The Influence of Air Temperature on Water Temperature and the Concentration of Dissolved Oxygen in Newfoundland Rivers

Abstract

Abstract:In this paper regression models are developed for predicting water temperature and the concentration of dissolved oxygen in rivers monitored by the Newfoundland and Labrador Real-Time Water Quality Monitoring (RTWQM) network. The developed models can be used to predict mean, maximum and minimum water temperatures and dissolved oxygen at the monthly, weekly and daily time scales. A nonlinear logistic model is found to best represent the S-shaped relationship between water temperature at the real-time stations and air temperature collected from meteorological stations 5-50 kilometers away. There is a clear tendency for monthly and weekly models to be more accurate for prediction than the daily models. Both linear and nonlinear exponential decay models were found to best represent the relationship between water temperature and dissolved oxygen at the real-time stations. A novel graphical method of linking air temperature to water temperature and dissolved oxygen has been developed and may prove to be a valuable simple tool in the assessment of the health of the rivers in the real-time network.Résumé : Ce papier décrit des modèles de régression qui prédisent la température de l'eau et la concentration d'oxygène dissous dans les rivières surveillées par le réseau Terre-Neuve-et-Labrador Real-Time Water Quality. On peut utiliser les modèles développés pour prédire les températures d'eau moyennes, maximales et minimales et les niveaux d'oxygène dissous dans l'eau aux échelles mensuelles, hebdomadaires et quotidiennes. Un modèle non-linéaire logistique représente mieux la relation entre la température de l'eau aux stations en temps réel et la température de l'air provenant des stations météorologiques de 5 à 50 kilomètres de distance. Il y a une tendance claire pour les modèles mensuels et hebdomadaires d'être plus précis pour la prédiction que les modèles quotidiens. Les modèles linéaires et non-linéaires de décroissance exponentielle représentent mieux la relation entre la température de l'eau et l'oxygène dissous aux stations en temps réel. Une nouvelle méthode graphique de relier la température de l'air à la température de l'eau et l'oxygène dissous a été développée; cette méthode devrait se révéler un outil précieux et simple pour évaluer la santé des rivières dans le réseau en temps réel.

Spatiotemporal Variation in Benthic-Invertebrates-Based Physical Habitat Modelling: Can We Use Generic Instead of Local and Season-Specific Habitat Suitability Criteria?

“…Although seasonal differences in macroinvertebrate-community abundance and composition have long been reported in literature [48][49][50][51][52], community-shifts in their habitat preferences have not been studied; we assume that such 'shifting behavior' may be associated with the seasonal fluctuation of environmental variables, which are known primary drivers of BMI-community changes, that is, shading, water temperature and dissolved oxygen [53]. As summer approaches, shading from the surrounding riparian vegetation is reduced, the water temperature increases, the dissolved oxygen concentration decreases [54] and consequently, faster flowing, deeper, better oxygenated habitats provide shelter against the changing environment. In contrast to the under-studied seasonal shifts, typological differences in the habitat preferences of BMIs have been previously documented, suggesting a preference for shallower water depths and lower velocities in smaller rivers [15,55].…”

Predicting Impact of Climate Change on Water Temperature and Dissolved Oxygen in Tropical Rivers

“…The objective was to determine the impact of climatic variables (precipitation and air temperature) on the water temperature to DO concentration relationship. Because studies have revealed the relationship between DO and water temperature to be strongly negative [46], in an effort to identify the best regression model that suited water temperature and DO concentration in the tropical climate, it was determined that the exponential model was found to be better suited to modeling low DO concentrations at higher water temperatures in temperate climate [46]. In addition, the relationship between the changes in streamflow to water temperature and DO concentration were presented using the regression model.…”

Accuracy of Hourly Water Temperatures in Rivers Calculated from Air Temperatures

“…Studies have shown that as time scale increases (daily, weekly, monthly), the regression of water and air temperature improved significantly [6,9,13,29]. Therefore, logistic regression models between daily mean water and air temperatures were also developed for the eight rivers in AL.…”

“…Studies have shown that as the time scale increases (daily, weekly, monthly, and annually), the model will be more accurate and reliable in estimating water temperatures [6,8,9,13,24]. The logistic regression model has been recently and widely used to estimate river water temperature [3,[25][26][27][28][29]. Morrill et al [28] evaluated the general temperature relationships (both linear and nonlinear) in 43 river and stream sites in 13 countries and indicated that the air/water temperature relationship is better fitted with non-linear regression.…”

“…Most of the previous studies focus on the daily, weekly or monthly relationship between air and water temperatures [8,9,13,25,29], but there is no simple or accurate model to estimate hourly water temperature in streams. Meteorological data required for deterministic models are often not available.…”