Model Calibration and Validation
Ebrahim Ahmadisharaf, Rene A. Camacho-Rincon, Harry X. Zhang, Mohamed M. Hantush, Yusuf M. Mohamoud
Abstract
This chapter presents the state-of-the-art in model calibration and validation approaches found in the literature as guidance for applications of models in total maximum daily load (TMDL) studies. It also presents data and sources of the data including maintained databases as required in TMDL modeling, followed by data management resources, calibration guidelines including manual and auto-calibration lists of hydrologic and water quality parameters needing calibration in the watershed models, and model performance testing criteria or protocols. The primary models used in TMDL studies are the watershed models simulating hydrologic, hydraulic, and water quality processes, and receiving waterbody models simulating hydrodynamic and water quality processes. The calibration of a model is generally based on a combination of qualitative and quantitative assessments of relative model performance. Manual calibration is widely used in the practice and is especially useful if model run times are prolonged. Pre-calibration checks are strongly recommended to identify primary goals.