i a variety of 
coding, computer 
ry, data base 
ta output. A 
Include software 
spatial and non- 
, A GIS must be 
;h the use of 
procedures for 
allow for data 
retrievable data 
ist include the 
lbsystems: 1) 
data entry of 
:a and data file 
including image 
:o format system 
>r raster data 
iter networking 
processing and 
4) Data base 
lata file access 
trch/extraction/ 
i) Data analysis 
.stical analysis 
Output software 
¡.g., photocopy, 
imputer tape, 
it a GIS must be 
an event on an 
cal, social and 
response (NVI), 
ces, land use 
n this process 
overlaying) for 
analysis in 
(i.e. impact), 
analysis for 
ng. 
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ermining impact 
would include, 
t and intensity 
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d food security 
sting stocks of 
ing regions and 
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, 1984). 
guration must 
capabilities to 
gital images, 
r animation and 
should include 
grid cell and 
r, choropleth, 
s other graphic 
line graphs. 
3t incorporate 
nputer network 
linkage or telecommunication to other data sources. 
Further, a GIS must include software to communicate 
with different computer operating systems. 
Communication linkages can also provide an 
alternative method for early warning communication 
through facsimile data transmission. 
The GIS software must be as versatile and 
comprehensive since the data sets are expensive. It 
must incorporate all functions previously defined, 
and must be operable on the above specified system. 
Very few GIS systems surveyed integrate GIS, image 
analysis, data base management and statistical 
functions required for the particular needs of AISC. 
Those identified and recommended include: 
1) Land Analysis System (LAS). Of the specified 
requirements, this system is the most versatile and 
complete package to accomplish the goals specified 
and identified above. LAS was designed by NASA/GSFC 
with remote sensing data processing, GIS and data 
base management in mind. The software is designed 
to run on a VAX configuration. 
2) System 600. The expanded version of System 600 
is basically capable to do the same as LAS. 
However, it has limited statistics and imaging 
processing capability and designed to run on a VAX 
8600/VMS version 4.2. The software cost ranges from 
$20,000 (limited version) to $150,000 for the 
expanded version. Other systems considered under 
this heading include Autogis, Geographies, ELAS/ARC- 
INFO, Champion, Deltamap, ELAS/SAGIS and ERDAS. 
However, none of these meets all the requirements 
set forth to AISC's suggested GIS requirements. Two 
software packages extracted from the survey have 
been identified for the workstation. They are: 
1) ERDAS 
2) Champion 
8.3 Hardware Needs 
In order to accomplish the data handling tasks 
specified in the preceding section, vast amounts of 
data must be processed in a proper computer 
environment. To exemplify hardware requirements, an 
analysis scenario has been created for Senegal. To 
maximize the efficiency of the computer system, an 
appropriate resolution must first be selected as the 
minimum spatial input. One square kilometer AVHRR 
data is suggested as the minimum resolution size. 
Therefore, in developing an assessment and modelling 
scenario for Senegal, 197,000 grid cells would be 
required for each data layer. 
Using the currently applied five variables, 
standard for AISC, require a minimum of 985 
Kilobytes of RAM. To make one manipulation of this 
data sets' five variables would require an 
additional 985 Kilobytes of storage. Several 
logical manipulations, such as simple overlay 
operations would quickly exceed the capacity of a 
micro computer. If multiple discriminate analysis 
were employed, a requirement of 32 bit word 
representation for real numbers would increase the 
RAM storage to 3.94 Megabytes per manipulation. 
These two factors of 32 bit word requirements and 
large RAM storage capabilities quickly exclude the 
use of any standard micro computer system. Only a 
super-micro computer system, such as the MICRO VAX 
II would be configured to meet the above needs. 
Further expansion of the current model to include 
five additional variables increases the minimum 
storage requirement by a factor of two. 
Natural disaster analysis procedures for Senegal 
would necessitate the use of at least eleven data 
sets. On the basis of 197,000 data cells per 
variable, a minimum of 2.2 million bytes of RAM 
storage will be used by the data sets. To make one 
manipulation of this data set, involving all 
variables, would require at least one additional 
file of 2.2 million bytes of storage. Several 
manipulations, even for simple overlay operations in 
a GIS, can overwhelm the capacity of microcomputers. 
A further consideration in multiple discriminate 
analysis, is that real numbers are generated which 
require 32 bit representation (Brumfield, 1983). 
The internal bus structure and registers must 
therefore efficiently handle 32 bit words. Any form 
of multi-variable analysis for a study area the size 
of Senegal will unavoidably process megabytes of 
information. Computer processing requirements in 
GIS analysis are far beyond the capabilities of most 
micro-systems. Large 32 bit word size mini 
mainframe or super-micro computer systems are needed 
for processing data in a GIS format to specifica 
tions required in AISC natural hazard monitoring, 
impact assessment and forecasting procedures. 
8.4 Hardware Systems 
The logical candidate to meet the hardware needs for 
such an extensive GIS would be a mini or mainframe 
computer system. Digital Equipment Corporation 
(DEC) provides a VAX series of mini computers which 
are compatible with the current NOAA VAX systems. 
The micro VAX II by DEC could provide an expanded 
environment with the forthcoming VAX cluster 
controller which would give NOAA/AISC an expandable 
processing system to handle the additional 
computational burden of the extensive GIS 
recommended in this paper. Further, as the global 
distribution of these data becomes involved in the 
development of regional network nodes, micro VAX II 
clusters would be cost-effective candidates at 
ninety percent of the processing capacity of a VAX 
11/780, equally configured, for that development. 
The fact that the micro VAX II and the VAX 11/780 
computer series are software compatible is also 
significant. 
In addition to the essential computer configura 
tion, the workstation would also include peripheral 
devices for all phases between data input and final 
analysis and display. This would consist of a 
digitizer table, 1600 and 6250 BPI tape drives, two 
450 mega-byte Winchester disc drives, high 
resolution color display, four to eight DEC VT 220- 
type terminals, a matrix plotter printer, a laser 
quality printer and an IBM/PC computer with Polygon 
communication software for potentially needed 
workstation software development. 
The above scenario would meet the requirements for 
an automated GIS to suit the needs of an 
organization such as NOAA/AISC at this time. The 
state of the art and the technology associated with 
the development of GIS changes rapidly. These 
developments are encouraging for the scientists who 
are forever searching for better ways to help 
alleviate some of the world's problems through 
objective means. 
REFERENCES 
Brumfield, J. & Brown W. 1983. Selected remotely 
sensed geodata bases consideration for GIS 
integration and modeling for energy resources 
management applications. Presented to the American 
Association for the Advancement of Science Annual 
Meeting, Detroit, Michigan. 
Brumfield, J, Miller, A., Robinson, V., & Boyd R. 
1985. Experiments in the spatially distributed 
processing of land resource data. Presented at 
the International Conference on Integration of 
Remotely Sensed Data in Geographic Information 
Systems for Processing of Global Resource 
Information. Washington, D.C. 
Calkins, H. & Tomlinson, R. 1977. Geographic 
information systems, methods and equipment of land 
use planning. Reston, Virginia: U.S. Geological 
Survey. 
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