Name
Will there be enough water? Progress towards a scientifically defensible water balance for Iqaluit's secondary water supply lake
Date & Time
Tuesday, May 9, 2023, 1:45 PM - 2:00 PM
Speakers
Description
“Unnamed Lake” in Nunavut’s capital city of Iqaluit represents the community’s best hope for a reliable freshwater supply that will meet the communities rapidly growing water demands. The lake has already been used once as a source for emergency resupply of Iqaluit’s municipal surface water reservoir. It is now being seriously considered for its potential as a longer-term supply. This is a relatively large and deep lake for the area, thus drawing attention as a promising future water source for the community, yet little is known about the renewable fraction of water that it offers. This issue has been compounded by a virtually impossible-to-gauge lake outflow, a problem that can only be solved through installation of a massive weir with major financial investment and significant delays due to water licensing requirements. Fortunately, we have collected some preliminary information on the major water balance terms of this lake, from spring to fall of 2022 . This presentation will highlight results from terrestrial and open-water eddy covariance measurements, precipitation inputs including end-of-winter snow water equivalent estimates available for recharge, and an indirect estimate of outflow discharge derived by gauging multiple downstream locations. These observations represent the first available hydrologic observations to help answer the questions: Will there be enough water for Iqaluit? And if so, for how long will it last, given the Arctic city’s current growth trajectory?
Location Name
Lynx
Full Address
Banff Park Lodge Resort Hotel & Conference Centre
201 Lynx St
Banff AB T1L 1K5
Canada
Abstract
Despite the recent advances, the identification of influential hydrologic processes and parameters of the process-based hydrologic model is still challenging. Part of the reason is the uncertain and interacting hydrologic process and the high dimensional parameter space. The motivation for this work is to effectively select an appropriate set of hydrologic processes and parameters for each basin on the globe, which is not necessarily the same everywhere. Here we evaluate the applications of the Structure for Unifying Multiple Modeling Alternatives (SUMMA) model to a large number of representative areas on the globe. Our objective is to identify the dominant hydrologic processes and sensitive model parameters for each representative area. First, sensitivity indices of the SUMMA parameters are computed using the VISCOUS global sensitivity analysis method. VISCOUS is the abbreviation of Variance-based Sensitivity Analysis using Copulas. Second, the sensitivity values are summarized per hydrologic process (e.g., snowmelt, surface runoff, infiltration, soil moisture, evapotranspiration, baseflow, and runoff) and per simulation statistic (e.g., mean, coefficient of variance, and autoregressive lag 1). The summarized sensitivity indices enable modelers to identify the most dominant hydrologic processes in each representative area. The results of this study will provide a foundation to estimate parameters in large-domain applications of process-based hydrologic models.
Session Type
Breakout Session