Study on Water Quality Model of Mei-Lun River in High and Low Flow Periods

• Main Authors: HUANG, YAN CHAO, 黃彥朝
• Other Authors: Chiang, Hann-Chyuan
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/s22rrb

碩士 === 國立宜蘭大學 === 環境工程學系碩士班 === 106 === River pollution is an important issue in environmental problems. With the development of the city, the river remediation becomes more and more important. This study aim at the water quality model for the Mei Lun River Basin in wet and dry seasons in Hualian county, Taiwan. The QUAL2Kw water quality model can quickly predict the water quality of the water body so as to understand the status of water pollution in the Mei Lun River Basin. We hope to establish a water quality model for the Mei Lun River in high and low flow periods in order to assess the variation of water quality and the difference between the wet season and the dry season. 　　We compare The River Pollution Index (RPI) of four monitoring stations in Mei Lun River Basin with its four water quality parameters, the variation of RPI with ammonia nitrogen (NH3-N) and biochemical oxygen demand (BOD) have the same trend, show that the NH3-N and BOD are key indicators in the river water quality. In addition, Shinshen Bridge and Jhongjheng Bridge are key monitoring stations in Mei Lun River. In this study, We use QUAL2Kw modeling Mei-Lun River Livestock Upstream to Jhongjheng Bridge in Mei-Lun River, Hualien County. In high flow period, the coefficient of determination (R2) of calibration and validation for flow are 0.9675, 0.9327 respectively. The mean absolute percentage error (MAPE) of calibration and validation for BOD are 11.4 %, 8.3% and for NH3-N are 14.9%, 17.2% respectively. However, in low flow period, R2 of calibration and validation for flow are 0.9748, 0.9289 respectively. The MAPE of calibration and validation for BOD are 13.3 %, 14.9 % and for NH3-N are 16.4%, 9.7% respectively. 　　In this study, the comparison with the simulation results of the 2017 and 2014 in high flow period, show that the concerntration of BOD and NH3-N in Shinshen Bridge are reduced obviously. The concerntration of NH3-N in Jhongjheng Bridge are reduced obviously, in addition, the concerntration of BOD in Jhongjheng Bridge are reduced, but its variation are little. In addition, the comparison with the simulation results in high flow period and low flow period, show that the BOD pollution in high flow period is higher than low flow period, because the concentration of BOD in Mei-Lun river is low and less monitoring data during in low flow period. The variation of the concerntration of NH3-N in upstream in high and low flow period is unobvious, but it is obvious in downstream, because of the pollution loading of Fuxing pumping station in low flow period is more than high flow period.