chiara Marchina  Ylenia Gelmini  Anam Amin  H. J. van Meerveld  Daniele Penna  Marco Borga 《水文研究》2021,35(3):e14095

Ressi is a small (2.4 ha) forested catchment located in the Italian pre-Alps. The site became an experimental catchment to investigate the water fluxes in the soil–plant–atmosphere continuum and the impact of vegetation on runoff generation in 2012. The elevation of the catchment ranges from 598 to 721 m a.s.l. and the climate is humid temperate. The bedrock consists of rhyolites and dacites; the soil is a Cambisol. The catchment is covered by a dense forest, dominated by beech, chestnut, maple, and hazel trees. The field set up includes measurements of the rainfall in an open area, streamflow at the outlet, soil moisture at various depths and locations, and depth to water table in six piezometers at a 5- or 10-min interval. Samples of precipitation, stream water, shallow groundwater and soil water are collected monthly for tracer analysis (stable isotopes (²H and ¹⁸O), electrical conductivity and major ions), and during selected rainfall–runoff events to determine the contribution of the various sources to runoff. Since 2017, soil and plant water samples have been collected to determine the sources of tree transpiration. Data collected in the period 2012–2016 are publicly available. Data collection is ongoing, and the data set is expected to be updated on an annual basis to include the most recent measurements.  相似文献   

Distinguishing streamflow trends caused by changes in climate,forest cover,and permafrost in a large watershed in northeastern China          下载免费PDF全文

Liangliang Duan  Xiuling Man  Barret L. Kurylyk  Tijiu Cai  Qiang Li 《水文研究》2017,31(10):1938-1951

Understanding how rivers respond to changes in land cover, climate, and subsurface conditions is critical for sustainably managing water resources and ecosystems. In this study, long‐term hydrologic, climate, and satellite data (1973–2012) from the Upper Tahe River watershed (2359 km²) in the Da Hinggan Mountains of northeast China were analysed to quantify the relative hydrologic effects of climate variability (system input) and the combined influences of forest cover change and permafrost thaw (system characteristics) on average annual streamflow (system response) using 2 methods: the sensitivity‐based method and the Kendall–Theil robust line method. The study period was subdivided into a forest harvesting period (1973–1987), a forest stability period (1988–2001), and a forest recovery period (2002–2012). The results indicated that the combined effects of forest harvesting and permafrost thaw on streamflow (+ 47.0 mm) from the forest harvesting period to the forest stability period was approximately twice as large as the effect associated with climate variability (+20.2 mm). Similarly, from the forest stability period to the forest recovery period, the decrease in average annual streamflow attributed to the combined effects of forest recovery and permafrost thaw (?38.0 mm) was much greater than the decrease due to climate variability (?22.2 mm). A simple method was used to separate the distinct impacts of forest cover change and permafrost thaw, but distinguishing these influences is difficult due to changes in surface and subsurface hydrologic connectivity associated with permafrost thaw. The results highlight the need to consider multiple streamflow drivers in future watershed and aquatic ecosystem management. Due to the ecological and hydrological susceptibility to disturbances in the Da Hinggan Mountains, forest harvesting will likely negatively impact ecohydrological processes in this region, and the effects of forest species transition in the forest recovery process should be further investigated.  相似文献   

Using hysteretic behaviour and hydrograph classification to identify hydrological function across the “hillslope–depression–stream” continuum in a karst catchment     

Runrun Zhang  Xi Chen  Zhicai Zhang  Chris Soulsby 《水文研究》2020,34(16):3464-3480

In cockpit karst landscapes, fluxes from upland areas contribute large volumes of water to low-lying depressions and stream flow. Hydrograph hysteresis and similarity between monitoring sites is important for understanding the space–time variability of hydrologic responses across the “hillslope–depression–stream” continuum. In this study, the hysteretic feature of hydrographs was assessed by characterizing the loop-like relationships between responses at upstream sites relative to subsurface discharge at the outlet of a small karst catchment. A classification of hydrograph responses based on the multi-scale smoothing Kernel -derived distance classifies the hydrograph responses on the basis of similarities between hillslope and depression sites, and those at the catchment outlet. Results demonstrate that the temporal and spatial variability of hydrograph hysteresis and similarity between hillslope flow and outlet stream flow can be explained by the local heterogeneity of depression aquifer. Large depression storage deficits emerging in the highly heterogeneous aquifer produce strong hysteresis and multiple relationships of upstream hydrographs relative to the outlet subsurface discharge. In contrast, when depression storage deficits are filled during consecutive rainfall events, depression hydrographs at the high permeability sites are almost synchronous or exhibit a monotonous function with the hydrographs at the outlet. This reduced hydrograph hysteresis enhances preferential flow paths in fractured rocks and conduits that can accelerate the hillslope flow to the outlet. Therefore, classification of hydrograph similarities between any upstream sites and the catchment outlet can help to identify the dominant hydrological functions in the heterogeneous karst catchment.  相似文献   

Runoff response of a small agricultural basin in the argentine Pampas considering connectivity aspects     

María Guadalupe Ares  Marcelo Varni  Celio Chagas 《水文研究》2020,34(14):3102-3119

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Unraveling complex hydrogeological processes in Andean basins in south‐central Chile: An integrated assessment to understand hydrological dissimilarity          下载免费PDF全文

Enrique Muñoz  José Luis Arumí  Thorsten Wagener  Ricardo Oyarzún  Victor Parra 《水文研究》2016,30(26):4934-4943

Groundwater storage, drainage, and interbasin water exchange are common hydrological processes but often difficult to quantify due to a lack of local observations. We present a study of three volcanic mountainous watersheds located in south‐central Chile (~36.9 ° S) in the Chillán volcanic complex (Chillán, Renegado, and Diguillín river basins). These are neighboring basins that are similar with respect to the metrics normally available for characterization everywhere (e.g., precipitation, temperature, and land cover). In a hydrological sense, similar (proportional) behavior would be expected if these catchments would be characterized with this general information. However, these watersheds show dissimilar behavior when analyzed in detail. The surface water balance does not fit for any of these watersheds individually; however, the water balance of the whole system can be explained by likely interbasin water exchanges. The Renegado river basin has an average annual runoff per unit of area on the order of 60–65% less than those of the Diguillín and Chillán rivers, which is contradictory to the hydrological similarity among the basins. To understand the main processes that control streamflow generation, two analyses were performed: (a) basin metrics (land cover, geologic, topographic, and climatological maps) and hydro‐meteorological data analyses and (b) a water balance model approach. The analyses contribute to a plausible explanation for the hydrogeological processes in the system. The soils, topography, and geology of the Chillán–Renegado–Diguillín system favor the infiltration and groundwater movements from the Renegado river basin, mainly to the neighboring Diguillín basin. The interbasin water exchanges affect hydrological similarity and explain the differences observed in the hydrological processes of these three apparently similar volcanic basins. The results highlight the complexity of hydrological processes in volcanic mountainous systems and suggest that a simple watershed classification approach based on widely available data is insufficient. Simple local analyses such as specific flow analysis with a review of the geology and morphology can contribute to a better understanding of the hydrology of volcanic mountainous areas.  相似文献   

Spatial aggregation of time‐variant stream water ages in urbanizing catchments          下载免费PDF全文

C. Soulsby  C. Birkel  J. Geris  D. Tetzlaff 《水文研究》2015,29(13):3038-3050

We calibrated an integrated flow–tracer model to simulate spatially distributed isotope time series in stream water in a 7.9‐km² catchment with an urban area of 13%. The model used flux tracking to estimate the time‐varying age of stream water at the outlet and both urbanized (1.7 km²) and non‐urban (4.5 km²) sub‐catchments over a 2.5‐year period. This included extended wet and dry spells where precipitation equated to >10‐year return periods. Modelling indicated that stream water draining the most urbanized tributary was youngest with a mean transit time (MTT) of 171 days compared with 456 days in the non‐urban tributary. For the larger catchment, the MTT was 280 days. Here, the response of urban contributing areas dominated smaller and more moderate runoff events, but rural contributions dominated during the wettest periods, giving a bi‐modal distribution of water ages. Whilst the approach needs refining for sub‐daily time steps, it provides a basis for projecting the effects of urbanization on stream water transit times and their spatial aggregation. This offers a novel approach for understanding the cumulative impacts of urbanization on stream water quantity and quality, which can contribute to more sustainable management. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献