1SPRS Workshop on Service and Application of Spatial Data Infrastructure, XXXVI(4/W6), Oct. 14-16, Hangzhou, China 
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FOUNDATION FRAMEWORK FOR CITY UNDERGROUND SPATIAL DATA 
Lei Xu\ Lixin Wu a,b , Defu Che a , Yun Jiang 3 
Institute of RS/GPS/GIS & Subsidence Engineering, China University of Mining and Technology, Beijing, 100083; 
Center for RS/GPS/GIS & Digital Mine Research, Northeast University, Shenyang, Liaoning, 110004 
KEY WORDS: Underground Spatial Data, Foundation Framework, Dynamical Three Dimensions, Digital City 
ABSTRACT: 
The foundation framework for underground spatial data aims to establish the platform for the underground spatial data sharing and 
integrating. The reasons lie in that: a) the long-term development of city construction has accumulated abundant underground spatial 
data and information; b) the development and utilization of city underground space demands for clear, detailed and visualized 
comprehensive city underground information. Based on the analysis of the characteristics, the foundation framework for city 
underground spatial data can be established by taking the regional geology data as its background, bedrock borehole as its skeleton, 
Quaternary borehole as its brace, engineering borehole as its contents and other data captured as its complementarities. Some key 
issues, such as multi-scale, multi-semantic, data dynamic updating must be solved. The foundation framework for urban underground 
spatial data offers not only uniform spatial coordinate and semantic system, but also the platform for comprehensive displaying and 
analysing the spatial data to support the mineral resources exploitation, geological disaster precaution and the urban underground 
space exploitation, plan, development and utilization. 
1. INTRODUCTION 
Digital Earth, Digital City and Digital Ming (Wu etc., 2000) 
demand for three-dimensional geo-scientific spatial data 
integration and integral visualization. For the difficulty and high 
cost to capture the underground spatial data, it is necessary to 
integrate all the underground data to comprehensively analysis 
and describe the characteristic and relationship of the 
underground spatial objects. Many times the need for data 
integration is so demanding that it does not matter if some 
details are lost, as long as integration achieved (Frederico T., 
2001 , 2000), because “we have a lot of data but we are 
information poor (Nghi, 2001)”. The spatial data integration 
needs the foundation framework containing variety kinds data 
(NSFC, 2001). The general three spatial data framework is the 
basic for the underground spatial visualization (Simon, 1994). 
However, the researches on general spatial data foundation 
framework usually pay attention to the geographical spatial data 
foundation framework. It aims to set up a uniform space-time 
positioning criteria with the characters of three dimension, 
dynamic, practical and high precision, so as to achieve the 
seamless integration for the multi-source data (Chen, 2002). 
The research on the foundation framework for city underground 
spatial data was neglected. This paper discusses the necessity to 
establish foundation framework for city underground spatial 
data as well as its characteristics, main contents and key issues. 
Besides, the application and value of the foundation framework 
are discussed. 
2. NECESSITY OF THE FOUNDATION FRAMEWORK 
FOR CITY UNDERGROUND SPATIAL DATA 
The spatial data framework from global, national to the regional 
scale, prefers to the foundational geographical spatial data. The 
foundational framework data mainly includes the contents, such 
as topography, geographical name, administration bourn, road 
traffic, water system, land cover, cadastre, habitat and remote 
sensing image et al.. It contains the two or three dimension 
geometry, attribute and correlativity information on the nature, 
economy, human culture and environment. The foundation 
framework can help the people to integrate, to retrieve and to 
show the interested information on nature, economy, human 
culture and environment according to the geographical 
coordinate and spatial location, and to analyze and to simulate 
the spatial distribution features, operational conditions and 
changing tendency (Chen, 2002; Chen, 2001; Chen, 1999). 
For the spatial data foundation framework to have general sense, 
it should include the underground spatial data. According to 
spatial cognition, each data belongs to certain spatial level, 
namely over-ground, surface and underground. The traditional 
foundation framework only includes the data of two spatial 
level, over-ground and surface. The underground data are 
missed or neglected. But actually, the three spatial levels are 
spatially correlated and interacted. If any level of spatial data is 
missed, the geographical spatial data framework must be 
imperfect. 
The reason for the establishment of foundation framework for 
the underground spatial data includes: 
Firstly, the city has accumulated abundant data and information, 
which provides for the data basic for the framework. Limited to 
many factors, such as data capturing method, cost and technique, 
the collection of the underground spatial data is much more 
difficult. The size of data set is the key to establish the 
foundation framework of underground spatial data. The data 
and information include city geology, underground engineering, 
civil defense engineering etc.. 
Secondly, the exploitation and development of the city 
underground space and the precaution of the city geological 
disaster are the motivation to establish the framework. Because 
of the complexity of the spatial geometry shape and the 
relationship between the underground spatial objects, it is 
difficult for the data captured by the single method to reflect