ISPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS”, Bangkok, May 23-25, 2001
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(3) Movement of a base unit area
The common boundary between two base unit areas is moved.
In data management, the common boundary between two
regions is eliminated and a new boundary line is generated. In
this case, the base unit number is unchanged.
6.3. Creation of total result data
Total information is created after each census in accordance with
base unit numbers. Such data corresponds to a connector for
each item (population, number of households, etc.). In this case,
the two-dimensional coordinate values of connectors inherit
coordinate values of base unit numbers.
reference point for feature space D‘, obtain the corresponding
population Wx. Set WxN = RN Wx.
(2) Division of a base unit area
6.4. Example application
By means of temporal analysis, differentials between total
information values at two time points can be obtained. Here, we
consider as an example the determination of changes in
population in base unit areas using the algorithm in 5.2. First, the
input information given below is specified. The base unit
boundaries and population totals at the two time points T, T 1 are
assumed to be as given in Figure 8.
D: Feature space representing base unit areas
P: Point inside region for which population change is to be
determined
T: Date of 1995 census (October 1st, 1995)
T: Date of 2000 census (October 1st, 2000)
By executing the algorithm described in 5.2, the output shown in
Figure 9 is obtained. Using the output results and the feature
space D 1 that represents population statistics, and executing the
algorithm shown below, the change in population between the
two time points T, T* can be obtained.
[Step 1]
By setting T as the system time and performing a feature
space search using Q as a reference point for feature space
D', obtain the population, W, at time T.
[Step 2]
Set T' as the system time and, for all Q', use the following
algorithm to determine WxN.
By performing a feature space search using Q'N as a
T; 1995.10.1
T: 2000.10.1
Figure 8. Example of Census Data
[Step 3]
Because the population, W 1 , at time T' is given by W' = WxN
. + WxN, the change in population between two time points T,
T is given by W - W'.
7. Conclusion
We have described a spatial temporal geographic information
system, DyMSIS. We have also made some proposals regarding
the application of this method to management of census data. In
the future, we intend to investigate the application of such
models to management of local government data and sampling
in disaster analysis.
REFERENCES
[1] K. Kakumoto, M. Hatayama, H. Kameda, and T. Taniguchi:
Development of Disaster Management Spatial Information
System (DiMSIS), GIS’97 Conference Proceedings,
