Estimation of pollutant fluxes into the Yellow River based on the LOADEST model

SUI Xiuguo; WANG Fangyu; MIAO Fengkai; WANG Xin; LI Zhengyan

doi:10.13984/j.cnki.cn37-1141.2025.03.015

Abstract：River pollutant flux estimation can provide scientific and technical support for environmental management such as marine water quality early warning and total control.However,the frequency of river water quality monitoring was currently low,and the common low-frequency manual monitoring data of 1-2 times per month could not meet the requirements of accurate pollutant flux estimation.In order to improve the accuracy of the pollutant flux estimation results of the Yellow River,this paper established the regression equation between pollutant fluxes and fluxes based on LOADEST model to estimate the fluxes of major pollutants such as COD,total nitrogen,total phosphorus and oil in the riv-er,using the daily flow data and monthly water quality data of the Lijin section of the river from 2009 to 2019.The results showed that the average annual fluxes of the above four major pollutants in the Yellow River were 31 × 104 t/a,8.9× 104 t/a,1.4× 104 t/a and 2.5× 102 t/a respectively,and the in-tra-year distribution of fluxes was closely related to the flood season,with the highest monthly flux in July and the lowest in February.The uncertainty in the estimation of COD fluxes to the sea in the river was the smallest,within 15％,and the uncertainty in the oil was the largest,around 30％-50％.LOADEST model gave excellent results for COD,TN and TP,but the results for oil were poor,so it is not recommended to use LOADEST model to estimate oil fluxes in preference.