Identifying Port Calls of Ships by Uncertain Reasoning with Trajectory Data

Considering that ports are key nodes of the maritime transport network, it is of great importance to identify ships’ arrivals and departures. Compared with partial proprietary data from a port authority or shipping company, approaches based on compulsory Automatic Identification System (AIS) data reported by ships can produce transparent datasets covering wider areas, which is necessary for researchers and policy makers. Detecting port calls based on trajectory data is a difficult problem due to the huge uncertainty inherent in information such as ships’ ambiguous statuses and ports’ irregular boundaries. However, we noticed that little attention has been paid to this fundamental problem of shipping network analysis, and considerable noise may have been introduced in previous work on maritime network assessment based on AIS data, which usually modeled each port as a circle with a fixed radius such as 1 or 2 km. In this paper, we propose a method for identifying port calls by uncertain reasoning with trajectory data, which represents each port with an arbitrary shape as a set of geographical grid cells belonging to berths inside this port. Based on this high-spatial-resolution representation, port calls were identified when a ship was in any of these cells. Our method was implemented with around 14 billion AIS messages worldwide over 8 months, and examples of the results are provided.

Open source tools to support Integrated Coastal Management and Maritime Spatial Planning

This paper describes an open source suite of libraries and tools to support research activities on marine and coastal environment. The suite was initially implemented for the ADRIPLAN portal, an integrated web platform aimed at supporting Maritime Spatial Planning (MSP) activities and other activities concerning the managing of marine environment for the Adriatic-Ionian region. The main elements of the implemented solutions are: i) a GeoNode implementation for sharing geospatial datasets and maps; ii) a new python library (RectifiedGrid) that facilitates the work with geographical grid data; iii) a new python library (Tools4MSP) to perform spatial analysis and assessment of human uses, pressures and the potential impact of maritime and coastal activities on the environment; iv) a new GeoNode plugin (called GeoNode-Tools4MSP) that provides interactive widgets to set up the analyses and to visualize and explore the results. The Tools4MSP and the developed software have been released as FOSS under the GPL3 license and are currently under further development.

Open source tools to support Integrated Coastal Management and Maritime Spatial Planning

This paper describes an open source suite of libraries and tools to support research activities on marine and coastal environment. The suite was initially implemented for the ADRIPLAN portal, an integrated web platform aimed at supporting Maritime Spatial Planning (MSP) activities and other activities concerning the managing of marine environment for the Adriatic-Ionian region. The main elements of the implemented solutions are: i) a GeoNode implementation for sharing geospatial datasets and maps; ii) a new python library (RectifiedGrid) that facilitates the work with geographical grid data; iii) a new python library (Tools4MSP) to perform spatial analysis and assessment of human uses, pressures and the potential impact of maritime and coastal activities on the environment; iv) a new GeoNode plugin (called GeoNode-Tools4MSP) that provides interactive widgets to set up the analyses and to visualize and explore the results. The Tools4MSP and the developed software have been released as FOSS under the GPL3 license and are currently under further development.

Open source tools to support Integrated Coastal Management and Maritime Spatial Planning

This paper describes an open source suite of libraries and tools to support research activities on marine and coastal environment. The suite was initially implemented for the ADRIPLAN portal, an integrated web platform aimed at supporting Maritime Spatial Planning (MSP) activities and other activities concerning the managing of marine environment for the Adriatic-Ionian region. The main elements of the implemented solutions are: i) a GeoNode implementation for sharing geospatial datasets and maps; ii) a new python library (RectifiedGrid) that facilitates the work with geographical grid data; iii) a new python library (MSPTools) to perform spatial analysis and assessment of human uses, pressures and the potential impact of maritime and coastal activities on the environment; iv) a new GeoNode plugin (called GeoNodeMSPTools) that provides interactive widgets to set up the analyses and to visualize and explore the results. The MSP Tools and the developed software have been released as FOSS under the GPL3 license and are currently under further development.

Glacier shrinkage across High Mountain Asia

An assessment of glacier shrinkage (reduction of area) for all of High Mountain Asia requires a complete compilation of measured rates of change and also a methodology for objective comparison of rates. I present a compilation from 155 publications reporting glacier area changes, and also a methodology that overcomes the main obstacles hindering comparison. Glacier areas are not always assigned uncertainties, and this problem is addressed with an error model derived from published estimates. The problem of discordant survey dates is addressed by interpolating measured areas to fixed dates at pentadal intervals. Interpolation error depends only incoherently on the time span between measurements, but strongly on glacier size: smaller glaciers, in addition to changing more rapidly on average, exhibit more variable rates of change. The overlapping boundaries of study regions are reconciled by mapping all of the information to a 0.5° geographical grid. When coupled with glacier area information from the Randolph Glacier Inventory, the widely observed inverse dependence of shrinkage rates on glacier size shows promise as a tool for treating incomplete spatial coverage. Over High Mountain Asia as a whole from 1960 to 2010, the unweighted average shrinkage rate is –0.57% a–1, but corrections for variable glacier size raise the average to –0.34% a–1, and filling unmeasured gridcells with rates based on size dependence alters the latter estimate to –0.40% a–1. The uncertainties in these rates are large. The Karakoram anomaly is found to be a zonal feature extending well to the east of the Karakoram proper.

EFFECTS OF MESH RESOLUTION ON THE SIMULATION OF SEVERE THUNDERSTORM: THE NEED OF PARALLEL COMPUTING AND DISTRIBUTED TECHNIQUES

In the design of civil structures, it is necessary to consider the effect of the dynamic loads caused by changes in meteorological conditions such as wind speeds or ice deposits. In Argentina, the Standard of the Argentine Electrotechnical Association (AEA, 2006) is used to calculate structures of electrical transmission networks. This Standard specifies the value that must be assigned to the load by effect of the wind. This value is obtained from the meteorological records measured at conventional meteorological stations such as those of the National Meteorological Service. Nevertheless, to fit this parameter, it is also necessary to carry out local studies with updated information, considering the roughness and, in certain cases, the relief of the ground. Computational mechanics addresses this problem and is currently being used to estimate the values of maximum winds by simulations of severe meteorological events. However, it is also necessary to evaluate the results of this tool to know its accuracy in relation to the parameters of the numerical model. This work shows the use of the Large-eddy Simulation considering two options in the choice of element size used for a geographical grid domain in the thunderstorm occurred in Aranguren, Argentina, in 1998. In the first option, a processor is used to compute this event through a 406-meter grid-spacing in horizontal direction and in the second option a four-processor parallel method is used to obtain a more refined 200meter grid-spacing. The last option allows simulating severe events such as down-burst or vortex occurrence with more details.