Irrigation is essential for profitable agriculture in the western
United States. It is the largest consumer of water and power in
Oregon. Conflicting uses of water and power and their scarcity demands
judicious planning for allocation of these resources. Creditable
baseline data are not only needed for irrigated crop acreages,...
The development of a geographic information system
(GIS) requires the development of large databases of
spatially related information. Scale, resolution and the
classification of thematic data can vary considerably in
terms of the level of detail at which the data are compiled
and converted to machine readable form. The level...
In this paper "map complexity" refers to the inherent
intricacy of a mapped geographic pattern. Map complexity and sample
size are two variables shown to influence the accuracy of
interpolated dasymetric maps.
An automated experiment was designed to investigate the
precise relationship among map complexity, sample size, and the
accuracy...
A psychophysical bisectioning experiment was performed
to evaluate equal steps within tint progressions on a high
resolution graphics terminal. In the bisectioning
experiment each respondent partitioned a tint progression
by interactively defining colors that were perceptually
equidistant between two previously defined colors. Twenty
test subjects performed the test on the...
Historically the U.S. Forest Service has used uncorrected
aerial photographs to delineate proposed and past management
activities on the land base it manages. Transferring a boundary
from an image not planimetrically correct to a planimetrically
corrected image introduces errors. Positional accuracy of
boundaries affects the number of acres the Forest...
Training high school students to conduct field mapping and data
collection of wildlife habitat on public lands produces important data for
local government geographic information systems and introduces students
to the field of geography. However, the positional accuracy of the spatial
data is important for use in a GIS, as...
Progress in the development of color CRT's and color
graphic hard-copy devices offers a new tool for the thematic mapper.
From a cartographic perspective, the technology for displaying and
producing color maps has advanced without concern for cartographic
principles and conventions in the employment of color. Since it is
necessary...
The purpose of this paper is to describe the
application of expert system concepts to cartographic
problems. Expert systems, a subfield of artificial
intelligence, are computer programs based on knowledge and
symbolic reasoning. The basic principles of expert systems
will be explained. Areas of cartography that are most
suitable for...
The purpose of this project, therefore, is to develop a GIS for a small
geographical area that is currently of high priority to the GLT. The development of this GIS will be documented in a sequential fashion, so that it may serve as a
framework for future endeavors. This paper...
Slope-aspect is the compass direction of a slope at a particular location on a given
surface, and can provide a graphic tool for people who require an understanding of
the pattern of slope-aspect variation across a landscape. Slope-aspect maps can be
helpful for terrain analysis, watershed management, building site analysis,...