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Centre for
1ian Nations 1
Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986
Soils an important component in a digital geographic
information system
Carlos R.Valenzuela*, Marion F.Baumgardner & Terry L.Phillips
Purdue University, Laboratory for Applications of Remote Sensing, West Lafayette, Ind, USA
* Present address: ITC, Enschede, Netherlands
ABSTRACT: There is an increasing use of digital geographic information systems to meet the demand for specific
accurate and rapid information of our resources. The degree of usefulness of this information depends on the
accessibility and efficiency of the methods utilized for input, storage, analysis, and retrieval of informatio
The demand for accurate and rapid soil information is growing in our society, thus the element soil, because
se of its importance, is one of the basic components of a complete geographic information system.
The Indiana soil association map at a scale 1:500,000 was digitized, projected to an Albers equal-area map
projection, rasterized, and stored in a geo-referenced database created for the state of Indiana, U.S.A. Using
the digital soils data stored in the geo-referenced database, new sets of data were generated by changing the
coding of the soil associations or by combining two or more of these new generated products. Among the new
digital data sets generated from the soils data are: Prime agricultural lands, Potential erosion, Dominant
drainage, Dominant relief, average Corn yields.
1 GENERAL
TAT, A Micro
n, Management,
ic Research
iversity, East
ser's Guide to
tion System -
lichigan State
Lgan.
The complexity and increasing volumes of available
information, and the demand for the storage, analysis
and display of large quantities of environmental data,
has led in recent years, to rapid development in the
application of computers to environmental and natural
resources data handling and the creation of sophisti
cated information systems (Tomlinson et al., 1976).
Effective utilization of large spatial data volumes
is dependant upon the existance of an efficient geogra
phic handling and processing system that will trans
form these data into usable information. The major
tool for handling spatial data is the geographic infor
mation system (Marble and Peuquet, 1983). Increasingly
data of all types are being collected and converted to
digital format. Extensive digital geographically orien
ted databases are being developed, and automated spa
tial information systems are used for storage, retrie
val, manipulation, analysis, and display of information
(Tom and Miller, 1974; Power, 1975; Knapp, 1978; Jerie
et al., 1980; Anderson and Bernal, 1983).
A digital geographic information system (GIS) is a
computerized system designed to stored, process and
analyse spatial data and their corresponding attribu
te information. Advances in computer technology and
techniques have made it possible to integrate a wide
range of information (Gribbs, 1984). Technological
advances have increased input techniques, storage, a-
nalysis and retrieval capabilities. Furthermore, there
has been a reduction in costs and an increase in ac
cessibility, so that a larger user community has been
developed (Moellering, 1982). Geographic information
systems have provided planners with a readily accessi
ble source of objective earth science related facts,
and an inexpensive, rapid and flexible tool for combi
ning these facts with various other products to create
decision alternatives (van Driel, 1975; Stow and Estes,
1981; Stoner, 1982).
A digital GIS is an information system which has as
its primary source of input a base composed of data
referenced by geographic coordinates and in which a
major part of the processing is done with a digital
computer (Kennedy and Meyers, 1977). It basically
performs the following major functions: a) Data in
put, b) Data storage and retrieval, c) Data manipu
lation, and d) Data output (Tomlinson et al., 1976;
Knapp, 1978; Nagy and Wegle, 1978; Jerie et al. , 1980;
Marble and Peuquet, 1983; Bartlocci et al., 1983; Va
lenzuela, 1985).
Basic information on the location, quantity and a-
vailability of natural resources is indispensable for
planning more retionally their development, use and/or
conservation. The demand for specific, accurate, and
rapid soil information is growing in our modern socie
ty. Soils, because of their importance in agricul
tural and non-agricultural matters, and their inherent
relationships with other environmental resources are
a basic and fundamental component of any complete geo
graphic information system.
Johnson (1975) points out that the conventional pre
paration of soil interpretive maps combining informa
tion of the soil resource with other resource informa
tion are excessively expensive, especially if various
source maps have to be converted to a common scale and
if the interpretive requirements are complex.
Automatic data processing systems have create inmen-
se opportunities for storing and disseminating soil
data (Bertelli, 1979). As the demand for interpretive
maps increases, computers are used to speedup and cut
down costs of the process (Bertelli, 1966; Shields,
1976; Bertelli, 1979; Miller and Nichols, 1979; Bie,
1980; Santini et al., 1983; Valenzuela, 1985).
The national Soil Handbook of the USDA Soil conser
vation Service (1983), indicates that the use of com
puter generated interpretive soil maps is encouraged
where the soil survey has been digitized because they
cost less than maps prepared by other means.
The objective of this study was to evaluate the sig
nificance of the element soils in the overall context
of a digital geographic information system.
2 METHODOLOGY
The digital geographic information system developed
at the Laboratory for Applications of Remote Sensing
of Purdue University, basically consists of five ma
jor subsystems: a) input subsystem, b) database sub
system, c) management subsystem, d) modeling and ana
lysis subsystem, and e) output subsystem. A simpli
fied schematic configuration of the system is illus
trated in Figure 1.
The soil association map of Indiana, USA, was pre
pared by the Indiana Soil Survey Staff of the United
States Department of Agriculture Soil Conservation
Service and Purdue University Agricultural Experiment
