Navigation Canals Research Articles

Impact of new, navigable canal through the Vistula spit on the hydrologic balance of the Vistula lagoon (Baltic Sea)

The object of research - the Vistula Lagoon is one of the two lagoons on the Polish coast, which is of great importance not only from an economic point of view, but also an environmental one. The purpose of the paper is to provide calculations on the current water balance for the Vistula Lagoon, before and after construction of a canal through the Vistula Spit. This is important because the construction of a new connection between the Vistula Lagoon and the Baltic Sea can result in changes in the lagoon's water balance, which in turn cause changes in the Vistula Lagoon biotic and abiotic environment. In addition, we wish to update the estimate of the water exchange between the Vistula Lagoon and the Baltic Sea through the Strait of Baltiysk and to estimate the exchange through the Vistula Spit canal after it is fully open. The main works consisted of researching source materials from various state institutions, which allowed to calculate the water balance of the Vistula Lagoon and perform mathematical modeling. These data include the amount of precipitation and evaporation, the amount of inflow from the catchment, the amount of inflow from polders, underground supply, the amount of inflow and outflow through the Strait of Baltiysk. The largest portion of the water received by a coastal lagoon comes from the adjacent ocean. In this case, it is about 75%. In addition, an array of catchment sources yields 20% of the studied lagoon's water. The Strait of Baltiysk constitutes the main outflow pathway for water exiting the Vistula Lagoon – close to 98% of outflow. Simulations have shown that the construction of the Nowy Swiat ship canal will not alter the water balance in the Vistula Lagoon to a meaningful extent. The problems that may emerge include those related to changes in the local biotic and abiotic environment due at the construction stage or in the period that follows resulting from the disturbance of highly polluted lagoon floor deposits. Thus it may be argued that the new canal is desirable from an economic or flood control point of view, but not from an environmental point of view.

CERCETĂRI EXPERIMENTALE PRIVIND RECOLTAREA STUFULUI CU AMBARCAȚIUNEA ELECTRICĂ “ERBA”

The article presents the results obtained from experimental research conducted with an electric equipment (a watercraft) for harvesting aquatic biomass (reed, cattail, water lily, etc.), remote controlled, symbolized as ERBA. This equipment was designed and built in Romania by researchers from INMA Bucharest and ICPE-CA, at the level of experimental model. The purpose of this equipment is to develop a national system of machines for cleaning lakes, navigable canals, and specific areas of the Danube Delta Biosphere Reserve from excess biomass that needs to be removed for the proper functioning of aquatic ecosystems. The harvested biomass is used as raw material for the production of liquid and gaseous fuels, as well as biofertilizers, which can be utilized as inputs in the bioeconomy. The phenological characteristics of the harvested biomass, the structural and functional characteristics of the vessel, the laboratory experimental records, the nautical indices, the exploitation indices, and the energy consumption were measured under different working conditions and regimes, and with different types of biomass.

A multibiomarker approach in clams (Ruditapes philippinarum) for a toxicological evaluation of dredged sediments

The Lagoon of Venice is often dredged for channel maintenance. To avoid harmful consequences to the ecosystem, a proper disposal of bottom sediments requires a preliminary evaluation of its potential toxicity before excavation. Here we evaluated the effects of polluted sediments on clams (Ruditapes philippinarum) using a multibiomarker approach. Bivalves were exposed for 3 and 14 days to five sediment samples collected along a navigation canal between Venice historical centre and the industrial area of Porto Marghera. Immunological, antioxidant, detoxification, and neurotoxicity biomarkers were analysed in haemolymph, gill, and digestive gland. As a control, sediment collected far from pollution sources was used. Two experiments were performed to assess potential seasonal/gametogenic influence in clam sensitivity. A different response of clam biomarkers was observed during the two experiments and among sampling sites. Clams’ digestive gland resulted to be the most sensitive tissue analysed showing significant differences among sites in all biomarkers analysed. Greater differences were present due to seasonality rather than exposure. The concentrations of metals and organic pollutants increased from the city centre to the industrial area, highlighting the influence that industrial activities had on the lagoon ecosystem. However, bioaccumulation in clams did not follow the same clear pattern, suggesting low bioavailability of compounds due to relatively high organic matter content. Biomarkers modulation was mainly driven by metals, both present in sediments and bioaccumulated. In comparison, effects of organic pollutants on the biomarkers tested were negligible. Other sources of contamination not investigated (e.g. pesticides) were suggested by neurotoxicity biomarkers alteration.

Contaminants from dredged sediments alter the transcriptome of Manila clam and induce shifts in microbiota composition

BackgroundThe reuse of dredged sediments in ports and lagoons is a big issue as it should not affect the quality and the equilibrium of ecosystems. In the lagoon of Venice, sediment management is of crucial importance as sediments are often utilized to built-up structures necessary to limit erosion. However, the impact of sediment reuse on organisms inhabiting this delicate area is poorly known. The Manila clam is a filter-feeding species of high economic and ecological value for the Venice lagoon experiencing a drastic decline in the last decades. In order to define the molecular mechanisms behind sediment toxicity, we exposed clams to sediments sampled from different sites within one of the Venice lagoon navigable canals close to the industrial area. Moreover, we investigated the impacts of dredged sediments on clam’s microbial communities.ResultsConcentrations of the trace elements and organic chemicals showed increasing concentrations from the city of Venice to sites close to the industrial area of Porto Marghera, where PCDD/Fs and PCBs concentrations were up to 120 times higher than the southern lagoon. While bioaccumulation of organic contaminants of industrial origin reflected sediments’ chemical concentrations, metal bioaccumulation was not consistent with metal concentrations measured in sediments probably due to the activation of ABC transporters. At the transcriptional level, we found a persistent activation of the mTORC1 signalling pathway, which is central in the coordination of cellular responses to chemical stress. Microbiota characterization showed the over-representation of potential opportunistic pathogens following exposure to the most contaminated sediments, leading to host immune response activation. Despite the limited acquisition of new microbial species from sediments, the latter play an important role in shaping Manila clam microbial communities.ConclusionsSediment management in the Venice lagoon will increase in the next years to maintain and create new canals as well as to allow the operation of the new mobile gates at the three Venice lagoon inlets. Our data reveal important transcriptional and microbial changes of Manila clams after exposure to sediments, therefore reuse of dredged sediments represents a potential risk for the conservation of this species and possibly for other organisms inhabiting the Venice lagoon.

The Construction of the First Volga-Don Canal of Peter the Great

This article studies the history behind the construction of a navigable canal meant to connect the Volga and the Don through their tributaries, the Kamyshinka and the Ilovlya, in 1697–1698. The authors aim to clarify the history of the first project of Peter the Great to modernise the country’s transport infrastructure and analyse it in the context of the events of the initial stage of the Petrine era. The study refers to maps and plans of the area, materials of office work – documents that both have been previously published and are introduced into scholarly circulation for the first time and come from the funds of the Russian State Archive of Ancient Acts, as well as the results of archaeological exploration carried out at the Selimov Val cultural heritage site in the village of Petrov Val in Kamyshin district of Volgograd Region. The study demonstrates that the period of 1697–1698 saw the construction of a structure meant to perform both fortification and hydraulic functions in the interfluve of the Kamyshinka and the Ilovlya. B. A. Golitsyn and E. I. Ukraintsоv controlled the construction, while Prince A. F. Shakhovsky directly supervised it. The project was authored by engineer J. Bröckell, and Peter I attached great importance to it, repeatedly discussing it with European statesmen and scientists during the Great Embassy. Pososhniye lyudi (people in sokha-based military service) were recruited in the settlements and districts of the Volga cities and did the construction work on the Kamyshinka. Logging was carried out along the River Sura in Alatorsky and Yadrinsky uyezds. By the end of 1697, a fortification was built where the Kamyshinka and the Ilovlya were closest to each other, the remains of the fortification perfectly preserved to this day. However, it turned out impossible to build a navigable canal. Having received news of the departure of J. Bröckell, the author of the first project, from the country in the winter of 1698, Peter I and other members of the Great Embassy began to look for and invite “sluice masters”, i. e. specialists in the construction of navigable canals. Thus, the first unsuccessful attempt to connect the Volga and the Don was why the tsar paid close attention to the theoretical and practical issues of building navigable canals as a significant area of science and technology.

The Spatio-Functional Role of Navigable Urban Canals in the City: Cases From London and Amsterdam

Cities incorporating navigable canals have played a crucial role in global trade and provided a platform for a range of activities for people from various locations. This research aims to comprehend the role of inner-city canals, formed as branches of shipping canals, in the spatial accessibility and functional structure of two contemporary urban systems: London and Amsterdam. Both cities are major post-industrial hubs in Europe and their spatial development and socioeconomic conditions have been greatly influenced by waterways. While the canal network in Amsterdam was planned alongside street layout planning in the early 17th century, serving commercial purposes, canals were integrated into London’s pre-existing urban form mainly for transportation in the 19th century. The current situation in these cities is impacted by this disparity in three ways: (a) the potential use of canals in the urban transportation system; (b) the spatial accessibility of street networks; and (c) the correlations between street accessibility and land use patterns in canal neighbourhoods. The research employs analytical methods of space syntax, geographic information systems, and statistical techniques to create and apply integrated urban models, incorporating spatial network measures, retail density, and functional diversity for street segments, to compare various urban conditions. The research reveals the crucial finding that the incorporation of canals into the street system leads to a substantial increase in the mean values of street network accessibility in Amsterdam. Additionally, the study highlights the vital contribution of diagonal streets linked with canal networks towards retail density in this city. In contrast, the accessibility measures and spatial patterns of urban functions in London are predominantly influenced by proximity to canals.

Impact of Backwater Tourism on Environment

Houseboat tourism is gaining popularity in Kerala's backwaters and interconnected navigable canals. Houseboats are the backbone of the Kerala Backwater Tourism Industry, and their physical and morphological characteristics make them less than ideal for supporting tourism operations. The number and variety of houseboats have, however, shed light on the state's natural and cultural resources, highlighting their vulnerability and the need for more cautious destination lifecycle management and appropriate government intervention to ensure their long-term viability. The research shows that houseboat tourism in Kerala is still in its early phases of development as a tourist product, but there is already evidence of change that raises both positive and negative sustainability concerns.

Use of Bituminous Geomembrane (BGM) to Waterproof Large Canals

Bituminous geomembranes (BGM) collaborate in the global challenge of improving water resources management by waterproofing hydraulic works. BGMs are multi-layered composite geomembranes with each of the components providing a technical benefit on large canals projects. These technical advantages include: A very low Manning coefficient for efficient water flow, extreme puncture resistance, which allows rapid deployment on rougher subgrades and permits many types of cover directly on top, excellent resistance to wind uplift due to their high surface mass, meaning installation can be done in strong winds up to 40 km/h. BGMs also have a very low coefficient of thermal expansion and do not wrinkle with changes in temperature like other polymeric membranes do. This is particularly useful in high heat projects when geomembrane is left exposed, providing a more secure project in the long run with less risk of wrinkle-induced cracks and failures. To illustrate this, this presentation will describe the composite structure of bituminous geomembranes and will explain its main advantages in the hydraulic field. All these will be presented with the description of test results in different types of large width canals: Canals for irrigation: in France, for the waterproofing of the Canal de Provence; in India, where the Maharashtra state decided to replace original concrete for a geomembrane lining system in Pench Canal. Navigable canals: in France where VNF (French Waterways) chose the BGM for waterproofing the repairs of its canals. A work near Montargis will be presented as well as waterways in England (Lancaster Canal) and Canada (Chambly Canal). Finally, hydroelectric power canals will be also described: at the Sankt Dyonisen power plant in the Alps in Austria and the Cumpeo power plant in the Maule region in Chile.

Promoting ecological solutions for sustainable infrastructure

Linear infrastructure networks such as roads, railways, navigation and irrigation canals, and power lines have grown exponentially since the mid-20th century. Most of these networks built before the 1990s have a significant impact on the environment. While there is no doubt that humanity needs infrastructure to ensure safe, secure and sufficient access to food, water and energy, it is essential to prevent the loss of biodiversity and ecosystems which are also at the basis of the provision of such fundamental services. Those complex, interconnected issues cannot be tackled without research and innovation, both in the fields of biodiversity and of infrastructure. IENE (Infrastructure Ecology Network Europe) was set up in 1996 to meet this need. Its mission is to promote the exchange of knowledge, experience and best practice in safe and sustainable pan-European transport infrastructure. With a status of an association today, this independent network has more than 400 members consisting of researchers, engineers, decision makers and infrastructure operators. IENE functions as an international and interdisciplinary forum. It supports cross-border cooperation in research, mitigation, planning, design, construction and maintenance in the field of biodiversity and transport infrastructure. Every two years, IENE organises an international conference to present cutting-edge research, identify pressing issues and problems, discuss effective solutions and map out future activities in the field of transport ecology and infrastructure. We are very glad to present you in this special issue some of the best scientific outcomes of the IENE 2020 conference, hoping that it will contribute to further breakthroughs in science and uptake in policy-making and practices on the ground. We commend the organising team of the University of Evora, Portugal, for their excellent programming of the conference and for having gathered exceptional scientists on the topic of biodiversity and infrastructure. They managed to host a high-quality event, despite the many adjustments that had to be done because of the covid-19, including postponing the conference to January 2021 and holding it entirely online. The topic of IENE conference 2020 was “Linear Infrastructure Networks with Ecological Solutions” and the motto was “working together”. This means that every stakeholder has a role to play, and that biodiversity should be considered at all governance scales and during all phases of the set-up of infrastructure. The papers selected here are of particular interest to follow the path set forth in the conference’s final declaration, that is included in this issue.

Współczesne doświadczenia i trendy w stosowaniu sztucznego zasilania polskich brzegów morskich i zalewów ze szczególnym uwzględnieniem Półwyspu Helskiego = Recent experience with and trends in the artificial nourishment of marine and lagoon beaches in Poland, with a particular focus on the Hel Peninsula

Artificial beach nourishment is one of key methods preventing coastal erosion and flooding, acting in support of the maintenance of much-disturbed coastal environments and their much-desired recreational functions. Beach fills have been implemented since the 1930s, though relevant conceptual studies in Poland were elaborated in the 1960s and 1970s. Recommendations at that time included a maximisation of the use made of sand dredged from navigation channels and canals, with a view to this being used to nourish abraded beaches near ports. In 1978, sand by-passing was implemented successfully at the Dźwirzyno and Rowy fishing harbors, with regular dredging of the approach channels and harbour canals being combined with the pumping of a water-sand mixture on the lee (eastern) side of breakwaters. These systems have remained operational through to the present day. Between 1980 and 2014, 32.2 M m3 of sand were deposited along the Polish coast and lagoon shores. This offered partial compensation of the reduced nearshore sand deficit, and served to increase resilience of beaches and the backshore in the face of erosion and inundation, while also helping with the contamination of beaches due to uncontrolled emissions in the course of events of the latter type. More than half of the total fill volume was deposited along the offshore coast of the Hel Peninsula, where a comprehensive scheme for coastal protection was implemented between 1989 and 1995. Following Poland’s adoption of the Coastal Protection Act 2003, fills became the most popular coastal-protection measure. Between 2004 and 2014 this measure was resorted to predominantly along offshore stretches of the Hel Peninsula, and at beaches adjacent to open sea ports on their lee (eastern) sides (including harbours from Łeba along to Dziwnów). Fills were also performed along the shores of the Gulf of Gdańsk, where erosion processes have accelerated in recent decades; and at the open-sea beaches near Jarosławiec, Ustronie Morskie and Niechorze. The latter installations operated in support of existing protection schemes. Comprehensive protection of the soft cliff between Rewal and Trzęsacz was also inaugurated, the background erosion tendencies ongoing their having coincided with anthropogenic activities causing disruption to local geodynamic processes. Since the time of adoption of the Coastal Protection Act, a total fill volume of 10.5 M m3 has been deployed, see Table 1. This represents about one-third of all the filling done from 1980 until 2014. Many positive changes are to be identified along the open-sea coast of the Hel Peninsula, on which more than 17.5M m3 of sand were deposited in the years from 1989 through to 2014, cf. Table 1, Figs. 3, 4 and 5. The large fill volumes achieved during the first 5 years of implementation of the protection scheme along the Peninsula resulted in rehabilitation of the nearshore seabed to such an extent that follow-up re-nourishment only needed to assume a lesser intensity. Morphometric parameters along the nourished beaches allow for them to be classified as very highly resilient in the face of hydrodynamic forces.Since erosion tendencies prevail in Poland’s coastal zones, any cessation of beach fills may result in a gradual loss depletion of the level of safety achieved. Thus, annual deposition of several hundred thousand m3 of sand along the offshore beaches of the Hel Peninsula continues to represent an absolute necessity if the current level of resilience is to be maintained. Reduction of nearshore sand deficits by way of beach filling represents the only method of preventing negative beach responses. Re-nourishments are determined by hydrological and morphodynamic factors, and should gain incorporation into the protection actions being planned by coastal authorities.

Valuing the Environmental Benefits of Canals and Canal Restoration Using House Prices

This paper values the local environmental benefits of historic, navigable canals using property values. We employ regressions on high-volume transaction data, controlling for micro-geographic fixed effects, and cross-check these estimates against a causal, difference-in-differences analysis of a local canal restoration project. We find a price premium within 100 m, suggesting benefits for canal-side properties with a direct outlook or immediate access, around 5% before the 2008 recession, falling to 3.4% by 2016. These locations have a higher proportion of new-build sales, suggesting they attract developers. Our calculations imply canals generate land value uplift of £0.8-0.9 billion in England and Wales.

Trying to choose the less bad route: Individual migratory behaviour of Atlantic salmon smolts (Salmo salar L.) approaching a bifurcation between a hydropower station and a navigation canal

Contrary to small- and medium-sized rivers, little attention has been paid to the downstream migration of Atlantic salmon smolts in large-sized rivers and the size-related impact of hydropower stations. From 2014 to 2016, we investigated the downstream migration of n = 72 acoustic-tagged smolts in the Meuse river at a bifurcation zone between a hydropower station equipped with three Kaplan turbines and a navigation canal. A hydrodynamic model that solves the depth-integrated shallow water equations on a Cartesian grid using a finite volume technique was used to infer the influence of water discharge and flow velocity on the smolts' behaviour upstream of the hydroelectric complex. Of the migrating smolts, 41.5% performed back and forth movements before approaching the complex for the first time, sometimes over long distances and at a slow pace, leading to significant delays (3–298 h). Beyond about 250 m3 s−1, the water flow direction changes towards the hydropower station with a gradual acceleration. A median water discharge of 161 m3 s−1 and associated median flow velocity of 0.14 m s−1 tended to favour a more direct and downstream movement towards the hydropower station. On the other hand, the navigation canal was mainly approached at low water discharge (median 132 m3 s−1), due to a higher flow velocity (median 0.11 m s−1) at the entrance. Of the released smolts, only 38.6% passed through the complex, of which 36.4% migrated by the navigation canal and 63.6% by the hydropower station, with a median research time of 04:44. Among all the released individuals, the escapement rate at the end of the study site was 2.9% by the canal and 8.3% by the Meuse river. This site, which offers two non-optimal, unattractive and unsafe migration routes, turns out to be problematic for successful downstream smolt migration.

Контроль системы течений и полей концентрации общего взвешенного и растворенного органического веществ в озере Донузлав в мае 2019 года

Based on the results of the expedition carried out in May 2019 by the A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS, data on the local system of currents and the structure of the content of the total suspended matter and dissolved organic matter fields in the waters of Donuzlav Lake are obtained. It is shown that the local system of currents in the upper layer of the lake waters is represented by two cyclonic eddy formations. At the bottom along the navigable canal, a pronounced current stream directed into the sea is noted. In the structure of the total suspended matter and dissolved organic matter fields, three anthropogenic maximums of concentration coinciding in location are found, which are located at the site of sand mining, in the area of the port and in the Shchelkunov Bay, where there is a household waste collector. In the structure of the field concentration of total suspended matter and dissolved organic matter, three sites of anthropogenic concentration maxima coinciding at the location are found. They are located on the sand mining site, in the port area and in the Shchelkunov Bay, where the household waste collector operates. Sand mining, port and household waste collector are the main sources of water pollution in Lake Donuzlav. In the area of the mussel-oyster farm, an increased concentration of dissolved organic matter is identified, as a likely consequence of the vital activity of mollusks concentrated here.

Metode određivanja brzine strujanja vode u kanalima u cilju zaštite kosina i dna kanala od rušenja

The paper analyzes the navigating conditions of the displacement type ships for the transport of our shipping companies on the channels of the Danube-Tisa-Danube hydro system in order to determine the navigation speed at which the speeds of water flow of opposite direction occur so that the channel banks and the bottom are protected from collapse. The methods applied in the work were created as a result of special research conducted on the Moscow and Volga-Don channels by two scientific institutions of the Russian Federation: the Main Research Institute of Water Transport (GIIVT) and the Scientific Research Institute of Water Transport (NIIVT). The results of this research have been published in literature in the Russian language. The aim of the authors was, based on these published methods, to examine and determine the impact of the movement of ships of our shipping companies on the shores and bottom of the canal as a new step in preparations for finding the optimal regime of navigation on navigable canals. Self-propelled (motor) ships for the transport of cargo of different types in channels of variable cross-sectional area and at different navigation speeds were subjected to calculations.

Individual variation influences avoidance behaviour of invasive common carp (

Uncontrolled biological invasions are reducing freshwater ecosystem diversity and resilience. Research is needed to evaluate whether non-structural deterrents are feasible within lock or canal environments. This study examined common carp (Cyprinus carpio) and buffalo hybrid (Ictiobus) movement patterns in response to acoustic and stroboscopic deterrents. Twelve strobe lights and one underwater speaker were deployed across the centre of a ship slip, with an environment analogous to a navigation canal. Common carp (n = 6) and Ictiobus (n = 4) were implanted with acoustic telemetry tags, and their behaviours were examined under control, stroboscopic, and acoustic stimuli for 60-min trial periods. Trials were run during the day and night for six straight days. Linear models determined that the stroboscopic and acoustic stimuli altered fish positioning within the ship slip, but produced weaker avoidance responses than those observed elsewhere. Weak responses were likely due to a strong preference for the open end of the ship slip and a lack of acoustic refuge during the acoustic treatment. Avoidance responses also differed widely among individuals of the same species, with fish expressing repeatability of avoidance radius size across trials. Ambient and stimulus sound-pressure levels should be carefully considered when deploying acoustic deterrents.

Modeling the Input of Suspended Solids’ Runoff from the River Don into Taganrog Bay in the Azov Sea

Using a mathematical model of wind currents, supplemented by a module for the suspended sediment silt transfer and sedimentation, the spatiotemporal features of the accumulation of river sediments in the Don avandelta in different wind conditions (east and west wind surges and light winds of variable directions) are identified. It is shown that the exposure to an east wind of 6 to 8 m/s during the entire settlement period (6–7 calendar days) makes the water movement in Taganrog Bay progressive, and under the action of a southwest wind of the same speed, the pattern of current lines changes over time from progressive movements on the first day to the formation of two circulation zones in the area of the city of Taganrog and in the central part of the Don avandelta. It is also shown that the fields of suspended matter concentration are similar for different fractions of solids. Under the action of the east wind, they stretch along the extension of the axis of the main delta arms at the bay; under the action of the southwest wind, they are pressed to the arms’ mouths. During the east wind surges, the heavy fractions of sediment settle in the area of the Azov-Don navigable canal, and the light ones are carried off by the stream towards the bay. During the west wind surges, the sedimentation of the suspended solids occurs near the estuary, the heavy fractions form three areas of bottom deformation near the mouths of the main delta arms and the light ones, only two areas.

Man's impact on the transformation of channel patterns (the Skawa River, southern Poland)

AbstractThe research objective was to answer the question, how and why have the patterns of the channels of the lower course of the Skawa River changed over the past 200 years? This problem is important in the context of contemporary waterway construction plans in Poland. Overall, this study shows the effects of natural restoration in the event of the destruction of bank protections. The Skawa River is a mountain tributary of the Vistula River (southern Poland). In the first step, the channels were classified in the period from the 19th to the 21st centuries. In the second step, it was checked how channelization, water damming, gravel mining, embankment construction, changes in the forest area and channel incision, determined the change of the channel patterns. There were four periods in the functioning of the Skawa riverbed. In the first period (before 1901), the reaches of a natural riverbed were sinuous, braiding, or anabranching. In the second period (1901–1943), the riverbed was completely channelized. In the third period (1943–2003), the riverbed had artificial, braiding, and sinuous reaches. In the fourth period (after 2003), the riverbed had high energy anabranching and sinuous reaches. This study shows that man led to the transformation of the Skawa River channel due to the building of the network of navigable canals and rivers. This study shows how various factors can determine changes in the channel pattern, and that the destruction of bank protections enables natural restoration and forming the braided or anabranching channel pattern.

Determining the Best Possible Speed of the Ship in Shallow Waters Estimated Based on the Adopted Model for Calculation of the Ship’s Domain Depth

Abstract The purpose and scope of this article is to present the best marine practices used to determine the ship’s domain depth (compared to the safety depth parameter in ECDIS) and the safest and best possible speed (also known as optimal speed) of the ship in restricted sea areas limited by the depth of navigation waters. The author also presents a method that can be used to estimate the safe speed of a ship in shallow waters and the so-called navigational risk factor (specified in the range from 0 to 1), using the safety depth parameter specified in ECDIS based on the analysis of a three-dimensional model of the ship’s domain. The essence of the method proposed in this paper is a systematic approach to the operation of a seagoing ship in the aspect of assessing its navigation safety (navigational risk factor) when manoeuvring in restricted sea areas, in particular in shallow waters including navigable canals and fairways.

A Study on Significance of Backwater Tourism and Safe Houseboat Operation in Kerala

The Backwaters of Kerala are historically important. The backwaters and interconnecting navigable canals have made a number of rural tourism destinations with matchless beauty.These backwater systems were once Kerala’s own trade highways.The major component of backwater tourism is houseboat cruising.The State has sensed the potential of backwater tourism in nowadays.Mass tourism movement in this sector caused for the multidimensional impacts on the economic,socio-cultural and bio-physical environment.Being an Eco-tourism product, backwater tourism needs sustainable and responsible tourism practice. Considering the need for the sustenance of the houseboat operation as a unique tourismproduct,it is mandatory to ensure the quality of facilities and services. In this paper, the researcher is trying to focus on the importance of backwater tourismin Kerala. Also giving special attention to identify various aspects of safe houseboat operations and the issues related. The major issues related to houseboat operation are lack of infrastructure,issues of licensing,issues of safety, environmental issues, and lack of quality services.In this study, the researcher is highlighting the need for the sustenance of the house boating by giving effective recommendations to reduce the negative aspects.

Heavy metals and 137Cs levels in macrophytes and temporal distribution in sediments – application for estuarine environment status assessment (Vistula Lagoon – southern Baltic)

Abstract The paper presents the first data on the concentrations of heavy metals (Cd, Pb, Zn, Cu, Ni, Cr, Mn) and 137Cs and their contamination ratios (CR) in the most abundant species of macrophytes in the Vistula Lagoon. No significant differences in the concentrations of heavy metals and 137Cs between macrophyte taxa or the influence of rivers flowing into the Vistula Lagoon on heavy metal concentrations in the area were found. The concentrations of heavy metals in macrophyte taxa varied in the following ranges: Cd – 0.1–0.7 mg kg−1 d.w.; Pb – 0.5–5.0 mg kg-1 d.w.; Zn – 29–390 mg kg-1 d.w.; Cu – 2.5–8.3 mg kg-1 d.w.; Ni – 0.4–6.8 mg kg−1 d.w.; Cr – 0.5–2.8 mg kg−1 d.w.; Mn – 380–8500 mg kg−1 d.w. Since the 1990s, a decline or stable state of heavy metal concentrations in bottom sediments has been observed, reflecting changes in the environment of the Vistula Lagoon. The linear sedimentation rate in the Vistula Lagoon was 3.3 mm y−1. The results presented in the paper can serve as a baseline for assessing changes in the environmental status of the Vistula Lagoon, which may occur as a result of future investments, including building a new navigable canal through the Vistula Spit.