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THE GEO-CODED MODEL BASED ON GEOGRAPHICAL KNOWLEDGE FORMALIZATION 
(Professor) Ma Ainai 
(The Institute of Remote Sensing, Peking University, China) 
(ISPRS Commission III) 
ABSTRACT 
Geographical knowledge formalization is the most important part of the design of the 
geographical knowledge base of Geographical Expert System (GES) . A kind of  Geo-coded Model 
(GCM) ‚which is composed of independent factors with geographical facts in proper order,is used 
as the principle of geographical knowledge formalization. There are two kinds of GCM:tree type 
and multi- index type model. This paper gives an essential part of GCM theory. 
Key Words: Geographical knowledge formalization,Geo-coded Model,Geographical Expert System. 
1. | HISTORY OF GEOGRAPHY AND 
ITS PRESENT SITUATION 
1.1 The division of general geography 
Looking back on the history of geography ,with 
the development of the science itself, there 
emerged division. Many kinds of branch 
geography, such as topography, climatology, 
hydrography, geomorphology, | pedogeography, 
biogeography, sesogeography [ Ma Ainai, 1987] 
landuse, 
urbangeography,  agrogeography, industrial 
geography, and transportation geography, etc. 
developed very quickly, and each branch went 
deeper and deeper into its own field. But on 
the other hand,division weakened the research 
on the more profound relation between these 
branches. As a result, the comprehensive 
geography, synthetic geography and systematic 
geography remained at a superficial level. 
1.2 Qualitative and guantitative description 
Qualitative description still dominates the 
science of geography, especially the 
comprehensive, synthetic, and systematic 
geography .Some quantitative methods have been 
introduced into branch geography,for example, 
precipatation, temperature,discharge,sediment 
discharge, elevation, particle size 
distribution, pH value, vegetation coverage, 
sesotic depth, growing areas, crop yield, 
industry output value, urban expanding rate, 
transport mileage, and freight volumn,etc.But 
the level of quantitative varies among above 
subjects. Some quantitative values are very 
simple, such as depth, area, etc. , some 
quantitative value are more complex, while 
more advanced instrument such as mass 
spectrometer,  chromatogram are employed. So, 
qualitative and quantitative level are quite 
different. 
1.3 Different expert has his own idea 
Division also gives rise to all kinds of 
experts, whose research works are expressed 
in thematic maps. While different expert 
has his own thoughts on the classification, 
thematic maps on the same subject in the same 
area is expressed in different ways. In spite 
of the existence of some standards (e.g. Land 
Use Standard of the United Nations, the 
Standard of the Geology Map ) , there is no 
uniform standard which can be used 
conveniently for experts in different fields. 
However, these maps,which can not be unified. 
are being used as base maps on comprehensive, 
synthetic and systematic geography for nature 
regionalization. 
2. THE SITUATION OF APPLIED REMOTE SENSING 
Systematic mapping is being worked on all 
over the world now. Using common topographic 
map and remote sensed ‘image, experts from 
different fields congregate together to 
achieve their interpreted maps. As mentioned 
above, the maps thus produced from the same 
basic maps varies with experts, and levels 
of the development of the subject.And even an 
expert can reach different result maps at 
different times. Being input to the GIS and 
becoming the content of the graphic data 
base, the sysmetic maps can only be used to 
induce new information based on the 
conditional model. The problems are: the 
thematic maps, such as geomorphological map, 
pedological map vegetation map, etc. all are 
not composed of independent factors, ( see 
paragraph 4) , thus one factor has been input 
more than once so graphic data is made 
redundant and polygons of differen thematic 
maps inconsistent. To make things even worse, 
such kind of map series lacks quantitative 
information and the overlay between them 
doesn't make much sense. Under such 
circumstances,why do we still insist inputing 
so many thematic maps into the GIS, and not 
seek a way more meaningful ? 
3.THE SITUATION OF COMPUTER UTILIZATION 
With the utilization of computer in the field 
of geography, such as Image Processing System 
(IPS), Geographical Information System (GIS), 
Geographical Expert System (GES) and Computer 
Aided Mapping (CAM) developed. Nowadays, not 
only data,but also knowledge can be processed 
with the computer. So the introduction of 
computer into geography not only means the 
increase of efficiency, but essentially the 
quantification and formalization of 
geography. 
Geographical data (GD) , which is composed of 
the attribution, quantitation, situation, 
timeliness and relationship of geographical 
elements, is only the  carrier-body of 
geographical information. Furthermore, 
geographical information and their 
relationships build up the content of 
geographical knowledge. At all events,we can 
express geographical data and knowledge using 
the computer. GCM,by which only a GCM map and