River Corridor Research Articles

The evaluation of Small River water pollution caused by tailing spill in the Northeast of China using high-resolution images

The global mining sector generates billions of tons of tailings stored in thousands of tailing ponds. The occasional spills of tailings resulting from dam failures or pipe damage can have devastating consequences, threatening nearby human populations and ecosystems, particularly those located along river corridors. Satellite remote sensing technology is a vital supplementary method to traditional field methods for monitoring and evaluating the water pollution caused by spilled tailings. The researchers have developed workflows to evaluate the effect of tailing spills on water quality using low and medium-spatial satellite imagery from satellite sensors. Due to insufficient spatial resolution, these workflows were hard to apply to monitor the water pollution caused by spilled tailing in small rivers. Using valuable on-site data from a river water pollution incident caused by spilled tailing, a workflow utilizing high-resolution satellite imagery (GF1) was developed. This workflow incorporates a machine learning algorithm (improved DeepLabV3+) to extract water masks first and a novel spectral index method to determine TSM concentrations. The improved DeepLabV3+ algorithm can obtain an accurate water mask no matter the water pixels, whether influenced by the tailing spills from GF1 imagery with IoU of 82.66%, Precision of 93.21%, Recall of 87.96%, and F1-score of 90.51%. A new spectral index combination algorithm that provides reliable TSM products for an extensive TSM magnitude range was presented to assess the level of water contamination. The strong correlation (R2 = 0.97) between in situ TSM and Mo concentrations suggests that the retrieved TSM products are suitable for assessing the water pollution caused by the spilled tailing. This workflow provides a method for monitoring and evaluating water pollution resulting from spilled tailings in small rivers. It utilizes high-resolution satellite data to observe and analyze the pollution levels.

Resilience in River Corridors: How Much Do We Need?

AbstractResilience in river corridors refers to the ability to absorb disturbance and maintain processes, forms, and functions that support the river ecosystem and provide ecosystem services. Resilience derives from characteristics such as three‐dimensional connectivity, spatial heterogeneity, and physical and ecological integrity. Resilience is important as climate warming and growing human populations and consumptive demands change the disturbance regime affecting river corridors. Consequently, river management increasingly focuses on enhancing natural characteristics that create river resilience via (a) identifying the processes and features that promote and sustain resilience, (b) identifying portions of a river network and/or river corridor that are most resilient or most influential in creating resilience at larger spatial scales, and (c) protecting and restoring features that create resilience. Although the basic conceptual framework for these activities is well established, critical questions remain with respect to how reach‐scale management creates catchment‐scale results.

On the transferability of residence time distributions in two 10-km long river sections with similar hydromorphic units

Quantifying hydrologic exchange fluxes (HEFs) at the stream-groundwater interface and their residence time distributions (RTDs) in the subsurface are important for managing the water quality and ecosystem health in dynamic river corridors. However, field measurements and directly simulating high-spatial resolution HEFs and RTDs can be time-consuming, particularly at watershed-scale. Recent research has proposed the potential application of using hydromorphic units (HUs), which cluster the bathymetry and surface water hydrodynamics attributes, to aid in RTD estimation. However, more pioneering studies have demonstrated that underground structure and large-scale river channel geomorphology are the primary factors controlling the HEFs and RTDs. To address this contradiction, this work evaluates the HEFs and resulting HU-RTD relationships for two 10-km long river sections along the Columbia River, leveraging a one-way coupled three-dimensional transient surface–subsurface water transport modeling framework. Applying such a framework at the two river sections with similar HUs allows for quantitative comparisons of HEFs and RTDs using both statistical tests and machine learning classification models. The comparison reveals that the similarity and transferability of the HU-RTD relationship is very low for the two investigated river sections. This suggests that, creating a general algorithm to estimate RTDs in large-scale river reaches based solely on surface water hydrodynamics and short-distance bathymetry topography data may be nearly impossible.

Reindeer prey mobility and seasonal hunting strategies in the late Gravettian mammoth steppe

Reindeer are part of the faunal suite that dominated central Europe during the last glacial cycle. Their importance to Late Gravettian hunters as prey and a source of raw materials (hide, bone, antler) is well attested, however the context of Late Gravettian reindeer predation is lesser understood. This paper presents an investigation of human and reindeer predator-prey interactions at the Late Gravettian kill-butchery site of Lubná VI, Czech Republic. We reconstruct seasonal mobility (87Sr/86Sr, δ18O), diet (δ13C, δ15N) and season of death (dental cementum) of up to nine reindeer prey, to inform on the strategic choices made by Late Gravettian hunters. Results indicate that most hunted reindeer lived year-round in the foothills of the Bohemian-Moravian highlands near where Lubná is located, at altitudes between ~ 200–450 m above present sea level, while a smaller number showed evidence of seasonal migration between this area and the open plains of the Elbe river corridor (Bohemian Cretaceous basin). No evidence for long distance migration of reindeer was detected, indicating that productive local environments were supporting reindeer herds within a single annual territory. Meanwhile, areas higher than ~ 450 m above present sea level were avoided entirely by all analysed individuals, consistent with these areas being topographic barriers to movement due to climate severity. We conclude that hunters visited Lubná as part of a logistically-organised subsistence strategy, deliberately targeting reindeer in late autumn when fat supplies, hides and antler are in prime condition knowing that they would reliably encounter their prey at this location.

The Fragility of Bedform‐Induced Hyporheic Zones: Exploring Impacts of Dynamic Groundwater Table Fluctuations

AbstractHyporheic zones are commonly regarded as resilient and enduring interfaces between groundwater and surface water in river corridors. In particular, bedform‐induced advective pumping hyporheic exchange (bedform‐induced exchange) is often perceived as a relatively persistent mechanism in natural river systems driving water, solutes, and energy exchanges between the channel and its surrounding streambed sediments. Numerous studies have been based on this presumption. To evaluate the persistence of hyporheic zones under varying hydrologic conditions, we use a multi‐physics framework to model advective pumping bedform‐induced hyporheic exchange in response to a series of seasonal‐ and event‐scale groundwater table fluctuation scenarios, which lead to episodic river‐aquifer disconnections and reconnections. Our results suggest that hyporheic exchange is not as ubiquitous as generally assumed. Instead, the bedform‐induced hyporheic exchange is restricted to a narrow range of conditions characterized by minor river‐groundwater head differences, is intermittent, and can be easily obliterated by minor losing groundwater conditions. These findings shed light on the fragility of bedform‐induced hyporheic exchange and have important implications for biogeochemical transformations along river corridors.

Physical and chemical characterization of remote coastal aquifers and submarine groundwater discharge from a glacierized watershed

AbstractCoastal aquifers play an important role in marine ecosystems by providing high fluxes of nutrients and solutes via submarine groundwater discharge pathways. The physical and chemical characterization of these dynamic systems is foundational to understanding the extent and magnitude of hydrogeologic processes and their subsequent contributions to the marine environment. We describe a km‐scale experimental field site located in a glaciofluvial delta entering Kachemak Bay, Alaska. Our characterization applies geophysical (ERT and HVSR), hydrogeologic (grain size analyses, slug tests and tidal response analyses) and geochemical (major ions and stable water isotopes) methods to describe the complexity of coastal aquifers in proglacial environments currently experiencing rapid transformations. The hydrogeologic and geophysical techniques revealed thick (20–84 m) sediments dominated by sands and gravels and delineated zones of freshwater, brackish water and saltwater at both high and low tides within the subterranean estuary. Estimates of hydraulic conductivities via multiple approaches ranged from 2 to 250 m d−1, with means across the four methods within the same order of magnitude. Tidal response analyses highlighted a coastal aquifer in strong connection with the sea as evidenced by clear spring‐ and neap‐tidal signals within a proximal piezometric hydrograph. Geochemical sampling revealed coastal groundwaters as substantially enriched in solutes compared to proximal river samples with limited variability across seasons. A clear connection between the Wosnesenski River and the adjacent aquifer was also observed, with concentrated recharge from the river corridor during the meltwater season. This combination of approaches provides the basis for a conceptual model for coastal aquifer systems within the Gulf of Alaska and an upscaled mean daily yield of freshwater and solutes from the delta subsurface. Our findings are critical for subsequent numerical simulations of groundwater flow, tidal pumping and chemical reactions and transport in these understudied environments. This approach may be applied for low‐cost, large‐scale hydrogeologic investigations in coastal areas and may be particularly useful for remote sites where access and mobility are challenging.

Hydrologic connectivity and dynamics of solute transport in a mountain stream: Insights from a long-term tracer test and multiscale transport modeling informed by machine learning

The movement of solutes in a watershed is a complex process with multiple interactions and feedbacks across spatial and temporal scales. Modeling the dynamics of solute transport along diverse hydrologic pathways within watersheds – from hillslopes to stream channels and in and out of the hyporheic zones – is challenging but critically important, as these processes integrate and contribute to the biogeochemical functioning of the river corridor up to the river network scale. Here we use results from a long-term network-scale tracer test at the H.J. Andrews experimental forest in western Cascade Mountains, Oregon, USA to inform a multiscale framework for transport in stream corridors. The framework uses a Lagrangian-based subgrid model to represent the effects of hyporheic exchange flow and advective transport at stream network scales. The spatially and temporally resolved stream discharge needed for the transport model is imputed across the river system by an entity-aware long short-term memory network. Modeled concentrations show good agreements with the observations and exhibit power scaling laws indicative of a very wide range of timescales over which hyporheic exchange flow occurs. Our results demonstrate a data-informed modeling framework that links dynamical processes occurring at small scales to a network context to help understand how changes at reach scale cascade into network-scale effects, providing a useful tool for sustainable river basin management.

Construction and Optimization Strategy of Ecological Security Pattern in County-Level Cities under Spatial and Temporal Variation of Ecosystem Services: Case Study of Mianzhu, China

Climate change and human activities are seriously affecting the ecological level and economic development of county-level cities. Mianzhu City is a typical county-level city located within the Chengdu-Chongqing Economic Circle and the Yangtze River Economic Belt. The study selected primary ecological sources by analyzing high-level ecosystem service functions over time, using Morphological Spatial Pattern Analysis (MSPA). Ecological resistance surfaces were constructed using natural factors to address ecological risks associated with future urbanization. The construction of the ecological security pattern (ESP) followed the source–corridor–node paradigm, incorporating changes in ecosystem service risks. From 2010 to 2020, ecosystem service functions and values in Mianzhu City declined overall, with significant spatial variations. Human activities increased in ecologically fragile areas, aggravating exposure to ecological risks from climate change and urban expansion. Ecological protection and restoration zones were identified, with nature reserves in the north and the southern center as the core. In 2020, 19 ecological sources and 46 ecological corridors were identified, with a spatial distribution pattern of “more length and short resistance in the north, less length and long resistance in the south”. Additionally, 41 ecological pinch points and 16 ecological barrier points were determined. Considering the spatial distribution of the core areas of ecosystem services and lands with human-intensive activities, setting up the general idea of the ecological restoration pattern centered on forests, river corridors, and natural and artificial landscapes. The study provides new insights into constructing and optimizing the ESP, offering crucial references for the rapid urbanization of ecological restoration and development planning in urban regions.

Visitors' recreational & leisure experiences in urban river corridors? A case study of Hutuo River in Shijiazhuang, China

Various physical environmental factors influence the recreational experience of urban river corridors, and understanding visitors' perceptions of these factors holds significant implications for promoting the health and well-being of urban residents. This study specifically focuses on the Hutuo River corridor in Shijiazhuang, China, and conducted a semi-structured questionnaire survey with 620 participants. The findings reveal that visitors mainly come here to socialize with family and friends in a natural environment and escape the city's hustle and bustle. Safety, management and maintenance, and overall conditions are the primary features visitors are concerned about in their experience. When addressing usage constraints, visitors highlight accessibility issues, including traffic congestion and overcrowding. Additional limitations encompass deficiencies in physical facilities, such as shortages of shared bicycles, convenience amenities, fitness facilities, and services catering to vulnerable groups. Moreover,challenges include unavailable toilet services and insufficient shaded areas along the riverbanks. Sociodemographic attributes such as gender, age, marital status,education level, monthly income, and residential distance significantly influence the recreational experience of urban river corridors, emphasizing the importance of considering diversity in urban planning and design. By comprehensively exploring the dynamics of urban river corridor utilization from a social-ecological perspective, our study's findings offer insights relevant to future design and maintenance endeavors.

Working with wood in rivers in the Western United States

AbstractRecognition of the important physical and ecological roles played by large wood in channels and on floodplains has grown substantially during recent decades. Although large wood continues to be routinely removed from many river corridors worldwide, the practice of wood reintroduction has spread across the United States, the United Kingdom and western Europe, Australia, and New Zealand. The state‐of‐science regarding working with wood in rivers was discussed during a workshop held in Colorado, USA, in September 2022 with 40 participants who are scientists and practitioners from across the USA, UK, Europe, and Japan. The objectives of this paper are to present the findings from the workshop; summarize two case studies of wood in river restoration in the western United States; and provide suggestions for advancing the practice of wood in river management. We summarize the workshop results based on participant judgements and recommendations with respect to: (i) limitations and key barriers to using wood, which reflect perceptions and practicalities; (ii) gaps in the use of large wood in river management; (iii) scenarios in which wood is generally used effectively; and (iv) scenarios in which wood is generally not used effectively. The case studies illustrate the importance of the local geomorphic context, the configuration complexity of the wood, and the potential for modification of river corridor morphology to enhance desired benefits. Moving forward, we stress the importance of collaboration across disciplines and across communities of research scientists, practitioners, regulators, and potential stakeholders; accounting for stakeholder perceptions of the use of large wood; and increasing non‐scientist access to the latest state‐of‐science knowledge.

Managed retreat and experimentation: realising opportunity in the Ōtautahi Christchurch residential red zone, Aotearoa New Zealand

ABSTRACT Managed retreat is becoming a prominent issue both nationally and internationally. This is due both to the threat of rising sea levels and the growing incidence of extreme weather events, but also reflects the increasing propensity for placing human assets in harm's way. We analyse how this observation plays out in Aotearoa, and offer a simple model, informed by our intergenerational perspective and mātauranga Māori. This model has three features: retreat, relocation, and re-imagining. It enables us to explore the capacity for positive outcomes to further lower long-term environmental and social risks. We apply the model to the Ōtākaro Avon river corridor in Ōtautahi Christchurch, formerly known as the residential red zone, created during the Canterbury earthquake sequence of 2010-13. We discuss what can be learned from the decade-long history of adaptation in the corridor as an exemplar for emerging areas of managed retreat elsewhere. By means of a thought experiment, we explore the potential of the area for provision of affordable, climate-resilient housing.

Hydrochemical evolution of groundwater in a river corridor: the compounded impacts of various environmental factors

Various environmental factors could induce groundwater hydrochemical evolution, which should be considered when addressing groundwater environmental issues. However, the complex interactions among the environmental controls remain unknown for a groundwater flow system spanning multiple geological units. To fill this gap, we conducted a study on the groundwater hydrochemical evolution in the fluvial corridor of the Fen River, Northern China, utilizing a combination of hydrogeochemical and multiple isotope methods. Results reveal that the groundwater in the corridor has significantly degraded due to high concentrations of SO42-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{SO}}_{4}^{2 - }$$\\end{document}, NO3-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{NO}}_{3}^{ - }$$\\end{document}, Cl−, or F−. We find an unordered evolution of the hydrochemical composition of groundwater along this corridor. These evolutions are driven by mineral dissolution/precipitation, dedolomitization, and cation exchange processes. Human activities play a significant role, with notable contributions including NO3-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{NO}}_{3}^{ - }$$\\end{document} fluxes from agricultural fertilizers, manure, and sewage, as well as SO42-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{SO}}_{4}^{2 - }$$\\end{document} fluxes arising from coal mining activities. The combination between karst spring areas and faults/uplifts, between coal-bearing strata and mining activities fosters the mixing of karst water/mine water with shallow groundwater, promoting dramatic hydrochemical evolution of groundwater. The flat terrain and the natural blockage formed by mountains significantly enhance water–rock interactions and groundwater evaporation by slowing groundwater flow. The contribution of evaporation on groundwater salinity ranges from ~ 0.2% to 4.8%, highlighting its importance in the groundwater hydrochemical evolution. This study unravels the multifaceted nature of groundwater hydrochemical evolution. It emphasizes the four types of environmental controls, including hydrogeochemical processes, climate factors, human activities, and variations in geological settings, can be equally important, which is usually ignored. The findings enrich our understanding of groundwater evolution and highlight the challenges encountered in regions composed of diverse geological units.

Diversity and Distribution Characteristics of Spontaneous Vegetation in Herbaceous Layer of Urban River Corridors in Harbin

Diversity and Distribution Characteristics of Spontaneous Vegetation in Herbaceous Layer of Urban River Corridors in Harbin

Rough ice cover modified hyporheic exchange: A numerical study on the mechanical effect propagating from the ice-water interface to the sediment–water interface

Many rivers are subject to ice-covered flow conditions in cold climate regions or during the winter months. The presence of ice cover can change stream flow hydrodynamics and thus affect the hyporheic exchange involved in many biogeochemical processes in aquatic environments. Among the various features of ice cover, its underside roughness is a main factor modifying the surface–subsurface flow hydrodynamics. To date, there has been little research on how ice cover affects the hyporheic exchange, even less on the effect of the ice cover roughness. This leaves open questions on the mechanical changes initiated at the ice-water interface and transferred to the water–sediment interface. In this study, a coupled surface–subsurface computational approach was used to model conjunctively the channel flow over dune bed and the underlying porous flow under different ice cover conditions. The results show that ice cover can enhance the hyporheic flux and reduce the hyporheic zone depth when compared to open channel flow at equivalent discharge. As the river flow depth increases to 4 times the height of the dune, the effect of the ice cover on the hyporheic flow becomes negligible. Within this effective range, the hyporheic flux via the channel water depth follows a power-law function. Ice cover roughness greatly augments the exchange rate while compresses the exchange space, therefore reduces flow residence time in the hyporheic zone. Based on the modeling results, prediction models were proposed for evaluating the impacts of ice cover roughness on the hyporheic exchange flux and depth. Our study indicates that hyporheic flow exchange is significantly impacted by the roughness of the ice cover which in turn the hyporheic exchange is likely to affect the river ice processes as well as the water quality and ecological functions throughout the river corridors.

Eco-friendly dredging methods of changing fluvial landforms for enhancing hydraulic habitat quality and river corridor continuum

Hydraulic habitat connectivity, including the longitudinal continuum respect and lateral flood pulse, is critical for fish survival and organism dispersal. Inappropriate and excessive dredging for prevent flooding may harm river ecosystems. The main objective of this study is to evaluate whether eco-friendly dredging presented by changing local river landforms incorporating the concept of nature-based solutions could grow fish habitat quality for improving river continuity and achieving flood control effects. By combining various mathematical models and empirical formulas and verifying them with the data obtained through field surveys, we explore the interconnections of hydrology, river morphology, and the habitat dynamics of four endemic fishes in an alluvial river. The relationship between habitat structure, flood risk, and river topography, flow discharge was presented as the reference for developing the proper river dredging approaches. The results reveal that the primary habitat defects were lack of high-quality habitat, unsatisfied habitat diversity, deficiency in refugia, and disconnectivity. Longitudinal disconnectivity was induced due to shallow water depth, while lateral disconnectivity is primarily caused by fast flow velocity, suggesting different and specific dredging methods were instructed. We recommend that the corresponding eco-friendly dredging schemes for longitudinal and lateral suitable habitat linkages increase fish habitat quality and river corridor continuity. The win-win strategy for enhancing the connection between suitable habitats sustains a more beneficial aquatic corridor and simultaneously achieves alluvial flood disaster risk reduction.

Valor económico de los servicios ecosistémicos asociados a los corredoresfluviales atlánticos en el noroeste de la Península Ibérica

Valuing the benefits of conserving river corridors is essential to recognize the contribution of this natural capital to our well-being. This study aims to quantify the economic value of welfare improvements from the restoration of Atlantic River corridor habitats in Natura 2000 Network sites in the northwest Iberian Peninsula included in the LIFE Fluvial project. The contingent valuation method was used to estimate a discrete choice econometric model of willingness to pay for actions that protect ecosystem benefits associated with riparian forest restoration, and more than 600 residents and visitors in four major project areas were surveyed in 2021. The average willingness to pay was almost € 53 per resident and year (annual benefit to residents for the use, enjoyment and knowledge of the ecosystem services provided by these sites) and € 42 per visitor and year. By extrapolating these values to the population and visitors of the most representative sample areas we got an economic value for this type of conservation action of 4.2 million euros per year, much higher than the cost of implementing the entire project (3.03 million euros).

Exploring Factors Influencing Recreational Experiences of Urban River Corridors Based on Social Media Data

River corridors, recognized as “blue–green infrastructure,” have become a crucial support system for urban sustainability in contemporary urbanized societies. Understanding the factors influencing the recreational experience along urban river corridors is paramount for enhancing visitors’ health and well-being. This study focuses on the Hutuo River Corridor in Shijiazhuang, China, collecting 3006 valid reviews from Dianping, a prominent review platform. We developed a text-based thematic model and conducted content analysis using this dataset. The main social (visiting time, duration of stay, motivation, safety, and visitors’ types and activities) and physical (natural elements, artificial facilities, maintenance and management, accessibility, distance, models of transportation, weather, and seasons) factors associated with recreational experiences were identified. We assessed visitor perceptions of urban river corridors and elucidated facilitators or barriers through textual content analysis in reviews. The results indicate the feasibility of employing social media data to study visitors’ recreational experiences along urban river corridors. This comprehensive exploration from a qualitative ecological perspective contributes valuable insights for urban planning and management. Moreover, the findings hold significant implications for understanding the usage patterns of river corridors in China and potentially in other countries.

A stream-aligned mixed polyhedral meshing strategy for integrated surface-subsurface hydrological models

Mesh refinement near river corridors is commonly deployed to resolve topographic details important for accurately representing riverine flow dynamics in watershed-scale spatially distributed integrated hydrology models. However, this increased accuracy comes with higher computational costs due to larger mesh and smaller time steps resulting from small mesh cells. We present a novel stream-aligned mixed-polygonal meshing approach that resolves river-corridor topography efficiently by placing long quadrilateral cells along the mapped center lines of the rivers and standard Triangulated Irregular Network (TIN) mesh in the rest of the domain. Our integrated hydrology simulations using mixed-polyhedral mesh generated from the mixed-polygonal approach closely match those using a highly refined extruded-TIN mesh but with a 96.43% reduction in the number of mesh cells and a 99.75% reduction in CPU hours. Conversely, coarser extruded-TIN meshes, due to poor water conveyance relative to the refined mesh simulations, yielded lower peak flows, longer recession curves, and higher inundation fractions.The creation of this mixed-polyhedral mesh is implemented within the Watershed Workflow tool, a Python-based workflow library for watershed simulation. We also implemented a layered process of hydrologic conditioning specific to the cells in the river corridor, which are explicitly meshed within the mixed-polyhedral mesh. The hydrologic conditioning enforces monotonic topographic gradients, removes spurious obstructions, and allows for burning-in depths of the river cells based on ancillary information. This approach paves the way for efficiently modeling narrow engineered channels and specifying river-specific hydrodynamic details and biogeochemical processes.

Dynamic mechanism of check dams on evolution of river corridors based on UAV telemetry combined with numerical simulations

AbstractCheck dams are a critical soil and water conservation engineering measure in gullies that significantly influence erosion, transportation, and sediment accumulation. Check dams help reduce erosion in the upstream area, ignoring the off‐site erosion reduction capacity due to erosion dynamics, and it also alters the morphology of gullies. The morphology of the gully cross‐section from the head to the inlet of the gully is mainly “V” shaped, “V, U,” transitional shaped, “U” shaped and trapezoidal shaped. The construction of check dams can force the geomorphologic evolution of the sub‐watershed to accelerate the transition to “old age” and reduce the allocation of sediment initiation during field sub‐flooding, thus promoting sediment deposition processes. The percentage of downstream scour hours in watersheds where check dams were constructed was 0.65% and 0.80%, respectively, compared to 19.78% and 19.06% in watersheds where there are no check dams. The results reveal the role check dam constructions play in gully morphology evolution from a hydrodynamic perspective and fill the gaps in off‐site erosion reduction, providing theoretical support for assessing the role of check dams in soil and water conservation work.

Analyzing the Vulnerability of Residential Buildings in the City of Chaitén: A Focus on an Extreme Event Scenario in a Disrupted River Corridor Following the Cataclysmic Volcanic Eruption of 2008

Pillared on the hydrodynamic simulation of an extreme flooding scenario, we subsequently evaluated the physical vulnerability of residential buildings utilizing an ad hoc developed indicator-based methodology. This method aimed to quantify the expected loss for each affected residential structure. The outcome of this assessment facilitated the creation of a detailed risk map, allowing for the identification of hotspots that require immediate prioritization in mitigation efforts. The results of our study revealed a concentrated impact of the flood, particularly in the northern sector of the city. Within this region, four high-risk areas were pinpointed, comprising 70 homes predominantly situated close to the active channel zones. Notably, our findings underscored that twelve residential buildings, located at shorter distances from the river, are particularly susceptible to the impacts of the flood, as indicated by the physical vulnerability index values. It is important to highlight that the developed methodology is specifically tailored for the analysis of lightweight, one or two-storey houses with exteriors constructed from wood and zinc plates, as opposed to structures built with concrete or stone masonry. This distinction is crucial, given the prevalence of such building types in the Chilean Patagonian region. We recommend extending the application of this methodology to other urban areas in the region, where analogous impacts are possible and similar architectural patterns are common.