The river flow rate calibration curve provided by the Water Resources Department of the Ministry of Economic Affairs will be unable to reflect the river flow in a short period of time due to the delay in the measurement operation of the river section. The goal of this project is to establish a water management model and operation method for river water quality and pollutant total assessment in Taiwan based on existing online real-time monitoring equipment for water pollution (such as Modern Water, FLO open channel flow meters, automatic continuous monitoring of heavy metals and ammonia nitrogen, etc.). Taking the key rivers of the Environmental Protection Agency to reduce ammonia nitrogen as an example, establish a hydraulic model to explore the normal flow of the target river section with the channel water level flow rate curve, and understand the relationship and influence of different river types on the water quality of heavy metals and the concentration of ammonia nitrogen. Collecting the rainfall data of the study area and the flow data of the water resources department's river measurement station to supplement the flow-related data. This method solves the previous dilemma that was limited to only interpreting the pollution status of the river from water quality concentration data, and then more objectively evaluated the actual situation of pollution. From the river discharge ephemeris data, it can be obtained that the river discharge changes greatly, but the general pattern is the same and there are obvious alternating periods of high and low water. The rationality and comparison of this data is more suitable for scientific and logical discussions. According to the total ammonia nitrogen pollution and river flow data from 2016 to 2020, it is found that the rainfall is a dry year in 2017 and 2020 respectively, and its is significantly lower than the average value of previous years. Although the water quality concentration of each station of the Environmental Protection Agency is relatively high, it is found that the change trend of the actual total pollution can be more objectively assessed after analyzing the river flow. It was the maximum total pollution occurred in 2016 whether in the New Chaojhouda Bridge, Donggang River or in the Chongdeda Bridge, Erren River. The reduction and decline of the total amount of ammonia nitrogen pollution in rivers shows that the reduction of ammonia nitrogen in the river water environment has its effect, reflecting the effectiveness of the implementation of the policy of using biogas slurry and biogas residue back to the field in the river basin.

Contamination Flux, Ammonia, Heavy Metals