GIS and Human Geography November 14, 2006
Announcements n n e. Seminar in GIS: Wednesday 22 November, 2006 Speaker: Mark Harrower (UWMadison) Title: Representing and visualizing time and geographic processes Time and Place: 17. 00. room 3514 Georg Sverdups Hus.
GIS Day – November 15 n n n Geodata Lecture 10. 00 -11. 00 (Audit. 4) Serversentrisk GIS – 2007 et paradigmeskifte innen GIS (cake and coffee served) GIS Stand at library (GIS quiz) GIS Course: Friday, November 17
Oslo Project 1. 2. 3. 4. 5. 6. 7. 8. Project description. Clearly state hypothesis or research focus Data sources and limitations (include table of metadata) Describe spatial distributions of data (include map) Focus on one particular bydel – provide general description (population, income, ethnic composition, changes in 2005, etc) (include map of Oslo bydel and inset map to identify location of your bydel) Describe supplementary data (for example, GPS data) mapped and supplementary data (list locations and coordinates in a table) (include bydel map) Analysis: what are your findings based on a mapping of your data? (conduct a spatial analysis, e. g. buffer, measure) Conclusion References
Oslo Project n Four examples of good projects from 2005 will be available for you to review in lab next week.
Masters Students n n Paper Option: Address a research question of your choice using GIS Include information about data capture; data manipulation and analysis; data output and display. Paper should include maps and preliminary results! This is not a thesis, but should represent a potential methodological contribution to it. It will be evaluated based on how it links GIS and your research topic to produce output.
Labs schedule n We can have extended lab hours in weeks 46 -48, but need students to volunteer to be responsible for signing up with Stine to gain access.
Midterm Quizzes n n n Average on Midterm Quiz 1: 20, 9 Average on Midterm Quiz 2: 21, 6 Grades will be assigned based on the total of the two quizzes: n n n 47 -50 = A 43 -46 = B 39 -42 = C 35 -38 = D 31 -34 = E Below 30 = F
Final Exam: December 1 n n n Short answers (Describe five GIS concepts or terms in no more than 3 or 4 sentences). Essay question (in several parts) Exams are available in Norwegian and English, and can be written in either language (or Swedish)
Sample exam questions n n You have just been hired as the head ”samfunnsgeograf” in Stokke kommune due to your expertise in social, economic, political, and cultural geography. The ordfører has no idea that you are also an expert in GIS. Your first assignment is to identify a location for a new airport that will be constructed in 2010, when capacity at Gardermoen and Torp is expected to be overwhelmed by commercial and charter flights. You are expected to select a site for the airport that will generate maximum economic revenue with minimal environmental, cultural, and social impacts. The ordfører does not use computers, and expects you to do your job with a pencil, ruler, and a paper map. 1) Write a memo to your boss making a strong argument as to why the kommune should use a GIS to select the optimal location for the airport. In your memo, be sure to define what a GIS is, describe the different components of a GIS, and present the advantages of using GIS instead of traditional paper maps and manual analysis. Emphasize how GIS could benefit Stokke kommune. You should also discuss the costs (in general terms, not in absolute kroner) and limitations. Your memo should present a clear argument as to why the kommune should invest in GIS. 2) Your memo was successful! The kommune has now bought you a PC with Arc. GIS software, a color printer, and a GPS. You have also gained access to the AREALIS database for Stokke kommune, which includes the Arc. GIS shapefiles described in Table 1. Now you need to get down to work. You have identified the following 5 criteria as being most important to the selection of the airport location. n n n n The terrain should be flat and free of water. The airport should be located within 3 km of the main highway, E 18. The airport can be built on farmland, but it should not be built on recreational land. Also, it cannot be located within 2 km of a protected area. The airport should be built at last 5 km from areas with high population density (tettsteder). To attract tourists to Stokke, there should be at least one cultural heritage site within 4 km of the airport. From Table 1, select the coverages (i. e. , shapefiles or layers) that you will use in your analysis. In a methodical manner, describe how you will go about identifying an optimal site for the airport, including any spatial analysis that you will do on your selected coverages. 3) Having used GIS to select an optimal location for the airport, you now want to describe to your boss some of the uncertainties associated with your results. What can you do to reduce the uncertainty?
n n The Norwegian Ministry of Foreign Affairs has contracted you to provide GIS consultancy services to the small Polynesian island of Niue on climate change adaptation, as part of Norway’s foreign development aid. You have two specific tasks. 1) Your first task is to convince the Premier of Niue, Hon. Mititaiagimene Young Viviani, and his three cabinet ministers that GIS is an ideal tool for planning the relocation of the population inland as well as for developing the tourism sector of the economy. n n n a) You must write a short memo to the Premier explaining what GIS is, and why it can be useful for settlement planning and tourism development, particularly in the context of an uncertain and changing climate. You should inform him about the type of investment they will have to make, and the limitations of GIS. 2) Your second task is to develop a GIS that can be used to successfully relocate the 2, 166 residents away from the coast. (As you see from the map that you downloaded from the Internet (below), most of the villages are currently located along the coast. ) The Niue Government would like all 14 villages to be relocated at least 3 km away from the coast, to accommodate potential sea level rise and stronger tropical storms. The new villages cannot be located inside of, or within a distance of 1 km of the Huvalu Forest Conservation Area. Also, the new villages must be located within 500 meters of an existing road. Finally, to encourage tourism development, each new village should be located within 2 km of one of the island’s 10 scenic points (this does not include the sites within the Huvalu Forest Conservation Area). Note: The following three sub-questions can be combined into one essay. n n n a) What types of GIS data do you need to carry out the relocation of residences and why? Describe whether each theme/data type is likely to be a point, line, polygon, or raster file. b) Outline the procedures for siting the new villages. What types of GIS spatial analysis would you perform to take into account the considerations described above? c) What factors are likely to be important to relocation plans that are not included in GIS data?
Review: n Last week we talked about spatial analysis – one of the most important features of a GIS
Spatial Analysis n Turns raw data into useful information n by adding greater informative content and value Reveals patterns, trends, and anomalies that might otherwise be missed Provides a check on human intuition n by helping in situations where the eye might deceive
Definitions n A method of analysis is spatial if the results depend on the locations of the objects being analyzed n n n move the objects and the results change results are not invariant (i. e. , they vary!) under relocation Spatial analysis requires both attributes and locations of objects n a GIS has been designed to store both
Measurement of Length n n n A metric is a rule for determining distance from coordinates The Pythagorean metric gives the straight-line distance between two points on a flat plane (a 2+b 2=c 2) The Great Circle metric gives the shortest distance between two points on a spherical globe n given their latitudes and longitudes
Transformations n Create new objects and attributes, based on simple rules n n involving geometric construction or calculation may also create new fields, from existing fields or from discrete objects
Spatial Interpolation n n Values of a field have been measured at a number of sample points There is a need to estimate the complete field n n n to estimate values at points where the field was not measured to create a contour map by drawing isolines between the data points Methods of spatial interpolation are designed to solve this problem
Other types of spatial analysis n n Data mining Descriptive summaries Optimization Hypothesis testing
Data Mining n Analysis of massive data sets in search for patterns, anomalies, and trends n n n spatial analysis applied on a large scale must be semi-automated because of data volumes widely used in practice, e. g. to detect unusual patterns in credit card use
Descriptive Summaries n n Attempt to summarize useful properties of data sets in one or two statistics The mean or average is widely used to summarize data n n centers are the spatial equivalent there are several ways of defining centers
The Centroid n n Found for a point set by taking the weighted average of coordinates The balance point
The Histogram n A useful summary of the values of an attribute n n showing the relative frequencies of different values A histogram view can be linked to other views n e. g. , click on a bar in the histogram view and objects with attributes in that range are highlighted in a linked map view
A histogram or bar graph, showing the relative frequencies of values of a selected attribute. The attribute is the length of street between intersections. Lengths of around 100 m are commonest.
Spatial Dependence n n There are many ways of measuring this very important summary property Most methods have been developed for points Patterns can be random, clustered, or dispersed Measures differ for unlabeled and labeled features (e. g. individual house locations, versus housing types)
Dispersion n n A measure of the spread of points around a center (“standard deviation”) Related to the width of the kernel used in density estimation
Fragmentation Statistics n Measure the patchiness of data sets n n e. g. , of vegetation cover in an area Useful in landscape ecology, because of the importance of habitat fragmentation in determining the success of animal and bird populations n populations are less likely to survive in highly fragmented landscapes
Three images of part of the state of Rondonia in Brazil, for 1975, 1986, and 1992. Note the increasing fragmentation of the natural habitat as a result of settlement. Such fragmentation can adversely affect the success of wildlife populations.
Optimization n n Spatial analysis can be used to solve many problems of design or create improved design (minimizing distance traveled or construction costs, maximizing profit) A spatial decision support system (SDSS) is an adaptation of GIS aimed at solving a particular design problem
Optimizing Point Locations n n The minimum aggregate travel (MAT) is a simple case: one location and the goal of minimizing total distance traveled to get there The operator of a chain of convenience stores (e. g. Deli Deluca) might want to solve for many locations at once n n where are the best locations to add new stores? which existing stores should be dropped?
Routing Problems n n Search for optimum routes among several destinations The traveling salesperson problem n find the shortest tour from an origin, through a set of destinations, and back to the origin
Routing service technicians for Schindler Elevator. Every day this company’s service crews must visit a different set of locations in Los Angeles. GIS is used to partition the day’s workload among the crews and trucks (color coding) and to optimize the route to minimize time and cost.
Optimum Paths n Find the best path across a continuous cost surface n n n between defined origin and destination to minimize total cost may combine construction, environmental impact, land acquisition, and operating cost used to locate highways, power lines, pipelines requires a raster representation
Solution of a least-cost path problem. The white line represents the optimum solution, or path of least total cost, across a friction surface represented as a raster. The area is dominated by a mountain range, and cost is determined by elevation and slope. The best route uses a narrow pass through the range. The blue line results from solving the same problem using a coarser raster.
Hypothesis Testing n n n Hypothesis testing is a recognized branch of statistics A sample is analyzed, and inferences are made about the population from which the sample was drawn The sample must normally be drawn randomly and independently from the population
Hypothesis Testing with Spatial Data n Frequently the data represent all that are available n n It is consequently difficult to think of such data as a random sample of anything n n e. g. , all of the census tracts of Los Angeles not a random sample of all census tracts Tobler’s Law guarantees that independence is problematic n unless samples are drawn very far apart
Possible Approaches to Inference n Treat the data as one of a very large number of possible spatial arrangements n n Discard data until cases are independent n n n useful for testing for significant spatial patterns no one likes to discard data Use models that account directly for spatial dependence Be content with descriptions and avoid inference
Summary n All methods of spatial analysis work best in the context of a collaboration between human and machine. One benefit of the machine is that it sometimes serves to correct any misleading aspects of human intuition. (Human can be poor at guessing the answers to optimization problems in space. )
GIS and Society: A Critical Assessment
Critiques in the academic literature: n n Sheppard, E. 1995. GIS and Society: Towards a Research Agenda. Cartography and Geographic Information Systems 22(1): 5 -16. Pickles, J. (ed). 1995. Ground Truth Pickles, J. 1997. Tool or Science? GIS, Technoscience, and the Theoretical Turn. Annals of AAG 87(2): 363 -372. http: //www. geo. wvu. edu/i 19/papers/position. html
Initiative 19: GIS and Society: The Social Implications of How People, Space, and Environment are Represented in GIS (began February 1996). n n n The initiative focused attention on the social contexts of GIS production and use and addresses a series of conceptual issues: In what ways have particular logic and visualization techniques, value systems, forms of reasoning, and ways of understanding the world been incorporated into existing GIS techniques, and in what ways have alternative forms of representation been filtered out? How has the proliferation and dissemination of databases associated with GIS, as well as differential access to spatial databases, influenced the ability of different social groups to utilize information for their own empowerment? n How can the knowledge, needs, desires, and hopes of marginalized social groups be adequately represented in GIS-based decision-making processes? n What possibilities and limitations are associated with using GIS as a participatory tool for more democratic resolution of social and environmental conflicts? n What ethical and regulatory issues are raised in the context of GIS and Society research and debate?
GIS as a tool? n The idea that GIS, or any technology, is simply a problem-solving tool views technology as the means to achieve a certain end. In this view, the goals are set independently, and technological development is the process of finding the tool that offers the best means to achieve that goal. In practice, however, it is difficult to separate means from ends.
n ”In other words, the social consequences of technologies go far beyond problem-solving to actually influencing the goals themselves, sometimes in dramatic ways (development of trade, cataloging of resources, definition of property ownership). ”
GIS is not just a tool for processing geographical information. n It is a social technology incorporating an entire institutional and intellectual infrastructure that delivers and markets GIS. It has to be understood within the social context in which it was developed.
Much of the lead in GIS technology has been taken in North America and Great Britain. Thus it reflects: n n n Priorities of US society, such as demands for military surveillance, The degree to which the private sector has dominated the development of GIS, The types of problems that potential customers for GIS wish to solve, Factors affecting data availability and cost, Weakness of geography as an intellectual discipline in the US, which affects the degree to which geographic expertise is used in the development of GIS.
GIS is based on Boolean or mathematical logic: n n n Deductive logic thought to allow the absolute truth or falsity of analytical statements to be assessed. But no absolute grounds exist for asserting the validity of mathematical logic. Alternative logics cannot be dismissed as inferior or subjective. Boolean logic is fundamentally an instrumental, or agorithmic, logic, directed to finding solutions to problems. But communication involves a different form of rationality. The focus on logic and problem-solving may hide other options and opportunities (eg siting of toxic waste dump).
Does GIS place limits on ways of representing space? n n Computational operations on spatially referenced information must conform to basic geometric rules and assumptions, such as those specifying the continuity or divisibility of space, and excluding simultaneous occupancy of the same location in space-time by different objects. In non-Western thought the range of possible conceptions of space is presumably much greater.
Problems with pattern analysis: n n n Different processes may produce the same pattern and the same pattern may be produced by different processes. This requires a theory to identify what the important relations are. GIS lacks this, often ignoring underlying theories. It provides a list of winners and losers, but provides no understanding as to why the differences occur.
GIS reinforces a tendency to rely on secondary data sources for empirical analyses. n n Geographical analysis driven by the availability of data, rather than letting data collection be driven by theory. Social power of information systems: private firms can get our credit card ratings, but we cannot get detailed financial information about those private firms…
Does GIS facilitate equal access to geographical information for all social classes? n n Information technology has placed information and the equipment to process it in the hands of more users, linked in increasingly complex ways. But the rapid development has resulted in increasingly sophisticated ways of using the information infrastructure to monitor and influence behavior. Groups with access to GIS may be able to make a better argument in conflictual political processes. Polarization of users and non-users.
Socio-economic applications in GIS n n Is there any real substance? Real estate, energy delivery, agribusiness, tourism, and communications, insurance, retailing, market analyses, delivery services, telecommunications, fast food location strategies, and so on. Missing are the analyses of ethical and political questions that emerge as GIS institutions and practices are extended into socioeconomic domains. Concepts, practices, and institutional linkages remain unproblematized; treated as normal and reasonable ways of thinking and acting.
The pursuit of social goals (eg land distribution) through GIS is a political process and cannot ignore this fact, no matter how much GIS may allow us to simulate possible alternative decision-making scenarios. Value-neutral GIS does not exist. GIS empowers the powerful and disenfranchises the weak and not so powerful through the selective participation of groups and individuals.
Data are usually treated unproblematically, except for technical concerns about errors. n n But every data set represents a multitude of social relations. In general, the more powerful do the finding out about the less powerful. Since most data are collected by the state (eg census data), GIS can be criticized as being a handmaiden of the state. This wouldn’t be a problem if all states were benign, but they aren’t.
n n n GIS neglects themes that are not included in the data. The poorer the country, the worse and less the data. Thus much of the world is neglected within GIS analyses. Alternative worlds for which there are no data are ruled out or excluded.
Information gathering as a commercial activity, producing a product for sale (eg, weather information) n n n Disadvantaged groups are least able to purchase the information that they need, especially information that is expensive to collect. Although more accurate information can improve understanding, it can also enable actors to act in more complex ways (eg, airline pricing). The more complex a society becomes, the more complex and expensive the information it needs to make sense of itself. GIS does not incorporate ”indigenous” knowledge. Diverse information possessed by different racial groups, classes, and genders is usually excluded.
Surveillance capabilities of GIS n n GIS has been linked with the academy, the state, and capital. ”Information society” as a misnomer that hides the increasing surveillant capability of state institutions and transnational corporate enterprises (see Pickles 1991).
Participatory GIS (PGIS) n n n A growing sub-field of GIS that responds to some of the criticisms of GIS Began in 1980 s with Participatory Rural Appraisal (PRAs) Adopted GIS and GPS technologies in the 1990 s
n n IAPAD (Integrated Approaches to Participatory Development) is an organization that uses and promotes PGIS. Many good examples are on their web site. ”PGIS practice is usually geared towards community empowerment through demanddriven, user-friendly and integrated applications of geoinformation and GIT, In which obviously, maps and map products become primary conduits. The practice is multidisciplinary, integrating outside experts with socially- and genderdifferentiated local knowledge experts. And it builds on high levels of stakeholders´ participation in the processes of spatial learning, decision making, and action. ” Ramaldi et al. 2004 (http: //www. iapad. org/participatory_gis. htm)
GIS and Geography n n GIS as ”the escalator that geography can ride to finally occupy its legitimate position as a significant member of the quantitative and empirical sciences” (Sheppard 1995, p. 5) Does GIS contribute to ”a growing split between ’techies’ and ’intellectuals’ in contemporary geography”? (Sheppard 1995, p. 5)
The power of GIS should not be underestimated, but at the same time GIS should not be overpromoted or blindly attacked. GIS provides a tool to use on geographical information. What they are used for and how to make best use of them depends on the attitudes and mindsets of their users and what they want to do with them.
What next? n n n ESRI Virtual Campus ESRI Brukerkonferanse (Feb 2007) WUN and e. Seminars GIS Internships GIS Club
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