Two climate change scenarios, the RCP (Representative Concentration Pathways) 4.5 and the RCP 8.5 in the fifth Assessment Report (AR5) by Intergovernmental Panel on Climate Change (IPCC), were applied in the Yocheon basin area using the SWAT (Soil and Water Assessment Tool) model to estimate changes in flow rates and pollutant loadings in the future. Field stream flow rate data in Songdong station and water quality data in Yocheon-1 station between 2013~2015 were used for model calibration. While R2 value of flow rate calibration was 0.85 and R2 value of water qualities were in the 0.12~0.43 range. The total study period was divided into 4 sub periods as 2030s (2016~2040), 2050s (2041~2070) and 2080s (2071~2100). The predicted results of flow rates and water quality concentrations were compared with results in calibrated periods, 2015s (2013~2015). In both RCP scenarios, flow rate and TSS (Total Suspended Solid) loadings were estimated to be in increasing trend while TN (Total Nitrogen) and TP (Total Phosphorus) loadings showed decreasing patterns. Also, flow rates and pollutant loadings showed larger differences between the maximum and the minimum values in RCP 4.5 than RCP 8.5 scenarios indicating more severe effect of drought and flood, respectively. Dependent on simulation period and rainfall periods in a year, flow rate, TSS, TN and TP showed different trends in each scenario. This emphasizes importance of considerations on time and space when analyzing climate change impacts of each variable under various scenarios.

상수관망 시스템은 다수의 이용자에게 용수를 공급하기 위한 사회기반시설물로써, 적절한 수압을 유지하고 안정적으로 용수를 공급할 수 있어 야 한다. 따라서 안정적인 설계와 효율적인 운영을 위해서는 상수관망 시스템의 용수 공급능력을 정량적으로 파악하는 것이 중요하다. 이러한 노력 의 일환으로 상수관망 시스템 내 에너지 거동을 통해 신뢰도를 정량화한 신뢰도 지수가 다양한 방법으로 개발되어 왔다. 대부분의 신뢰도 지수는 공통적으로 절점에서의 최소요구수두 및 초과수두의 형태로 공급된 에너지를 기반으로 산정되며, 일부 지수의 경우 상수관망에 공급된 총 에너지 또는 용수 공급과정에서 손실된 에너지를 추가적으로 고려하여 산정된다. 본 연구에서는 상수관망의 용수 공급 과정에 따른 에너지 구성 요소를 소 개하였으며 기존에 개발된 몇 가지 신뢰도 지수를 대상으로, 상수관망의 공급부하 상황을 고려한 시나리오 분석을 통해 신뢰도 지수의 적용성을 알 아보고자 하였다. 또한, 각 절점 별 지수값을 도시함으로써, 상수관망 내 신뢰도의 공간적 분포를 나타내어 분석함으로써 보다 확장된 시스템 신뢰 도 지수의 활용방안을 제시하였다.

Milyanggang mid-watershed is located in downstream of Nakdong river basin. The pollutants from that watershed have an direct effect on Nakdong river water quality and it's control is important to manage a water quality of Nakdong river. A target year of Milyanggang mid-watershed water environment management plan is 2013. To predict a water quality at downstream of Milyang river, we have investigated and forecasted the pollutant source and it's loading. There are some plan to construction the sewage treatment plants to improve the water quality of Milyang river. Those are considered on predicting water quality. As results, it is shown that the population of Milyanggang mid-watershed is 131,857 and sewerage supply rate is 62.2% and the livestock is 1,775.300 in 2006. It is estimated that the population is 123,921, the sewerage supply rate is 75.5% in 2013. The generated loading of BOD and TP is 40,735 kg/day and 2,872 kg/day in 2006 and discharged loading is 11,818 kg/day and 722 kg/day in 2006 respectively. Discharged loadings were forecasted upward 1.0% of BOD and downward 2.7% of TP by 2013. The results of water quality prediction of Milyanggang 3 site were 1.6 mg/L of BOD and 0.120 mg/L of TP in 2013. It is over the target water quality at that site in 2015 about 6.7% and 20.0% respectively. Consequently, there need another counterplan to reduce the pollutants in that mid-watershed by 2015.