CGRG Bibliography of Canadian Geomorphology
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Author : Caldwell, R.J.l.; and Fay, D.M.
Date : 2004.
Title : Statistical comparison of Great Lakes water levels forecasts.
Publication : 11th Annual International Conference on the St. Lawrence River Ecosystem. "Managing our Waters: Great Lakes / St. Lawrence River Ecosystem". NAVCANADA Conference Centre, Cornwall, Ontario. May 18-19th, 2004.
Issue :
Page(s) : 3.
Abstract
Environment Canada, Cornwall, and the U.S. Army Corps of Engineers, Detroit District, issue coordinated, 6-month forecasts of water levels for each of the Great Lakes each month. These two agencies begin by independently producing probabilistic forecasts using several different techniques (up to three or four methods each). These techniques differ in regards to their consideration and use of such important information as initial conditions, historic data, antecedent conditions, or climatological outlooks. In turn, each agency then selects one forecast to arrive at that month’s Canadian and U.S. forecasts. These are then combined (usually using arithmetic averaging) to arrive at one, coordinated forecast that is readily available to all binational stakeholders and the public. A statistical comparison of these separate forecasts was undertaken that focused on the 50% probability of exceedence forecasts (sometimes titled “most probable” or “expected”). Comparisons used as many of the forecasts as possible to ensure that the broadest ranges of hydrological conditions were encompassed. The analysis considered root mean square error, bias, correlation, maximum error, and skill (a measure of how well extreme levels are forecasted). Results demonstrated that, although there are often notable differences between individual forecasts, over the course of several years, no one technique offered significant improvements over the others. Nonetheless, all methods used offered marked improvements over the “reference forecast”, which consisted of simply taking the initial lake levels and applying long term average month-to-month level changes to arrive at 6-month forecasts of each lake’s levels.
Bibliography of Canadian Geomorphology