1. Annongxi third-phase river environment improvement project The three sections (upstream, construction section, and downstream) of this department have a normal pH value of 7.2~8.5 in 2020, a water temperature of 17.1~30.6℃, and a conductivity of 498~612 μmho/cm. , The dissolved oxygen is between 6.3~11.0 mg/L, which is a higher dissolved oxygen. The flow rate here is more turbulent. The three stages of biochemical oxygen demand are all lower than 1.0mg/L, and the measured value of chemical oxygen demand is between ND~18.8 mg/L, but the Escherichia coli group is higher than the standard value of 10 CFU/100mL, and the three-stage measured value is between 460~110,000 CFU/100mL. The downstream is affected by the discharge of densely populated domestic sewage, resulting in the value of Escherichia coli On the high side, the three-stage measured value of ammonia nitrogen is between ND~0.32mg/L, which is lower than the standard value of 0.5mg/L, and the suspended solids are between 7.1~1,320 mg/L, March, May, September The monitoring values ​​in October and October were relatively high. The study concluded that the sudden increase in rainfall before monitoring caused the disturbance of the riverbed to increase the concentration of suspended solids. Substituted into the RPI river pollution degree index calculation, it was found that the upstream was 2.2 slightly polluted, and the construction section was 1.9. Slightly) polluted, and 1.8 in the downstream is not (slightly) polluted. 2. Environmental improvement plan for slow-moving roads and water activities of Yilan River The three sections (upstream, construction section, and downstream) of this section (upstream, construction section, and downstream) are normal in 2020 when the pH value is between 6.9 and 7.9, the water temperature is between 19.3 and 29.9℃, and the conductivity is between 124 and 367 μmho/cm. , The dissolved oxygen is between 2.3~8.1mg/L, most of the three stages of biochemical oxygen demand are below 1.0mg/L, only in May at Qinghe Bridge (2.7 mg/L) and Liwu Bridge (2.2mg/ L), at Qinghe Bridge in August (4.0 mg/L), the measured value of chemical oxygen demand is between ND~21.7mg/L, the colony of Escherichia coli are all higher than the standard value of 10 CFU/100mL, and the measured value of three stages is between 6,000 ~530,000 CFU/100mL, of which the test day in May was mainly due to heavy rainfall accelerating the discharge of domestic sewage to the river through the gate, so the E. coli group data increased. The measured value of the three stages of ammonia nitrogen was between 0.02~1.31mg/L, suspended The solid is between 4.5~363 mg/L, Li Wuqiao (363mg/L). Substituted into the RPI river pollution degree index calculation, it is found that the upstream is 1.4 which is not (slightly) polluted, the construction section is 2.1 which is lightly polluted, and the downstream is 1.9 which is not (slightly) polluted. 3. Sixteen Drainage Environment Improvement Projects The three sections (upstream, construction section, and downstream) of the department are normal in 2020 with pH values ​​between 7.0 and 8.2, water temperature between 19.9 and 33.3°C, and conductivity between 34 and 392 μmho/cm. , Dissolved oxygen is between 1.4~9.7mg/L, the biochemical oxygen demand is 2.0 mg/L measured by Wumingqiao in July, 16 copies of Siluqiao measured 3.4 mg/L in April and 3.7 mg measured in May , 2.6 mg/L measured in June, 4.1 mg/L measured in August, 1.5 mg/L measured in April by Xinwuyuan Bridge, 4.3 mg/L measured in April, 3.8 mg/L measured in August In addition, the rest are below 1.0mg/L, the chemical oxygen demand measurement value is between ND~45.5mg/L, the coliform group is higher than the standard value of 10 CFU/100mL, and the three-stage measurement value is between 13,000~1,300,000 CFU/ 100mL, suspended solids between 3.2~29.4mg/L, substituting into the RPI river pollution degree index calculation, it is found that the upstream is 1.5 (slightly) polluted, the construction section is 2.9 is slightly polluted, and the downstream is 1.9 is not polluted. (Slightly) Contaminated. 4. The second phase of water environment improvement project around Nanfangao area in Suao Town, Yilan County The pH of the three sections (upstream, construction section, and downstream) of this section in 2020 was between 6.7 and 10.6, the water temperature was between 17.1 and 29.6 ℃, which was normal, and the conductivity was between 217 and 1,620 μmho/cm. The oxygen content is between 0.2~6.7mg/L, the biochemical oxygen demand is between <1.0~401 mg/L, the chemical oxygen demand measured value is between 19.5~652mg/L, the E. coli group is less than 10 CFU in July /100Ml, the remaining months are all higher than the standard value of 10 CFU/100mL, the three-stage measured value is between 170,000~70,000,000 CFU/100mL, and the suspended solids are between 5.1~302mg/L, which is substituted into the RPI river pollution degree index calculation. The pollution index integral value of the water quality of the third stage of the second phase of the water environment improvement project in the southern Australia area is 7.9 for serious pollution in the upstream, 7.4 in the construction section, and 8.3 in the downstream.

Forward-looking plan, water quality monitoring