GIS-based Water Quality Management System of Coastal Area

s There has been growing demands to manage water pollution of west coastal region in S.Korea due to the large scale of urbanization along the coastal zone. For more effective water quality management, GIS based integrated water quality management system has been developed. The integrated system implies to integrate the analysis of the phenomena of coastal zone as the inflow of water pollutants as inlands changes. The integrated system includes pollutant database, water quality models for inland area and offshore areas, and GUI. Once the initial pollutants were estimated, discharging pollutants were calculated and the concentration rate was estimated using a model for the stream flow inland. Based on the concentration rates of the pollutants from inland areas, the offshore water quality model was run to see the fluctuation of water pollution in the coastal zone. The coastal zone was divided into finite number of cells and modeling was made for individual cells using coastal water quality forecasting model. Numerous scenarios were adopted to see the changes of water pollutant as conditions changed. The integrated system developed from this study can demonstrate its dedication for better management of water pollution thereby lead to BMP(Best Management Practice) for the coastal zone. 1. Study Area The purpose of this study is to develop WQMS for Saemangeum watershed which locates west coastal area in Korean Peninsula based on the linkage of Water Quality Model-QUALKO model-and GIS database to estimate water quality effectively in this area. The QUALKO model was developed by modifying QUAL2E (EPA, 1995) to analyze domestic stream water quality. The study area--Saemangeum watershed--is shown in Fig. 1. Two major water systems within the watershed are Mangyeong and the Dongjin rivers. It has 5 cities such as Gimjae, Jeonju, Iksan, Wanju, Jeongup, and 3 Guns (districts). Total area of the watershed is 3,300km and can be divided into 5 sections; Mangyeong river, Dongjin river, West coastal region, Gyewhado region, and Saemangeum lake. Also it can be classified into 20 small watersheds and subdivided into 123 subdivided sub-catchments. The Mangyeong river is the longest river with the length of 38km while Wonpyeong river the shortest with the length of 20km. Wonpyeong river has no tributaries and relatively less point sources, dams, and reaches. Main sources of pollutant sources on Saemangeum watershed are population, livestock, landuse, disposal of wastewater, nursery, spa etc. Farming area is 41.3% of total watershed area, relatively higher than other land uses in the area. A total of BOD loading of this area is 88,142kg/day, and 45.0% of them are from population. Most people live in Jeonju and Iksan cities located in Mangyeong river area. For the purpose of water quality modeling, streamflows have been divided by numerous elements and each element has 500 m in length. Dongjin river has 17 reaches and 54 elements with 37 point sources 1 Professor, Department of Geoinfomatic Engineering, Inha University, Yonghyundong, Incheon, S.Korea, 402-751, kyehyun@inha.ac.kr, 82-32-860-7602 2 Graduate student, Department of Geoinfomatic Engineering, Inha University, Yonghyundong, Incheon, S.Korea, 402-751, kyehyun@inha.ac.kr, 82-32-860-7602 3 Researcher, Korea Agricultural & Rural Infrastructure Corporation, Rural Research Institute, Ansan, Kyunggido, S.Korea, 426170, kylee@karico.co.kr EnviroInfo 2005 (Brno) Informatics for Environmental Protection Networking Environmental Information Copyright © Masaryk University Brno, Brno 2005. ISBN: 80-210-3780-6