A Decision Support Model－DSS/IPC Applied for River Water Quality Management Yi- Yi-Ching Chen & Huu Tuan Do （Dept. of Environmental Engineering, Dayeh University, Changhua ） River system Rivers Mean Mean Flow [ Abstract ] Banrko Width (m) depth (m) 750 10 (m3/s) 500 A proper method can help the manager of water resource planning to KimNguu 350 6 100 ThiNghe 138 5 120 bring out the correct decision. A decision support system for Lor 520 7.2 250 integrated pollution control model (DSS/IPC) was developed by the DackRon 680 8.5 350 g World Bank and several support institutes. It provides ability in DongNair 2100 10 750 assessing environmental problems and arriving at cost-effective BenThuy 100 4.5 50 solutions among those available tools to decision-makers. This Bondro 100 5 60 Baro 350 6 250 instrument permits rapid estimations of the extent and impacts of Cau 120 4 75 pollution in a given situation and provides support for decisions on ThuBon 250 5.6 260 pollution management. In this study, the advantages of DSS/IPC for river water pollution analysis and management are introduced. Layout map of study area Examples of analyzing a scenario situation of pollution in a planned ※ Simulated results and discussion water body by this model are carried out and demonstrated. To identify the major pollution sources, the DSS/IPC model shows detail Discussions will be concentrated on those topics as: (1)Identify pollution loads per year for each district according pre-run on all the quantity of effluents discharged into surface water; (2)Identify least- point sources from each factory. In this case, the major pollution sources cost set of pollution abatement measures that will reduce the ambient of BOD5 are from district 5 (257,697.2tons) and district 1 (224,373.8tons). level of BOD5 to archive legislated standard; (3)A GIS support to In 723,161.4tons of total BOD5 discharged per year, textiles enhance the management of river water quality. The model can be used manufacturing occupies 51% (366,726.2tons). to propose solutions of further industrial development and water use As shown in Table below the load and percentage of major pollution to maintain water quality standard for managers and decision-makers. sources in each river are listed. In addition, the model proposes series of Key words: Effluent control, Water quality, Decision support system reduction measure for managers to cut down the percentage of effluent (DSS), geographic information system (GIS) concentration discharged into environment. [ Introduction ] Major pollution sources Percentage distribution of discharged BOD5 Effluent control has advantages such as controlling the sources and Water BOD5 Percen Pe rce ntage of discharge d BOD5 among industrial body Sources Major profession loaded t activ itie s (tons) quantity of pollutants; setting emission charge for pollutants; reducing 15% Baro 13 Textile 87,829 (76.6%) 4% 3% confliction of multi-purposes in using river water sources; planning River manufacturing 4% Banrko Textile effectively for future development of industries activities that use river River 23 manufacturing 114,537 53.45% 5% 51% water sources or discharge into river. Most software about water Meat processing 4,792 (32%) 9% 9% Cau Grain mill quality simulation including QUAL2E (or QUAL2K) and WASP can only River 7 products 3,183 (21.3%) Textile s Cook ing Oil Chem ical calculate and forecast the movement of sediment, particles, Industrial Sew age Drugs and M e dicines Pulp and Paper chemicals 4,272 (28.7%) M alt and Bee r Other concentration of BOD5, COD, toxicants along the river and the mixing Kimngu Olive oil 21,000 55,25% u River 5 length, etc. But they can not calculate and estimate the suitable Animal glue 12,509 32.9% Thubon 9 Textile 68,411 86.3% quantities of water pollutants discharged into the rivers or lakes. They River manufacturing can neither calculate total costs of control options, by using standardized engineering-type cost functions nor long-run marginal The results as listed in Table below include annual pollutants cost schedules for achieving a certain level of emission reduction of a concentration and the excess load (higher than the standard of 10mg/l) chosen pollutant. But with a decision support system for integrated of all river. Base on this results user can identify which rivers are serious pollution control model DSS/IPC, it can be done. polluted and need to deal with BOD5 concentrations and exceed load in rivers [ Description of model DSS/IPC ] ※ Cost measurement Water body BOD5 Conc. (mg/l) BOD5 Excess Load (tons/year) DSS/IPC was developed in 1997 and it permits rapid estimations of the Through the results of cut- Baro River 19.4 70,024 Bondro River 6.4 - extent and impacts of pollution in a given situation and provides down BOD5 concentration to Banrko River 13.6 157,675 support for decisions on pollution management. The DSS/IPC system legislated standard, the total Benthuy River 8.6 - cost is about 127,538,815US$ Cau River 11.3 1,747.5 comprises a set of extensive databases and a number of computation Dongnair to improve water quality in River 6.5 - modules. Its use of standard emissions factors, simple dispersion Dackrong models, and cost functions enables analysts to arrive at reasonable polluted rivers. Base on this River 6.6 - analysis, the BOD5 effluent Kimnguu 17.1 15,720.6 estimates even when field data are inadequate. River The technique of Geographical Information System (GIS) could be charge could be set up to Lor River 8.6 - Thubon River 14.7 25,209.8 incorporated. It is also a powerful tool for managing water quality 2,000US$/ton to encourage Thinghe River 8.2 - through its skills in visual and spatial analysis. Also, supported with factories pay more attention to cost analysis module, the system allows user to calculate the value of improve their equipment or Improvement cost after applying reduction measures strategic control measures. process The LRMC must be Origina Improve Expand Averag LRMC Water body l Conc. d Conc. Cost e cost (US$/to especially considered by (mg/l) (mg/l) (US$/year) (US$/ton) n) investors and decision-makers, Baro 19.5 9.80 43,524,88 1,061 631 River 4 [Example of case study with DSS/IPC ] too. For example, as shown in Banrko 13.6 5.57 46,863,11 1,905 671 River 2 figure with improved cut-down, ※ Scenario of case Cau 11.3 8.72 1,514,709 540 220 the reduction of BOD5 from River Virtual example of analyzing a scenario situation of pollution in a Kimnguu 9.76 mg/l to less than 8mg/l in River 17.1 8.75 455,985 94 22 planned water body by this model are applied to a city with 2,860,000 Thubon River can cause the Thubon 14.7 9.76 35,180,12 2,083 951 of population, area 1,408.6km2 in 6 districts , with study area of lake- River 5 additional money of river system and industrial factories distribution (Textile 16,584,915US$ which is pretty manufacturing , Farming , Meat processing , Food processing , Grain high. mill products, Industrial chemicals, Cooking Oil manufacturing , Sugar manufacturing, etc ). [Conclusions ] There are 11 rivers within the city in which two major rivers, Banrko Though the DSS/IPC model can play River and Dongnair River, are most concerned. To maintain the as a tool for rapid and rough assessment quality of water supply the legislated standards is intended to be only, example did show the capability of controlled. The water quality standards can help user set up model. Nevertheless, it gives us an indication LRMC of removing BOD5 across achievements of water pollution control. about the point where the problems are likely industries in Thubon River to occur, the relation of different pollution sources, and the costs and 第十一屆海峽兩岸環境保護學術研討會 ** 第十一屆海峽兩岸環境保護學術研討會 ** 哈爾濱工業大學 (2007.6.8~12) effects associated with alternative pollution control strategies.