UCL Department of Geography
Dr. Paul J. Densham
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Dr. Paul J. Densham



Reader in Geography
Department of Geography

Email: p.densham@ucl.ac.uk
Tel: +44-(0)20-7679-0578
Fax: +44-(0)20-7679-0565

Postal address:
Department of Geography
Pearson Building,
Gower Street,

Office address:
G21 Pearson Building

Office hours for the Autumn Term:

Tuesdays:  11:00 to 13:00
Fridays:      11:00 to 12:00



I took up an appointment as Lecturer in Geographic Information Systems (GIS) at University College London on January 1st, 1994, and was promoted to Reader in October, 1996 - prior to this, I was Assistant Professor of Geography at the State University of New York at Buffalo (1988-1993). Whilst at SUNY Buffalo, I was a Principal Investigator and Research Fellow in the National Centre for Geographic Information and Analysis (NCGIA). I have held Adjunct Faculty appointments in the Departments of Geography at the University of Iowa and SUNY Buffalo.

I hold a B.A.(Hons) in Geography and Economics from the University of Keele, U.K. (1983), an M.Sc. in Operational Research from the University of Birmingham, U.K. (1984), and a Ph.D. in Geography from the University of Iowa, U.S.A. (1990). My Ph.D. thesis is entitled Decision Support for Reorganizing Settlement Systems and developed methods for the interactive elicitation and validation of people's preferences and for solving large location-allocation models.

I am or have been Principal or Co-Principal Investigator on grants from sources including the U.S. National Science Foundation (in the U.S.A., Australia and India), The European Commission, EPSRC, ESRC, Environmental Systems Research Institute (Redlands, CA), The Iowa State Departments of Transportation and Education, the Midwest Transportation Centre, Manufacturers and Traders Bank (Buffalo, NY), Sun Microsystems, Inc (Mountain View, CA) and Cadcorp (Stevenage, UK).

I led: the NCGIA's sixth research initiative Spatial Decision Support Systems with Michael Goodchild; the NCGIA's seventeenth research initiative, Collaborative Spatial Decision-Making (CSDM), with Marc Armstrong and Karen Kemp; and the NCGIA's research investigation Parallel Computation and GIS.



  • Method for Minimizing Street Crossings and Meeting Maximum Capacity Constraints in a Network Design. Inventors: Y. Ding and P.J. Densham. U.S. Patent Number 5,963,544, granted 5th October, 1999.
    Abstract: A method for designing a telecom network includes retrieving data corresponding to a plurality of network node locations, a plurality of subscriber locations and other relevant information such as associated street blocks and distance values. Each network node location and subscriber location combination having a distance value there between greater than a maximum distance is initially eliminated. Thereafter, each network node location and subscriber location combination is assigned a priority value, based on constraints such as the proximity between their associated street blocks and/or the maximum capacity of each network node location. The total sum of priority values and total number of subscriber locations are then calculated for those sets of network node locations and corresponding subscriber locations that are selected by the algorithm. A final set of network node locations and assigned subscriber locations is identified by determining the set having the lowest total sum of priority values, which minimizes the street crossings in the design, and the highest number of subscriber locations.
    Details at: http://www.delphion.com/details?pn=US05963544__


  • Salt, J., P.J. Densham, V. Chell, H. Prophet, J. Hogarth, R. Penninx, J. Doomernik, C. Wihtol de Wenden, and V. Vuddamalay, 1998. Feasibility Study for a European Migration Observatory. Office for Official Publications of the European Communities, Luxembourg. ISBN 92-828-3360-7.
  • Salt, J., J. Clarke, S. Schmidt, J. Hogarth, P.J. Densham and P. Compton, 1999. Assessment of Possible Migration Pressure and its Labour Market Impact Following EU Enlargement to Central and Eastern Europe. RR138, Department for Education and Employment, London. ISBN 1-84185-070-5.
  • Committee on Planning for Catastrophe: A Blueprint for Improving Geospatial Data, Tools and Infrastructure, 2007. Successful Response Starts with a Map: Improving Geopatial SUpport for Disaster Management. National Academy of Sciences, Washington, D.C. ISBN 978-0-309-10340-4.

Book Chapters

  • Densham, P.J., 1996. Visual interactive locational analysis, in P. Longley and M. Batty, eds., Spatial Analysis: Modelling in a GIS environment, GeoInformation International, Cambridge, pp. 185-206.
  • Densham, P.J. and M.P. Armstrong, 1998. Spatial analysis, in R.G. Healey, S. Dowers, B.M. Gittings and M.J. Mineter, eds., Parallel Processing Algorithms for GIS, Taylor and Francis, London, pp. 387-413.
  • Densham, P.J. and M.P. Armstrong, 2003. Integrative data structures for collaborative modeling and visualisation in spatial decision support systems, in Encyclopedia of Life Support Systems, United Nations, New York.
  • Schietzelt, T.H. and P.J. Densham, 2003. Location-allocation in GIS, in P.A. Longley and M. Batty (eds.), Advanced Spatial Analysis, ESRI Press, Redlands.

Journal Articles

  • Densham, P.J. and G. Rushton, 1996. Providing spatial decision support for rural service facilities that require a minimum workload. Environment and Planning B, 23, pp. 553-574.
  • Ding, Y. and P.J. Densham, 1996. Spatial strategies for parallel spatial modelling. International Journal of Geographical Information Systems, 10(6), pp. 669-698.
  • Batty, J.M. and P.J. Densham, 1996. Decision support, GIS, and urban planning. Systemma Terra, V(1), pp. 72-76.
  • Araújo, M.B., P.J. Densham, R. Lampinen, W.J.M. Hagemeijer, A.J. Mitchell-Jones, J.P. Gasc and C.J. Humphries, 2001. Would environmental diversity be a good surrogate for species diversity? Ecography, 24, pp. 103-110. (Click here for a PDF file.)
  • Araújo, M.B., P.J. Densham and C.J. Humphries, 2003. Predicting species diversity with ED: the quest for evidence. Ecography, 26(3), pp. 380-383.
  • Araújo, M.B., P.J. Densham and P.H. Williams, 2004. Representing species from patterns of assemblage diversity. Journal of Biogeography, 31, pp. 1037-1050.
  • Barkan, J.D., P.J. Densham and G. Rushton, 2006. Space matters: designing better electoral systems for emerging democracies. American Journal of Political Science, 50(4), pp. 926-939.
  • Bauere, V., P.J. Densham, J. Millar and J. Salt, 2007. Migrants from central and eastern Europe: local geographies. Population Tends, 129, pp. 7-19.
  • Armstron, M.P. and P.J. Densham, 2008. Cartographic support for locational problem-solving by groups. International Journal of Geographical Information Science, 22(7), pp. 721-749.
  • Simão, A., P.J. Densham and M. Haklay, 2009. Web-based GIS for Collaborative Planning and Public Participation: an application to the strategic planning of wind farm sites. Invited submission to Journal of Environmental Management, for inclusion in a special issue: "Collaborative GIS: Perspectives on decision support and visualization". Journal of Environmental Management, 90(6) May 2009, pp. 2027-2040.

Conference Proceedings

  • Armstrong, M.P. and P.J. Densham, 1995. Cartographic support for collaborative spatial decision-making. Proceedings, Twelfth International Symposium on Computer-Assisted Cartography (Auto Carto 12), pp. 49-58.
  • Armstrong, M.P. and P.J. Densham, 1995. Toward the development of a conceptual framework for GIS-based collaborative spatial decision-making. Proceedings, 2nd ACM Workshop on Advances in Geographic Information Systems.
  • Armstrong, M.P. and P.J. Densham, 1995. Collaborative spatial decision-making: a look at the dark side. Proceedings, GIS/LIS '95, pp. 11-19.
  • Armstrong, M.P. and P.J. Densham, 1997. Toward a network map algebra. Proceedings, Thirteenth International Symposium on Automated Cartography (Auto-Carto13), pp. 1 - 10.
  • Simão, A. and P.J. Densham, 2004. Designing a web-based public participatory decision support system: the problem of wind farms location. Proceedings, CORP 2004 and Geomultimedia 04, 9th International Symposium on ICT in Urban and Regional Planning, pp. 265-274.
  • Simão, A., M. Haklay and P.J. Densham, 2005. Where to locate wind farms? An internet-based public participation system. Proceedings, GISPlanet, Estoril (Portugal), 30th May – 2nd June, 2005.

Technical Reports

  • Densham, P.J., M.P. Armstrong and K.K. Kemp, 1995. Collaborative Spatial Decision-Making: Scientific Report for the Specialist Meeting. Technical Report 95-14, National Center for Geographic Information and Analysis, Santa Barbara, CA., 184 pp.



My research interests can be grouped into three major themes:

  • the development of algorithms for locational analysis and the investigation of new solution methods;
  • the integration of spatial analysis and modelling with geographical information systems (GISs) to develop spatial decision support systems (SDSSs) for use by individuals and groups; and,
  • the investigation and use of new computational environments (parallel and heterogeneous processing environments) to support the development of new algorithms and to improve human-computer interaction (HCI) in SDSSs.

Much of my work in these areas has formed part of research programmes at the U.S. National Center for Geographic Information and Analysis (NCGIA) and UCL's Centre for Advanced Spatial Analysis (CASA). Within the Department of Geography, I am a member of the GIS and RS Research Group and an associate of the Migration Research Unit. With the MRU, I have been working on how to integrate GIS and SDSS into migration information systems, especially based on the WWW (see EMIN, for example), to improve decision-makers' access to information and the tools to analyse it.

These three streams of work are mutually reinforcing because my research in locational analysis is the focus of my integration work with GISs, and the application of the resulting systems raises questions that require new algorithms to be developed. In both these streams of work, response times heavily influence users’ perceptions of HCI. Parallel processing and heterogeneous computing environments (HCEs) enable researchers to improve response times and to develop new ways of solving problems. Research into these computational environments supports the development of new locational algorithms, and architectures and implementation strategies for SDSSs.

The development of algorithms for locational analysis

Gerard Rushton (Iowa) and I developed a new data structure and implementation strategies that exploit the spatial structure of location-allocation problems. When applied to the vertex substitution algorithm and its derivatives, these strategies dramatically reduce solution times - making feasible the solution of very large problems. Building on this work, we designed a new algorithm, the Global-Regional Interchange Algorithm (GRIA), that produces solutions with the same characteristics the vertex substitution algorithm but does markedly less work. Solution times are reduced further and proportionally larger reductions in processing costs occur as problem size increases.

The data structures and implementation strategies in GRIA underlie the algorithms in the Locational Analysis Decision Support System (LADSS) - a prototype modelbase management system (MBMS) distributed by the NCGIA. I have investigated other types of heuristic solution methods, including genetic algorithms. Catherine Dibble (Ph.D. student, Buffalo) and I designed and implemented a genetic algorithm that solves location-allocation problems. Built around the same data structures as LADSS, this algorithm is effective but slow.

Spatial decision support systems

My early work on SDSSs focused on defining the characteristics of such systems and setting out system architectures. Subsequent work (much of it associated with the NCGIA’s Research Initiative co-led with Michael Goodchild) has addressed the problems associated with the design and implementation of the various components of SDSSs and improving the levels of human-computer interaction (HCI) that they support. A number of systems have been built to test solutions to these problems and applied in a range of problem domains.

Human-computer interaction

A SDSS must be able to display the results of analyses using appropriate maps and graphics. While most GISs produce thematic maps and graphics, they are limited in their support of domain-specific map types. Working with Marc Armstrong and others, I have developed a functional taxonomy of cartographic displays for use in locational decision-making to visualise different components of models and their results.
To explore their decision space, decision-makers must be able to combine analytical and graphical representations of their problem in flexible ways. Unfortunately, cartographic displays play only limited roles in the decision-making processes supported by many current SDSSs. HCI would be improved if systems provided multiple, simultaneous representations of a problem, users could interact with any of these representations, and the system responded by invoking the appropriate capability and automatically updated all available representations of the problem. The provision of such visual interactive modelling interfaces to SDSSs raises all sorts of system design issues and has been a major research area for me over the past few years. I have set out the basic requirements for visual interactive modelling in locational analysis and shown how the data structures in LADSS can be used to support multiple, linked representations. Because the underlying data structures are common, changes made to one representation can be used to update others. While the computational burden of supporting visual interactive modelling can be considerable, parallel processing and heterogeneous processing environments provide one solution to this problem. Maps can be constructed in parallel and algorithms within the MBMS can be implemented in such environments.

Collaborative Spatial Decision-Making

I co-led, with Marc Armstrong (Iowa) and Karen Kemp (NCGIA), the NCGIA Research Initiative Collaborative Spatial Decision-Making. This Initiative addressed the problem that while groups often are charged with addressing complex spatial problems, most GISs, SDSSs and spatial analysis tools are designed for individual use. My interests in this area focus on collaborative tools for modelling and visualisation.

More recently, I have been involved in setting a research agenda with the U.S. Interagency Group on Decision Support and the Aurora Partnership. This partnership has evolved into a coalition of researchers, practitioners, and decision-makers from federal, state, and local government agencies, educational institutions, private-sector entities, and NGOs aimed at facilitating the development and use of decision support tools, systems, and services for place-based management. This coalition, represented by PlaceMatters, seeks specifically to address the needs of policymakers, land and resource managers, and community leaders.


The LADSS MBMS has been used in SDSSs to reorganise services in both the U.S. and India. My contribution has been in terms of system design, the development and implementation of new algorithms, and field testing. Other applications I have worked on include a SDSS that integrates a suite of exposure-effects models with ARC/INFO. My contribution to this project was in system design and the development of the data management interface and scenario manager. I was involved in a two-year, UNDP-funded project to build a Public Distribution System: a GIS-based SDSS that incorporates location-allocation and routeing models and features a scenario manager. Two of the Indian development team came to UCL to work on the system’s design with me.

Within UCL’s Migration Research Unit (MRU), I have worked on a stream of research concerning how to provide access to statistical and other information sources for a diverse user base. I co-directed research on a feasibility study for the establishment of a European Migration Observatory and, subsequently, the European Migration Information Network, in which I took responsibility for the ICT-related aspects. My interest is in using GISs to visualise the information held in web-accessible databases so that users can locate and access information using maps and other visual methods and then visualise stocks, flows, and other types of information using a variety of representations, including maps and graphics.

I have worked with researchers at the Natural History Museum on the application of location-allocation models to the analysis of species distributions across Europe. Three papers on this work have been published: the first, in Ecography, initiated a dialogue in the literature that has continued in both Ecography and the Journal of Biogeography.

I have worked with Gerry Rushton and Joel Barkan, both University of Iowa, on the development of a new set of algorithms and associated SDSS capabilities to design electoral districts. We have published one paper on this work.

Parallel and heterogeneous processing environments

There are three motivations for examining parallel and heterogeneous computing environments: first, the computational characteristics of these processing environments mean that they are able to support new approaches to solving problems; second, with access to GISs, SDSSs, and disaggregate spatial databases, decision-makers increasingly wish to solve problems larger than traditional computing platforms can accommodate; and, third, new modelling environments, such as visual interactive modelling, greatly increase the computational demands of SDSSs.

A crucial step in the design and implementation of parallel software is to decompose a problem and its solution algorithm into parallel processes. Yuemin Ding (Ph.D. student, Buffalo), Marc Armstrong and I have worked to develop a theoretical basis for decomposition that exploits the peculiar structure of spatial problems; we have used this work to implement spatial algorithms with a range of computational characteristics: shortest path algorithms, a new hill-shading algorithm, and an algorithm that generates Delaunay Triangulations.

More recently, I have examined the use of heterogeneous processing environments to support SDSSs for locational analysis. Heterogeneous processing environments are suites of computers with different architectures, each of which has a set of processing characteristics that match the computational requirements of one or more parts of a complex problem. Marc Armstrong and I analysed the computing requirements of popular algorithms used to solve location-allocation problems and matched them with appropriate computer architectures. On the implementation side, we have looked at how to support both analysis and display with parallel processing; and I have integrated two forms of parallel processing computers with my LADSS software and developed a user interface that makes their use transparent to the user.





My current teaching is to undergraduates and to masters students.

Undergraduate Courses

  • 1003 - Data Acquisition and Interpretation
    A required course for all first-year, single honours undergraduate geography students.

MSc Courses (Geospatial Analysis (GSA) and Geographic Information Science (GISci))

  • GEOGG126 - Representation, Structures and Algorithms - GSA & GISci
    This core module introduces students to the ways in which spatial data can be represented, stored and manipulated within computers and explores the data models, data structures and algorithms that are fundamental to GISs and methods of spatial analysis.
  • GEOGG127 - Spatial Decision Support - GSA & GISci
    This optional module examines the principles of spatial decision support and explores system architectures, development frameworks, and the role of evidence-based spatial decision support in and policy-making.
  • GEOGG152 Locational and Network Analysis with GIS - GSA & GISci
    An optional module introduces students to methods of locational and network analysis, that have long been one of the focii of spatial analysis, and to their implementation and use in commercial GISs to address a broad range of applications in society.

I am convenor of MSc GSA. Course details can be obtained at www.ucl.ac.uk/gis.

PhD Students

Previous Ph.D. students at UCL

  • Ana Simão, 2009.
    A learning-enhancing, web-based public participation system for spatial planning:  an application to the wind farm siting problem.
    Ana joined CASA in January 2003 to start her MPhil/PhD research under the topic "A Spatial Decision Support System for Groups in Strategic Land and Environmental Planning – Application to the Location of Wind Power Plants". Ana holds a Land Management Engineering degree from Instituto Superior Técnico (IST), Lisbon, Portugal and an MSc degree in Civil engineering, specialization in Hydraulics and Water Resources from University of Coimbra, Coimbra, Portugal.
  • Muki Haklay, 2002.
    Public Environmental Information Systems: Challenges and Perspectives.
    Muki has been a research student in the Department of Geography and a research student in CASA - he is now a Professor in UCL's Department of Civil, Environmental and Geomatic Engineering. Muki's research focuses on the use of GIS and the WWW in environmental policy setting, decision-making, and public participation.
  • Christopher Brookes, 1998.
    A Genetic Algorithm for Optimal Patch Design in GIS.
    Chris used genetic algorithms and GISs to design landuse allocation schemes that take shape into account; he is particularly interested in the application of these methods to animal habitats and nature reserves. The generation and evaluation of large populations of alternatives was investigated as part of his research.
  • Bruce Mitchell, 1998.
    Bruce was co-supervised by Dr. Ian Hamilton of the School of Slavonic and East European Studies, University of London. Bruce's research focused on the use of census data and associated cartographic products to misrepresent the mix of different ethnic groups in the 1930s and 1940s in Eastern Europe.

Previous Ph.D. students at SUNY Buffalo


  • Yuemin Ding, 1993. Strategies for Parallel Spatial Modelling Using MIMD Approaches.

Member of Supervisory Committee

  • Holly Dickinson, 1990. Deriving a Method for Evaluating the Use of Geographic Information in Decision Making.
  • Sylvia Ashrafiuon, 1991. Competitive Strategies and Location in the U.S. Automotive Industry.
  • Scott Freundschuh, 1992. Spatial Knowledge Acquisition of Urban Environments from Maps and Navigation Experience.
  • Michael Gould, 1993. Map Use, Spatial Decisions, and Spatial Language in English and Spanish.
  • Hui Lin, 1993. Reasoning and Modeling of Spatiotemporal Intersection.
  • Victor Wu, 1993. Querying Spatial Metadata Based on Spatial Objects.
  • Chris Weber, 1994. Sonic Enhancement of Map Information: Experiments Using Harmonic Intervals.
  • Frank Xia, 1994. A 3-D Data Model for Water Quality Modelling.
  • May Yuan, 1994. Representation of Wildfire in Geographic Information Systems.
  • Andrew Curtis, 1995. Investigations into the Location Specific Variations in Spatial Representation, Spatial Cluster Formation and Hierarchies.

External Ph.D. Examiner

  • Xuan Zhu, 1995. A Knowledge-based Approach to the Design and Implementation of Spatial Decision Support Systems. Department of Geography, University of Edinburgh.
  • Nicholas King, 1995. Achieving Spatial Decision Support with GIS: a Case Study in Water Resources Management in South Africa. Department of Geography, State University of New York at Buffalo.
  • Etches, Adam, 2001. A Network Information System: Application to Transportation. Department of Geomatic Engineering, University of Newcastle.

Previous M.Sc. Project Supervision at UCL

  • Eric Hermans, 1994. Investigating the Linkages Between Space Syntax and Census Data.
  • Ehab Bassili, 1995. Geodemographic Analysis of Chain Store Locations.
  • Kevin Loughlin, 1995. An Object-Oriented Approach to Locational Analysis.
  • Noy Salleh, 1995. Provision of Services in Water Village (Brunei): A GIS Methodology.
  • Demetris Stathakis, 1995. Location-Allocation Models: The Case of ATMs.
  • Tak-sang Wong, 1995. Application of Location-Allocation Models to Community Facilities Planning in Hong Kong.
  • Stephen Fleetwood, 1996. Investigating the Potential of ArcView to Offer Spatial Decision Support Systems Functionality.
  • David Tulett, 1996. GIS and Transportation: the Case of Cycleway Implementation.
  • Matthew Wright, 1996. Exploratory Spatial Data Analysis: GIS and Epidemiology.
  • Suhartono, 1997. Decision Support in Military Geographic Information.
  • Bethan Thomas, 1997. Locational Analysis of the Public Health Laboratory Service.
  • Timothie Biggs, 1998. GIS and Local Government Planning for Open Spaces.
  • Simon Funnell, 1998. Network Analysis from a Military Perspective using GIS.
  • Ghulam Rabbanni, 1998. GIS and Epidemiology: Local Indicators of Statistical Association.
  • Dominic Stubbins, 1998. Developing an Internet-Based Tool for the Interactive Visualisation of Location-Allocation Problems.
  • Karigomba, Wilbert, 1998. Customised GIS to Support Urban Planning - A Case Study of Westminster. (Second supervisor.)
  • Plachta, Ewa, 1998. The Potential Role of GIS - A Case Study in Peckham, London. (Second supervisor.)
  • Atkinson, Mike, 2000. Spatial Data Use in the Local Government of London. Can the Local Authorities Serve the Greater London Authority With the Data it Requires?
  • Bengtsson, Louise, 2000. Acquiring Data About Pedestrian Movements Using Internet Map Server Technology.
  • Yau, Eric, 2000. Applying a Spatial Decision Support System in Environmental Impact Assessment: A Study in Victoria Harbour Reclamation.
  • Boiling, Ed., 2000. Towards an Internet GIS for Oil Spill Emergency Planning on the River Thames. (Second supervisor.)
  • Comben, Stephen, 2000. A Hierarchical Coordinate System for Encoding Globally Distributed Raster Spatial Data. (Second supervisor.)
  • Edney, Stephen, 2001. Interface Issues in Web-based GIS: A Development of Client-side Digitising Techniques. (Second supervisor.)
  • Monk, Daniel, 2001. Utilising Gegraphic Information in Aiding Emergency Planning Response.
  • Morris, Christopher, 2001. An Investigation into the Use of GIS in the Analysis of Passenger Travel Patterns on the London Underground Tube Network.
  • Hall, Robert, 2002. Cycle routes in NW London. (Second supervisor.)
  • Mann, Gareth, 2002. Sampling Simulation for Water Quality Data Collection Methods. (Second supervisor.)
  • Roemmele, Emma, 2002. Isle of Man Coastal Environment GIS for Decision Support. (Second supervisor.)
  • Stow, Christopher, 2002. Statistics and GIS - Business Analysis of Yell Database. (Second supervisor.)
  • Tuffour, Anthony, 2002. SDSS for Dredging Planning. (Second supervisor.)
  • Gadenz, Simone, 2003. Design of a Flexible Web Mapping Tool to Deploy in Reuters AlertNet Web Site. (Second supervisor.)
  • Jones, Kate, 2003. The Spatial Distribution of General Practices and Their Patients in the King's Cross Area, and How They Relate to Markers of Deprivation. (Second supervisor.)
  • Lloyd, Ann K. M., 2003. Making and Using a GIS Tool to Study Climatological Station Representativity.
  • Sowa, Sheikh Siddy, 2003. Creation of a Large Topological Dataset for London M25 Area Using Oracle Spatial and Laser Scan's Radius Topology. (Second supervisor.)
  • Vassardani, Maria, 2003. Cascading Web Mapping Services. (Awarded a distinction overall.)
  • Xu, Lei, 2003. Traffic Microsimulation Within GIS. (Second supervisor.)
  • Kelebeng, Timon, 2004. Botswana Integrated Land Information System.
  • Tzouvali, Georgia, 2004. Theory and Applications of 2D Topology in Transport GIS: Implementation and Comparison of the Topological Structures Two Leading Vendors Provide.
  • Bosher, Steven, 2005. Applying Accessibility to Public Access Webmapping Sites.
  • Nutkins, Richard, 2005. Walkability: Transport for London Research on the Monitoring and Modelling of Walking Quality in London, Towards a Walkability GIS. (Second supervisor.)
  • Pradhan, Sudip, 2005. A Web-based Public Participatory Spatial Decision Support SYstem for Wind Farm Siting. (Second supervisor.)
  • Ram, M., 2005. Integrating Plant Dispersal Mechanisms in Population Fragmentation Models. (Second supervisor.)
  • Rickles, P. 2005. Web Profiles - Elevation Cross-sections with Vegetation. (Second supervisor.)
  • Skarlatidou, Alexandra, 2005. The Current State of the Online Mapping Industry: A Usability Study of the Multipmap Public Service and that of its Competitors. (Second supervisor.)
  • Forlani, Armando, 2009. Spatial Analysis and Decision Support for Prioritisation of Pavement Treatment Programme.

Previous M.Sc. Project Supervision SUNY Buffalo


  • Kuitunen, Sandi, 1991. Development of Database Requirements for Parcel-Based GIS.
  • Lembo, Arthur, 1991. A Structured Methodology for GIS Requirements Analysis.
  • Willer, David, 1991. A Spatial Decision Support System for Bank Location: A Case Study. (Co-Supervisor)
  • Huang, Chao-Min, 1992. An Aggregate Retail Analysis of Supermarkets in Amherst and Williamsville, New York.
  • Williams, James, 1992. Elderly Population and Mobility Change.
  • Cui, Xiabo, 1993. Design and Implementation of a Spatial Query and Information Display System for Real Property Management in Local Government.
  • Mckinney, James, 1993. Cartographic Representation of Solutions to Location-Allocation Models. (Co-Supervisor)



Selected Consultancies


  • Environment Public Authority, Kuwait.

    Member of a consultant team for the Environmental Monitoring Information System of Kuwait (eMISK) Project.  The project will establish, build and maintain a comprehensive geo-environmental database of Kuwait along with an enterprise level GIS system for access, update and analysis of the environmental data; my role is in developing the project’s spatial decision support capabilities.


  • National Information Centre, Sana'a, Yemen.
    Member of a team that undertook feasibility studies into the establishment of a Decision-making Support Information Unit and Geographical Information Systems Unit in Yemen.  I worked as a subcontractor to Consultancy Solutions Limited (CSL, UK) partnered with GISCON Solutions (Germany).
  • Kuwait Institute for Scientific Research, Kuwait.
    Project Consultant for the National Educational Atlas for Services and Infrastructure, State of Kuwait - Phase 1.  Undertook the initial user needs and systems analysis and produced a conceptual design for the Atlas, including its geodatabase.
  • Environmental Systems Research Institute, Redlands, CA.
    Consulted on the conceptual design of the Network Analysis Module of ARC/INFO; designed and developed a prototype for the module's location-allocation modelling capabilities; assisted with the implementation of the commercial version of the module (released in version 7.0); and developed extensions to the module for future releases.
  • Verdi Ryan Associates, Buffalo, NY.
    Consulted on the design and implementation of locational, demographic and consumer analyses for the reorganisation of existing, and the design of new, bank branch networks in the U.S.A. and other parts of the world.
  • NYNEX Science and Technology, White Plains, NY.
    Consulted on the design and implementation of locational, demographic and consumer analyses for cellular telephone and cable television systems; the role of spatial decision support systems in the optimisation of telecommunications and cable television networks; and collaborative spatial decision-making environments and their relevance to NYNEX's network design activities. This work led to the award of a U.S. Patent.
    Details at: http://www.delphion.com/details?pn=US05963544__
  • Imperial Cancer Research Fund (voluntary)
    Consulted on the design and implementation of a GIS and spatial analyses to support the Fund's retail activities and supervised an M.Sc. student who was carrying out much of the work for his project.



The following links are taken from my "favourites" list and represent sites that I have found particularly useful or interesting.

Shackleton's last expedition on the Endurance seen through the lens of photographer Frank Hurley

KODAK: The Endurance
Hosted by Kodak, this site uses Hurley's photographs to tell the story of Shackleton's ill-fated (1914 - 1916) expedition to Antarctica. Well worth a visit.

Picture archive of Scott, Shackelton and others

Freezeframe Project: historic polar images, 1845-1982
Digitised collection of historic images held by the Scott Polar Research Institute at Cambridge.

Dr. John Snow

John Snow - an historical giant in epidemiology
A site by enthusiasts! Hosted by UCLA, this site provides a wealth of infomation on Dr. Snow and his pioneering use of spatial analysis to identify the sources of Cholera outbreaks in London


Places that I work at

UCL (University College London)
CASA (Centre for Advanced Spatial Analysis)

or have worked at

State University of New York at Buffalo
NCGIA (National Center for Geographic Information and Analysis)
The NCGIA at the University at Buffalo
The University of Iowa

Sites on GIS, SDSS and CSDM

UCGIS (University Consortium for Geographic Information Science)
U.S.-based consortium of universities with GIS/GISci programmes.
The Orton Family Foundation
The home site for a foundation that supports the adoption of place-based spatial decision support systems in the U.S.
ESRI (Environmental Systems Research Institute)
Homepage for the market leading GIS vendor.
ESRI (UK) Ltd.
Homepage of ESRI U.K.
CT Centre for Geography, Geology and Meteorology Home Page
U.K.-focused site for educational resources.
DSS Resources
An interesting and informative site on mainstream DSS.
The UW-UI Collaborative Spatial Decision-Making (CSDM) Home Page
Tim Nyerges and Piotr Jankowki's site. Lots of useful links and resources.
Some great work that uses 3D visualisation and linked representations to explore community design issues.
Designing better electoral systems for emerging democracies
A co-production between Gerry Rushton and Joel Barkan, at the Universityof Iowa, and myself. Details of an SDSS that we are building and refining.
A German site that provides access to a series of locational analysis algorithms that can be donwloaded and used in your own programs.

Libraries, Journals and Conferences

GISRUK Homepage
Information on the Conference Series.
GeoSpatial Solutions
Magazine homepage.

Telephone Directories

UKPhonebook.com - UK telephone numbers
A good UK 'phone book.
BT PhoneNetUK
British Telecom's UK online 'phone directory
Yellow Pages UK Homepage
Catalogue with pointers to 'phone books all over the world.
Telephone Directories on the Web, Phone Books, White Pages, Yellow Pages
English language catalogue of 'phone books - other languages available.

Denshams on the Web

My own domain - brings you back to this site at UCL.
Densham and Associates Pty. Global Maritime Distress and Safety System (GMDSS).
This site showcases the work of artist Robert Densham from San Luis Obispo, California.




Nick Mann and I are the UCL Site Representatives for the Digimap Service. In the Map Library in the Department of Geography, 26 Bedford Way, we can print maps locally (up to A3 in size) for those people who do not have access to colour printing facilities.

What is Digimap?

Digimap is an on-line service, provided through EDINA, that allows users to view and create maps of any location in Great Britain using Ordnance Survey map data. Users can also download Ordnance Survey map data for use in other software packages, such as Geographical Information Systems (GIS), drawing software and CAD.

Digimap was launched in January 2000.

Who has access to Digimap?

Digimap is available to all staff and registered students at UCL - if you have a current, valid ID card, then you will be able to register for the service.

How do I register for a personal account on Digimap?

The steps to be completed to gain access to Digimap are described on the Library Services web pages.  Each student needs their own account to use Digimap.


If you have problems with Digimap and require help, please contact us by email geog-digimap@ucl.ac.uk or by 'phone (25530 (Nick) or 30578 (Paul)) in the first instance.



Selected recent research grants:

  • Dynamic Spatio-Temporal Location Strategies for Emergency Vehicles.
    September 2001 to September 2004
    ESRC CASE Award.
    P.J. Densham.
    This award funded a Ph.D. student (Torsten Schietzelt) to work with myself and Cadcorp (industrial partner) on emergency vehicle location strategies.
  • European Migration Information Network (EMIN) Project.
    November 2000 to October 2001
    Odysseus Programme, European Commission.
    Co-Principal Investigators: J. Salt (Project Director) and P.J. Densham.
    Total funding: € 111,843
    Odysseus Programme: € 85,430
    UCL Match: € 26,413
    This award is to continue and maintain the European Migration Information Network (EMIN) Project.
  • European Migration Information Network (EMIN) Project.
    November 1999 to October 2000
    Odysseus Programme, European Commission.
    Co-Principal Investigators: J. Salt (Project Director) and P.J. Densham.
    € 94,000
    The EMIN Project implements two of the principal recommendations of the Feasibility Study for a European Migration Observatory: first, to provide a co-ordinated network of information on the availability of statistical data; and, second, to link together access to various types of migration network using a world wide web site. To minimise the resources required to implement the web site and database, public domain software has been used wherever possible rather than commercial software with its high initial and recurrent costs. The project principally makes more acessible to current and new users of migration statistics information that already exists using the WWW. The major role for the EMIN is to co-ordinate access to data and information using up-to-date technology.
  • A Virtual Reality Centre for the Built Environment: Specialising in Research Applications and Training for Construction, Retailing and Transport.
    October 1996 to September 1999
    Department of Trade and Industry (Technology Foresight Programme).
    Co-Principal Investigators: J.M. Batty, A. Penn (Project Directors), P.J. Densham, D.P. Chapman, B. Hillier, R. Mackett, M. Slater and G. Winch.
    OST Funding: £1,100,000
    Industrial Match: £2,200,000
    The VR Centre researches ways of producing built environments using virtual reality techniques. The Centre disseminates its research findings to those who locate, design, construct, deliver and manage such facilities, enabling them to explore ways in which the highest quality environments can be produced. Companies from the construction, retailing and transport sectors, along with computer and software vendors, provide matching funds for the centre. My role in the centre consists of three elements: work on linking urban design tools with GIS; the development of retailing applications that integrate GIS, spatial analysis and VR; and participation in the development and operation of a partnership programme that disseminates VR methods and practices into industry.
  • Feasibility Study on the Possible Creation of a European Migration Observatory
    January 1995 to January 1996
    European Commission, Brussels.
    Co-Principal Investigators: J. Salt (Project Director) and P.J. Densham
    ECU 299,360 (Approximately £230,000)
    My role in this project was to evaluate new methods for storing, accessing and disseminating digital migration information - particularly GIS and the World-Wide Web. This task involves travelling to sites making innovative use of these technologies to assess the advantages and pitfalls of the approaches taken and to see what lessons might be learnt for a possible Migration Observatory.