Formulation, calibration and verification of a mathematical model for Kalamas river, Greece

Abstract

The formulation, calibration and verification of a relatively simple 1-D model, for the determination of water quality in Kalamas River, is presented. The mathematical model consists of mass balance equations for three water quality variables (BOD, total phosphorus and dissolved oxygen), which are derived by applying the mass conservation principle to a small, but finite, control volume within the flow. The model is validated using scarce field data from 3 monitoring stations of the Hellenic Monitoring Network while the pollution loads of Kalamas are estimated using the literature and data from the Hellenic Special Secretariat of Water. Taking into account the significant level of uncertainty and scarcity of the available field measurements and the uncertainty of the estimated pollution loads, the calibration and verification of the model can be characterized as satisfactory. Then, the model is applied to investigate the effect of a hypothetical scenario, regarding a diversion of a main tributary, on the concentration of the examined water quality variables. The model can be used in its present formulation only as an approximate tool for the water management of Kalamas River because of the scarcity and uncertainty of the field measurements and pollution loads that are used for the validation of the model.