Marko Perkovic

A generic ballast water discharge assessment model as a decision supporting tool in ballast water management

One of the critical issues in species invasion ecology is the need to understand and evaluate the dimensions and processes of aquatic organisms transfer with vessels ballast water. The assessment of the quantity of ballast water discharged as the medium of transfer is one of the basic elements of the decision making process in ballast water risk assessment and management. The possibility to assess this in advance of the vessels arrival to a port enhances the management process and gives port authorities a decision supporting tool to respond in time with adequate measures. A new generic ballast water discharge assessment model has been prepared. The model is based on vessel cargo operation and vessel dimensions. The model was tested on real shipping traffic and ballast water discharge data for the Port of Koper, Slovenia. The results show high confidence in predicting whether a vessel will discharge ballast water, as well in assessing the quantity of ballast water (to be) discharged. Highlights? A model to predict ballast water discharge was developed. ? The model was applied to the Port of Koper and verified on reported data from vessels. ? The model assesses vessel specific ballast water discharges. ? Ballast water discharge information is crucial for risk assessment and management. ? The model is a decision support tool for a more effective management in shipping.

Oil spill detection using COSMO-SkyMed over the adriatic sea: The operational potential

In this paper the potential of COSMO-SkyMed is examined for oil spill detection, focusing on the Adriatic Sea. The low revisit time and the radiometric characteristics of COSMO-SkyMed point to good suitability of the instrument for operational oil spill detection in the area. The possibility of querying Automatic Identification System (AIS) data over the area, with almost no coverage gaps, offers a unique instrument to aid verification activities and the eventual identification of the discharging ship.

Confidence levels in the detection of oil spills from satellite imagery: from research to the operational use

Detected oil spills are usually classified according to confidence levels. Such levels are supposed to describe the probability that an observed dark feature in the satellite image is related to the actual presence of an oil spill. The Synthetic Aperture Radar (SAR) derived oil spill detection probability estimation has been explored as an intrinsic aspect of oil spill classification, which fundamentally computes the likelihood that the detected dark area is related to an oil spill. However, the SAR based probability estimation should be integrated with additional criteria in order to become a more effective tool for the End Users. As example, the key information for the final users is not the confidence level of the detection “per se” but the alert (i.e. the potential impact of the pollution and the possibility to catch the polluter red-handed) that such detection generates. This topic was deeply discussed in the framework of the R and D European Group of Experts on remote sensing Monitoring of marine Pollution (EGEMP) and a paper was published in 2010. The newly established EMSA CleanSeaNet service (2nd generation) provides the alert level connected to the detection of a potential oil spill in a satellite image based on the likelihood of being an oil spill in combination with impact and culprit information.

Geospatial modelling of metocean and environmental ancillary data for the oil spill probability assessment in SAR images

The confidence level of oil spill detections in satellite Synthetic Aperture Radar (SAR) imagery requires the analysis of many different factors. Unfortunately, oil slicks are not the only phenomena which can appear as a dark feature in a SAR image. These include a number of parameters like wind speed, currents, internal waves, upwelling sea areas, algae bloom, mixing water areas, et cetera. These phenomena are called look-alikes. The largest challenge in detecting oil spills in SAR images remains in the accurate discrimination between oil spills and look-alikes. This study introduces the vantages of using geospatial analysis of various metocean data (e.g. wind speed and direction, sea surface temperature, wave direction, ocean colour data) and environmental ancillary data (e.g. vessel traffic, port locations) as a supplementary information source for the oil spill probability assessment in SAR imagery. The analysed data exists in different formats with different value scales. In addition, the parameters of the metocean data analysis are not equally important for a reliability of oil spill detection. The weight of metocean parameters depends on the impact of natural phenomena on SAR systems (e.g. wind and currents have pro rata more influence on the probability than sea surface temperature and chlorophyll-a) and the area of interest (e.g. chlorophyll-a is a more important value for the Baltic Sea than for the Mediterranean Sea). The derived oil spill probability categorisation based on the weighted analysis of metocean environmental ancillary data could be a useful tool for authorities for an efficient planning of cost-intensive verification flights.

Oil Pollution in Slovenian Waters: The Threat to the Slovene Coast, Possible Negative Influences of Shipping on an Environment and Its Cultural Heritage

Slovenian waters and the Slovenian coast are situated within and along the Gulf of Trieste at the northernmost part of the Adriatic Sea. Despite the extremely small area concerned, this seascape is rich in cultural heritage ranging from pre-Hellenic hillforts to currently operating traditional saltpans, with cities built mainly in the Venetian style, a region with protected waters and coasts that is passed by a relatively large number of commercial vessels. The absence of a historic calamity here is perhaps a mere function of probability and size. But if that’s been the luck of Slovenian waters, the risk is concomitantly greater with the rapid increase of traffic including dangerous cargos in ships plying in and very near this particularly sensitive shallow sea. And the fact is, accidents have occurred, the fragile ecosystem and rich heritage sites avoiding damage through sheer luck; yet they are increasingly under threat, at the mercy of elements man-made and natural that need only align malignantly for a catastrophe to occur. Case studies show recent events that might well be deemed near misses. Even minor instances of operational discharge represent a determined threat to the health of Slovenian seas.

Oil Spills in the Adriatic Sea

Despite the northwest-southeast orientation of the Adriatic Sea, commercially it is virtually a north–south sea, as it penetrates deep into the European continent, nearly to the foot of the Alps. Large vessel traffic is dense, and accordingly there is a great deal of operational pollution along with the constant threat of accidents and incidents. Researchers have developed the means to detect much of the pollution in the Adriatic, to estimate its extent, and even the means, through satellite images and the process of backtracking, to identify polluters. These techniques promise that the increasing volume of traffic in the Adriatic may coincide with a reduction of pollution from commercial vessels. However, many other sources of oil pollution are of concern, including offshore industry, fishing, natural seeps, extraction of natural gases and oil from beneath the seabed and the corroding wrecks from as long as 70 years ago. There is also concern that legislation is not strict enough in the cases of platforms and chemical tankers. Further issues and complications derive from the nature of the sea, which is shallow and is fed by a high number of streams and rivers. The Adriatic, as is actually the case for the entire Mediterranean, is classified as a Special Area (according to MARPOL Annex I), which limits the amount of legal discharging of oily wastes, for instance. In addition, since few years the possibility to extend to the Adriatic the status of Particularly Sensitive Sea Area (PSSA) is under discussion. Yet the likelihood that traffic will increase and the causes of pollution detailed here will persist suggests that the need for continued scientific intervention and further legislation will also increase if the Adriatic is to maintain a semblance of a healthy environment.

The Necessity of Applying Sar Imagery to Oil Spill Modeling in Cases of Data Obfuscation

Oil spill monitoring is all the more important during circumstances that prevent immediate action, such as the recent crisis in Lebanon during the Israel-Lebanon war. Conditions of war prevented the acquisition of routine and necessary information, such as: the precise quantity of oil lost to the sea, the rate and duration of escape flow (in this case initial reports were that the oil was ‘spilled’ during two separate events, yet subsequent images suggested continuous flow over a period of at least two weeks), the type of oil, precise locations, and shore characteristics. Accurate simulation of the Lebanon slick was possible only by using SAR imagery which, for one instance, demonstrated that the behavior of the slick ran counter to expectations informed by knowledge of winds, currents, and waves; that is, though the main mass behaved according to models, running up along the coast was a thin layer of oil spread up to 20 km out to sea, extending northward approximately 200 km. If this event may be of any benefit, it will be that it leads to the improvement of the applicable models by considering what has been learned by running our models for an extended period over a vast area in these particular circumstances.

Docking system based on laser measurements: Port of Koper case study

Smart systems are utilized in ports to provide safe handling of container carriers. A docking system, enabling very precise measurement of distance from vessel to quay aims to provide safe berthing. Such a system, supported by piloting functions (navigational chart and others) provides independent and reliable navigational information, reducing the amount of time spent on the procedure and eliminating uncertainties that could otherwise lead to accidents or incidents-at the very least delays. The increase in container throughput at Koper was made possible by extensive dredging activities and a pier extension. These activities have lengthened the container terminal so that it is now possible to berth a large mother vessel. To assure safe navigation through the narrow and bending channel, a laser-ranging system has been implemented. When a large container vessel is positioning alongside a quay where inadequate fenders are in place and Ship-to-shore (STS) cranes are close to the approaching ship, special care is required and parameters such as precise vessel position, transversal speed, and vessel-approaching angle are of great importance. To provide the information in real time, a laser docking system has been developed and integrated with metocean data. This paper will present the layout of the system and the first results related to the observed docking of large container vessels calling at the Port of Koper.

The Increase in Container Capacity at Slovenia's Port of Koper

The ports of the northern Adriatic are ranged in three countries. Kopers is the only one in Slovenia and therefore of distinctive import to the country, which with its limited coastal space has no other options for expanding maritime trade than increasing the capacity of this one extant port. The state of Slovenia is the largest shareholder and the future development of the port depends on decisions made by the Ministry of Infrastructure. The increase in container throughput in the Port of Koper requires a reconstruction and extension of the current container terminal as an absolute priority. Regarding economic sustainability, the extension must be in line with the estimated growth of traffic as well as with the exploitation of present and future terminal capacities. The occasional expansion projects must fulfill environmental and safety requirements. For large container vessels (LOA more than 330 m) calling at the Port of Koper the safety of the berthing and departure conditions have to be simulated under various metocean conditions. At the same time manoeuvres should not be intrusive – expected propeller wash or bottom wash phenomena must be analysed. When large powerful container vessels are manoeuvring in shallow water bottom wash is expected and because sediments at the port are quite contaminated with mercury some negative environmental influence is expected. The most important expected investment in the container terminal is therefore extending (enlarging) and deepening the berth. The paper will present statistics and methods supporting container terminal enlargement and a safety and environmental assessment derived from the use of a ship handling simulator.

Fluid Dynamic Models Application in Risk Assessment

Risk is a common name for the probability of a hazard turning into a disaster. Vulnerability and hazard are not dangerous in and of themselves, but if they come together, they generate a risk. However, risk can be reduced and managed. If we are careful about how we treat the environment, and if we are aware of our weaknesses and vulnerabilities to existing hazards, then we can take measures to make sure that hazards do not turn into disasters. Hazard from LNG (Liquefied Natural Gas) cargo begins in the first processing stage of natural gas liquefaction and loading the substance into LNG tankers. The transport itself over the sea is the safest part of the distribution process, as is demonstrated by the statistic of nautical accidents in the past 40 years (DNV, 2007, Perkovic et al., 2010 & Gucma, 2007). A review of a Rand Corporation document (Murray et al.) published in 1976 indicates a high level of safety for LNG tankers. The document indicates that in the initial 16-year history (from 1959 up to 1974) there had been no significant accidents. It should be noted, though, that in 1974 the world LNG fleet included only 14 vessels; by November, 2009, there were 327 vessels, a figure expected to increase to 350 vessels sometime in 2010 (LNG Journal, 2008). The DNV (Det Norske Veritas) counts 185 nautical accidents involving LNG tankers, all without severe consequences for the crew. The frequency of LNG tanker accidents is therefore 5.6 x 10-2 per ship year. The findings of the DNV (2007) furthermore demonstrate that the potential loss of life for the LNG crew member is 9.74 x 10-3 or less, considering the occupational fatality rate onboard gas tankers is 4.9 x 10-4. The analysis of the northern Adriatic Sea (Petelin et al. 2009), or, precisely, the gulf of Trieste, demonstrates that nautical accidents should occur with a frequency of 1.25 x 10-2 per year, assuming the current traffic density, and increases to 2.62 x 10-2 if the ship traffic increases by 100%. The hazard associated with LNG is mainly in its potential to cause severe fires resulting in heat radiation. If a large quantity of LNG is spilled into a pool, the cloud that is formed as it evaporates is a mixture of natural gas, water vapour, and air. Initially the cloud is heavier than air (due to its low storage temperature) and remains close to the ground. The buoyancy moves the natural gas upward at a gas temperature of around 170 K (-1030C), as experimentally demonstrated by ioMosaic (2007). The major influences on natural gas diffusion are environmental conditions. The cloud moves in the direction of the wind and the wind causes the cloud to mix with more air. If the concentration of gas in the air is between 5% and 15% it is flammable and burns if it contacts any ignition source. A concentration of gas smaller than 5% will not ignite and if the concentration is over 15% the air becomes saturated. The explosion of natural gas is not possible in open spaces because