EVENT-BASED INCREMENTAL UPDATING OF CADASTRAL DATABASE 
Xiaoguang ZHOU *° Jun CHEN ° Zhilin LI° Jianjun ZHU" Jie JIANG” 
‘Department of Geomatics, Central South University, Changsha, China, 410083- zxg@mail.csu.edu.cn 
? National Geomatics Center of China, 1 Baishengcun, Zizhuyuan, Beijing, China, 10004 - chenjun@nsdi.gov.cn 
"Dept. of Land Surveying and Geo-Informatics, Hong Kong Polytechnic University, Hong Kong - Iszlli@polyu.edu.hk 
KEY WORDS: Incremental Updating; Land Subdivision Events; Spatial Changes; Topological relationships; Automation; Cadastral 
Database; Dynamic Operations. 
ABSTRACT: 
Incremental updating of cadastral database means that master spatial data set is updated when any change (geometric or semantic) 
occurs, the change can be recorded, updated and provided successively to users. During this process, a set of editing operations is 
needed to add, delete or amend cadastral spatial objects (intermediate points, boundary points, boundary segment, and parcels). An 
event-based automatic (or semi-automatic) incremental updating of cadastral database method (named as EBIU-CDB) is presented in 
this paper, which is based on the land subdivision event and the topological relationship between two parcels. The land subdivision 
event (including split, union, reallocation and modification of the common border between two parcels) is given at first; an extended 
4-intersection model used to describe the topological relations between two parcels is presented, 7 kinds of possible topological 
relations between two parcels at the same time are concluded by this method; split event is used as an example to illustrate EBIU-CDB, 
7 kinds spatial change of split event are presented, and the updating algorithm is followed. The approach was implemented using 
VC++ in ORACLE9I SPATIAL and MAPINFO 6.5 platform. 
(intermediate points, boundary points, boundary segment, and 
1. INTRODUCTION parcels), to solve spatial (geometrical, topological) and temporal 
conflicts problems, maintain spatial (geometrical, topological) 
Cadastral database is a type of database using land parcels as : s 
and temporal consistency of the records [ZHOU Xiaoguang, 
spatial units to collect, store, and update the parcels’ location, = 
CHEN Jun, et al, 2002]. 
shape, rights, and land use information (land parcel is the fei ; : E ; : 
So far, the updating of core cadastral spatial database is carried 
smallest salable area, and the geometric feature is equivalent to 
polygon in this paper)[Khaled K, 1992; CHEN Jun, et al, 2000; 
ZHOU Xiaoguang, CHEN Jun, et al, 2003]. In cadastral systems, 
out manually and interactively. With the incremental spatial 
changes information, it will be determined by data producers 
which objects should be added, deleted and amended, how to 
various changes (spatial and semantic) take place incrementally 3 : : ; 3 
solve problems of spatial (geometrical and topological) conflicts 
through transactions based on conveying rights from one owner es : : 
and maintain the consistency of the records [Oosterom, 1997]. A 
to another. In order to show the current status, to record the o : e 3 
large amount of editing operations are needed. As this interactive 
history and the cause of changes, an incremental updating is : - 
process is an error-prone and labor-intensive process, automatic 
needed after a change occurred. Incremental updating means that ? z = : : : ; 
= execution of these editing operations is desired [Cooper A, Peled 
the cadastral database is updated when any geometric or : ; ; S 
SS LR de A. 2001; ZHOU Xiaoguang, CHEN Jun, et al, 2002]. This study 
semantic changes occur, and that the changes are recorded, the ; n : 
aims to automate the updating process of cadastral database. 
updating process can be tracked, the updates are provided = : s f 
Since the changes of parcels are caused by land-subdivision 
successively to users [ZHOU Xiaoguang, CHEN Jun, et al, j : ; jud 
events (such as split, union, reallocation) and different events 
2003;]. During such a process, a set of editing operations is En : ; 
may cause different changes to the parcels involved, the updating 
needed to add, delete or amend cadastral spatial objects 
Corresponding author. ZHOU Xiaoguang, Doctoral candidate; Tel: +86-8879515; E-mail: zxg@mail.csu.edu.cn 
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