Month: August 2011

Geospatial Predictive Modelling of the Neolithic Archaeological Sites of Magnesia in Greece

/ Matt Artz

International Journal of Digital EarthInternational Journal of Digital Earth, Volume 4, Issue 5, 2011, pages 421-433

Konstantinos G. Perakis and Athanasios K. Moysiadis

“Sources of heterogeneous geospatial data such as the elevation, the slope, the aspect, the water network and the current settlements related to the known Neolithic archaeological sites of Magnesia, are used in an attempt to confirm the existence and allow for the prediction of other archaeological sites using predictive modelling theory. Predictive modelling allows the update of the problem solving strategy as soon as new data layers are available. The Dempster–Shafer Theory also commonly referred to as evidential reasoning (ER) is used to compose probability maps of areas of archaeological interest from physiographical and historical data. The advantage of this theory is that the ignorance is quantified and used to compose the probability maps named as belief, plausibility and belief interval for the archaeological sites. The final digital probability maps show that the Neolithic archaeological sites can be detected in the prefecture of Magnesia. This research study forms a methodological tool for the prediction of new archaeological sites in other areas of archaeological interest according to the physiographical and historical characteristics of the archaeological period being examined. It also contributes to the digital earth modelling and archaeological site protection, one of the most critical and challenging global initiatives.”

An Assessment View to Evaluate whether Spatial Data Infrastructures Meet their Goals

/ Matt Artz

Computers, Environment and Urban SystemsComputers, Environment and Urban Systems, Volume 35, Issue 3, May 2011, Pages 217-229

Łukasz Grus, Watse Castelein, Joep Crompvoets, Theo Overduin, Bastiaan van Loenen, Annemarie van Groenestijn, Abbas Rajabifard, and Arnold K. Bregt

“Research highlights:

  • As a result of the research, a SDI goal-oriented assessment view has been proposed.
  • The practical applicability of the proposed assessment view has been demonstrated by its implementation in the Dutch SDI case.
  • The presented goal-oriented SDI assessment approach offers a specific and rational assessment which helps to evaluate SDIs for accountability purposes.
  • The design of the assessment view is generic, so it can be used to measure the extent of goals realization of any infrastructures with clearly defined and agreeable goals and where all of the stakeholders can be identified and approached.

“The motives for constructing Spatial Data Infrastructures (SDIs) are often based on their anticipated benefits for society, economy, and environment. According to those widely articulated but rarely proven benefits, SDI coordinators have been defining more specific objectives to be achieved by their SDIs. However, there is a limited number of assessment approaches that are able to demonstrate whether SDIs indeed realize the intended goals. In this article we develop, apply and evaluate an assessment view for evaluating the extent to which SDIs realize their goals. The assessment view has been developed stepwise using the Multi-view SDI assessment framework as a guideline. The application of the proposed view in the Dutch SDI demonstrates its potential. In addition, the evaluation of the proposed view by the potential users confirms to a certain extent its usability. The results also show that the ease of determining assessment indicators depends on the precision with which the SDI goals are formulated.”

Geography of Twitter Networks

/ Matt Artz

Social NetworksSocial Networks, Available online 25 August 2011

Yuri Takhteyev, Anatoliy Gruzd, and Barry Wellman

“Highlights:

  • We examine the influence of distance and related variables on Twitter ties.
  • A substantial share of ties (39%) lies within the same metropolitan region.
  • For non-local ties distance, borders, and language differences affect Twitter ties.
  • The number of airline flights between the parties is the best predictor of ties.

“The paper examines the influence of geographic distance, national boundaries, language, and frequency of air travel on the formation of social ties on Twitter, a popular micro-blogging website. Based on a large sample of publicly available Twitter data, our study shows that a substantial share of ties lies within the same metropolitan region, and that between regional clusters, distance, national borders and language differences all predict Twitter ties. We find that the frequency of airline flights between the two parties is the best predictor of Twitter ties. This highlights the importance of looking at pre-existing ties between places and people.”

Remote Sensing as a Botanic Garden Tool

/ Matt Artz

ArnoldiaArnoldia, Volume 69, Number 1, 2011

Ericka Witcher and Patrick Griffith

“Remote sensing is a tool already in use for plant exploration, ecology, forestry, habitat restoration, and other related fields. It also has great potential in botanic gardens for botany, horticultural science, and management purposes. At Montgomery Botanical Center, located in Coral Gables, Florida, we were able to improve our assessment of the property with the addition of new software that provided the capability for deeper evaluation of the collections and natural resources using remote sensing imagery and data. By adding LIDAR (Light Detection And Ranging) imagery to maps and employing techniques normally used at larger regional scales, new information was discovered about the garden and its collections.

First-Return LIDAR image of MBC property

First-Return LIDAR image of MBC property showing topmost surfaces, where bright yellow is the highest elevation and deep blue is the lowest. By Ericka Witcher for Montgomery Botanical Center

“Garden maps serve multiple purposes. Their primary use is as a location catalog—what a garden has and where it is. People who use the garden, whether staff or visitors, will want to know where certain features are at some point. The information displayed in this kind of map can reflect the vastly different purposes of, say, a researcher examining different subspecies of Coccothrinax miraguama (miraguama palm), an irrigation technician repairing a break, or a visitor looking for the restroom, but all three of their garden maps would need to show what things are and where they are located. On the other hand, maps can also be used for more dynamic purposes in the garden. New areas of horticultural and scientific interest can be illuminated through the addition of a spatial or geographic component—where things are in relation to something else. Spatial relationships in a botanical garden, for example, can examine how close vulnerable plants are to open spaces or high-use visitor areas, how tree canopies change over time, or the density of plantings. Expanding beyond the property, considerations regarding latitude and regional topography can be taken into account. Integrating a garden map into a Geographic Information System (GIS) is a way to keep and readily analyze a lot of data about a lot of different things in a garden.”

Globalisation and Wage Differentials: A Spatial Analysis

/ Matt Artz

The Manchester SchoolThe Manchester School, Special Issue: Regional and Spatial Economics, Volume 79, Issue 5, pages 1018–1034, September 2011, Published online 25 August 2011

Bernard Fingleton and Michelle Catherine Baddeley

“Fujita, Krugman and Venables (FKV) develop a model in which international wage differentials encourage industrial mobility. We argue that globalization has another important dimension. Shocks may originate in a single country but, with modern transportation and telecommunications media, shocks spread quickly and with multiple shocks complex spillovers will be generated. We assess these forces in an analysis of international wage convergence, identifying a non-linear relationship and showing that not all countries converge. Given that the FKV model omits many of the causes of non-convergence, our evidence further demonstrates that the FKV model could usefully be extended.”

Analysis of Traffic Hazard Intensity: A Spatial Epidemiology Case Study of Urban Pedestrians

/ Matt Artz

Computers, Environment and Urban SystemsComputers, Environment and Urban Systems, Volume 35, Issue 3, May 2011, Pages 230-240

Hoe-Hun Ha, Jean-Claude Thill

“Research highlights:

  • Intensity of urban pedestrian collisions is modeled through a spatial epidemiologic approach.
  • Environmental factors are significant drivers of pedestrian traffic hazard intensity.
  • Socio-demographic of neighborhoods are significant drivers of pedestrian traffic hazard intensity.
  • Young and adult pedestrian traffic hazard intensities follow rather distinct logics.
  • Intersection and mid-block crashes differ by their socio-economic correlates and spatial distribution.

“Traffic safety studies have underscored the hazardous conditions of pedestrians in the United States. This situation calls for increased public awareness of the pedestrian safety issue and better knowledge of the main factors contributing to traffic hazard for urban pedestrians. The purpose of this spatial epidemiology research is to gain greater insights into the geographic dimension exhibited by the intensity of traffic collisions involving urban pedestrians. Pedestrian crashes are studied in Buffalo, NY for years 2003 and 2004. Factors of hazard intensity are determined and compared for three age cohorts as well as for collisions occurring at intersections versus mid-block locations. Physical road characteristics and density of development, as well as socio-economic and demographic variables and potential trip attractors are examined. Spatial regression models are used to account for spatial dependencies. Econometric analysis underscores that all classes of environmental factors tested are significant drivers of pedestrian traffic hazard intensity. Results of the geographic analysis indicate that young and adult pedestrian traffic hazard intensities follow rather distinct logics. In addition, intersection and mid-block crashes differ by their socio-economic correlates, as well as their spatial distribution in the urban fabric.”

Street-level Spatial Interpolation Using Network-based IDW and Ordinary Kriging

/ Matt Artz

Transactions in GISTransactions in GIS, August 2011, Volume 15, Issue 4

Narushige Shiode and Shino Shiode

“This study proposes network-based spatial interpolation methods to help predict unknown spatial values along networks more accurately. It expands on two of the commonly used spatial interpolation methods, IDW (inverse distance weighting) and OK (ordinary kriging), and applies them to analyze spatial data observed on a network. The study first provides the methodological framework, and it then examines the validity of the proposed methods by cross-validating elevations from two contrasting patterns of street network and comparing the MSEs (Mean Squared Errors) of the predicted values measured with the two proposed network-based methods and their conventional counterparts.

A cross-validation study using a dense, urban street network containing 148 sample locations (Data 2): (a) the elevation at each sample location shown in metres, (b) prediction accuracy of NT-IDW, (c) prediction accuracy of PL-OK, and (d) prediction accuracy of NT-OK. The prediction accuracy of each method is examined through cross-validation of the elevation at sample locations and the amount of MSE to the closest integer is shown next to each sample location. Darker circles represent larger MSE values (i.e. lower accuracy)

“The study suggests that both network-based IDW and network-based OK are generally more accurate than their existing counterparts, with network-based OK constantly outperforming the other methods. The network-based methods also turn out to be more sensitive to the edge effect, and their performance improves after edge correction. Furthermore, the MSEs of standard OK and network-based OK improve as more sample locations are used, whereas those of standard IDW and network-based IDW remain stable regardless of the number of sample locations. The two network-based methods use a similar set of sample locations, and their performance is inherently affected by the difference in their weight distribution among sample locations.”

Geographic Information Systems for the Plant Sciences

/ Matt Artz

ArnoldiaArnoldia, Volume 69, Number 1, 2011

Brian J. Morgan

“The disciplines of the plant sciences and geography have been intertwined as far back as circa 300 BCE when the Greek scholar Theophrastus, frequently referred to as the “Father of Botany,” described the habitat and geographical distribution of plants in his first work on the subject titled Enquiry into Plants (Historia Plantarum). It wasn’t until the sixteenth century and the establishment of the world’s first botanical garden in Padua, Italy, that the leading icon of modern geography, the map, found its permanent place in the plant sciences by documenting the locations of woody plants in the garden for identification purposes. Today, location—the unifying theme of geography— has taken on an even more important role in the plant sciences where it is considered an essential attribute to record, and variable to consider, for the study of plants in fields ranging from agriculture to ecology.

Analysis of plant condition at the Arnold Arboretum reveals a cluster of plants in poor condition

Analysis of plant condition at the Arnold Arboretum reveals a cluster of plants in poor condition (indicated by red dots), in this case mostly eastern hemlocks (Tsuga canadensis) damaged by hemlock wooly adelgids.

“In the digital age that we live in, the cataloging of plants and the analysis of the influence that location plays on the growth and distribution of them is increasingly performed using geographic information systems (GIS). GIS is commonly defined as a system of personnel, computer hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information. GIS merges the visual aspects of a map with the analytical power of a database, and allows plant scientists to view, question, understand, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts. In our rapidly changing world, GIS gives scientists the power to quickly understand and formulate solutions to the problems presented by our most complex issues such as population growth, resource consumption, and climate change.”

GeoWeb and Crisis Management: Issues and Perspectives of Volunteered Geographic Information

/ Matt Artz

GeoJournalGeoJournal, Published Online 27 June 2011

Stephane Roche, Eliane Propeck-Zimmermann, and Boris Mericskay

“Mapping, and more generally geopositioning, has become ubiquitous on the Internet. This democratization of geomatics through the GeoWeb results in the emergence of a new form of mapping based on Web 2.0 technologies. Described as Web-mapping 2.0, it is especially characterized by high interactivity and geolocation-based contents generated by users. A series of recent events (hurricanes, earthquakes, pandemics) have urged the development of numerous mapping Web applications intended to provide information to the public, and encourage their contribution to support crisis management. This new way to produce and spread geographic information in times of crisis brings up many questions and new potentials with regard to urgency services, Non Governmental Organisations (NGO), as well as individuals. This paper aims at putting into perspective the development of GeoWeb, both in terms of technologies and applications, against crisis management processes.”

Toward an Improved Data Stewardship and Service for Environmental and Ecological Science Data in West China

/ Matt Artz

International Journal of Digital EarthInternational Journal of Digital Earth, Volume 4, Issue 4, 2011

Xin Li, Zhuotong Nan, Guodong Cheng, Yongjian Ding, Lizong Wu, Liangxu Wang, Jian Wang, Youhua Ran, Hongxing Li, Xiaoduo Pan, and Zhongming Zhu

“Sharing of scientific data can help scientific research to flourish and facilitate more widespread use of scientific data for the benefit of society. The Environmental and Ecological Science Data Center for West China (WestDC), sponsored by the National Natural Science Foundation of China (NSFC), aims to collect, manage, integrate, and disseminate environmental and ecological data from western China. It also aims to provide a long-term data service for multidisciplinary research within NSFC’s “Environment and Ecology of West China Research Plan” (NSFC West Plan). An integrated platform has been developed by the WestDC, and this has the function of data sharing, acting as a knowledge repository. Major data sets developed by the WestDC include basic geographic data, the regionalization of global data set for China, scientific data for cold and arid regions in China, scientific data for the cryosphere in countries that neighbor China, data relating to the inland river basins in northwestern China, and data submitted by the NSFC West Plan projects. In compliance with the “full and open” data sharing policy, most data in the WestDC can be accessed online. Highlights include detailed data documentation, the integration of data with bibliographic knowledge, data publishing, and data reference.”