Rapid Sizing and Performance Evaluation of Submarine Outfalls with Line Diffusers

Based on limited available data, engineers are often called upon to prepare preliminary designs of new outfalls or to screen the performance of existing ones in the context of developing rational management schemes for urban and or industrial effluents. In view of this need, our objective is to develop a simplified procedure, able to provide guidance with minimal field information and capable of utilizing any relevant marine survey data that may exist for enhancing the accuracy of predictions. For achieving the previous objective, the relations for all three dilution mechanisms are considered simultaneously, so as to have their combined impact analyzed. A set of baseline conditions is defined by assigning typical and typical-adverse values to selected input variables. Sensitivity analysis is performed, helping to further simplify the problem. The simplified model is analyzed in terms of its functional dependencies, and nomograms are developed, offering a convenient solution of the baseline problem. This baseline solution is easily adapted to local conditions through a correction multiplier factor computed on the basis of actual marine survey data that may exist.