TITLE:
Investigation of Long-Term Climate and Streamflow Patterns in Ontario
AUTHORS:
Amin Azarkhish, Ramesh Rudra, Prasad Daggupati, Jaskaran Dhiman, Trevor Dickinson, Pradeep Goel
KEYWORDS:
Climate Change, Hydrology, Ontario, Streamflow, Precipitation, Temperature
JOURNAL NAME:
American Journal of Climate Change,
Vol.10 No.4,
December
17,
2021
ABSTRACT: To develop mitigation and adaptation strategies for undesired consequences of climate change, it is important to understand the changing hydrological and climatological trends in the past few decades. Although the changing climate is a cause of concern for the entire planet, its effects can vary significantly on a regional scale. Canada has experienced a rapid rise in the annual mean surface air temperature in the past decades. The current study aims to investigate trends in monthly mean precipitation, rainfall, snowfall, maximum and minimum temperature, as well as baseflow, surface runoff, and total streamflow values for the province of Ontario, Canada. To the best of the author’s knowledge, a similar study involving rural and urban watersheds, that quantifies the impact of changing climate on temperature and other hydrological processes over a period ranging from 1968 to 2017, has not yet been conducted for Ontario. Man-Kendall trend test was used to analyze trends in the above mentioned climatic and hydrometric parameters for rural and urban watersheds situated in the northern and southern parts of Ontario. The results of this study indicate that the mean monthly minimum temperatures for rural watersheds situated in southern Ontario have increased significantly for the winter and summer months, which may have caused an increase in snowmelt and consequently the streamflow for the winter months in the region. Unlike the watersheds in southern Ontario, the northern watersheds witnessed relatively fewer instances of significant changes in mean monthly temperatures, and in some cases, declining rates have been noted. Similarly, only a few watersheds in the north saw a substantial drop in baseflow over the summer months. For nearly all the months, the average monthly minimum and maximum temperatures were found to increase for urban watersheds. The streamflow, baseflow, and surface runoff increased, likely due to rapid urbanization, resulting in a lower infiltration rate. These results will contribute towards the decision-making processes and development of alternate water management policies within the province, taking into account the regional variations in climate change’s impact on the hydrology of Ontario’s watersheds.