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,...
With increased attention being focused on the remaining old-growth
forest resource in the Pacific Northwest a way to ecologically rate forest stands is
needed to assist the U.S. Forest Service in its management decisions. A Geographic
Information System (GIS) model was developed to rate old-growth stands in a 49,500
acre...
Animated cartography is still a new field. It has been experimented with for years, but it
has not gained general usage except partially in use by the news media. Nevertheless, certain
subjects cry out for displaying the patterns of movement over time, such as historical patterns of
migration and settlement,...
The visualization of climate patterns is a major theme in cartography. Short-term
dramatic weather events such as hurricanes and tornado outbreaks are mapped and
displayed immediately in order to capitalize on the sensational nature of the events, and
to quickly and accurately convey the information to emergency workers and the...
Equal value gray scales are frequently employed by cartographers to choose gray tone area
symbols. Several researchers have tried to quantify perceived gray tone as a function of percent area inked or
reflectance but results have varied. The influence of pattern and texture on gray tone perception is considered
a...
An inventory of existing land use maps developed by Oregon county planning departments has been made through use of questionnaires and interviews. The degree of consistency has been examined with regard to the types of base maps, scales, projections, base information, and classification schemes employed. Recommendations have been made for...
Efficient management of natural resources requires the ability to utilize and integrate information. The challenge is to fully utilize this information base with its various degrees of accessibility, ever increasing volume and dispersed nature. The manager must be familiar with media types used to store, manage and communicate this information....
The application of the collinearity solution by resection of the interior and exterior
orientation parameters of historical photographs is investigated. The spatial coordinates of seven
or more identifiable control points in the field of view of an historical photograph, combined
with image coordinates of the control point images, allow solution...
For many years, psychologists have studied
the principles of psychophysics. Recently, cartographers
have been considering psychophysical theory in
color attribute analysis to aid in the design of maps.
An experiment was conducted using the partitioning
method by which the Munsell value scale was determined
to find (R,G,B) coordinates giving equally...
Because of declines in salmon populations in recent years, the health of salmon habitat, in particular, is the focus of many resource agencies. The objective of this study is to use GIS to predict the location of suitable habitat. With data from an extensive set of stream surveys, GIS was...
Many studies have looked at human settlements around individual volcanoes for
volcanic risk analyses, but few have done a comparative study to identify possible global
patterns. With the use of Landsat ETM+ data, this study identifies and compares urban
proximity to the Decade Volcanoes to identify volcanic settlement patterns. These...