Application of QUAL2K to Establish the Water Quality Model and Management Strategies for Kao-Ping and Tung-Kang Rivers

• Main Authors: Jih-Sheng Huang, 黃日昇
• Other Authors: Yi-Chu Huang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/60892143088636644518

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 97 === Water resource is important to the daily life of people, and also the place where all contaminants equilibrates and accumulates. The exclusive environmental characteristics increase the difficulties to develop the water resources in Taiwan. Allocation and management of water resources become increasingly difficult due to the disproportionate distribution of rainfall on spatial-time basis and precipitous topography. The water quality of the rivers, which influences the people’s life and health, is quite important to the environment and exploitation of water resources. Therefore, water resource is precious and its conservation is also very important. Kao-Ping and Tung-Kang basins are the major rivers in the Kaohsiung and Pingtung areas. Also they are the vital water sources for the civil, agricultural and industrial purposes. However, due to the rapid economic growth, industrial development and population growth in recent years, the water quality of rivers are heavily polluted by the discharges from the municipal, industrial and livestock’s wastes. The pollutant loadings discharged into the Kao-Ping and Tung-Kang basins still exceed the self-purification capacity of rivers that caused the water resources not to achieve the optimal planning. In this study, QUAL2K was utilized to establish the water quality model of targeted Kao-Ping and Tung-Kang basins and further applied to simulate the water quality status of basins in concern as an assessment tool for the planning of management strategies of water resources. Based on the simulation results of the assimilation capacity and the amount of pollution reduction, the respective average reduction rates of BOD and NH3-N were at least 42.0% and 28.3% for Kao-Ping basin as well as at least 89.2% and 90.8% for Tung-Kang basin to make the water quality meet the regulation objectives of the A class water quality and the B class water quality of each upstream reaches above Kao-Ping Weirs and Tung-Kang Bridge under various flow rates of rivers such as Q95, Q75, Q60, and Q25. The results from the predicted variation tendency of water quality of Kao-Ping and Tung-Kang basins demonstrated the amount of headwater siphoned had significant influences on the water quality of rivers. The upstream flow rates diminished due to the water taken reduced the river’s assimilation capacity. At the variation of flow rates, the water quality was easily influenced due to the reduction of river’s buffer ability. The concentration of pollutants varied significantly with the amount of water siphoned from the rivers. The reductive amounts of flow rates were much less than the downstream flow rates, the variation of downstream water quality due to water taken was less than that of upstream water quality. The results of this study can be referred to the simulation and management strategy of river water quality.