Abstract

The paucity of information about stepwise regression has led the authors to compile this account because of its potential value in addressing synergistically complex environmental issues. Useful sources are identified for researchers who may wish to compile their own stepwise regression (all possible regressions) application. Results from one such application are documented herein. The example used to document stepwise regression is concerned with determining the best numerical method to predict where nearshore waves shore-break. The original definition posited by McCowan in 1894 suggested that nearshore waves are water depth limited (i.e., related to water depth only). Subsequent investigators, feeling the answer must be more complicated, have included bed slope, wave steepness considerations, the surf similarity parameter, and other parameters in endeavors to “refine” predictive power. However, this study confirms to a highly significant level that nearshore waves are depth limited. Statistical results indicate that d_b = 1.277 H_b, where d_b is the water depth at the shore-breaking position and H_b is the average shore-breaking wave height. The result is so close to the McCowan original result of d_b = 1.28 H_b that McCowan’s relationship prevails as the standard instrument for prediction.