Wyniki wyszukiwania - BazTech

1

Potential use of mangroves as nature-based solutions to improve navigation conditions in a Port in southern Brazil

Previti L. S., Alfredini P.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2023

|

Vol. 17 No. 3

507--513

EN

Mangroves and the associated shoal forest known as ‘restinga' are ecosystems of great ecological relevance that play a significant role in the protection of the coastline in tropical regions. In Brazil, the coastal region has been severely affected by urban expansion. The Paranaguá Port, located in Paraná State (Brazil), is the fourth most important Brazilian port in throughput, and is located in an estuarine region which features large mangrove forests. An historical assessment of its inner access channel dredging rates was made to assess the impacts that the expansion of the Port in the last 30 years may have caused to the ecosystem. In the following, the historical data concerning the dredged volume in the inner access channel was compared to the mangrove and the shoal forest associated variation, aiming to establish a potential correlation between vegetation and siltation in the inner access channel to show as the preservation or restoration of specific ecosystems has potential to Nature-Based Solutions.

2

Prediction of wetland loss due to sea level rise around the largest port area in Latin America

Alfredini P., Arasaki E.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2021

|

Vol. 15 No. 3

677--682

EN

Santos’s mangroves are important wetlands located in Brazilian coast, a fishing area inside Santos Bay. The overall healthy mangroves area along the riparian zones influencing the Santos Estuary is around 25.20 km2. The resulting tidal level recorded from Port of Santos tide gauge (from 1940 to 2014), also located in the estuary, shows consistent increasing trend. One healthy mangrove was selected for a previous qualitative biological survey to better understand the characteristics of the habitat to be monitored and evaluated about the possible impacts in the next decades. The mangroves situated a few meters upper from the sea level and some other areas have the risk to be submerged till 2085 which will seriously affect the riparian mangroves biome. Indeed, the mangrove area is confined downward by the low tide level and upward by existing structures, roads, rural and urban areas.

3

Behavior of sea level in the period of 1980 to 2017 on the port area of gulf of Maranhão, Brazil

Alfredini P., Arasaki E., Fortner E.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2021

|

Vol. 15 No. 3

683--686

EN

The Gulf of Maranhão, North Coast of Brazil, is one of the regions in the world with largest tidal ranges. The Port Area of Maranhão, in São Marcos Bay, represents the second most important in Brazil. The port facilities are naturally sheltered from swell, with nautical operations and maintenance dredging volumes directly conditioned by macro-tides, which exceed the 6.0 m tidal range, and associated tidal currents, which can reach 7.0 knots. In order to assess the behavior of sea levels in recent decades, in view of the influence of climate changes on tides in various ports around the world, a period of two lunar nodal tidal cycles of 18.61 years, from 1980 to 2017, was investigated using unpublished data recorded in tide gauges. The trend pattern obtained was analyzed statistically and, unlike many other port areas, a sensitive stability of the mean sea level was noted. An important conclusion is about the reduction in HHW and increasing in LLW, leading to a reduction in tidal ranges, in tidal currents and a significant reduction of the shear stress in the bottom, which may increase the dredging rates in the port areas in the next decades, due to an increasing siltation.

4

Fluid Mud and Nautical Bottom – Concept and Application in Itajaí Port Complex (Brazil)

Pion L.M., Alfredini P.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2019

|

Vol. 13, no. 2

445--452

EN

Considering the demand for mooring larger ships at Brazilian port terminals, both private and public, in a scenario of growing exports, engineering interventions that can provide improvements in the vessel’s maximum allowed dimensions can represent significant profits. Hence, this work presents an approach of Nautical Bottom, defined as the minimum depth in which ships can navigate without significant adverse effects in ship control and maneuverability without physical damage, with the goal of raising the maximum ship draft allowed in nautical spaces with fluid mud beds. Due to its rheological properties, fluid mud, in general, allows for vessels navigate with low or negative under keel clearance, respecting the established Nautical Bottom concepts. In addition, fluid mud layer thickness at port areas can possibly vary according to hydrodynamics and sedimentologic variations. This article presents an analysis of fluid mud thickness variations within the Itajaí Port Complex (Santa Catarina, Brazil) turning basin, where fluid mud layers are up to 2.5 meters thick, by means of analyses of bathymetric surveys and numerical modeling. The Itajaí Port Complex is located at the Itajaí-açu river estuary, which presents high variability of river discharge and suspended sediments. From bathymetric surveys, it is possible to observe fluid mud thickness from 0.5 to 2.5 meters. Numerical simulation results indicate suspended sediment load as a main environmental aspect for fluid mud thickness variations in the study area.

5

Estimation of Sea Level Rise in Santos Port (Brazil)

Alfredini P., Arasaki E.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2019

|

Vol. 13, no. 2

453--458

EN

Santos Port is located in São Paulo State Coast (Brazil), in an estuarine area inside Santos Bay named Baixada Santista. The currents behavior is forced by tides. The resulting tidal level variability (high tide, mean sea level and low tide) recorded from Santos Dock Company tide gauge (1940 to 2014), the longest series of continuous record of tides in Brazil, shows a consistent increasing trend. The estimation about the magnitude of mean sea level rise (MSLR) in recommendations, guidelines or requirements issued by different countries and agencies from 1990 provide examples of different approaches used around the world in comparison with the local trends obtained for Santos Port. It is concluded that MSLR will have a considerable impact upon the port, with approximately 1.0 m rise estimated from 1990 to 2100. Baixada Santista is a lowland situated a few meters upper from the sea level and some areas are possible to be submerged in the end of this century. Other two locations in São Paulo State Coast, Cananeia and Ubatuba, respectively to the SE and NW of Santos, were also compared with the port tidal data to evaluate the consistency of the trends.

6

Estimation and impacts of sea level rise in Santos Port and Adjacent Areas (Brazil)

Alfredini P., Arasaki E.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2018

|

Vol. 12, no. 4

739--744

EN

Santos Port is located in Brazilian coast, in an estuarine area inside Santos Bay named Baixada Santista. The currents behavior is forced by tides. The resulting tidal level variability (high tide, mean sea level and low tide) recorded from Santos Dock Company tide gauge (1940 to 2014) shows a consistent increasing trend. The estimation about the magnitude of mean sea level rise (MSLR) in recommendations, guidelines or requirements issued by different countries and agencies from 1990 provide examples of different approaches used around the world in comparison with the local trends obtained for Santos Port. It is concluded that MSLR will have a considerable impact upon the port and adjacent areas, with approximately 1.0 m rise estimated from 1990 to 2100. Baixada Santista is a lowland situated a few meters upper from the sea level and some areas are possible to be submerged in the end of this century. Not only the wetlands of mangroves will be affected, but also the infrastructures, residential zones and the port will face problems. The major SLR impacts upon port operation will be the reduction of freeboard of the quays, flooding of storage yards (and other low storage areas) and of the internal transport tracks or rails. Also the increasing sedimentation in the nautical areas of access channels, turning basins and berths, will induce more maintenance dredging.

7

Alternative study for the Nautical and Shore Protection Structures in the Estuary of Santos, Brazil

Alfredini P., Arasaki E., Bernardino J.C.M, Da Silva G.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2018

|

Vol. 12, no. 2

375--380

EN

For the enlargement of the nautical dimensions of Santos Port Outer Access Channel (Brazil), training walls crossing the Offshore Bar are needed. The training walls choice to reduce dredging rates also induces to consider a coupling planning between nautical purposes and shore protection measures, as Santos Municipality have serious erosion problems nowadays due to the urban growth in the backshore and sea level rise. For decision support, the Hydraulic Laboratory of Engineering School of University of Sao Paulo was commissioned to study in a composite mathematical and scale model. Results include changes in wave height and direction and current speed analysis to conditions with training walls and segmented breakwaters. The water renewal was also analyzed to the condition with segmented breakwater and compared to current situation, based on hydrodynamics results and considering that this structure can reduce water quality in this area.

8

Impact of climate changes on the Santos Harbor, São Paulo State (Brazil)

Alfredini P., Arasaki E., Pezzoli A., Fournier J.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2013

|

Vol. 7, no. 4

609--617

EN

Santos Harbor Area (SHA) in Sao Paulo Coastline (Brazil) is the most important marine cargo transfer terminal in the Southern Hemisphere. A long term relative tidal level variability assessment shows a consistent response to relative sea level rise. A wave data base Wave Watch III was compared with a long term wave data-base generated by the ERA40-ECMWF (2003), both local validated. The current bed level of SHA Outer Channel is -15.00 m (Chart Datum or, in abbreviation, CD), maintained by dredging. According to the cargo throughput forecast, in 2025, the Access Channel will have to be deepened to level of -17.00 m. The feasibility of that choice is discussed from a technical, economical and conceptual navigation point of view in that context. A data set found from a scale model of the whole area of Santos Bay, Estuary and nearby beaches, showed the impact of maritime climate changes upon the coastal area. In the previous researches developed by the authors, it was demonstrated that the wave climate, the tides and tidal currents affect harbor and coastal structures maintenance, beaches stability, tidal inlet, sediment transport, saline intrusion and wetlands. Considering the increasing of the sea hazards and the high values of the infrastructures in that coastline, it is necessary to mitigate the risks. Hence, based on the results obtained by the authors, are highlighted guidelines strategies suggested for Access Channels dimensions, wharves free-board, jetties dimensions, dredging rates, rigid and flexible littoral defenses and land protection against flooding (including wetlands).

9

Coastal Area Prone to Extreme Flood and Erosion Events Induced by Climate Changes: Study Case of Juqueriquere River Bar Navigation, Caraguatatuba (Sao Paulo State), Brazil

Arasaki E., Alfredini P., Pezzoli A., Rosso M.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2012

|

Vol. 6, no. 4

571--577

EN

According to the IPCC, the forecast for the year 2100 is an increasing of global average temperature, whose impacts in winds, waves, tides, currents and bathymetry will produce real risks of extreme events due to climate changes. Juqueriquere River is Sao Paulo State (Brazil) North Coastline major waterway. Due to minimum channel depths in the coastal bar, navigation is only possible for small leisure crafts and fishing boats and some cargo barges during higher tidal levels. This study case has been evaluated according to the relative sea level and wave climate scenarios forecasting, based on the meteorological recognition patterns of the last decades data for tides and waves. The impact of climate changes is obtained from this knowledge. The main goal of this paper is to have the initial conceptual description about the impacts on the bar navigation conditions of Juqueriquere to obtain guidelines for master nautical plans.

10

Analogical Manoeuvring Simulator with Remote Pilot Control for Port Design and Operation Improvement

Alfredini P., Gerent J. P., Arasaki E.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2011

|

Vol. 5, no. 3

315--322

EN

The use of an Analogical Simulator in shiphandling-manoeuvre tests (SIAMA) in waterways constitutes a useful tool for providing improvements in port design and manoeuvring rules, which, when en-hanced with other relevant hydraulic studies of Froudian scale models, is a source of valuable statistical in-formation. The time-scale of physical models fast-time runs complie with the square root of the linear scale, in this study-case the model time was 13.04 times faster than prototype. More than 1500 official tests having been undertaken since 1993 by 13 official pilots of three harbours, for manoeuvring and project optimization in 7 piers, with 10 berths, and radio-controlled ore carriers of 75,000, 152,000, 276,000 365,000, 400,000 and 615,000 dwt. The laboratory facilities belong to the Escola Politécnica of Sao Paulo University, Brazil. The port area studied comprised fairways, turning basins and berths. The ships and tugs were unmanned, with tug performance exerted by air fans.