Drivers of water level fluctuations and hydro-meteorological trends in Great Lakes

Session: 53. - Great Lakes Water Level Fluctuations and Water Management

Aisha Javed, University of Toronto Scarborough, [email protected]
Vincent Cheng, University of Toronto Scarborough, [email protected]
Agnes Richards, Environment Canada, [email protected]
George Arhonditsis, University of Toronto Scarborough, [email protected]

Abstract

Water level fluctuations are an on-going concern in the Laurentian Great Lakes and have been the focus of many Great Lakes studies over the past several decades. Here, we present multiple regression models that examine the relationship between water level change and potential predictor causal factors in Lake Michigan-Huron. According to the Mallow’s criterion, the top eight ranked models involved evaporation (no lag) as the key predictor, followed by inflow (no lag), and outflow (4 months lag). The highest ranked model, however, involved the presence of all five main predictors: evaporation, inflow, outflow, runoff, and precipitation. In addition to elucidating the main drivers of water level fluctuations, the emergence of an intensified hydrological cycle presents a significant challenge in the ability to tease out long-term trends in hydro-meteorological variables. Through the non-parametric Mann-Kendall test, our analysis identified significant upward trends in minimum air temperature. On the other hand, maximum air temperature demonstrated weakly decreasing trends over space and time. Evaporation was found to be increasing from late spring until early fall, runoff was characterized by elevated trends in the winter, and time-series analysis of the over-lake precipitation revealed mostly non-significant statistical trends. 

1. Keyword
water level fluctuations

2. Keyword
modeling

3. Keyword
Great Lakes basin

4. Additional Keyword
Trend analysis

5. Additional Keyword
Hydro-meteorological variables