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4 Geography's Techniques
Pages 47-69

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From page 47...
... These techniques reflect the conscious decisions of geographers about the kinds of information that are important to collect; the spatial scales at which information should be collected, compiled, analyzed, and displayed; data sampling strategies and experimental designs; data representation; and methods for data analysis. As theoretical paradigms change, so do the techniques for empirical research.
From page 48...
... Perhaps the best current examples are GISs that store, manipulate, and display geographically referenced information. The potential of GISs to handle large quantities of spatially related information fills an important need in research, education, and applied work in the public and private sectors.
From page 49...
... The focus of this chapter on techniques for empirical analysis should not be taken to mean that methodological contributions in geography have been restricted to observation and hypothesis testing. For the past 20 years the discipline has been a fertile field of theoretical research, particularly in conceptualizing and modeling geographic processes.
From page 50...
... so 1 945 REDISCOVERING GEOGRAPHY 160- UNITED STATES 20 BO 4o ant 1 945 1 950 '~L 1 955 1 960 I 1 965 1 970 160 - UN ITED Kl NG DOM 20 L~ll -80 ...
From page 51...
... Fieldwork allows geographers to make direct observations in places where local data are missing or unreliable and to check the validity of existing secondary sources such as census statistics. While the increased availability of remote sensing imagery would seem to reduce the need for fieldwork in some research, in truth it makes such work even more important because accurate interpretation of imagery depends on detailed knowledge of the actual patterns on the ground.
From page 52...
... Remote Sensing Remote sensing is defined here as the detection and recording of electromagnetic radiation signals from the Earth's surface and atmosphere using sensors placed aboard aircraft and satellites. These signals are usually recorded in digital form, where each "digit" denotes one piece of information about an average property of a small area of the Earth.
From page 53...
... GEOGRAPHY'S TECHNIQUES 53 FIGURE 4.2 This photograph shows a GPS (mounted on the rider's back) being used to record positional data while traversing remote highlands of the Dominican Republic for a research project on Quaternary paleoclimatology and biogeography.
From page 54...
... The acquisition of global land cover data has been recognized as a top priority by the National Research Council and the International Geosphere-Biosphere Programme (e.g., Townshend, 1992; NRC, 19941. Geographers have also played key roles in the collection and processing of remotely sensed data for the National Oceanic and Atmospheric Administration's Coastwatch Change Analysis Project, a joint state and federal program designed to monitor environmental changes in coastal wetlands, uplands, and submerged habitats.
From page 55...
... Rain gauge networks provide spatial samples of the continually varying global precipitation field. Their spatial distributions are neither random by design nor demonstrably random in effect (see Figure 4.31; nevertheless, the nodes of these sampling networks (the rain gauge locations)
From page 57...
... Many geographers believe that a large dividend would come from integrating GISs as information science with visualization techniques and spatial analysis methods. The following subsections provide a brief review of some of the substantive methodological contributions of the discipline to display and analysis techniques.
From page 58...
... The newly released "ExplOregon: A Geographic Tour of Oregon" (a 1995 multimedia CD-ROM developed by William Loy with Digital Chisel software by Pierian Spring Software) is changing the way that the geography of Oregon is taught and learned in schools throughout the state.
From page 59...
... .. ~i+.~,, ~,,.,~'l~'"""'~'~s~s~ '1 · , $~ K it, , ¢ ~i 59 which sets them apart from computer mapping systems, is the ability to perform spatial analyses to address research and application questions.
From page 60...
... referencing to a basic calculation are also possible for example, going beyond questions about the total length of a city's sewer lines to questions about the total length of sewer lines in a given area in a particular city and what proportion of this length is more than 50 years old. GISs are also capable of more complicated operations such as (1)
From page 61...
... Researchers constructed databases that contain spatial coordinates of the study area and "layers" of information about the canyon's vegetation, surficial geology, and hydrology. These three characteristics are being monitored and analyzed to determine trends through time in riparian vegetation growth, habitat, and "events" such as channel scouring and channel .
From page 62...
... A particularly important component of the project involves rapid field mapping by local technicians using handheld GPS monitors integrated with pen computers. Data are gathered and fed directly into the GIS to allow for updated mapping and integration with remotely sensed images.
From page 63...
... Using the power of human vision to recognize patterns and synthesize spatial information increases the capacity of geographic researchers to cope with this data volume. For example, a simple 48 X 48 matrix of fiscal transfers for the United States generates 2,256 pieces of information for each time period considered.
From page 64...
... Research in this field also includes the development of new data transformation and symbolization techniques and the development of computer interfaces to allow interactive analysis of spatial data (see Sidebar 4.54. In the field of multimedia research, cartographers are developing techniques and computer interfaces that allow animation to be used as a tool for spatial pattern recognition.
From page 65...
... There is a growing need to address such issues as truth in representation, particularly in relation to the use of GVis and GISs in public policy applications. Spatial Statistics The analysis of geographically referenced information poses statistical challenges not faced in most other disciplines.
From page 68...
... Because geographic data often fail to meet distributional assumptions necessary for classical statistical procedures, geographers have been at the center of attempts to develop distribution-free methods for estimating statistical relationships among variables. They also have been involved in the development of methods for estimating prior probability distributions, either through Monte Carlo simulations that generate reference distributions unique to each locality or by developing Bayesian methods that allow investigators to incorporate knowledge of known relationships in statistical investigations.
From page 69...
... Research is also needed to understand how to separate environmental effects from other geographic variations in health research how, for instance, to separate environmental factors that cause cancer from the density of susceptible populations when searching for cancer clusters. This last example illustrates the importance of research in addressing important public policy questions.


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