Seaport operability is key to the economic viability of ports. Metocean conditions (e.g., wind, s... more Seaport operability is key to the economic viability of ports. Metocean conditions (e.g., wind, short waves, and infragravity waves) affect this operability when certain thresholds are exceeded. This paper describes a method for the global mapping of seaport operability risk indicators using open-source metocean data. This global-scale assessment provides a geographic overview of operability risks and first-order insights into the most relevant metocean risk indicators at each location. The results show that locations around the equator and inland seas have lower operability risk than locations farther away from the equator. “Hotspots” are mainly located along the southern capes (Cape of Good Hope, Leeuwin, Horn), around the ‘Roaring Forties’, and at exposed locations along the oceans. Of the metocean parameters considered, short waves are found to be the most critical risk indicator for port operability at most locations. Using (the insights of) this study, port authorities, operat...
Coastal erosion is a serious issue for many beaches along the East coast of South Korea. In order... more Coastal erosion is a serious issue for many beaches along the East coast of South Korea. In order to better understand and mitigate the coastal erosion a framework of data analysis techniques and numerical models has been set up. This framework is used to study the relevance of different coastal erosion processes acting on different temporal scales for the beaches of Anmok and Namhangjin. The results indicate that especially the construction of a port led to severe erosion at the down-drift beach. Nowadays this erosion is to a large extent mitigated by the construction of coastal protection measures. Nevertheless, changes of in the beach states in the foreshore of the Korean East coast as well as storm erosion during extreme events, can still lead to (temporal) coastline retreat in the order of 20-30 m. The interactions between the erosion processes and the design of effective protection measures require further investigation.
Satellite imagery provides a unique source of data given its spatial and temporal coverage. In th... more Satellite imagery provides a unique source of data given its spatial and temporal coverage. In this study, a detection algorithm has been developed and tested to automatically determine the satellite derived waterline (SDW). The SDWs have been compared with traditional coastline measurements at two locations along the Dutch coast, where high quality in-situ data is ample available. The findings are that the SDW can be detected with sub pixel precision, with offsets of about 6.5 m in case of Sentinel-2 images. Also for longer time scales, similarities are found between coastline dynamics based on the SDW positions and traditional indicators based on topographic measurements, hence the SDW may serve as a coastal state indicator. This shows that a time series of SDW positions can be used to study coastal dynamics for any coastal stretch to get a first understanding of the coastline evolution in the period of 1984 –
To accommodate for the transport of goods and commodities worldwide, new seaports are being devel... more To accommodate for the transport of goods and commodities worldwide, new seaports are being developed and existing ports are being extended and optimized. Increasing urbanization of coastal areas and rising awareness for the value of our ecosystems ask for solutions that align port infrastructure with the requirements from society and nature. Hence, design and optimization of both new and existing ports become more and more a multidisciplinary effort requiring an assessment of multiple design aspects at the same time. The Coastal Design Support (CoDeS) tools framework is developed with the aim of bringing together tools that support the design and optimization of coastal infrastructure on multiple physical design aspects in a multidisciplinary setting. These tools aim primarily on obtaining quick insights in physical (design) parameters in the preliminary design stages of coastal infrastructure, when time and budget is often limited and the design freedom is still relatively large. ...
In Africa, several new seaport developments are being considered. In sedimentary environments, su... more In Africa, several new seaport developments are being considered. In sedimentary environments, such port developments can have adverse impacts on the evolution of adjacent coastlines. To learn from past port engineering practice, we created a unique database containing the coastline evolution and characteristics of 130 existing African seaports. Whereas the systematic mapping of coastal impacts was previously hampered by data availability, innovative automated satellite image processing techniques have enabled us to intercompare ports at an unprecedented continental scale. We found large geographical differences with respect to the beach evolution. The total detected changes in the beach area between 1984 and 2018 totaled 44 km2, of which ca. 23 km2 is accretion and ca. 21 km2 is erosion. The top 10% “hotspot” ports account for more than 65% of these changes. These hotspots exhibit common characteristics, namely: they are located on open coastlines, have large alongshore sediment tr...
In process-based numerical models, reducing the amount of input parameters, known as input reduct... more In process-based numerical models, reducing the amount of input parameters, known as input reduction (IR), is often required to reduce the computational effort of these models and to enable long-term, ensemble predictions. Currently, a comprehensive performance assessment of IR-methods is lacking, which hampers guidance on selecting suitable methods and settings in practice. In this study, we investigated the performance of 10 IR-methods and 36 subvariants for wave climate reduction to model the inter-annual evolution of nearshore bars. The performance of reduced wave climates is evaluated by means of a brute force simulation based on the full climate. Additionally, we tested how the performance is affected by the number of wave conditions, sequencing, and duration of the reduced wave climate. We found that the Sediment Transport Bins method is the most promising method. Furthermore, we found that the resolution in directional space is more important for the performance than the res...
Coastal engineering design studies often rely on detailed numerical models that involve various m... more Coastal engineering design studies often rely on detailed numerical models that involve various mono-disciplinary physical processes, complex numerics and large computational demands. As a consequence, these models are particularly useful to address specific questions that arise during project phases focusing on detailed design. In contrast, during early project phases focusing on project feasibility, proof-of-concept and preliminary engineering efforts, these detailed numerical models suffer from their aforementioned characteristics. Now, aspects such as interactivity, flexibility and multi-disciplinary assessment are of importance. Simple yet fast tools and empirical relations offer a lot of potential to fill this gap, but are typically not as systematically developed as detailed numerical models. This results in a deficit in consistent integration of disciplines, robustness, interactivity and potential flexibility.
Nearshore sandbar patterns can affect the hydrodynamics and, as a result, the beach morphodynamic... more Nearshore sandbar patterns can affect the hydrodynamics and, as a result, the beach morphodynamics in the nearshore zone. Hence, spatial and temporal variability in the sandbars can influence beach accretion and erosion. Understanding the variability of the sandbar system can therefore be crucial for informed coastal zone management. So far, the methods to study sandbar dynamics mainly include datasets of video observations or occasional bathymetric surveys. However, at most locations around the world, these types of data are not or only scarcely available. In this paper we present an alternative method to analyze long-term sandbar variability by means of freely available satellite imagery. These images are globally available since the 1980’s and, thus, have the potential to be applicable at any location in the world. Here, we will illustrate the methodology by means of a case study at Anmok beach at the South Korean East coast.
Coastal zones around the globe host about two-third of the world population. Besides their econom... more Coastal zones around the globe host about two-third of the world population. Besides their economical and social value, coastal areas are extremely valuable from an ecological point of view. Nevertheless, coastal zones are also extremely vulnerable. Erosion and associated loss of land is the most evident sign of this vulnerability. Adequate solutions require knowledge of the underlying morphodynamics and ecological processes. The Dutch experience shows that a very effective and sustainable way to deal with coastal erosion is to work with nature. In case of sandy costs, the most appropriate material for restoring, raising or building out sandy coasts is sand. Different approaches and tools have been developed in recent years as design basis to deal with erosion control and management of sandy coasts. The use of different approaches is mainly linked to the spatial and temporal scale of the problem under consideration. The present paper describes results from different erosion manageme...
In order to conceive any realistic plan for post-Katrina island restoration, it is necessary to u... more In order to conceive any realistic plan for post-Katrina island restoration, it is necessary to understand the physical processes that move sand along the littoral drift zone off the coast of Mississippi. This littoral zone influences the character of the Mississippi barrier islands as they exist in an ever changing cycle. To help in this understanding, a sediment transport model was conducted to establish a current sediment budget for the islands. This study evaluated the existing regional sediment transport magnitudes and directions for the Mississippi and Alabama barrier islands fronting Mississippi Sound including daily conditions and hurricanes. A method was developed to incorporate all relevant hurricanes from 1917 to 2010 in the analysis. For the long term average net longshore transport along the southern shorelines of the barriers (i.e. exposed to the Gulf of Mexico), the contribution of year-averaged conditions and hurricanes are of similar order of magnitude, although the...
Worldwide, communities are facing increasing flood risk, due to more frequent and intense hazards... more Worldwide, communities are facing increasing flood risk, due to more frequent and intense hazards and rising exposure through more people living along coastlines and in flood plains. Nature-based Solutions (NbS), such as mangroves, and riparian forests, offer huge potential for adaptation and risk reduction. The capacity of trees and forests to attenuate waves and mitigate storm damages receives massive attention, especially after extreme storm events. However, application of forests in flood mitigation strategies remains limited to date, due to lack of real-scale measurements on the performance under extreme conditions. Experiments executed in a large-scale flume with a willow forest to dissipate waves show that trees are hardly damaged and strongly reduce wave and run-up heights, even when maximum wave heights are up to 2.5 meters. It was observed for the first time that the surface area of the tree canopy is most relevant for wave attenuation, but that the very flexible leaves ha...
Long-term considerations of repeated and increasing sand extraction on the Netherlands Continenta... more Long-term considerations of repeated and increasing sand extraction on the Netherlands Continental Shelf (North Sea) may lead to the creation of a mega-scale extraction trench in front of the Dutch coast (length hundreds of km, width over 10km, depth several m). We investigate the impact of such a huge topographic intervention on tidal dynamics, which is a key aspect in
Seaport operability is key to the economic viability of ports. Metocean conditions (e.g., wind, s... more Seaport operability is key to the economic viability of ports. Metocean conditions (e.g., wind, short waves, and infragravity waves) affect this operability when certain thresholds are exceeded. This paper describes a method for the global mapping of seaport operability risk indicators using open-source metocean data. This global-scale assessment provides a geographic overview of operability risks and first-order insights into the most relevant metocean risk indicators at each location. The results show that locations around the equator and inland seas have lower operability risk than locations farther away from the equator. “Hotspots” are mainly located along the southern capes (Cape of Good Hope, Leeuwin, Horn), around the ‘Roaring Forties’, and at exposed locations along the oceans. Of the metocean parameters considered, short waves are found to be the most critical risk indicator for port operability at most locations. Using (the insights of) this study, port authorities, operat...
Coastal erosion is a serious issue for many beaches along the East coast of South Korea. In order... more Coastal erosion is a serious issue for many beaches along the East coast of South Korea. In order to better understand and mitigate the coastal erosion a framework of data analysis techniques and numerical models has been set up. This framework is used to study the relevance of different coastal erosion processes acting on different temporal scales for the beaches of Anmok and Namhangjin. The results indicate that especially the construction of a port led to severe erosion at the down-drift beach. Nowadays this erosion is to a large extent mitigated by the construction of coastal protection measures. Nevertheless, changes of in the beach states in the foreshore of the Korean East coast as well as storm erosion during extreme events, can still lead to (temporal) coastline retreat in the order of 20-30 m. The interactions between the erosion processes and the design of effective protection measures require further investigation.
Satellite imagery provides a unique source of data given its spatial and temporal coverage. In th... more Satellite imagery provides a unique source of data given its spatial and temporal coverage. In this study, a detection algorithm has been developed and tested to automatically determine the satellite derived waterline (SDW). The SDWs have been compared with traditional coastline measurements at two locations along the Dutch coast, where high quality in-situ data is ample available. The findings are that the SDW can be detected with sub pixel precision, with offsets of about 6.5 m in case of Sentinel-2 images. Also for longer time scales, similarities are found between coastline dynamics based on the SDW positions and traditional indicators based on topographic measurements, hence the SDW may serve as a coastal state indicator. This shows that a time series of SDW positions can be used to study coastal dynamics for any coastal stretch to get a first understanding of the coastline evolution in the period of 1984 –
To accommodate for the transport of goods and commodities worldwide, new seaports are being devel... more To accommodate for the transport of goods and commodities worldwide, new seaports are being developed and existing ports are being extended and optimized. Increasing urbanization of coastal areas and rising awareness for the value of our ecosystems ask for solutions that align port infrastructure with the requirements from society and nature. Hence, design and optimization of both new and existing ports become more and more a multidisciplinary effort requiring an assessment of multiple design aspects at the same time. The Coastal Design Support (CoDeS) tools framework is developed with the aim of bringing together tools that support the design and optimization of coastal infrastructure on multiple physical design aspects in a multidisciplinary setting. These tools aim primarily on obtaining quick insights in physical (design) parameters in the preliminary design stages of coastal infrastructure, when time and budget is often limited and the design freedom is still relatively large. ...
In Africa, several new seaport developments are being considered. In sedimentary environments, su... more In Africa, several new seaport developments are being considered. In sedimentary environments, such port developments can have adverse impacts on the evolution of adjacent coastlines. To learn from past port engineering practice, we created a unique database containing the coastline evolution and characteristics of 130 existing African seaports. Whereas the systematic mapping of coastal impacts was previously hampered by data availability, innovative automated satellite image processing techniques have enabled us to intercompare ports at an unprecedented continental scale. We found large geographical differences with respect to the beach evolution. The total detected changes in the beach area between 1984 and 2018 totaled 44 km2, of which ca. 23 km2 is accretion and ca. 21 km2 is erosion. The top 10% “hotspot” ports account for more than 65% of these changes. These hotspots exhibit common characteristics, namely: they are located on open coastlines, have large alongshore sediment tr...
In process-based numerical models, reducing the amount of input parameters, known as input reduct... more In process-based numerical models, reducing the amount of input parameters, known as input reduction (IR), is often required to reduce the computational effort of these models and to enable long-term, ensemble predictions. Currently, a comprehensive performance assessment of IR-methods is lacking, which hampers guidance on selecting suitable methods and settings in practice. In this study, we investigated the performance of 10 IR-methods and 36 subvariants for wave climate reduction to model the inter-annual evolution of nearshore bars. The performance of reduced wave climates is evaluated by means of a brute force simulation based on the full climate. Additionally, we tested how the performance is affected by the number of wave conditions, sequencing, and duration of the reduced wave climate. We found that the Sediment Transport Bins method is the most promising method. Furthermore, we found that the resolution in directional space is more important for the performance than the res...
Coastal engineering design studies often rely on detailed numerical models that involve various m... more Coastal engineering design studies often rely on detailed numerical models that involve various mono-disciplinary physical processes, complex numerics and large computational demands. As a consequence, these models are particularly useful to address specific questions that arise during project phases focusing on detailed design. In contrast, during early project phases focusing on project feasibility, proof-of-concept and preliminary engineering efforts, these detailed numerical models suffer from their aforementioned characteristics. Now, aspects such as interactivity, flexibility and multi-disciplinary assessment are of importance. Simple yet fast tools and empirical relations offer a lot of potential to fill this gap, but are typically not as systematically developed as detailed numerical models. This results in a deficit in consistent integration of disciplines, robustness, interactivity and potential flexibility.
Nearshore sandbar patterns can affect the hydrodynamics and, as a result, the beach morphodynamic... more Nearshore sandbar patterns can affect the hydrodynamics and, as a result, the beach morphodynamics in the nearshore zone. Hence, spatial and temporal variability in the sandbars can influence beach accretion and erosion. Understanding the variability of the sandbar system can therefore be crucial for informed coastal zone management. So far, the methods to study sandbar dynamics mainly include datasets of video observations or occasional bathymetric surveys. However, at most locations around the world, these types of data are not or only scarcely available. In this paper we present an alternative method to analyze long-term sandbar variability by means of freely available satellite imagery. These images are globally available since the 1980’s and, thus, have the potential to be applicable at any location in the world. Here, we will illustrate the methodology by means of a case study at Anmok beach at the South Korean East coast.
Coastal zones around the globe host about two-third of the world population. Besides their econom... more Coastal zones around the globe host about two-third of the world population. Besides their economical and social value, coastal areas are extremely valuable from an ecological point of view. Nevertheless, coastal zones are also extremely vulnerable. Erosion and associated loss of land is the most evident sign of this vulnerability. Adequate solutions require knowledge of the underlying morphodynamics and ecological processes. The Dutch experience shows that a very effective and sustainable way to deal with coastal erosion is to work with nature. In case of sandy costs, the most appropriate material for restoring, raising or building out sandy coasts is sand. Different approaches and tools have been developed in recent years as design basis to deal with erosion control and management of sandy coasts. The use of different approaches is mainly linked to the spatial and temporal scale of the problem under consideration. The present paper describes results from different erosion manageme...
In order to conceive any realistic plan for post-Katrina island restoration, it is necessary to u... more In order to conceive any realistic plan for post-Katrina island restoration, it is necessary to understand the physical processes that move sand along the littoral drift zone off the coast of Mississippi. This littoral zone influences the character of the Mississippi barrier islands as they exist in an ever changing cycle. To help in this understanding, a sediment transport model was conducted to establish a current sediment budget for the islands. This study evaluated the existing regional sediment transport magnitudes and directions for the Mississippi and Alabama barrier islands fronting Mississippi Sound including daily conditions and hurricanes. A method was developed to incorporate all relevant hurricanes from 1917 to 2010 in the analysis. For the long term average net longshore transport along the southern shorelines of the barriers (i.e. exposed to the Gulf of Mexico), the contribution of year-averaged conditions and hurricanes are of similar order of magnitude, although the...
Worldwide, communities are facing increasing flood risk, due to more frequent and intense hazards... more Worldwide, communities are facing increasing flood risk, due to more frequent and intense hazards and rising exposure through more people living along coastlines and in flood plains. Nature-based Solutions (NbS), such as mangroves, and riparian forests, offer huge potential for adaptation and risk reduction. The capacity of trees and forests to attenuate waves and mitigate storm damages receives massive attention, especially after extreme storm events. However, application of forests in flood mitigation strategies remains limited to date, due to lack of real-scale measurements on the performance under extreme conditions. Experiments executed in a large-scale flume with a willow forest to dissipate waves show that trees are hardly damaged and strongly reduce wave and run-up heights, even when maximum wave heights are up to 2.5 meters. It was observed for the first time that the surface area of the tree canopy is most relevant for wave attenuation, but that the very flexible leaves ha...
Long-term considerations of repeated and increasing sand extraction on the Netherlands Continenta... more Long-term considerations of repeated and increasing sand extraction on the Netherlands Continental Shelf (North Sea) may lead to the creation of a mega-scale extraction trench in front of the Dutch coast (length hundreds of km, width over 10km, depth several m). We investigate the impact of such a huge topographic intervention on tidal dynamics, which is a key aspect in
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