Mv 
  
* To determine location and water pressure of 
water factory, tower, pump. 
* To determine the big consumers' consum- 
ption and the nodes them belong to. 
  
[ Data Preparation ] 
  
  
  
V 
Parameter Deduction A 
Pipe Net Adjustment | 
  
  
  
  
Pipe Net Optimization | 
  
  
  
Result Display 
( Figure 1. Establishment of optimal model in urban infrastructure ) 
3.3.2 Parameter Deduction 
It needs to deduce some medium parameters from 
formulas after data preparation. These parameters 
include: overall length of pipe line, total water 
consumption of big consumers, flow of each node, 
and so on, then system distributes preliminary flow 
and calculates the economical 
speed of flow. 
3.3.3 Pipe Net Adjustment 
Determined the position of water factory, water 
tower, water pump, and given out the most 
unfavorable point or the lest pressure of water, 
system derives the loss of water pressure from the 
parameters matrix and calculates the flow of pipe 
section. granting system a threshold ( for example 
0.0001), when the maximal difference of the pipe 
section flow which is obtained after twice adjust- 
threshold, it finishes the 
procedure of repeated adjustment. 
ment less than the 
3.3.4 Pipe Net Optimization 
365 
Changes of block factors must bring new 
requirement to the infrastructure, so it needs to 
rebuild dynamic balance. The following figure is a 
flow chart of pipe net optimization, it describes the 
whole procedure of pipe net optimization in detail 
(figure 2.). 
When factors of some blocks change, such as Floor 
Area Ratio, population, building density (etc.), 
updating the indexes of blocks directly on the 
computer, deriving the volume of water, and 
distributing it to the relative nodes, system can 
calculate the optimal diameter of pipe through 
pipe adjustment now. Comparing the diameter of 
the designed pipe and the current pipe, system 
diagnoses results automatically : if the diameter 
of designed pipe is less than or equal to the 
current one, it shows that the pipe can still 
satisfy the requirements when block capacity has 
changed, otherwise, it shows the pipe has been 
overloaded and need to be renewed into a designed 
pipe with bigger diameter. System also prompts 
user to update with red flash. After updating the 
pipe diameter, system repeats the procedures 
described upon , until it satisfies the balance 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996