33 2 Spatial data: - Vector: administration boundary, industry, river network, road,.
The sources of secondary data from: 1
Current data from PROKASIH Clean River Program 2
The government Regulation Document 3
Monthly Report from Industry 4
Other sources of data
3.9 Public Perception Processed with Fuzzy Method
There are some condition related to the opinions of publicstakeholders, especially for river segment which has low capacity. Although some industry not so polluted,
sometimes a river segment has a bad condition caused by low discharge, high domestic pollution, etc.. In many chances, we need some stakeholderspublic opinion related to
these rivers condition. By using Fuzzy Logic, the best choice of some alternatives can be resulted. More stakeholders gives opinion is better, because computer can compute it,
resulting only the best alternative within certain Alpha-Cut Value as a valid result. In this research, there are five alternatives can be chosen as follow:
Table 6 . Five alternatives for River Segment Evaluation
Description L1
L2 L3
L4 L5
River condition Very Good Good
Fair Moderate
Bad Description
Level 1 is the best choice among five
river an overview to the river condition.
It means that the intention usage of
this river perform to drinking water or any
other use with the similar requirements.
Level 2 is the second choice
where the river can be used for
service water, recreational,
gardening, or any other use
with the similar requirements.
Level 3 is the third choice
where the river can be used for
fresh water aquacultures,
farming or any other use with
the similar requirements
Level 4 is the forth
choice where the river can
be used for irrigation
water or any other use with
the similar requirements.
Level 5 is the last
choice where the
river has lower
quality than others L1-
L4
34 Making the decision for each status of river segment related to stakeholder’s opinion
can use Fuzzy Method. This approach is used to get the best alternative from public sidepoint of view. For instance some alternative called L1, L2…L5. Which one the best
alternative? Each audience has the different choice among some those alternatives. The method can be explained step by step as follow:
• Step 1. Defining the alternatives, e.g. L1, L2, L3, L4, L5 Opinion 1,2,3,4,5 • Step 2: Opinion Collecting according to stakeholders.
For instance: P1 = L1, L3, L2, L4, L5 P2 = L2, L1, L3, L4, L5 …. etc. for each stakeholder P3, P4 … Pn
After this step, We have a lot of alternatives of opinion or solution from many audience depend on the number of people opinion or total respondent.
• Step 3: To calculate a lot of opinion where L1 better than L2 and so on. • Step 4:
To calculate the degree or level of alternatives group Li on Lj Formulae: SLi,Lj = NLi,Ljn ......................................................................... 1
Where, NLi,Lj: Number of audience, whose choose Li on Lj.
• Step 5:
To make relation matix of alternatives choicing using fuzzy
• Step 6:
To calculate the α-cuts value according to matrix result above.
• Step 7:
To give some recomendationdecision based on the α-cuts value. Fuzzy system will
give one result of decision only, which are exactly and more satisfy from the Stakeholders point of view within alternatives ranks value.
35
3.10 Water Quality Standard
