Stream Temperature Predictions for River Basin Management in the Pacific Northwest and Mid-Atlantic Regions Using Machine Learning

Journal Article · Thu Mar 24 00:00:00 EDT 2022 · Water (Basel)

DOI:https://doi.org/10.3390/w14071032· OSTI ID:1856620

Weierbach, Helen ; Lima, Aranildo R. ; Willard, Jared D. ; Hendrix, Valerie C. ; Christianson, Danielle S. ; Lubich, Michaelle ; Varadharajan, Charuleka

Stream temperature (Ts) is an important water quality parameter that affects ecosystem health and human water use for beneficial purposes. Accurate Ts predictions at different spatial and temporal scales can inform water management decisions that account for the effects of changing climate and extreme events. In particular, widespread predictions of T_s in unmonitored stream reaches can enable decision makers to be responsive to changes caused by unforeseen disturbances. In this study, we demonstrate the use of classical machine learning (ML) models, support vector regression and gradient boosted trees (XGBoost), for monthly T_s predictions in 78 pristine and human-impacted catchments of the Mid-Atlantic and Pacific Northwest hydrologic regions spanning different geologies, climate, and land use. The ML models were trained using long-term monitoring data from 1980–2020 for three scenarios: (1) temporal predictions at a single site, (2) temporal predictions for multiple sites within a region, and (3) spatiotemporal predictions in unmonitored basins (PUB). In the first two scenarios, the ML models predicted Ts with median root mean squared errors (RMSE) of 0.69–0.84 °C and 0.92–1.02 °C across different model types for the temporal predictions at single and multiple sites respectively. For the PUB scenario, we used a bootstrap aggregation approach using models trained with different subsets of data, for which an ensemble XGBoost implementation outperformed all other modeling configurations (median RMSE 0.62 °C).The ML models improved median monthly T_s estimates compared to baseline statistical multi-linear regression models by 15–48% depending on the site and scenario. Air temperature was found to be the primary driver of monthly T_s for all sites, with secondary influence of month of the year (seasonality) and solar radiation, while discharge was a significant predictor at only 10 sites. The predictive performance of the ML models was robust to configuration changes in model setup and inputs, but was influenced by the distance to the nearest dam with RMSE <1 °C at sites situated greater than 16 and 44 km from a dam for the temporal single site and regional scenarios, and over 1.4 km from a dam for the PUB scenario. Our results show that classical ML models with solely meteorological inputs can be used for spatial and temporal predictions of monthly T_s in pristine and managed basins with reasonable (<1 °C) accuracy for most locations.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Biological and Environmental Research (BER), Climate and Environmental Sciences Division
• Grant/Contract Number: AC02-05CH11231.; AC02-05CH11231
• OSTI ID: 1856620
• Alternate ID(s): OSTI ID: 1869667
• Journal Information: Water (Basel), Journal Name: Water (Basel) Vol. 14 Journal Issue: 7; ISSN 2073-4441
• Publisher: MDPI AG
• Country of Publication: Switzerland
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
stream water temperature
machine learning
catchments
modeling
predictions in unmonitored basins