Volume No. 4 Issue No.: 1 Page No.: 34-48 July-Sept 2009

 

AHP AND WATER QUALITY MODEL IN DECISION SUPPORT SYSTEM FOR SEA BASS SUSTAINABLE CULTURE IN BANG PAKONG BASIN THAILAND.

 

Sompop Rungsupa

Inter-department of Environmental Science, Graduate School, Chulalongkorn University, Bangkok, 10310 (THAILAND).

 

Received on : May 29, 2009

 

ABSTRACT

 

A Decision Support System for Sea Bass Culture in Bang Pakong Basin, Thailand consists of 3 components, Water Quality Modeling; Qual2k, Analytical Hierarchy Process (AHP) and the Bang Pakong watershed GIS. The Bang Pakong watershed GIS was generated to demonstrate activities, water quality status, waste and pollution loading which link to forecast changed in water quality modeling, Qual2k. The AHP was prepared for inputting existing problems, goals, criteria, sub-criteria and alternatives in problem solving process for sea bass culture. A case on mass mortality of Sea Bass (Lates calcariferous) in cages culture at Bang Pakong River mouth around the end of each year was selected. An AHP table was assigned by fisheries researchers and computed for weighting on preference level for each criteria and sub-criteria. Discharged waste from Irrigation canal (Khlong Phan Thong Kayai) nearby show the most probable cause. After waste loading from all activity were located position with distanced from Bang Pakong watershed GIS, then Qual2k was used to simulate for waste loading input. The irrigation canal, Khlong Phan Thong Kayai, opening at 3 kilometers upstream of the Sea Bass cage area. The problems which caused mass mortality appeared in November which was coincided with high runoff. Simulations for outflow at the rate of 100 m3/sec with BOD 200 mg/L caused high ammonia concentration and lowest dissolved oxygen around the cage culture area which would be resulted in mass mortality of sea bass. Co-operations with the Royal Irrigation Department to regulate the flow rate below 100 m3/sec and BOD less than 200 mg/L was suggested as an alternative measures. Treatment of water inside irrigation canal before discharged, plan for moving the sea bass cages to upstream, water quality monitoring and a warning system and dredging of the river bottom were also suggested. Target group for the system were Fisheries researcher and Biologist.

 

Keywords : Decision Support System, Analytical Hierarchy Process, Qual2K Water Quality Model, Bang Pakong watershed

 

 

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