Relationships between environmental metrics and water temperature: a case study of Polish lowland rivers

The article presents relations between environmental metrics and water temperature in small Polish lowland rivers and describes their spatial temperature patterns. Water temperature data was obtained from measurements conducted on nine sites during summer of 2015 with the use of digital data loggers. Selected environmental metrics in the catchments areas were calculated and correlated with water temperature parameters. The results showed that water temperature patterns were generally similar across catchments, except for sites with strong human influence, which caused a decrease in the number and power of statistically significant relationships between environmental metrics and water temperature parameters. The best‐explained water temperature parameter was the minimum and mean daily range, while the best environmental predictors were the Strahler order, catchment area, mean catchment elevation and forested area. Most of the relations proved to be theoretically justified and could be used to further improve temperature monitoring studies and the management of water resources.