A General Linear Approach to Stream Water Quality Modeling

The problem of meeting stream dissolved oxygen standards while optimizing some objective is treated. New properties of the oxygen sag equation allow the constraint set of such mathematical programs to be described to a high degree of accuracy by linear inequalities; except for upper and lower bounds on pollutant discharges, three linear constraints at most are required per reach. Constraint elimination techniques are developed that can further reduce the number of constraints necessary. As a means of highlighting the potential power of these techniques to large-scale models they are applied to two well-known examples from the literature.