Visual Analysis of Place Connectedness by Public Transport

The concept of place connectedness (traditionally termed `accessibility') refers to the ability of people to reach various services and to participate in activities. Connectedness by public transport is especially important for underprivileged and elderly people while the active use of public transport by the general population contributes in reducing traffic congestions and air pollution in cities. Place connectedness analyses are performed for a variety of purposes. In communication with transportation experts, we performed the conceptual modeling of the domain of problems related to place connectedness, defined the system of analysis tasks, and matched the tasks to visual analytics techniques that are capable to support them. In this paper, we introduce the task typology and present the visual analytics techniques using several example scenarios of place connectedness analyses

Route Packing: Geospatially-Accurate Visualization of Route Networks

We present route packing}, a novel (geo)visualization technique for displaying several routes simultaneously on a geographic map while preserving the geospatial layout, identity, directionality, and volume of individual routes. The technique collects variable-width route lines side by side while minimizing crossings, encodes them with categorical colors, and decorates them with glyphs to show their directions. Furthermore, nodes representing sources and sinks use glyphs to indicate whether routes stop at the node or merely pass through it. We conducted a crowd-sourced user study investigating route tracing performance with road networks visualized using our route packing technique. Our findings highlight the visual parameters under which the technique yields optimal performance

Optimal Cartographic Representation of Geographical Mobile Phenomena on Thematic Maps

Nature is full of geographical kinetic phenomena; some are tangible such as population emigration, money transfer, goods movement and transportation. Yet others are intangible such as energy, thoughts, reputation and civilization. These phenomena have got specific characteristics while moving such as the movement’s route, speed, locations, strength of the kinetic phenomena and their type and structure. Different geographical kinetic phenomena can be illustrated on maps called “Animation Maps”, which are considered part of the Thematic Maps, based on their nature and function by the motion symbols. This article studies most of the cartographic representation methods that are used in designing Thematic Maps. It also concentrates on motion symbolizing methods. It studies the nature and types of kinetic phenomena and identifies their different characteristics, and presents and analyzes its numerous demonstration ways on maps, using animation symbols. Finally, it reveals the best ways to design and present Animation Maps. This paper aims to study kinetic phenomena and their kinds and characteristics, and to analyze the methods currently used to demonstrate them on Animation Maps. This leads to suggest new methods and ways in this field, in order to assist in demonstrating geographical phenomena on maps accurately and clearly. The study reached a number of results such as determining cartographic representation methods and their fields, and finding the best optimal representation methods of kinetic geographical phenomena, and their different characteristics on Thematic Maps, and thus determining the best methods to design and present Animation Maps

The Association Between Anticyclonic Weather Changes Over the Central Gulf Coast and Large-Scale Circulation Changes.

Trends in winter extratropical anticyclonic weather type frequencies (1961-1989) were examined for New Orleans, Louisiana, in order to identify the effects of global climatic change on regional-scale circulation changes over the central Gulf Coast. The number of days dominated by surface continental anticyclones (CH days) was found to have decreased significantly over time, while Pacific anticyclone (PH) frequency showed significant temporal increase. Therefore, 50 kPa geopotential height variability, 50 kPa geostrophic flow, and surface atmospheric variables were examined to determine whether changes in these features have accompanied the frequency changes in weather types. Prior to PH days, areas of greatest height variability were located over the subtropics. Many of these action centers were characterized by heights that have increased and stabilized over time. This suggests that the meridional gradient of atmospheric mass between the subtropics and extratropics may have increased prior to CH days over the Gulf Coast. Composite flow patterns during times of these extremes verified that increased zonal flow may have contributed to the relative paucity of CH events in recent years. Prior to PH days, height variance was concentrated more on the northern fringes of the subtropics than for CH height fields. The presence of a deep trough over eastern North America may not be as important in producing a PH day as in creating a CH day, but the increasing tendency for slight meridional flow over eastern North America may have advected more Pacific anticyclones to the Gulf Coast over time. This degree of amplification may not be sufficient to force continental anticyclones to the region. Collectively, these results verify that changes in continental and Pacific anticyclone frequency are linked to changes in the large-scale flow, and that atmospheric temporal and spatial scale interactions are important in winter. Some significant trends in meteorological variables during CH and PH days were found. Many of these tendencies may be related to large-scale circulation changes on CH and PH days, but others may be produced by changes in the atmosphere in general. No significant trends in the weather type intensities as a whole were identified