What drives differences in water quality during different hydrological periods in Dongting Lake, China?

Credit: CC0 Public Domain

Lakes are essential components of global hydrological and biogeochemical cycles. River-connected lakes are characterized by high-frequency hydrological rhythms.

Water quality in such lakes may be more sensitive to variation in the complex environment, resulting in variability in quality during different hydrological periods.

A team of researchers from the Institute of Subtropical Agriculture (ISA) of the Chinese Academy of Sciences studied the differences in and its driving factors during different hydrological periods in Dongting Lake, China.

The study was published in Environmental Pollution on Sept. 4.

Dongting Lake is a typical river-connected lake. The researchers selected the 15-year quality dataset (2004-2018) to explore the variation trends of water quality and their relationship with water level in different hydrological periods.

They found that the difference in water level in different hydrological years was primarily due to the difference in water level in the lake phase.

Total nitrogen concentration of wet years was significantly higher than that of dry years over hydrological years, which was mutually affected by contaminant loads and water level regulation.

The contributions of the lake phase to the total sewage discharge successively decreased from 64.54% in wet years to 59.47% in dry years, while the river phase showed the opposite trends. This is because most of the contaminant was flushed into the lake under high-flow conditions, and indicates that the water regimes of different hydrological periods play an important role in determining water quality.

The relationship between water level and water quality parameters of Dongting Lake varied with different hydrological years; in addition, the water quality in different hydrological phases clearly separated the and river phases, and confirmed the significant effect of water level fluctuations on water quality in inter- and intra-annual scales.

More information: Mingming Geng et al, Is water quality better in wet years or dry years in river-connected lakes? A case study from Dongting Lake, China, Environmental Pollution (2021). DOI: 10.1016/j.envpol.2021.118115

Journal information: Environmental Pollution

Citation: What drives differences in water quality during different hydrological periods in Dongting Lake, China? (2021, September 9) retrieved 22 February 2024 from https://phys.org/news/2021-09-differences-quality-hydrological-periods-dongting.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

How spatiotemporal water quality variations are affected by hydrological conditions in Dongting Lake


Feedback to editors