Karen ShiloGIS Assignment OneBarbara ParmenterAugust 11, 2008

GIS Assignment One:Brief Project Report Example

I. Project Gigalapolis

Project Name: Project GigalapolisURL: http://www.ncgia.ucsb.edu/projects/gig/

Researchers’ Names and Institutions: Jeannette Candau at the U.S. Geological Survey (USGS) and Dr. Keith Clarke at the University of Santa Barbara Geography Department.

Reasons for the study:Urban growth will have tremendous impacts on current and future infrastructure and resources. It could also be a strong driver of global change and rising awareness for energy and other resource conservation for decades to come. Project Gigalopolis has extended and refined the former urban growth model, enabling predictions at regional, continental and eventually global scales.

Time period Involved:The project data goes back to 1929. The scope of the project however includes projections up through the 21st century.

Data Used and Where the Data Came From:One example of data used is a database that was generated for the South Coast. Its multiple historical land use layers were accumulated on a building-by-building basis from 1929 to the present. This broad accumulation of data arguably could lend greater precision to model inputs and calibrations. These data inputs include Slope, Land Use, Excluded, Urban, Transportation, and Hillshade inputs. A scenario file is then created where variables are set. The inputs in the scenario files then control the outputs of which there are two: Image Outputs and Statistical Outputs.

Geographic Extent of the Study Area:The model has been successfully implemented in San Francisco, Chicago, Washington-Baltimore, Sioux Falls and more recently on the South Coast of California. The long-term goal of the project, however, is development to continental and eventually global scales.

Software and Analytic Methodology Used (if given):The Urban Growth Model (UGM) is a C program running under UNIX. It can be formatted for any standard C compiler, but some minor changes in the code might be

necessary for execution in new environments. In order to implement the model, a good understanding of C programming is necessary.

The coupled models together are referred to as SLEUTH, originally derived from the simple image input requirements of the models: Slope, Land cover, Exclusion, Urbanization, Transportation, and Hillshade inputs.

What was done during the study:SLEUTH begins with a set of initial conditions, a.k.a. the input data configuration of the landscape. A set of growth parameters are then applied to this data to simulate urban driven land cover change as realistically as possible. For example, two types of suitability are used to measure the likelihood of urban growth: the exclusion layer i.e. water, swamps, etc. and the slope. It is an interesting fact that a slope above 21% cannot be urbanized. These parameters comprise an urban growth cycle that consists of four steps: Spontaneous Growth, New Spreading Centers, Edge Growth, and Road Influenced Growth.

Results of the research:Many publications have utilized the SLEUTH model including both Urban Dynamics and Urban Retrospectives Publications. A master’s thesis utilizing this model by J.C. Candau in 2002 was titled Temporal Calibration Sensitivity of the SLEUTH Urban Growth Model. In the thesis, J.C. discusses how the model allows new hypotheses of urban evolution to be developed. For instance, in the Santa Barbara historical data, the number of clusters increases in the early part of the data set, slightly decreases, and then displays a sharp increase. The trend of the metric could potentially describe a pattern of cyclical behavior with regards to urban cluster size over time. In addition several publications, distinct PowerPoint presentations were developed such as Analyzing Urban Land Use Changes in Urban Environments and Using SLEUTH for Transportation Planning, employed in GIS Workshops in Washington D.C.

Other Pertinent Information about the Project:I found it interesting that in an effort to create greater communication for SLEUTH users, a discussion board was created and hosted by the UC Santa Barbara Geography Department.

Appendix: Sample Gigalapolis Maps. For note: They picked a great project name. II. Additional Questions:

1. Think about the issues or research questions addressed in the project, and why the spatial/geographic aspects in the project are significant (assuming they are). Could the project be accomplished without mapping or spatial analysis?

The integration of data from a variety of sources is key to the validity of any hypothesis including those regarding urban growth. Types of database structure and design issues influence data quality and data documentation, which are an integral

part of any project. In this project in particular, one of the primary impetuses for the project was to trace trends of urban growth over time. Capturing the temporal cycles of urban growth inherently prescribed the large accumulation of inputs not only only over time but in several regions. Though perhaps the data could have been collected in excel and presented without mapping or spatial analysis, the use of GIS validated and expanded the data and its uses greatly.

2. What further questions would you like to see explored in a project like this? Are these questions spatial or non-spatial? Explain.

With further development of the model, I would have liked to see hypotheses linking urban growth trends with energy and natural resource consumption. Having the spatial capabilities to compare rising population growth in multiple urban areas directly with rising energy and resource consumption could be valuable in demonstrating that more attention is needed to mitigate U.S. consumption of energy and the development of alternatives.