URISA Journal
Table of Contents
Volume 19, Number 2

Download Volume 19, Number 2 in PDF format

In this issue:

• An Assessment of GIS-Enabled Walkability Audits
  Marc Schlossberg, Asha Weinstein Agrawal, and Katja Irvin
• Institutional and Organizational Barriers to Effective Use of GIS by Community-
  Based Organizations
  Ann-Margaret Esnard
• Coupling Multiagent Geosimulation and Spatial OLAP for Better Geosimulation
  Data Analysis
  Walid Ali, Bernard Moulin, Yvan Bédard, Marie-Josée Proulx, and Sonia Rivest
• An Interoperable Portal Supporting Prototyping Geospatial Applications
  Myra Bambacus, Phil Yang, John Evans, Marge Cole, Nadine Alameh, and Stephen Marley
• A Comprehensive Process for Linear Referencing
  Kevin M. Curtin, Greta Nicoara, and Rumana Reaz Arifin
• When Data Sharing Becomes Institutionalized: Best Practices in Local
  Government Geographic Information Relationships
  David L. Tulloch and Francis Harvey

Note: Complete text of Journal articles are in Adobe Acrobat (.pdf) format

Reading, ‘Riting, ‘Rithmetic...GIS - The Fourth “R” in Education?

(Version 11/7/07)

Donna L. Goldstein

ABSTRACT: For better or worse, computers have revolutionized every aspect of our lives. As we quickly make the transition from an industrial to an information age, computer literacy skills have become a basic necessity. Technology skills are now referred to as the "Fourth R" in education. To successfully learn and use GIS (Geographical Information Systems) technology, one must incorporate the skills of reading, writing, and arithmetic. Understanding and utilizing a GIS system requires a holistic combination of reading instructions, data, and maps; writing hypotheses, reports, and presentations; and using arithmetic to understand queries and spatial analysis. Thus the 4th R as it relates to GIS is a new elevated skill that incorporates the three original R’s in education. Teaching GIS may be just the boost our public educational system needs to adequately prepare students for entrance into the emerging global society.

Automatic Generation of High Quality 3D Urban Buildings from Aerial Images

(Version 11/5/07)

Ahmed F. Elaksher and James S. Bethel

ABSTRACT: High quality 3D building databases are essential inputs for urban area Geographic Information Systems. Since manual generation of these databases is very costly and time consuming, the development of automated algorithms is of great need. This article presents a new algorithm to automatically extract accurate and reliable 3D building information. High overlapping aerial images are used as input to the algorithm. Radiometric and geometric properties of buildings are utilized to distinguish building roofs in the images. This is accomplished using image segmentation and neural network techniques. A rule-based system is used to extract the vertices of the roof polygons in all images. The 3D coordinates of these vertices are computed using photogrammetric mathematical models. The algorithm is tested on a number of buildings in a complex urban scene. Results showed a detection rate of 99% and a false alarm rate of 5.0%. The root mean square error for the extracted building vertices is 0.25 meter using 1:4000 scale aerial photographs scanned at 30 micron.

Using GIS to Quantify the Anthropogenic-Induced
Raven Threat to Desert Tortoise

(Version 10/4/07) 

Blodwyn M. McIntyre, Thomas E.J. Leuteritz and Mark P. Kumler

ABSTRACT: Common ravens (Corvus corax) are a threat to desert tortoise (Gopherus agassizii) populations in the Mojave Desert. The U.S. Army is expanding its National Training Center (NTC) at Fort Irwin near Barstow California. This will involve the translocation of several hundred tortoises from the expansion area to several new sites outside of the base. In this study we use GIS to quantify the threat ravens pose to desert tortoises in the translocation area prior to initial tortoise release. A survey of ravens within the translocation area allows for a comparison to raven densities at this site in the future. A spline with barriers analysis was used to create a density surface over the translocation area. According to this analysis, raven densities were highest in association with anthropogenic features, linear features, and features with vertical strata. This paper may be the first to actually make a spatially-based connection between highway rest stops and elevated raven densities based on real data.  The study also provides scientists with a baseline for ongoing research into the effectiveness of tortoise translocation.

GeoFIS: Flood Insurance System for Trinidad - A Case Study for San Juan Downstream

(Version 8/3/07)  

F. Canisius and C. Nancy

ABSTRACT: Flood is one of the severe and common natural perils risking life and property in every corner of the world and has become more frequent in resent years due to increasing human intrusion in the environment. Damages caused by flood create great loss to individuals and it is difficult to recover from impacts. Since there are many factors that influence the flooding and cannot be prevented there is no other better way to quickly recover from financial loss than insuring properties. Flood insurance is providing financial protection against losses from flooding. In some countries, though flood insurance is available still the individuals could not able to obtain flood insurance or facing prospect of higher premium. This is because insurance companies charge premium based on region rather than location of individual house. In case of Trinidad, very general traditional way of premium calculation is in practice combined with standard property insurance. By integrating GIS to flood insurance flood risk of each and every individual private house can be evaluated and come up with reasonable premium. In this study GIS based flood insurance system was developed for Trinidad to handle flood insurance for private households and applied to San Juan Downstream to demonstrate feasibility to use the system. The system uses flood and house information from GIS database and client provided information to bring out reasonable premium based on business related variables from insurance companies. This will enable both parties of the insurance market to be benefited.