Quantifying cumulative changes in water quality caused by small floodgates in Taihu Lake Basin - A case in Wuxi

Lan Feng; Pan Hu; Ming-Ming Chen; Bai-Lian Li

doi:10.1016/j.scitotenv.2023.165608

Quantifying cumulative changes in water quality caused by small floodgates in Taihu Lake Basin - A case in Wuxi

Sci Total Environ. 2023 Nov 20:900:165608. doi: 10.1016/j.scitotenv.2023.165608. Epub 2023 Jul 18.

Authors

Lan Feng¹, Pan Hu², Ming-Ming Chen³, Bai-Lian Li⁴

Affiliations

¹ College of Civil Engineering, Nanjing Forestry University, Nanjing 210037, China; Ecological Complexity and Modeling Laboratory, Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA. Electronic address: fenglan0108@126.com.
² College of Civil Engineering, Nanjing Forestry University, Nanjing 210037, China.
³ College of Engineering, University of Alabama, Tuscaloosa, AL 35401, USA.
⁴ Ecological Complexity and Modeling Laboratory, Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA.

PMID: 37474064
DOI: 10.1016/j.scitotenv.2023.165608

Abstract

Small floodgates in the river network area own some characteristics: considerable quantity, wide range and short adjustment time, and intercepts the one-dimensional constant flow of rivers, which induce a great impact on riverine water quality. In this study, a typical urban floodgate-controlled reach was selected, and analyzed through the monthly data of four pollutant indicators TN, TP, COD_Mn and NH₃-N at six sampling sites S1-S6 in 2016-2018. The principal component analysis and correlation analysis showed that TP was a representative indicator and there was a positive correlation between various pollutants. The difference test and linear regression showed that the concentration of pollutants at different sampling points varied greatly, and the pollutant concentrations in the longitudinal direction of the river showed a cubic-linear regression. The cluster system and CCME WQI showed that the water quality in the urban floodgate-controlled reach is "marginal" state, and TN and NH₃-N are severely exceeding the standard. The "cumulative changes" of the floodgate on the pollutant input to the environment appeared spatial heterogeneity.

Keywords: Cumulative changes; Great impact; Rivers; Small floodgates; Water quality.