ISPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS", Bangkok, May 23-25, 2001 
development. How to realize the GIS of the valley as soon as 
possible is the problem we face. 
The studies of GIS have developed by leaps and bounds 
in the last 20 years. Meanwhile barriers that hindered the wider 
applications of GIS were, 
1), the high cost of hardware and software and the latter 
would cost more than the former in the future [1]; 
Ml M2 M3... Mn 
'1' >1 nL >1 
input U(t) i 
* GIS 
l 
In the figure is the feed time of information; T is the time of 
output information; and T>t. According to the general system 
theory [6], an open system has following characteristics, 
1) ,Integration; 
2) ,Feedback; 
3) ,Equi-purpose. 
Based on the theory, the design method of an information 
system includes three periods as follows[7], 
1) ,life period; 
2) ,abstract period; and 
3) ,determination period. 
Here, we are going to emphasize the first period which is 
relevant to the network GIS in recent years. 
The first period can be divided into three phases, i.e. 
(1) ,the design of information system, including the detail 
explanation of the functional and technical standards of the 
system; 
(2) ,the realization of the system, working out programme 
and commands that are concurrent with the detail standards; 
(3) ,upholding the system, the purpose of which is 
adapting the system to the change of the environment of the 
system. 
When the environment of the system takes great changes, for 
example, the technology that supports the system is 
out-of-date or the structure and regulations of management of 
the system are revised completely, the new period of the 
system begins. 
With the development of GIS by leaps and bounds recent 
years, the concept of Components GIS and Internet/intranet 
GIS has appeared in media. This concept marked the new era 
of period of GIS. And this is usually linked with computer 
2) , the inefficiency of the spatial analysis system [2]; 
3) ,the difficulties of development of user's programme^]; 
4) ,the uncurrentness of data[3-5]; 
5) ,the gap in renewing information. 
A GIS is an open dynamic system in reality. It can be 
shown as following, 
1 output Y(T) 
> 
l 
networks. According to the different network structures, that is 
LAN(Local Area Network),Internet(WEB),and Intranet, the 
ways to construct each system are dfferent. Speciallly, three 
sub-ways for Internet GIS constructing which are titled as CGI 
way, Java way, and COM/DCOM way must be considered and 
compared within my research work in this field 
Geographically speaking, there are some important areas 
and departments distributed in the valley. So the best way to 
establish the GIS for the River Lanchang valley will be the 
DISTRIBUTED GIS. The main problems included are three 
aspects: 
1, the establishment of distributed GIS in the valley of 
River langchang; 
2, the standards of data and the conventions for data 
transmission ; 
3, the data and software share in a distributed GIS with 
intranet or Internet network; 
4, the construction of network for the system. 
3. GPS Technologies To Be used in the 
LanChang Basin Area of Yunnan Province of 
China 
The first and important step of the project will be the 
establishment of a refined control system of the 
Lanchang-Mekong River valley. The project will include: 
1) ,the horizontal control system; and 
2) ,the vertical control system. 
How to establish the control systems is the problem we face. 
The establishment of horizontal control system with GPS has 
been determined. The problem left is how to establish the 
vertical control system in the area.