Estimation of tributary total phosphorus loads to Hamilton Harbour, Ontario, Canada, using a series of regression equations

Linking Dominant Rainfall‐Runoff Event Hydrologic Response Dynamics With Nitrate and Chloride Load Estimates of Three Boreal Shield Catchments

“…While these models were calibrated using grab sample data covering a wide range of hydrologic response conditions (Figure S1), this approach assumes that constituent concentrations of grab samples were representative of the average conditions of the day that they were collected. Indeed, similar models have been used to predict solute concentrations or loads in a range of studies (e.g., Leigh et al, 2019;Long et al, 2015;Runkel et al, 2004), and here, the level of fit obtained during model calibration was relatively high. With that said, this approach does not allow for finer solute export dynamics, like first flush and hysteresis, to be characterized or associated with rapid fluctuations in hydrologic response Inamdar et al, 2004.…”

“…All rights reserved. models have been used to predict solute concentrations or loads in a range of studies (e.g., Leigh et al, 2019;Long et al, 2015;Runkel et al, 2004) and here, the level of fit obtained during model calibration was relatively high. With that said, this approach does not allow for finer solute export dynamics, like first flush and hysteresis, to be characterized or associated with rapid fluctuations in hydrologic response (Inamdar et al, 2004.…”

A review of the current state of process-based and data-driven modelling: guidelines for Lake Erie managers and watershed modellers

“…This implementation of exploratory analysis during the planning stage can be mainly realized with data-driven (or empirical) watershed models that represent an appealing complementary tool to process-based modelling. In particular, more parsimonious empirical models would provide a statistically rigorous means to identify overlooked or newly appeared nutrient "hot spots" or "hot moments" and potential critical pathways (Kovacs et al, 2012;Long et al, 2015). Outputs of data-driven watershed models can also be used to highlight the necessary improvements in subroutines of complex overparameterized models and pinpoint the information required to constrain, validate, and verify them (Arhonditsis et al, 2019a,b).…”

“…A great deal of the investigations of climate-induced changes on watershed hydrology have revolved around the characterization of the flow discharge-nutrient concentration relationships depending on the watershed physiography, land-use patterns, and antecedent soil moisture conditions Godsey et al, 2009;Long et al, 2014Long et al, , 2015. TP concentrations correlate strongly with flow, as particulate constituents are generally transported by overland flow or via soil macropores to tile drains, and can be remobilized from the streambed/bank Macrae et al, 2007;Vidon and Cuadra, 2011).…”

“…The characterization of surface runoff and subsurface processes during flow events is particularly critical, in light of recent evidence that both total phosphorus and phosphate loads can vary by three orders of magnitude between wet and dry conditions, with storm events and spring freshets driving peak daily loads in urban and agricultural watersheds, respectively (Long et al, 2014;. One of the research priorities to rectify the misrepresentation of eventflow conditions should thus be the design of high frequency, event-based, water quality sampling coupled with water stable isotope analysis ( 18 O and 2 H) to distinguish between baseline and extreme-event conditions; especially if the frequency of such meteorological events will continue to increase with climate change (Klaus and McDonnell, 2013;Long et al, 2015). A number of recent studies have advocated the finer granularity of this framework in order to effectively integrate across the different scales of interest between climate and water quality research (Michalak, 2016;Ockenden et al, 2017).…”