The calibration, validation, and sensitivity analysis of DoSag an in-stream dissolved oxygen model /

by Cathey, Anna M.

Eighty four percent of dissolved oxygen (DO) impaired streams in Georgia occur within five physiographic regions in the coastal plain. This high number of violations in one area poses the question; is the natural level of DO in these streams less than the minimum set by the state? Streams in southern Georgia display several characteristics responsible for low levels of DO such as low gradient channels, high temperatures, and low to zero flow. The Georgia Environmental Protection Division plans to use a program called DoSag to model natural levels of DO in these streams. The objective of this research was to determine the applicability of DoSag in the coastal plain. This paper describes the parameter estimation, calibration, sensitivity analysis, and validation of the model in the coastal plain of Georgia. The paper's conclusion discusses a matrix of dominant causes of low DO including: sediment oxygen demand, reaeration, temperature, and streamflow.