No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Optimization of safe navigability conditions in shallow inland waters: The Routinav app
Abstract
Safe navigation in inland waters subjected to tide requires dedicated forecasts of meteorological and oceanographic variables, such as local tidal height, currents, wind and atmospheric pressure. Indeed, it is more difficult to navigate inland shallow waters subjected to intense morphologic dynamics, and therefore characterized by the non-linearity of the tidal height propagation throughout the channels, traduced by important changes in tidal amplitude and phase, especially when no navigation aids are installed. In this context, this work objective is a mobile application (Routinav) development that allows simulating the navigability conditions in inland shallow waters. Firstly, a monitoring system was installed on volunteer boats and validated in Ria de Aveiro, showing high accuracy in depth and position acquisition. Secondly, was designed and applied an algorithm allowing the identification of navigable and non-navigable route segments, according to the updated depth and forecasted tidal height by the hydrodynamic model. Based on this algorithm, was created an agile prototype used to build up the Routinav mobile application for iOS (iPhone OS) and Android operating systems.
... Despite both offshore and coastal waters presenting challenges to navigation, such as limited infrastructure for immediate aid [10], or intense currents and unexpected winds, inland waters pose even more demanding navigation conditions due to shallower depths, narrower channels, intertidal channels, and non-linear tidal propagation [11], demanding precise and anticipatory data on a vessel's position and the real water depth [10,12] to avoid grounding. Due to these conditions, it is particularly challenging for ships and vessels with drafts higher than the available water height (observed depth) [13] to navigate through shallow navigation channels, such as bars, rivers, and harbors [12,14]. ...
... Despite both offshore and coastal waters presenting challenges to navigation, such as limited infrastructure for immediate aid [10], or intense currents and unexpected winds, inland waters pose even more demanding navigation conditions due to shallower depths, narrower channels, intertidal channels, and non-linear tidal propagation [11], demanding precise and anticipatory data on a vessel's position and the real water depth [10,12] to avoid grounding. Due to these conditions, it is particularly challenging for ships and vessels with drafts higher than the available water height (observed depth) [13] to navigate through shallow navigation channels, such as bars, rivers, and harbors [12,14]. Shallow channels pose a risk of grounding, which can lead to significant delays and potential damage to vessels. ...
... By understanding tidal patterns, vessels can plan their routes to take advantage of favorable tidal currents, reducing travel time and fuel consumption. Also, deferred acquisition allows for the analysis of data acquired during a voyage and the subsequent optimization of future routes, thereby contributing to overall maritime safety and efficiency [8,12,48]. The sharing of these types of data is also crucial to update or create hydrodynamic predictive models, including input from scientists and experts as well as regular and experienced sailors. ...
Maritime navigation safety relies on preventing accidents, such as collisions and groundings. However, several factors can exacerbate these risks, including inexistent or inadequate buoyage systems and nautical charts with outdated bathymetry. The International Hydrographic Organization (IHO) highlights high costs and traditional methods as obstacles to updating bathymetric information, impacting both safety and socio-economic factors. Navigation in inland and coastal waters is particularly complex due to the presence of shallow intertidal zones that are not signaled, where navigation depends on tidal height, vessel draw, and local knowledge. To address this, recreational vessels can use electronic maritime sensors to share critical data with nearby vessels. This article introduces a low-cost maritime data sharing system using IoT technologies for both inland (e.g., Ria de Aveiro) and coastal waters. The system enables the collection and sharing of meteorological and oceanographic data, including depth, tide height, wind direction, and speed. Using a case study in the Ria de Aveiro lagoon, known for its navigational difficulties, the system was developed with a Contextual Design approach focusing on sailors’ needs. It allows for the real-time sharing of data, helping vessels to anticipate maneuvers for safer navigation. The results demonstrate the system’s potential to improve maritime safety in both inland and coastal areas.
... The atmospheric model has a spatial resolution of 12 km and hourly outputs. The input of Aveiro lagoon discharge was obtained from an operational hydrodynamic model for the lagoon using the MOHID model and operated by Hidromod (Picado et al., 2022). ...
Implementing AI in all fields is a solution to the complications that can be troublesome to solve for human beings and will be the key point of the advancement of those spheres. In the marine world, specialists also encounter some problems that can be revealed through addressing AI and machine learning algorithms. One of these challenges is determining the depth of the seabed with high precision. The depth of the seabed is utterly significant in the procedure of ships at sea occupying a safe route. Thus, it is considerably crucial that the ships do not sit in shallow water. In this article, we have addressed the fuzzy c-means (FCM) clustering algorithm, which is one of the vigorous unsupervised learning methods under machine learning to solve the mentioned problems. In the case study, crowdsourced data have been trained, which are gathered from vessels that have installed sound navigation and ranging (SONAR) sensors. The data for the training were collected from ships sailing in the south part of South Korea. In the training section, we segregated the training zone into the diminutive size areas (blocks). The data assembled in blocks had been trained in FCM. As a result, we have received data separated into clusters that can be supportive to differentiate data. The results of the effort show that FCM can be implemented and obtain accurate results on crowdsourced bathymetry.
Shallow coastal lagoons driven by tidal processes are extremely dynamic environments prone to continuous natural and anthropogenic pressures. The hydrodynamics of these systems deeply depends on the effect of local morphology on the tidal propagation, so their permanent evolution constantly changes tidal dependent processes. For this reason, the present work aims to review the main characteristics of Ria de Aveiro hydrodynamics, a shallow lagoon located at the Atlantic Coast of Portugal, evaluating its evolution over the last 30 years (between 1987 and 2020) and investigating the main morphological changes in its origin. For this purpose, a comparative analysis is performed to determine the main process, including the observed hydrodynamic changes: Deepening of the inlet channel or of the main lagoon channels. To achieve these goals, the authors explored a remarkable database including bathymetric, tide gauge, and salinity data from 1987 until the present. This analysis is completed by the exploitation of a hydrodynamical model (Delft3D), validated against field data. Several simulations were performed to analyse changes in tidal propagation along the lagoon channels (considering the main semi-diurnal constituent M2), tidal asymmetry, tidal currents, tidal prism, and salinity patterns. The results show that the general deepening of the lagoon observed between 1987 and 2020 led to important changes in the lagoon hydrodynamics, namely the increase/decrease of the M2 constituent amplitude/phase, as well as the increase of tidal currents and salt intrusion within the entire lagoon, with the changes being amplified towards the head of the main channels. Although the inlet deepening partially contributed to the modifications found, the results revealed that the deepening of the main lagoon channels had the most significant contribution to the changes observed during the last 30 years.
The present study aims to research the physico-chemical processes in two under-researched coastal systems located on the west and south Portuguese coast—Mira Estuary and Ria de Alvor—through the development and exploitation of dedicated coupled physical and water quality models. Both systems are highly dynamic, supporting a wide range of biological diversity; however, they are characterized by distinct environmental and oceanographic conditions, enhancing the importance of a comparative approach. In this context, the Delft3D modeling suite was implemented and successfully calibrated and validated for both systems, accurately reproducing their hydrodynamic, hydrographic, and chemical features. A broad characterization of Mira Estuary and Ria de Alvor was carried out. Results show that the tidal wave interacts differently with the different geomorphology of each estuary. The tidal wave amplitude decreases as it propagates upstream for both estuaries; however, the magnitude for Ria de Alvor is higher. A flood tidal dominance was found for Mira Estuary, allowing the transport of well-oxygenated water into the estuary, contributing to high residence times in the middle estuary and therefore to poor dissolved oxygen (DO) replenishment. Ria de Alvor shifts from ebb dominance at the central area to flood dominance upstream with low residence times, allowing an effective exchange of water properties. Results also reveal that the water temperature is the dominant driver of seasonal dissolved oxygen variations in both estuaries, with the lowest levels occurring during the late summer months when the water temperature is highest. In addition, pH is influenced by biological activity and freshwater inflow.
Augmented Reality devices are about to reach mainstream markets but applications have to meet user expectations in terms of usage and ergonomics. In this paper, we present a reallife outdoor Marine Augmented Reality Navigational Assistance Application (MARNAA) that alleviates cognitive load issues (orientation between electronic navigational devices and bridge view) for vessels and recreational boats. First, we describe the current application and explain the requirements to draw relevant and meaningful objects. Secondly we present the 3D chart generator that extracts and provides the meaningful information to the application. Then, we detail our Marine Mobile Augmented Reality System (MMARS) and a generic architecture that can embeds MARNAA application. Finally, we present results and implementations.
Existing ship scheduling approaches either ignore constraints on ship draft (distance between the waterline and the keel), or model these in very simple ways, such as a constant draft limit that does not change with time. However, in most ports the draft restriction changes over time due to variation in en-vironmental conditions. More accurate consideration of draft constraints would allow more cargo to be scheduled for trans-port on the same set of ships. We present constraint programming (CP) and mixed integer programming (MIP) models for the problem of scheduling ships at a port with time-varying draft constraints so as to op-timise cargo throughput at the port. We also investigate the ef-fect of several variations to the CP model, including a model containing sequence variables, and a model with ordered in-puts. Our model allows us to solve realistic instances of the problem to optimality in a very short time, and produces bet-ter schedules than both scheduling with constant draft, and manual scheduling approaches used in practice at ports.
The natural evolution of the estuary-coastal lagoon system of the Ria de Aveiro, Portugal, was halted in 1808 by the construction of a new inlet/outlet channel through the sand spit which isolates it from the Atlantic Ocean. In consequence, tidal amplitudes in the lagoon increased from 0.07-0.13 m to over 1 m, Improvements to the channel since 1936, including construction of jetties, breakwaters and dredging, have increased its cross-sectional area. This has caused a steady increase in tidal amplitude to between 2.5 and 2.8 m, the erosion of mud flats, salt marsh and old salt pans, the widening and deepening of channels, and a greater capacity for sediment transport and dispersal due to the increased tidal currents. The volume of the tidal prism calculated for spring tides is now 1.7 times that in 1951; thus areas bordering the lagoon, especially agricultural fields, are experiencing a progressively increasing risk of flooding and salt water contamination at high water. Any future increase of mean sea level will contribute to an increase of both area and volume of the water mass and could cause important changes to the dynamics of the system. An increase in mean sea level of 0.1 m will, for example, correspond to an increase of 5 % in the capacity of the system and contribute to an increase in the speed of tidal propagation. The resulting increase in the volume of the tidal prism will be up to 22 % of the present maximum value.
Sado estuary (Portugal) is a mesotidal well-mixed estuary. The flow however, displays strong three-dimensional features associated with bathymetry variations. The flow is simulated using a three-dimensional primitive equation model based on the finite-volume method and incorporating a new concept for the vertical discretization. The innovative features of the model are analysed and the advantages of the finite-volume method to implement the generic vertical discretization are put into evidence. The model was validated using water level, velocity and salinity measurements in several stations along the estuary. Results show the influence of main channel's strong curvature on the generation of secondary flows inside the estuary. The steep bathymetry of the outer platform gives rise to a recirculation flow in the vertical plane that lasts for most of the tidal cycle. This structure is considered important for the sediment transport in that region. The above mentioned non-linear effects leave their print in both the transient and residual velocity fields. The results obtained help to understand the role of three-dimensional structures on the water exchange and sediment transport in the estuary. The results also confirm the suitability of the approach used in this model to simulate estuarine and coastal flows with strong three-dimensional effects. © 2001 Ifremer/CNRS/IRD/Éditions scientifiques et médicales Elsevier SAS Résumé ˛ Modélisation 3D dans l'estuaire du Sado avec une nouvelle approche par discrétisation verticale générique.Lestuaire du Sado (Portugal) est brassé par une marée méso-échelle, mais l uécoulement y présente des aspects
A high quality data collection has been carried out between 2004 and 2014 to develop the first trophic ECOPATH model for the functioning of the sub and intertidal zones of Ria de Aveiro. This schematic representation allows the characterization of the most important compartments of biomass and flows of energy representing the functioning of the ecosystem, and can be used in the fields of decision-making and management. The model considered 26 functional groups from primary producers to top-predators and two different fisheries (artisanal and leisure), and showed that Ria de Aveiro is a dynamic ecosystem dominated by a high biomass of primary producers, where the transference of energy among compartments is, to a large extent, accomplished through the detritus path. The model also provides several ecological indicators on the state of maturity of the ecosystem, showing that Ria de Aveiro is in an intermediate state of maturity with a relatively complex food web and resilience to environmental changes. As discussed, this state of maturity is probably determined by human action pervading the system to advance in the expectable ecological succession of a coastal lagoon. These aspects , together with indicators of elevated fishing pressure and predation within the system, underline the necessity of controlling illegal extraction activities and monitoring the biomass of the main functional groups of the system, especially top predators, in order to keep the functioning of the ecosystem of Ria de Aveiro in its current condition.
The planning of vessel navigation along a tidal river is a complex task that can affect the efficiency of inland ports and intermodal chains. The availability of water may represent a significant restriction to port accessibility, having an impact on waiting times, cost and even safety. This paper presents a heuristic procedure to schedule vessels on a tidal waterway, which seeks to optimise navigation according to a multi-criteria objective function combining the number of vessels serviced, the total waiting time, the waterway occupation time and the number of crossing operations, where the term “crossing” implies inbound and outbound vessels passing each other. The procedure requires a previous step of estimation of real-time water depth, which identifies the critical points or navigation bottlenecks along the waterway, and contemplates the possibility of vessels having to anchor in the middle of their journey and wait for next tide rise. We validate the procedure through its application to a set of real and test problems and show that its results are reliable in terms of performance and solution quality.
Ria de Aveiro is a shallow vertically homogeneous lagoon, located in the Northwest of Portugal, connected to the Atlantic through a very narrow artificial channel, and supplied with freshwater by two major rivers, Antuã and Vouga. The present study describes the application of a twodimensional depth integrated mathematical model, to predict tide-induced water level and depth mean current for the entire lagoon. The model computes time series of those variables as well as their instantaneous distribution at different times of the tidal cycle. Properties of tides and tidal currents in Ria de Aveiro are characterized and discussed. Special emphasis is given to the study of the hydrodynamic behaviour of the lagoon in extreme conditions of astronomical tide forcing, considering spring and neap tide conditions. Tides propagate from the mouth of Ria de Aveiro and are present in the entire lagoon. The tidal amplitude decreases with the distance from the mouth while the phase lag in the high and low water (which is different) increases. The tidal range increases for the spring tide at the far end of the channels correspond to a local increase of the high tide level, which result in a fortnightly variation of the mean levels at those places.
In the January 1977 issue of this Journal an article ‘The new buoyage system’ by the Hydrographer of the Navy was one of the many steps taken during the past two years to explain to chart users what IALA System A is all about. Newspapers, magazines, schools of navigation, yachting clubs and commercial printers have all helped to spread the gospel. There are on the market a variety of booklets, wall charts, plastic models, cassette teaching aids and films. The new symbols used to portray the details on the charts can be found in Navigation Publication NP735, available from Admiralty chart agents.
A s-coordinate three-dimensional model, regional ocean modeling system (ROMS), was implemented in the Western Iberian region ranging from the coast to 11 degrees W aiming high-resolution tidal simulations for an homogeneous ocean. The features for tidal heights and ellipses for the principal constituents, M-2, S-2, N-2, K-2, K-1, O-1, P-1 and Q(1), were imposed at the boundaries of the model. A tidal analysis for heights and tidal currents was done allowing to calculate two-dimensional distribution of amplitudes and three-dimensional structure of tidal currents. The amplitudes and phases for heights agree with previous results and observations, showing a good precision on the tidal propagation in the interior of the domain. Tidal kinetic energy is dominated by the semi-diurnal components, mainly M2, and increases on the shelf. Over the Lisbon Promontory the diurnal component K, is however the second more energetic harmonic. Vertical variation of tidal ellipse parameters evidences the different structure of semi-diurnal and diurnal tidal components, as well as differences between the open sea and shelf tidal Circulation. (c) 2006 Elsevier Ltd. All rights reserved.
Ria de Aveiro is a shallow coastal lagoon located in the Northwest coast of Portugal. The implementation and the assessment (calibration and validation) of the hydrodynamic, salt and heat transport models for Ria de Aveiro lagoon is presented. During the calibration the models parameters were adjusted to give the best fit of the model results to the field data. The hydrodynamic model calibration was carried out by comparing measured and predicted time series of sea surface elevation for 22 stations. The root-mean square of the difference between those values was determined and harmonic analysis was performed in order to evaluate the model ability to reproduce the tide propagation along the main channels of Ria de Aveiro. Validation of the hydrodynamic model was performed comparing measured and predicted sea surface elevation values for 11 stations, as well as velocities in the main flow direction for 10 stations and water flows for 6 stations. The salt and the heat transport models were calibrated comparing measured and predicted time series of salinity and water temperature for 7 stations. These models were validated comparing the model results with an independent field data set. Results indicate that the hydrodynamic, the salt and the heat transport models for Ria de Aveiro were successfully calibrated and validated.
This work describes the application of hydrodynamic (ELCIRC) and transport (VELA and VELApart) models to the Ria Formosa lagoon (Portugal) to study the impact of the relocation of the Ancão Inlet. Located in the south of Portugal, this lagoon is a mesotidal barrier island system that communicates with the sea through 6 inlets. The Old Ancão Inlet was artificially closed and the New Ancão Inlet was relocated into a westward position. This work investigates the hydrodynamic patterns and the potential pathways of tracers in Ria Formosa in two distinct configurations: before and after the Ancão Inlet relocation. The hydrodynamic model was successfully calibrated and validated against elevation, velocity and inlet discharges data, accurately reproducing the tidal propagation. The inlet relocation increases the magnitude of tidal currents, residual velocities and the tidal prism across the bar, suggesting a better stability. The tracers transport simulations suggest enhanced water exchanges through the Ancão Inlet and smaller residence times in the western part of Ria Formosa with the present configuration. Overall, it is concluded that the Ancão Inlet relocation had a positive contribution towards increasing the water renewal of the western part of the lagoon, thus decreasing its vulnerability to pollution.
In Ria de Aveiro, tides are distorted as they progress from the mouth toward the end of the channels. The general characteristics of the tidal wave are those of a damped progressive wave, presenting a decrease of the tidal amplitude and an increase of the phase lag due to bottom friction. According to the results obtained, Mohid-2D was successfully implemented, revealing an accurate reproduction of the tidal propagation within Ria de Aveiro. Therefore, the model can be used in future studies concerning the lagoon's hydrodynamics.
Guide to Marine Meteorological Services
WMO, World Meteorological Organization, 2018. Guide to Marine Meteorological
Services.