The Importance of Distance to Resources in the Spatial Modelling of Bat Foraging Habitat

PLoS ONE, published 25 Apr 2011

Ana Rainho, Jorge M. Palmeirim

“Many bats are threatened by habitat loss, but opportunities to manage their habitats are now increasing. Success of management depends greatly on the capacity to determine where and how interventions should take place, so models predicting how animals use landscapes are important to plan them. Bats are quite distinctive in the way they use space for foraging because (i) most are colonial central-place foragers and (ii) exploit scattered and distant resources, although this increases flying costs. To evaluate how important distances to resources are in modelling foraging bat habitat suitability, we radio-tracked two cave-dwelling species of conservation concern (Rhinolophus mehelyi and Miniopterus schreibersii) in a Mediterranean landscape. Habitat and distance variables were evaluated using logistic regression modelling. Distance variables greatly increased the performance of models, and distance to roost and to drinking water could alone explain 86 and 73% of the use of space by M. schreibersii and R. mehelyi, respectively. Land-cover and soil productivity also provided a significant contribution to the final models. Habitat suitability maps generated by models with and without distance variables differed substantially, confirming the shortcomings of maps generated without distance variables. Indeed, areas shown as highly suitable in maps generated without distance variables proved poorly suitable when distance variables were also considered. We concluded that distances to resources are determinant in the way bats forage across the landscape, and that using distance variables substantially improves the accuracy of suitability maps generated with spatially explicit models. Consequently, modelling with these variables is important to guide habitat management in bats and similarly mobile animals, particularly if they are central-place foragers or depend on spatially scarce resources.”

Dubai’s GIS Enhances Operations to Support Continued Growth

Esri License Agreement Enables Enterprise-wide GIS in World’s Fastest-Growing City

Dubai Municipality signed an enterprise license agreement (ELA) with Esri’s United Arab Emirates distributor GISTEC, making ArcGIS software available throughout the organization to help meet the planning and operational demands of Dubai’s rapid growth.

“This is a landmark decision because it not only helps the municipality become more effective but also benefits all the citizens in the emirate of Dubai,” says AbdulHakim Abdul Kareem Malik, director of the Dubai Municipality GIS department.

With broader access to the latest ArcGIS software, the municipality intends to leverage GIS technology and share geospatial data between departments.  The enterprise-wide GIS is expected to improve disaster response capabilities; citizen services; and the planning, design, construction, and management of Dubai’s expanding infrastructure and facilities.

“The ELA provides us with the products and flexibility we need as we plan to migrate our existing cadastre and certification management systems to the ArcGIS 10 platform, making it easier to access and use data,” says Malik. “The resulting streamlined business processes will help serve our citizens in their day-to-day requests and provide accurate spatial and nonspatial information.”

Further details on Dubai Municipality are available at To learn about Esri ELAs, visit For more information on GISTEC, visit

[Source: Esri press release]

Least Cost Distance Analysis for Spatial Interpolation

Computers & Geosciences, Volume 37 Issue 2, February 2011

Jonathan A. Greenberg, Carlos Rueda, Erin L. Hestir, Maria J. Santos, and Susan L. Ustin

“Spatial interpolation allows creation of continuous raster surfaces from a subsample of point-based measurements. Most interpolation approaches use Euclidean distance measurements between data points to generate predictions of values at unknown locations. However, there are many spatially distributed data sets that are not properly represented by Euclidean distances and require distance measures which represent their complex geographic connectivity. The problem of defining non-Euclidean distances between data points has been solved using the network-based solutions, but such techniques have historically relied on a network of connected line segments to determine point-to-point distances. While these vector-based solutions are computationally efficient, they cannot model more complex 2- and 3-dimensional systems of connectivity. Here, we use least-cost-path analyses to define distances between sampled points; a solution that allows for arbitrarily complex systems of connectivity to be interpolated. We used least-cost path distances in conjunction with the inverse distance weighting interpolation for a proof-of-concept interpolation of water temperature data in a complex deltaic river system. We compare our technique to Euclidean distance interpolation, and demonstrate that our technique, which follows connectivity rules, yields are more realistic interpolation of water temperature.”

Marine Modeling as a Service

ISW-2011: Integrating Sensor Web and Web-based Geoprocessing, An AGILE 2011 Conference Workshop; Utrecht, The Netherlands, April 18, 2011

Michael Bauer, Christoph Wosniok, and Rainer Lehfeldt

“Modeling marine environments is a necessity to provide basic knowledge for decision making in coastal zone management. Current modeling software is usually implemented as stand-alone solutions. With the trend towards data infrastructures, efforts need to be made to introduce marine modeling into such infrastructures on an interoperable basis in order to improve its capabilities. We propose a service architecture, relying on trusted OGC services like the Web Processing Service or the Sensor Observation Service. We briefly summarize an implementation strategy.”

An Environmental Decision Support System for Spatial Assessment and Selective Remediation

Journal Environmental Modelling & Software, Volume 26 Issue 6, June, 2011

Robert N. Stewart and S. Thomas Purucker

“Spatial Analysis and Decision Assistance (SADA) is a Windows freeware program that incorporates spatial assessment tools for effective environmental remediation. The software integrates modules for GIS, visualization, geospatial analysis, statistical analysis, human health and ecological risk assessment, cost/benefit analysis, sampling design, and decision support. SADA began as a simple tool for integrating risk assessment with spatial modeling tools. It has since evolved into a freeware product primarily targeted for spatial site investigation and soil remediation design, though its applications have extended into many diverse environmental disciplines that emphasize the spatial distribution of data. Because of the variety of algorithms incorporated, the user interface is engineered in a consistent and scalable manner to expose additional functionality without a burdensome increase in complexity. The scalable environment permits it to be used for both application and research goals, especially investigating spatial aspects important for estimating environmental exposures and designing efficient remedial designs. The result is a mature infrastructure with considerable environmental decision support capabilities. We provide an overview of SADA’s central functions and discuss how the problem of integrating diverse models in a tractable manner was addressed.”

Studying Cartographic Heritage: Analysis and Visualization of Geometric Distortions

Computers and Graphics, Volume 35 Issue 2, April 2011

Bernhard Jenny and Lorenz Hurni

“Old maps are increasingly used as a source for historical research. This is a consequence of the increased availability of old maps in digital form, of the emergence of user-friendly Geographical Information Systems, and of a heightened awareness of the unique information stored in old maps. As with every source for historical studies, when old maps are georeferenced and information is extracted for historical research, the accuracy and reliability of the geometric and semantic information must be assessed. In this paper, a method based on a series of geometric transformations is presented, which transforms control points of a modern reference map to the coordinate system of an old map. Based on these transformed points, the planimetric and geodetic accuracy of the old map can be computationally analyzed and various visualizations of space deformation can be generated. The results are graphical representations of map distortion, such as distortion grids or displacement vectors, as well as statistical and geodetic measures describing the map geometry (e.g., map scale, rotation angle, and map projection). The visualizations help to assess the geometric accuracy of historical geographical information before using the data for geo-historical studies. The visualizations can also provide valuable information to the map historian about the history of a particular map and its creation.”

URISA’s GIS in Public Health Conference Details Announced

URISA is pleased to announce the details of its 2011 GIS in Public Health Conference, taking place in Atlanta, June 27-30, 2011. The deadline to take advantage of discounted registration and hotel fees is June 1.

“What makes this conference such a valuable experience is the mix of academics and practitioners, experienced GIS professionals and younger public health staff, with students from a variety of disciplines as well.  While the trainings, lectures and presentations add to one’s knowledge, the real perk of the conference for me is the interactions that occur during scheduled breaks and over dinner and evening activities.  I came away from the last conference in Providence very inspired, and developed a new graduate seminar in Spatial Perspectives in Community and Family Health at my university in part as a result of the conference.”  Russell Kirby, PhD, MS, FACE – University of South Florida

The conference was developed primarily from submissions received through the Call for Abstracts. More than 80 abstracts were received. Two preconference workshops will be presented:

  • Introduction to Public Participation GIS (PPGIS): Using GIS to Support Community Decision-Making (URISA-Certified Workshop)
  • Tools for Common Challenges in Public Health GIS: Aggregation, Smoothing and Masking

In addition to the twenty-one comprehensive educational sessions on topics ranging from “Using Mapping to Assess Community Health Risk” to “Applications in GIS and Remote Sensing for Environmental Health”, three keynote speakers will be featured:

  • Geomedicine: A Patient’s Perspectivepresented by Bill Davenhall, Global Manager – Health and Human Services, Esri
  • GIScience in Public Health: Chagas’ Disease, Dengue and West Nile Virus – presented by Dr. Gonzalo M. Vazquez-Prokopec, Research Scientist, Department of Environmental Studies, Emory University
  • GIS and Health: Where Can We Go from Here? – presented by Dr. Ellen K. Cromley, Assistant Clinical Professor, Department of Community Medicine and Health Care, University of Connecticut School of Medicine

The poster session is a key part of the conference with nearly 30 participants to date. Exhibits and networking events round out the conference experience.

For complete conference, exhibits, travel and registration information, visit

[Source: URISA press release]