Dominant factors influencing changes in the water quantity and quality in the Dianshi Reservoir, East China

Abstract

This study aims to identify the major factors affecting the water quality and quantity of the Dianshi Reservoir and to determine the potential risks facing the Dianshi Reservoir under the combined effects of climate and human activities. Multi-year data (2010 to 2019) were collected, and comparative analysis, trend analysis, Pearson correlation analysis, stable isotopes, and Morlet wavelet analysis were used conjunctively. The results showed that precipitation and runoff are the main recharge sources of the Dianshi Reservoir. The reservoir water level was mainly influenced by industrial and domestic water uses. Ammonia-nitrogen (NH₄⁺-N), total phosphorus (TP), total nitrogen (TN), and chemical oxygen demand (COD_Mn) were the main pollution indices in the Dianshi Reservoir. Animal excrement responsible for organic pollution entered the reservoir through surface runoff, while sewage discharge, fertilizer application, and leaf decomposition were the main sources of NH₄⁺-N, TP, and TN in the reservoir. Wavelet analysis indicated that water quality was greatly affected by the human activities before 2016, while the effects of precipitation, temperature, and evaporation gradually increased after 2016 and became the main factors after 2018. In addition, the management measures of the Dianshi Reservoir are not comprehensive, resulting in potential risks to water quantity regulation and water quality protection. It is, therefore, necessary to formulate a water regulation program and a comprehensive reservoir safety protection system.

KEYWORDS:

• Drinking water source
• water environment safety
• Potential risk
• Dianshi Reservoir

Acknowledgments

Thanks are due to the Sanmen Water Resources Bureau and the Dianshi Reservoir Management Station for their support in providing us with the data and information. The editor and reviewers are also acknowledged for their useful and constructive suggestions and comments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contributions

Fengmei Su contributed to conceptualizing the central idea, analyzed the date, and wrote the initial draft of the paper. Peiyue Li contributed to refining the ideas, carrying out additional analyses and finalizing this paper. Misbah Fida contributed to the writing and revisions.

Data availability statement

This manuscript does not contain associated data.

Additional information

Funding

This research was financially supported by the National Natural Science Foundation of China (42072286 and 41761144059), the Fundamental Research Funds for the Central Universities of CHD (300102290717 and 300102299301), the Fok Ying Tong Education Foundation (161098), and the National Ten Thousand Talent Program (W03070125).