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Abstract
Nankan and Laojie creeks are local rivers in the northern part of Taiwan. Their mainstream and tributaries cover most of the the population and factories in Taoyuan city. The early government′s administration emphasized more on the economic development and did not pay much attention to river quality management and pollution prevention. Furthermore, at that time people generally lacked the correct concept on the environmental protection, resulting in the deterioration of river water quality and destruction of natural landscape. The 21st century is the era of sustainable development for human beings. The government should not only pursue for economic development, but also enact and enforce the environmental protection laws and regulations for establishing a safe, healthy and comfortable environment. Because the river water quality relates the national living conditions and the health. This thesis aims to inspire social awareness of environmental protection, and then encourage public environmental action, to enhance the water environment quality, and restore the water ecosystem, to create a beautiful body hydrophilic space, to achieve universal environmental vision. This thesis evaluate the water quality data of the Nankan and Laojie Creeks in Taoyuan during the last ten years, with the frequency of one sample per month. This paper took general water quality parameters including hydrogen ion concentration index (pH), dissolved oxygen (DO), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), suspended solid (SS), the coli group (Coliform group), the ammonia nitrogen (NH3-N), total phosphorus (TP) and heavy metals including cadmium (Cd), lead (pb), chromium (Cr+6), arsenic (As), mercury (Hg), copper (Cu), zinc (Zn), manganese (Mn), and silver (Ag) as the water quality parameters. The river pollution index (RPI) and water quality index (WQI7) are then applied to evaluate the trends of water quality of two creeks. Analysis of water quality trends on Nankan and Laojie Creeks shows that the river pollution indexes (RPI) varied from 3 to 6, indicating the moderate pollution of two creeks. On the other hand, the water quality indexes (WQI7) varied from 45 to 65. In conclusion, ammonia nitrogen (NH3-N) remains the most serious pollutant of both Nankan and Laojie Creeks during the last decade and effective strategies should be taken to greatly reduce the discharge of ammonia nitrogen (NH3-N)into the creeks to improve the water quality.
Key words: River Pollution Index (RPI), Water Quality Index (WQI7), target pollutant | en_US |