Methane Levels of a River Network in Wuxi City, China and Response to Water Governance

• Main Authors: Lingling Li, Renhua Yan, Bin Xue
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Water
• Subjects: methane; urban river; water quality; water governance
• Online Access: https://www.mdpi.com/2073-4441/12/9/2617

The majority of rivers are a CH₄ source that accounts for an important proportion of annual global emissions. However, CH₄ evasion from urban river networks has received disproportionately less attention than their contribution. The effect of water governance on water quality and CH₄ emission in urban areas remains unclear. Water quality, CH₄ concentrations, and fluxes from a river network in Binhu District, Wuxi City, and their response to water governance were analyzed in this study. CH₄ concentrations in the investigated rivers ranged from 0.05 μmol L⁻¹ to 16.37 μmol L⁻¹ (2.47 ± 4.5 μmol L⁻¹, medium 0.23 μmol L⁻¹), and CH₄ diffusive fluxes were 75.55 ± 171.78 μmol m⁻² h⁻¹ with a medium of 6.50 μmol m⁻² h⁻¹. CH₄ concentration showed a significant correlation with water quality parameters, especially for NH₃–N (r = 0.84, <i>p</i> < 0.001). Significant differences in water quality and CH₄ levels were found between sites that had conducted water management and those that continued to exhibit poor water quality. Our analysis showed that rivers under water governance have a positive tendency toward water ecological restoration, and a significant decrease in CH₄ efflux to the air can be achieved after extensive and intensified water governance.