Madison County, New York, February 20, 1993.
TITLE: First PhD dissertation on digital map analysis
EVENT START DATE: June 20, 1969
A doctoral dissertation in Geography at The Pennsylvania State University by Mark Stephen Monmonier, titled "On the Use of Digitized Map Sampling and Measurement: An Example in Crop Ecology," was defended in June 1969. The Ph.D. degree was awarded in September 1969. This was the first PhD dissertation to address the use of digitized land cover and elevation maps for slope and overlay analysis.
QUOTING FROM THE ABSTRACT: "Doctoral dissertation in Geography at The Pennsylvania State University by Mark Stephen Monmonier, titled "On the Use of Digitized Map Sampling and Measurement: An Example in Crop Ecology," defended in July 1969. Degree awarded September 1969. First PhD dissertation to address use of digitized land cover and elevation maps for slope and overlay analysis. "An attempt is made to present a compact and concise exposition of methods useful for measuring, directly with a digital computer, the geometry and interrelationships of spatial distributions.
Major attention is both to contour maps and to domain, i.e. choropleth, dasymetric, or property, maps. While the treatment is primarily concerned with digitized rectangular map arrays, other representations, such as chain-encoded contours and domain boundaries, are also described. Numerous currently employable, as well as some potentially more valuable, means for obtaining digitized maps are discussed, together with preparations required to permit measurement and correlation analysis.
The main measurement techniques developed are related to the local surface geometry of points; these techniques include the determination of maximum slope, direction of maximum slope, slope in a particular direction, and surface area. After computer sensing of the terrain configuration around the point in question, and after finding the orientation of the flat element plane representing the surface at that point, the appropriate mathematical formula is then applied to achieve one or more of the above measurements. Various methods are presented for conducting the necessary computer search for contours in the vicinity of the array location for which a measurement is needed, as are the procedures for efficient systematic and random sampling.
As a means of illustrating the above techniques, a digitized map analysis is then applied to a case study in which relationships are demonstrated between the topographic and edaphic environment and the locations of orchards for two sample sites on the fringes of South Mountain in Adams County, Pennsylvania. Topographic slope and slope direction, along with several important soil characteristics, are sampled both randomly and along automatically computed geodesic paths in an attempt to estimate the significance of the air drainage and the edaphic factor as elements and localizing orchard sites. . . .
Additional potentially useful applications of digitized map analysis other than those employed in this study, together with some improvements needed for a more complete investigation of situation, are discussed. It is concluded that future generations of computing machinery should greatly expand the scope of digitized map measurement, correlation, and transformation procedures.”
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First PhD dissertation to address use of digitized land cover and elevation maps for slope and overlay analysis. Co-advisors: George F. Deasy and Anthony V. Williams. See Penn State Geography Theses list, at https://scholarsphere.psu.edu/downloads/r4x51hk94m. Key results were subsequently published as Mark Monmonier, "Digitized map measurement and correlation applied to an example in crop ecology," Geographical Review 61 (1971): 51–71.