River Dikes Research Articles

Mapping and characterization of the liquefaction impacts of the July and October 2022 earthquakes in Northwestern Luzon, Philippines

The 25 July 2022 MW 7.0 and 25 October 2022 MW 6.4 earthquakes caused liquefaction in the lowlands of Northwestern Luzon, Philippines. With the widespread liquefaction occurrence, a methodology was developed for mapping and assessing its impacts, which combined mapping techniques, geomorphological analysis, review of historical liquefaction accounts and empirical equations, utilization of available remote sensing technologies, and application of various geophysical and geotechnical equipment. The majority of liquefaction impacts of the MW 7.0 earthquake occurred along the Abra River delta, while the MW 6.4 earthquake had most of its liquefaction impacts concentrated in river dikes and abandoned channels across the Solsona Basin. Grain size analysis confirmed that the sediments indeed had the potential to liquefy. The soil parameters obtained using the refraction microtremor (ReMi) and screw driving sounding (SDS) tests also showed strong correlations, with liquefaction potential values ranging from low to high. Soil period values were also consistent with the ReMi and SDS results.The results of this study emphasize that: 1) detailed mapping and assessment of areas affected by liquefaction is valuable in aiding researchers and planners in hazard mitigation; and 2) the geophysical and geotechnical approaches employed are suitable and less invasive alternatives in site-specific liquefaction potential assessment.

Alien species distribution mapping using satellite and drone fusion on river dikes along the Tone River, Japan

Alien species distribution mapping using satellite and drone fusion on river dikes along the Tone River, Japan

Law on nature conservation versus reasonable conservation measures concerning the treatment of river dikes

Law on nature conservation versus reasonable conservation measures concerning the treatment of river dikes

Occurrence of sand boils landside of a river dike during flooding: A geophysical perspective

The study of internal erosion of earth dams, dikes, and levees is an essential ingredient to address their safety. Indeed, internal erosion is known to be a major cause of failure for dams and levees. Several sections of the Agly river dike (south-west France) are affected by the appearance of sand boils on the side of the protected zone. These phenomena generally occur without any significant erosion of the dike itself. In order to better understand the reasons for these phenomena, we took advantage of a drought (dry riverbed) to image, using induced polarization tomography, the subsurface from the riverbed to the plains extending inland behind the areas prone to these pathologies. Induced polarization imaging is a geophysical technique that extends the classical electrical resistivity tomography to include low-frequency polarization mechanisms. This approach shows that the river dike is partly built on a sand-filled paleochannel, allowing water to flow under the dike and its clay core during river floods. During floods, underground flow under the dike is responsible for sand boil phenomena on the side of the protected zone. Numerical hydraulic simulations show that the discharge zone has specific concentration points, particularly at the toe of the dike even when the permeability of the sand filling the paleochannel is homogeneous. These concentrated discharges are controlled by the water level in the river, the geometry of the dike and the shape of the clay-sand interface of the paleochannel. This study highlights the role of geophysical techniques, especially induced polarization, in providing key information to better understand erosion and fluidization phenomena affecting river dikes.

Dykes and ‘nature’. Results of a survey on the perception of dykes and their evolution in 21st century France

The traditional paradigm of dyke management focuses on water defense. This article analyzes the perception and representation of coastal and river dikes among a sample of 828 residents and users. Five scenarios for the evolution of dikes were proposed to the respondents. Among these scenarios, maintaining the dikes in their current state is the most desired, while vegetation is the least rejected. In contrast, the scenarios of reinforcement and opening/lowering the dikes encounter notable rejection. This surprising refusal of reinforcement could indicate a shift in the perception of dike management in France, while the rejection of their opening remains consistent with the limited development of soft coastal and river defenses. Furthermore, the respondents' choices are strongly influenced by their relationship with nature, even though they refer to a nature that is anthropized and tamed. These results are important for developing scenarios for the evolution of dikes in the face of climate change challenges and for better communicating with audiences that are often unreceptive to innovations.

Seismic inspection and countermeasures for existing embankments in Japan

Many embankments have been constructed in Japan, but most have lacked seismic design, except for important embankments, such as earth dams. However, because embankments are often damaged by large earthquakes, seismic inspections have recently been carried out on existing embankments, and countermeasures have been taken to deal with unstable embankments. This paper describes the seismic inspection methods and countermeasures currently implemented in Japan for river dikes, tailings dams, and embanked residential lands. River dikes are dangerous when they subside and their crests become lower than the river water levels. Therefore, seismic inspections are being carried out using a simple static method to analyze the amount of subsidence against level 2 seismic motion. Countermeasures are being taken, such as compacting the ground under the vicinity of the toe of a dike. For tailings dams, dynamic analysis is performed for level 2 seismic motion, and seismic inspection is performed based on the amount of slip displacement. As countermeasures, solidification etc. have been implemented. There are 51,306 large residential areas embanked in hilly valleys in Japan. Soil investigations and stability analyses will be conducted in these areas as secondary screenings, and these areas are currently being prioritized for such screenings. It will likely be many years before the screenings and countermeasures are completed.

River dike grasslands can reconcile biodiversity and different ecosystem services to provide multifunctionality

River dikes are secondary habitats that support species-rich grasslands when maintained by low-intensity mowing or grazing. Besides erosion control and habitat creation, dike grasslands have provided several other ecosystem services (ESs), such as biomass production and recreation. Despite the existence of trade-offs between ESs, the overarching aim of restoration and management on river dikes is to increase its multifunctionality. We believe that multiple land uses can be reconciled with biodiversity conservation. Here, we propose a conceptual framework for assessing grassland multifunctionality, and test its application using river dikes as a model system. We also present some practical implications based on vegetation surveys and manipulative experiments along the Rivers Danube and Inn in S Germany. We identified four main ESs of dike grasslands ranked by importance: erosion control, conservation of habitats, recreation and biomass production. These ESs are closely linked to general biodiversity aspects, such as species richness. Therefore, ESs can be controlled by site preparation, trait-based seeding design and grassland management. As the multifunctionality of dikes becomes more important under climate change, the spatio-temporal variability of the dike vegetation must also be considered. In conclusion, dike grasslands are an interesting model for restoration and nature conservation, since they have high potential to deliver multiple ESs while increasing biodiversity. However, restoration and management of dike grassland would benefit from more cooperation between conservation and river authorities, and by implementing ecological knowledge and using experiments to test new management or restoration approaches.

Application of Complex Geophysical Methods for the Detection of Unconsolidated Zones in Flood Dikes

The flood levees in the vicinity of Krakow city (Poland) are, in some places, over 100 years old. Thereupon, in the flood dike, and its subsoil, can appear unconsolidated zones, which, during the flood stage, can be a simple way of water flow and/or even can be the place where the levee body will be destroyed. This phenomenon took place in Wawrzeńczyce village, near Krakow city, during the flood in 2010. The geophysical research was carried out, in order to develop a methodology of recognition of potential areas where the levee body can be damaged. The geophysical surveys were conducted with the use of electrical and electromagnetic methods, as well as utilizing the seismic method. The general identification of examined media was realized by the electrical resistivity tomography (ERT) method. The ERT surveys were supplemented by capacitively-coupled resistivity (CCR) measurements, in order to analyze the usefulness of the CCR method for the examination of river dikes and reduction of interpretation ambiguity. The ground penetrating radar (GPR) method detected small anomalies in the body dike, due to the very high resolution of this method, which were not detected by the ERT and CCR techniques. During GPR surveys, non-standard measurement techniques were applied. Finally, the high-resolution seismic reflection (HRSR) method provided a clear and high-resolution image of the dike structure up to the water table and assisted with the identification of the hazard non-consolidated zones.

The evocation of sea and river dikes in France in Le Monde: the role of the press in stimulating reflection on the future of dikes in the 21st century

Les digues, qui s’étendent en France métropolitaine sur environ 9 000 km, ont été considérées jusque-là comme un objet technique servant principalement à se défendre contre les inondations. Des évolutions récentes d’ordre climatique, politique et social poussent les acteurs territoriaux à se pencher sur leur devenir et à redéfinir leur(s) rôle(s) et leur apparence paysagère au xxie siècle. Pour les y aider, on peut s’intéresser aux représentations sociales associées, en France, à cet objet technique, afin de dégager leurs caractéristiques et leurs permanences ou évolutions. Une analyse de contenu de la presse quotidienne nationale a ainsi été effectuée en s’appuyant sur les archives du Monde depuis sa création. Les représentations des digues dans Le Monde montrent une hiérarchie décroissante des enjeux liés à ces ouvrages – de la Défense contre les eaux, constamment prioritaire, aux Usages, présents sur toute la période, et enfin à la Nature et au Paysage, constamment minoritaires – et une forte séparation de ces quatre enjeux qui empêche qu’on prenne en considération les digues de façon globale, sous toutes leurs facettes. Le corpus utilisé met aussi en exergue un faible intérêt, en France, pour les méthodes souples de gestion des digues, globalement très peu évoquées dans Le Monde, en particulier pour les digues fluviales. Ainsi, la primauté donnée jusqu’à nos jours aux enjeux de défense et aux usages semble être à la fois la cause et la conséquence de l’importance majeure prise par des méthodes rigides de gestion des digues. En parallèle, la faible importance accordée aux enjeux de nature et de paysage semble être la cause et la conséquence du faible essor de la défense douce et de méthodes souples de gestion de ces ouvrages. Ces résultats sont discutés dans l’optique de favoriser un renouvellement des recherches et de la gestion des digues en France.

Special Issue on Digital Geometry Processing for Large-Scale Structures and Environments

The application of digital geometry processing is undergoing an extension from small industrial products to large-scale structures and environments, including plants, factories, ships, bridges, buildings, forests, and indoor/outdoor/urban environments. This extension is being supported by recent advances in long-range 3D laser scanning technology. Laser scanners are mounted on various platforms, such as tripods, wheeled vehicles, airplanes, and UAVs, and the laser scanning systems are used to efficiently acquire dense and accurate digitized 3D data of the geometry, called point clouds, of large-scale structures and environments. As another technology for the acquisition of digital 3D data of structures and environments, 3D reconstruction methods from digital images are also attracting a great deal of attention because of their flexibility. The utilization of digital 3D data for various purposes still has many challenges, however, in terms of data processing. The extraction of accurate and meaningful information from the data is an especially important and difficult problem, and many studies on object and scene recognition are being conducted in many fields. How to acquire useful and high-quality digital 3D data of large-scale structures and environments is another problem to be solved for digital geometry processing to be widely used. This special issue addresses the latest research advances in digital geometry processing for large-scale structures and environments. It covers a broad range of topics in geometry processing, including new technologies, systems, and reviews for 3D data acquisition, recognition, and modeling of ships, factories, plants, forests, river dikes, and urban environments. The papers will help the readers explore and share their knowledge and experience in technologies and development techniques in this area. All papers were refereed through careful peer reviews. We would like to express our sincere appreciation to the authors for their excellent submissions and to the reviewers for their invaluable efforts in producing this special issue.

Flood Hazard Assessment of Residential Areas Outside the Protected Area of the Red River Dike System in Hanoi, Vietnam

Flood Hazard Assessment of Residential Areas Outside the Protected Area of the Red River Dike System in Hanoi, Vietnam

Value of information of combinations of proof loading and pore pressure monitoring for flood defences

Spatial variability and limited measurements often result in low reliability estimates of geotechnical failure modes of dikes (i.e., earthen flood defences). Required dike reinforcements are usually not executed within a few years after inception, which enables efforts to improve reliability estimates by reducing uncertainty. Often decision makers are unclear on whether uncertainty reduction is worth investing, and which (combination of) methods yields the highest Value of Information (VoI). This paper presents a framework to assess the VoI of two uncertainty reduction methods (proof loading and pore pressure monitoring) for a case study of a typical river dike with an insufficiently stable inner slope, using a decision tree. In all cases, a positive VoI was found for at least one strategy consisting of a proof load test, monitoring or both. The optimal strategy of proof loading and monitoring has a VoI of 4.0 M€, being a reduction in total cost of 25% compared to a conventional dike reinforcement. It was also found that sometimes proof loading enhances the VoI of pore pressure monitoring, which demonstrates the benefits of jointly considering different methods in a single decision tree. The decision framework yields insight in total cost and VoI of risk reduction strategies, which enables decision makers to determine where proof loading and/or pore pressure monitoring are efficient, leading to more efficient flood defence asset management.

Development of geosynthetic-reinforced soil embankment resistant to severe earthquakes and prolonged overflows due to tsunamis

Many railway embankments sustained extensive damage due to the tsunami triggered by the 2011 off the Pacific Coast of Tohoku Earthquake, and the operations of several railway lines were suspended for an extended period of time.Numerous studies have been conducted on enhancing the earthquake resistance of embankments, and this has led to the wide application of geosynthetic-reinforced soil (GRS) structures. However, only a few studies have been conducted on enhancing the tsunami resistance of embankments.Based on onsite surveys and wave model experiments, the authors concluded that the damage to embankments was mainly caused by the large-scale earthquake occurring prior to the onset of the tsunami, and by the prolonged tsunami overflows that eroded the embankment bodies and the supporting ground.In this study, therefore, two types of model tests were performed in order to propose a sturdy tsunami-resistant soil structure that exhibits ductile behavior against an earthquake prior to the onset of a tsunami as well as against prolonged overflowing.It was confirmed that conventional embankments with sufficient seismic stability can be rapidly eroded by overflowing. On the other hand, the GRS method was found to be very effective for resisting the erosion of embankments due to overflowing.Furthermore, given that the collapse of river dikes and levees due to overflows is often reported during heavy rainfall events, the findings obtained in the study are considered applicable to embankments as well as to river dikes and levees.

Engineering Flood Protection on Mountain Rivers

The effect of river flood on the channel and settlements is discussed. The insufficiency of cleaning the channel to increase the river capacity and the shortcomings of the effect of the river dikes on the channel are justified. It is proposed to use flood-control dams (rapids) on tributaries for detention of floodwaters in the flood formation zone.

Stability Analysis of Dike to Impound Freshwater in Brackish Water Estuarine Environment

This paper presents the stability analysis of a dike proposed to impound the river flood waters within an estuary near the west coast of south India. The proposed dike will be located within Ashtamudi Lake, the second largest lake in the state of Kerala, India, separating fresh water from brackish water. Constructing a dike at Munro Island portion of Ashtamudi, which is about 9.23 km from Arabian Sea coast, can meet the water demands of the region as well as prevent the sinking of Island during high tide. The river dike is designed to construct artificially as rock filled structures. The stratigraphy in the top 2 m consists of clayey mud underlined by fine to medium sand up to 6 m followed by alternate layers of clay and sand up the investigated depth of 15 m. In this paper, the stability of the dike located in an estuarine environment has been investigated and the factor of safety values have been determined with varying water level conditions and varying properties of the underlying soil. A detailed parametric study using RocScience software is presented, considering all the design conditions. The expected settlement of the dike is estimated considering the soil profile at the location both manually as well as using software Geo5. Both were in good agreement and the maximum possible settlement was found to be less than half a meter.

Application of Traceability System for Dumping Garbage of North Canal Embankment Based on Ai Artificial Intelligence Recognition

Based on the analysis of the process of retrospective management of dumping garbage in the North Canal embankment, the AI artificial intelligence technology is proposed for image recognition of the retrospective system of dumping garbage in the North Canal embankment. The developed system can accurately obtain the photo information, and analyzes the design and implementation process of the river dike dumping traceability system by taking the dumping of the North Canal River Dike as an example.

A Technical Solution to Improve the Existing River Dikes for both Flood Prevention and Transportation Purposes

In the demand for socio-economic development, today, many river dikes in Vietnam are planned to be used as roads, and this is an indispensable trend. However, these river dikes have general characteristics of being filled with various types of soil which are heterogeneous, and not being compacted following the criteria before filling, so they need to be reinforced for both ensure the flood prevention safety and meet the technical requirements of traffic roads. In Vietnam and in the world, there are no specific studies on the re-use of the existing weak soil of embankments with adhesives, namely fly-ash and cement for treatment of foundation that meet the technical requirements of the upper base layer when transportation is involved. In this study, the authors focus on the solution of using the existing weak soil of embankments with fly-ash and cement to strengthen the stability of the river embankment served as the upper base layer in the traffic load affected zone, and the river embankment sub-structure combined with transportation purpose. By using methods of laboratory experiment, the authors propose the appropriate river embankment sub-structure to guarantee flood prevention and transportation combination.

An analytical model of wave overtopping flow velocities on dike crests and landward slopes

An accurate description of the maximum flow velocity across flood-protective structures is necessary in order to determine the stability of the landward slope and the amount of cover erosion. In this paper, two new formulas are derived to describe the change in the maximum overtopping flow velocity along the dike crest and the adjacent landward slope. These formulas are coupled in an effort to accurately predict the velocities in wave overtopping events. This analytical model is validated using 244 data points from flume tests and 300 data points from field tests on river dikes in the Netherlands. The modelled flow velocity shows good agreement with the measured flow velocity, with a Nash-Sutcliffe efficiency factor varying from 0.49 to 0.87. Also, the derived formulas are compared with existing formulas for wave overtopping flow velocities and overall showed a better performance for a wide range of geometries and covers.

Key issues on seepage analysis in mountain river embankment

Seepage control is one of the key technical problems faced by mountain river embankment construction. Seepage analysis is an important way to achieve optimal design of dike seepage control. The floods of mountainous rivers are steeply rising and falling, the peaks are concentrated and short. The dikes are relatively difficult to form stable seepage. Taking the river dike in the upper reaches of Xinxi River in Jinyun County as an example, this paper comprehensively analyzes the characteristics of topography, geological structure and anti-seepage scheme, establishes the three-dimensional finite element model of the dike, and uses the parabolic Signorini-type variational inequality method to calculate the unstable seepage of the embankment. The research results have a guiding significance for the optimal design of seepage control measures for mountain river embankments.

Back to the future: Viewing a 1992 flood risk study through a 2017 lens

Here we examine whether a study conducted 25 years ago (1992) would have had different conclusions if concepts and analytical methods developed since then had been used. The 1992 problem was to identify a strategy for reducing flood risk in the Netherlands by, for example, strengthening the river dikes against the risk of flooding. Since then, conditions related to flooding have been recognised as increasingly uncertain. In response, a new paradigm for strategic planning has emerged: the “adaptive planning approach,” which aims to identify and assess strategies allowing for change, learning, and adaptation over time. We found that using the adaptive planning approach in 1992 would not have changed the main conclusions. But, it would have made explicit the need for the identification of vulnerabilities of the chosen strategy, a monitoring system to keep track of the uncertainties, and the possible actions to deal with the vulnerabilities that can be taken as the world evolves.