Investigating water quality sensitivity to climate variability and its influencing factors in four Lake Erie watersheds

• Published in: Journal of environmental management 2023-01, Vol.325, p.116449-116449, Article 116449
• Main Authors: Wang, Runzi, Ma, Yueying, Zhao, Gang, Zhou, Yuhan, Shehab, Isabella, Burton, Allen
• Format: Article
• Language: English
• Subjects: Climate change; Conservation practice; Great lake; Land cover; Soluble reactive phosphorus
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2022.116449

Climate change alters weather patterns and hydrological cycle, thus potentially aggravating water quality impairment. However, the direct relationships between climate variability and water quality are complicated by a multitude of hydrological and biochemical mechanisms dominate the process. Thus, little is known regarding how water quality responds to climate variability in the context of changing meteorological conditions and human activities. Here, a longitudinal study was conducted using trend, correlation, and redundancy analyses to explore stream water quality sensitivity to temperature, precipitation, streamflow, and how the sensitivity was affected by watershed climate, land cover percentage, landscape configuration, fertilizer application, and tillage types. Specifically, daily pollutant concentration data of suspended solid (SS), total phosphorus (TP), soluble reactive phosphorus (SRP), total Kjeldahl nitrogen (TKN), nitrate and nitrite (NOx), and chloride (Cl) were used as water quality indicators in four Lake Erie watersheds from 1985 to 2017, during which the average temperature has increased 0.5 °C and the total precipitation has increased 9%. Results show that precipitation and flow were positively associated with SRP, NOx, TKN, TP, and SS, except for SRP and NOx in the urban basin. The rising temperatures led to increasing concentrations of SS, TKN, and TP in the urban basin. SRP and NOx sensitivity to precipitation was higher in the years with more precipitation and higher precipitation seasonality, and the basins with more spatially aggregated cropland. No-tillage and reduced tillage management could decrease both precipitation and temperature sensitivity for most pollutants. As one of the first studies leveraging multiple watershed environmental variables with long-term historical climate and water quality data, this study can assist target land use planning and management policy to mitigate future climate change effects on surface water quality. [Display omitted] •The climate effect on water quality depends on watershed characteristics.•33-year daily pollutant concentration was used in four Lake Erie watersheds.•RDA was applied to explore factors affecting water quality sensitivity to climate.•Precipitation intensity was positively correlated with TP, SRP, and NOx.•No-tillage and reduced tillage can reduce water quality sensitivity to climate.