Drainage Catchment Research Articles

Continental Scale Regional Flood Frequency Analysis: Combining Enhanced Datasets and a Bayesian Framework

Flood frequency analysis at large scales, essential for the development of flood risk maps, is hindered by the scarcity of gauge flow data. Suitable methods are thus required to predict flooding in ungauged basins, a notoriously complex problem in hydrology. We develop a Bayesian hierarchical model (BHM) based on the generalized extreme value (GEV) and the generalized Pareto distribution for regional flood frequency analysis at high resolution across a large part of North America. Our model leverages annual maximum flow data from ≈20,000 gauged stations and a dataset of 130 static catchment-specific covariates to predict extreme flows at all catchments over the continent as well as their associated statistical uncertainty. Additionally, a modification is made to the data layer of the BHM to include peaks over threshold flow data when available, which improves the precision of the discharge level estimates. We validated the model using a hold-out approach and found that its predictive power is very good for the GEV distribution location and scale parameters and improvable for the shape parameter, which is notoriously hard to estimate. The resulting discharge return levels yield a satisfying agreement when compared with the available design peak discharge from various government sources. The assessment of the covariates’ contributions to the model is also informative with regard to the most relevant underlying factors influencing flood-inducing peak flows. According to the developed aggregate importance score, the key covariates in our model are temperature-related bioindicators, the catchment drainage area and the geographical location.

Redesign Drainage Channel in Jetis District Mojokerto Regency

There are up to 50-centimeter-high puddles on the road due to the Jetis Road Drainage Channel in Mojokerto Regency's incapacity to handle the flood discharge from the drainage catchment area. The Jetis Road drainage channel's size and channel bed slope will be affected by the meeting point of the 1000 m long secondary channel and the Jetis Road drainage outlet. The objective of this research is to evaluate the efficiency of drainage channel design considering the implications of the drainage existing condition due to inconsistent dimension and sedimentation. The drainage channel is designed to handle a total discharge of 4.6 m3/sec during 10 years return of period. Under these circumstances, a trapezoidal channel with a width of one meter and a depth of two meters is needed. The Jetis Road drainage channel's enlarged dimensions result in a flood water level of 1.8. The Jetis Road drainage channel has a freeboard of 0.2 meters since the flood water level that occurs in the channel with its new dimensions is 1.8 meters. The flow rate in the intended channel serves as the control in this study to determine channel size. The channel's maximum flow velocity of 1.44 m/sec satisfies the 1.5 m/sec maximum flow velocity allowed in concrete channels.

Drainage reorganization and alluvial architecture of endorheic basins: The Lower Cretaceous record of the Chubut Group in the Golfo San Jorge Basin (Patagonia, Argentina)

The size, shape, and organization of depositional systems in endorheic basins are controlled by the tectonic and climatic history of the sedimentary basin and its boundaries. We evaluate the changes in the alluvial architecture of the Matasiete (Aptian) and Castillo (Albian) formations of the Chubut Group (Cretaceous) in the endorheic Golfo San Jorge Basin (Patagonia, Argentina) analyzing a ∼150 km transect along the San Bernardo Fold Belt, subsurface data, and coeval fluvial successions of the Los Adobes Formation in the nearby Cañadón Asfalto Basin. The Aptian Matasiete Formation represents an externally-sourced, high-accommodation fluvial system with its headwaters in the current Cañadón Asfalto Basin, flowing toward the alkaline lake of the Pozo D-129 Formation through N–S oriented sedimentary corridors of tectonic origin. Low sinuosity, fixed channels with ribbon geometries (mean thickness 7.3 m, W/T ratio 14) are encased in red-colored floodplain fines, whereas stratigraphic intervals rich in resedimented tuffs contain braided rivers with W/T ratio up to 90. Deposition of the overlying Albian Castillo Formation occurred in a W-E elongated basin disconnected from the Cañadón Asfalto Basin, comprising aggradational, volcaniclastic floodplain deposits and smaller-scale fluvial channels of narrow-sheet geometries (mean thickness ∼ 3m, mean W/T ratio 45). The Castillo Formation shows spatial variation in fluvial styles and channel sizes, with intermittent to ephemeral rivers of small scale near the headwaters and seasonal, perennial rivers in downstream positions. Alluvial architecture changes between the Matasiete and Castillo formations reflect changes in the configuration of the basin boundaries, subsequent re-organization of the channel networks, and variable supply of volcaniclastic particles to drainage catchments of different hierarchy that evolved in areas with large variation of the preserved thickness. Comparable geomorphic scenarios in the Okavango Macrobasin show multiple base levels (lacustrine, ephemeral pans), several drainage catchments of variable orientation, scale, and behavior (perennial, intermittent to ephemeral), and exotic rivers adjacent to minor-scale courses.

Tectono‐sedimentary evolution of high‐displacement crustal‐scale normal faults and basement highs on rifted margins: Klakk Fault Complex and Frøya High, Mid‐Norwegian Margin

AbstractCrustal‐scale high‐displacement (>10 km) normal faults are not captured in existing tectono‐sedimentary models of rift basins. We used 2D and 3D seismic reflection and well data to perform a structural and source‐to‐sink analysis of the southern part of the Klakk Fault Complex and the western part of the Vingleia Fault Complex, Mid‐Norwegian rifted margin. The north–south trending Klakk Fault Complex has a zig‐zag to sinuous plan‐view geometry, forming a series of structural recesses and salients along strike. In cross‐section, the fault complex has a listric to convex‐up or low‐angle planar geometry with displacements above 20 km. This fault complex exhumed basement highs, the Frøya High and Sklinna Ridge, in its footwall and created a series of supradetachment basins, for example, the Rås Basin, in its hanging wall. In contrast, the northeast‐southwest trending Vingleia Fault Complex has a zig‐zag geometry in plan view and planar to listric geometry in cross‐section and displacement of up to 5 km. This fault has the Frøya High in its footwall and the southern Halten Terrace in its hanging wall. Restoration of selected structural cross‐sections shows a prominent fault‐parallel ridge, up to 15 km east of the Klakk Fault Complex interpreted as a palaeodrainage divide. This divide separates steep drainages developed along the west‐dipping footwall scarp to the Klakk Fault Complex, from broader, gentler east‐dipping drainages up to ca. 10 km long developed on a back‐tilted dip slopes along the eastern side of the Frøya High and Sklinna Ridge. Progressive headward erosion of active flank catchments was enhanced around topographically elevated structural salients to the point of capturing previous dip‐slope‐directed drainages during the earliest Cretaceous. A network of submarine canyons develop down‐dip of the drainage catchments along the Klakk Fault Complex scarp, whose geometries and length are controlled by their location with respect to the structural salients or recesses, and the presence of fault terraces. The middle Jurassic‐earliest Cretaceous synrift deposits form two seismic sequences that are filled with five distinctive seismic facies that record the evolution from a linked normal fault during rift climax to a high‐displacement stage. During the high displacement stage, exhumed local continental core complexes formed structural salients, separated along strike by structural recesses at the heads of supradetachment basins. Key elements of the high‐displacement fault stage include (i) the development of structural salients at sites of rift climax displacement maxima, (ii) development of supradetachment basins in rift climax displacement minima and (iii) migration of major depocentres away from the centre of rift climax fault segments. We synthesise these observations into a generic tectono‐sedimentary model for high‐displacement faults.

Stream sediment geochemical anomaly mapping based on the dynamic enhanced weighted drainage catchment basin method for mineral exploration

Accurately determining the presence of subterranean deposits is challenging due to the intricate geological processes that give rise to these deposits. The use of stream sediment geochemical data to identify and map geochemical anomalies is a widely employed technique in mineral exploration and offers a robust indicator of the possible presence of mineral deposits. This research presents a comparison between the weighted drainage catchment basin (WDCB) technique and its improved version, the dynamic enhanced weighted drainage catchment basin (DE-WDCB) approach, in the context of mineral exploration. We constructed a model of the catchment basin for the study area, clarified the upstream and downstream relationships between the basins, determined the background value in each basin via the trend surface method, and carried out geochemical anomaly mapping based on the DE-WDCB method. Then we conducted two comparative experiments using the WDCB method, employing both dynamic and nondynamic classification methods for anomaly classification. Finally, we compared the mineralization of the three methods and find that the DE-WDCB method exhibited superior performance in identifying sedimentary manganese ore anomalies, followed by the dynamic grading WDCB method and the nondynamic grading WDCB method. These results indicated that the DE-WDCB method revealed excellent performance when applied to stream sediment geochemistry in prospecting, hence enhancing its utility in mineral resource exploration.

A web-based urban hydrology model for municipal scale applications

Extensive data and computational requirements limit the application of existing urban hydrology models at municipal scales. Community-enabled Lifecycle Analysis of Stormwater Infrastructure Costs (CLASIC) is a web-based deployment of the SWMM model with decoupled hydrologic and hydraulic components to enable hydrologic assessment at the municipal and larger scales. This study comprehensively evaluates the performance validity of CLASIC for characterization of hydrologic responses against SWMM and observed data. Furthermore, global sensitivity analysis is used to explore the significance of hydrologic and hydraulic model parameters across spatial and temporal scales. CLASIC reliably represents the urban hydrological processes and accurately quantifies stream discharge at the municipal scale and temporal scales greater than the catchment's time of concentration. Notably, the computational requirements of CLASIC are substantially lower than those of SWMM as the catchment drainage area increases. The application of CLASIC for flood assessment may be conducted with careful examination of the estimated peak discharge at sub-daily timescales.

Catchment Properties Shape Seasonal Variation in Groundwater‐Surface Water Interaction—Geogenic Silica as a Proxy for Hydrological Turnover Induced Mixing

AbstractThe cumulative and bidirectional groundwater‐surface water (GW‐SW) interaction along a stream is defined as hydrological turnover (HT) influencing solute transport and source water composition. However, HT proves to be highly variable, producing spatial exchange patterns influenced by local groundwater, geology, and topography. Hence, identifying factors controlling HT poses a challenge. We studied spatiotemporal HT variability at two reaches of a third order tributary of the river Mosel, Germany. Additionally, we sampled for silica concentrations in the stream and in the near‐stream groundwater. Thus, creating snapshots of the boundary layer between ground‐ and surface water where HT occurs, driven by mixing processes in the hyporheic zone. We utilize an enhanced hydrograph separation method, unveiling reach differences in storage drainage based on aquifer dimension and connectivity. The data shows a site‐specific negative correlation of HT with discharge, while hydraulic gradients correlate with HT only at the reach with faster catchment drainage behavior. Examining silica concentrations between stream and wells shows that silica variation increases significantly with the decrease of HT under low flow conditions at the slower draining reach. At the fast draining reach this relationship is seasonal. In Summary, our results show that stream discharge shapes the influence of HT on solute transport. Yet, reach drainage behavior shapes seasonal states of groundwater storages and can be an additional control of HT. Hence, concentration change of pollutants could be masked by HT. Thus, our findings contribute to the understanding of HT variability along streams and its ability of influencing physico‐chemical stream water composition.

GIS-based spatial approaches to refining urban catchment delineation that integrate stormwater network infrastructure

Rapid urbanization and escalating climate change impacts have heightened stormwater-related concerns (e.g., pluvial flooding) in cities. Understanding catchment dynamics and characteristics, including precise catchment mapping, is essential to accurate surface water monitoring and management. Traditionally, topography is the primary data set used to model surface water flow dynamics in undisturbed natural landscapes. However, urban systems also contain stormwater drainage infrastructure, which can alter catchment boundaries and runoff behavior. Acknowledging both natural and built environmental influences, this study introduces three GIS-based approaches to enhance urban catchment mapping: (1) Modifying DEM elevations at inlet locations; (2) Adjusting DEM elevations along pipeline paths; (3) Applying the QGRASS plug-in to systematically incorporate infrastructure data. Our evaluation using the geographical Friedman test (p > 0.05) and Dice Similarity Coefficient (DSC = 0.80) confirms the statistical and spatial consistency among the studying methods. Coupled with onsite flow direction validation, these results support the feasibility and reliability of integrating elements of nature and built infrastructure in urban catchment mapping. The refined mapping approaches explored in this study offer improved and more accurate and efficient urban drainage catchment zoning, beyond using elevation and topographic data alone. Likewise, these methods bolster predictive stormwater management at catchment scales, ultimately strengthening urban stormwater and flooding resilience.

A decentralized multi-agent framework for urban flood management

The management of water resources in urban environments is challenging due to the existence of numerous stakeholders and the large number of affected people. In this paper, agents in an urban environment are categorized as active, passive, and monitoring agents, and a new mechanism is proposed to determine the flood control motivation functions (FCMFs) of active agents. An FCMF shows the motivation of an agent for investing and participating in a flood control activity. Also, for the first time, the effectiveness of a conflict resolution model based on asynchronous distributed constraint optimization (ADOPT) is evaluated for urban flood management. To evaluate the effectiveness of the proposed framework, it is applied to the eastern drainage catchment of Tehran, the capital city of Iran. The FCMFs of active stakeholders are modeled using some mathematical functions. To determine the FCMFs of active agents, an economic optimum point is suggested. This point is determined based on the construction costs of flood control infrastructures and flood damage costs. The utility functions of passive agents are modeled using a regression analysis. Flood management scenarios include a combination of water transfer canals, pipes, and ponds with real-time operating methods. ADOPT is used for solving Distributed Constraint Optimization Problems (DCOPs). The goal in DCOPs is to assign values to these variables in an approach that maximizes a global objective function while satisfying the constraints of each agent. The results show that by using the ADOPT-based conflict resolution model, the average depth of flooding is reduced from 24 cm to about 10 cm, and this is associated with the satisfaction of more than 90 percent of stakeholders. A decline in Average Flood Depth (AFD) has been observed with increased usage of technological methods such as constructing ponds or transferring water outside the basin. However, stakeholder desirability is critical and both technical and stakeholder interests should be taken into account to ensure project viability.

Degradation and protection of cut slopes in weathered gneiss; a 40 year case study

The retreat of two roadside cut slopes in weathered gneiss in the Middle Himalaya of east Nepal has been assessed by engineering geological mapping, sequential photography and slope profiling over a 40 year period, from 1979 to 2018, allowing approximate degradation rates to be calculated. The rate of removal of completely weathered gneiss and residual soil was about twice that of highly weathered material, primarily reflecting increased micro-cracking and breakdown of feldspars and micas in the weathered fabric. Surface water erosion by rilling and gullying in the summer monsoon wet season was the dominant process affecting the slopes, with landsliding (mainly by soil falls and debris slides) playing a secondary role. Drainage and bio-engineering protection measures applied to the slopes within the first 3–12 years after excavation were effective in reducing the degradation rate by between one and two orders of magnitude once the slopes had developed a moderate vegetation cover. The total volume of material removed from the slopes over four decades is equivalent to average rates of ground lowering in the range of 150–320 and 2–4 mm a −1 before and after protection works, respectively. The latter range is similar to long-term denudation rates measured in drainage catchments in the region with similar settings. Supplementary material: One figure in three parts showing slope retreat over time for a complete set of 28 measured cross-sections and two tables giving details of calculated cross-sectional area losses and approximate intersectional volumetric losses of slope material are available at https://doi.org/10.6084/m9.figshare.c.7005885

The Assessment on the Flood Mitigation Strategies of the Local Government Unit of Santo Tomas, Davao del Norte: A Basis for Policy Formulation

This study evaluates flood mitigation strategies implemented by the LGU of Santo Tomas, Davao del Norte, focusing on indicators such as Rehabilitation of River Banks, Bridges, Dredging, and Reforestation. Through random sampling in selected barangays, 377 respondents provided feedback, indicating Very High Descriptive Equivalents for all strategies. However, the detailed analysis identifies the Rehabilitation of River Banks as an area for improvement (mean score: 4.19), emphasizing the need for enhanced catchment drainage, floodwater capacity, and sediment yield reduction. Recommendations include regular maintenance of drainage channels, river widening, and the establishment of riparian buffer zones. Future research should explore flood-prone residents’ perceptions of LGU strategies. A proposed policy on River Bank Rehabilitation emphasizes an ecosystem-based, participatory approach to enhance resilience, increase public awareness, and promote sustainable development. Strategies encompass riparian vegetation restoration, bank stabilization, invasive species control, water quality improvement, floodplain management, and public education. Implementation rests with the LGU of Sto. Tomas and stakeholders, with ongoing monitoring and evaluation to ensure effectiveness and facilitate adjustments. This study provides valuable insights and a practical policy framework to enhance flood mitigation, specifically focusing on river bank rehabilitation in LGU-Santo Tomas, Davao del Norte.

Can local drain flow measurements be utilized to improve catchment scale modelling?

Tile drains constitute a shortcut from agricultural fields to surface water systems, significantly altering the transport pathways and fate of nitrate during transport. A correct representation of tile drainage flow is thus crucial for estimating nitrate load at the catchment scale and to identify optimal locations for N-mitigation measures. Drainage is a local process, controlled by local properties and drain configurations, which are rarely known for individual fields, making drainage flow and transport a challenging task in catchment scale models. This study tests the potential for improving drainage flow dynamics at catchment scale, by utilising local drainage flow measurements in a spatial calibration scheme. A distributed hydrological model, MIKE SHE, for the agricultural-dominated Norsminde catchment (145 km2) in Denmark, was calibrated using spatially distributed surrogate parameters (pilot points) to represent heterogeneity in the soil (top 3 m) and the deeper geology below 3 m. The model was calibrated using hydraulic heads, stream discharge, and measured drainage flow from eight drain catchments. Drain measurements were very important in guiding the calibration of top 3 m and subsurface pilot points located in the drainage fields, showing that drain flow hold information on both local (shallow) and regional (deeper) flow patterns. Contrarily, pilot points located outside the drained fields were mainly sensitive to the hydraulic head measurements and the summer water balance of the stream discharge on a catchment scale. Consequently, incorporation of the drain data improved local performance, but did not improve the parameterization and drain description of the entire catchment. Exploitation of the drain flow information is thus difficult beyond the drain catchments, and other approaches are needed to extrapolate and exploit the local data.

A framework for real-time operation of urban detention reservoirs: Application of the cellular automata and rainfall nowcasting

Detention reservoirs are employed in urban drainage systems to reduce peak flows downstream of reservoirs. In addition to the volume of detention reservoirs, their operational policies could significantly affect their performance. This paper presents a framework for the real-time coordinated operation of detention reservoirs using deep-learning-based rainfall nowcasting data. Considering the short concentration time of urban basins, the real-time operating policies of urban detention reservoirs should be developed quickly. In the proposed framework, a cellular automata (CA)-based optimization algorithm is linked with the storm water management model (SWMM) to optimize real-time operating policies of gates at the inlets and outlets of detention reservoirs. As CA-based optimization models are not population-based, their computational costs are much less than population-based metaheuristic optimization techniques such as genetic algorithms. To evaluate the applicability and efficiency of the framework, it is applied to the east drainage catchment (EDC) of Tehran metropolitan area in Iran. The results illustrate that the proposed framework could reduce the overflow volume by up to 60%. For complete flood control in the study area, in addition to the real-time operation of detention reservoirs, constructing five tunnels with a total length of 13200 m is recommended. To evaluate the performance of the CA-based optimization model, its results are compared with those obtained from the non-dominated sorting genetic algorithm III (NSGA-III). It is shown that the CA-based model provides similar results with only 5% of the run-time of NSGA-III. A sensitivity analysis is also performed to evaluate the effects of optimization models’ parameters on their performance.

Estuarine Hypoxia—Identifying High Risk Catchments Now and Under Future Climate Scenarios

AbstractHypoxic blackwater events occur worldwide, affecting inland and coastal waters. These events have been exacerbated by man‐made floodplain drainage, leading to large‐scale fish kills and ecological degradation. This paper presents a new method to identify estuarine catchment areas that are most likely to generate hypoxic conditions. The method uses established risk factors, including vegetation type, inundation extent and duration, ground‐truthed in eastern Australia. A catchment is at higher risk of hypoxic blackwater generation if (a) it is located where floodwaters are high and/or drainage is impeded, (b) the site topography includes an extensive, low‐lying floodplain; and/or (c) the land‐use and environmental characteristics have a high deoxygenation potential. Consequent impacts to an estuary are determined by the floodplain connectivity with the estuary, and the discharge characteristics of the catchment drainage system. Where multiple, proximate catchments have similar drainage conditions, compounding plumes of hypoxic blackwater can overwhelm the assimilation capacity of the estuary. Climate change may significantly increase the volume and frequency of blackwater events in estuarine environments as a result of reduced drainage due to sea level rise, higher temperatures, and more intense and sporadic rainfall events. It is recommended that management measures be introduced to mitigate the effects of climate change and avoid further widespread hypoxic blackwater events.

Characterising the regional growth of on-farm storages and their implications for water resources under a changing climate

Water demand for agricultural activities has caused a growth in small on-farm storages (i.e., ≥ 0.1 ha to ≤ 10 ha) in many areas worldwide, thereby increasing the capture of landscape runoff which otherwise would enter the catchment drainage system. The cumulative effects of these on-farm storages (colloquially known as farm ponds or farm dams) can result in reduced mean annual flows, particularly during dry years. Climate change, which will very likely exacerbate extreme weather conditions including droughts, may accelerate the growth of farm dams in semi-arid agricultural areas with limited access to surface water. The aim of this study is to evaluate farm dam development and total farm dam water volumes at regional scales using Landsat water indices (WIs). The Murray-Darling Basin (MDB, 1.061 million km2) in south and eastern Australia, which has experienced a sustained growth in farm dams in the 1990s and early 2000s, is used as a case study. Using a pixel validation dataset, four WIs were trialled for their capabilities to detect the presence of water in farm dams. Of the WIs tested here, AWEIshadow showed the best performance. As a result, AWEIshadow was used to establish the year in which water was first observed (i.e., its year of commission) in 727,081 farm dams across the MDB and to calculate the total farm dam volume in the region. Farm dams’ volume in the MDB increased more than twofold between 1990 and 2020, from 1241.0 MCM (million cubic meters) to 2,629.5 MCM. The growth differed across MDB regions, generally accelerating during the ‘Millennium Drought’ (2001–2009). In the entire MDB, there was rapid development in the 1990s with 3.1% growth. Growth was 2.5% from 2000 to 2010, tapering off to 0.6% from 2010 to 2020.In Robertson et al. (this issue), the year-by-year growth in farm dams’ volume were used in a rainfall-runoff model thereby incorporating the time-varying effects of farm dams. Robertson et al. (this issue) show that explicitly modelling farm dams improves the model’s performance relative to a traditional rainfall-runoff model that ignores the effects of farm dams. Hence, this improves the capability of assessing the direct impacts of farm dams and their potential growth in climate change studies.

EUSEDcollab: a network of data from European catchments to monitor net soil erosion by water

As a network of researchers we release an open-access database (EUSEDcollab) of water discharge and suspended sediment yield time series records collected in small to medium sized catchments in Europe. EUSEDcollab is compiled to overcome the scarcity of open-access data at relevant spatial scales for studies on runoff, soil loss by water erosion and sediment delivery. Multi-source measurement data from numerous researchers and institutions were harmonised into a common time series and metadata structure. Data reuse is facilitated through accompanying metadata descriptors providing background technical information for each monitoring station setup. Across ten European countries, EUSEDcollab covers over 1600 catchment years of data from 245 catchments at event (11 catchments), daily (22 catchments) and monthly (212 catchments) temporal resolution, and is unique in its focus on small to medium catchment drainage areas (median = 43 km2, min = 0.04 km2, max = 817 km2) with applicability for soil erosion research. We release this database with the aim of uniting people, knowledge and data through the European Union Soil Observatory (EUSO).

Site-specific spatiotemporal occurrence and molecular congener distributions of naphthenic acids in Athabasca oil sands wetlands of Alberta, Canada

The Athabasca oil sands region (AOSR) of Alberta, Canada is notable for its considerable unconventional petroleum extraction projects, where bitumen is extracted from naturally-occurring oil sands ore. The large scale of these heavy crude oil developments raises concerns because of their potential to distribute and/or otherwise influence the occurrence, behaviour, and fate of environmental contaminants. Naphthenic acids (NAs) are one such contaminant class of concern in the AOSR, so studies have examined the occurrence and molecular profiles of NAs in the region. We catalogued the spatiotemporal occurrence and characteristics of NAs in boreal wetlands in the AOSR over a 7-year period, using derivatized liquid chromatography-tandem mass spectrometry (LC-MS/MS). Comparing median concentrations of NAs across these wetlands revealed a pattern of NAs suggesting NAs in surface waters derived from oil sands deposits. Opportunistic wetlands that formed adjacent to reclaimed overburden and other reclamation activities had the highest concentrations of NAs and consistent patterns suggestive of bitumen-derived inputs. However, similar patterns in the occurrence of NAs were also observed in undeveloped natural wetlands located above the known surface-mineable oil sands deposit that underlies the region. Intra-annual sampling results along with inter-annual comparisons across wetlands demonstrated that differences in the spatial and temporal NA concentrations were dependent on local factors, particularly when naturally occurring oil sands ores were observed in the wetland or drainage catchment.

The Impact of Blue‐Green Infrastructure and Urban Area Densification on the Performance of Real‐Time Control of Sewer Networks

AbstractUrban areas are constantly developing and thereby affect the local water cycle. Real‐time control (RTC) strategies are used to operate urban drainage systems optimally during these transitions. This paper aims to develop a methodology to study the impacts of common gradual changes occurring in the urban environment (densification of the urban area and implementation of blue‐green infrastructure), forming cumulative transitions, on the functioning of real‐time optimization procedures. A new generic methodology, relying on a comprehensive evaluation strategy based on three indicators assessing the continued optimal performance of RTC was proposed. This methodology was applied to two urban drainage catchments in Eindhoven and Rotterdam using both probabilistic and projected transitional paths. Based on the results obtained it can be noted that the performances of the RTC procedures were not strongly affected by the modeled transitions although the relative performance compared to the maximum performance potential decreases significantly with the large‐scale implementation of blue‐green infrastructure, indicating that the revision of RTC procedures could improve the sewer system functioning further. The relative performance loss associated with the modeled transitions was higher for model predictive control compared to heuristic RTC procedures for one case study and vice versa for the other. Continuous re‐evaluation of the RTC strategy is, therefore, an important but overlooked part of the implementation of RTC procedures.

Remotely Sensed Data, Morpho-Metric Analysis, and Integrated Method Approach for Flood Risk Assessment: Case Study of Wadi Al-Arish Landscape, Sinai, Egypt

Evaluating and predicting the occurrence and spatial remarks of climate and rainfall-related destructive hazards is a big challenge. Periodically, Sinai Peninsula is suffering from natural risks that enthuse researchers to provide the area more attention and scientific investigation. Extracted information from the morpho-metric indices aids in understanding the flood potentiality over various sizes of drainage catchments. In this work, the morpho-metric analysis has been used in order to model the relative signals of flood vulnerability of 16 catchments in northern Sinai. The geospatial technique has been applied to process the digital elevation models (DEMs) in order to produce different analysis maps. Basic geometries, in addition to several morpho-metric indices, were extracted and analyzed by investigating the digital elevation models. Three different effective methods were applied separately to build up three models of flood susceptibility behaviors. Finally, two flood susceptibility signals were defined: the integration method and accurate pixel level conditions models. The integrated method analysis indicates that the western half of the study landscape, including catchments (12, 13, and 14), presents high levels of flood susceptibility in addition to catchment 9 in the eastern half, whereas the other catchments were found to provide moderate levels. The integrated flood susceptibility final map overlaid one of the most effective topographic indices (topographic position index, TPI). The integrated results aided in understanding the link of the general catchments morphometry to the in situ topography for mapping the different flood susceptibility locations over the entire study landscape. Therefore, this can be used for investigating the surface-specific reduction strategy against the impacts of flood hazards in the proposed landscape.

The shape-shifting form of UK floodplains: Fusing analysis of the territorially constructed with analysis of natural terrain processes

Physically, river floodplains have both the subdued morphology of natural terrain created as extreme discharges and sediments pass through catchment drainage systems and, to an increasing extent, the forms that arise from purposeful human constructions. Together, these direct out-of-channel inundation. As defined here, ‘territories’ and their humanly constructed physical forms have historically consumed or modified naturally created ‘terrains’ in a collection of actions that we summarize as ‘morphophagia’. A more inclusive physical geography is presented, adding-in explanations for the evolutionary phasing of humanly-generated, but environmentally functioning, physical forms in the UK in the Modern Era (since c.1500 CE). Floodplain developments here took place in five main episodes of historically-contingent accumulation: the Early Modern (c.1500–1780 CE) started with a framework of purposeful owned land, and then followed periods that can be related to Kondratieff global economic phases (c.1790–1840,1840–1900,1900–1947,1947–2000 CE). Three different groups of forcings operated: (1) the compartmentalizing and patched infill patterns set by territorial units, rights and developer ownerships; (2) the availability, motivations and timings for capital and labour investment; and (3) the evolving technical possibilities exploited by entrepreneurs and agents. Epistemic frameworks for broadening the analysis of coupled terrain and territory systems, exploring actuating social forces as much as their symptomatic physical outcomes, are discussed. Globally, there have been different forcings, timings and emplacement layouts operating at scales from local river reaches to city expansion and economic regions. As perceptions of environmental stasis now disintegrate, enthusiasm for reinvigorating economic growth, with further population increase and sprawling construction may, as in the past, discount the hazards of floodplain occupation. When and why risky anthropo-physical floodplain emplacements occur needs greater systematic understanding as social and economic initiatives are being considered.