River model calibration, from guidelines to operational support tools

Numerical modelling is now used routinely to make predictions about the behaviour of environmental systems. Model calibration remains a critical step in the modelling process and different approaches have been taken to develop guidelines to support engineers and scientists in this task. This article reviews currently available guidelines for a river hydraulics modeller by dividing them into three types: on the calibration process, on hydraulic parameters, and on the use of hydraulic simulation codes. The article then presents an integration of selected guidelines within a knowledge-based calibration support system. A prototype called CaRMA-1 (Calibration of River Model Assistant) has been developed for supporting the calibration of models based on a specific 1D code. Two case studies illustrate the ability of the prototype to face operational situations in river hydraulics engineering, for which both data quality and quantity are not sufficient for an optimal calibration. Using CaRMA-1 allows the modeller to achieve the calibration task in accordance with good calibration practice implemented in the knowledge base. Relevant reasoning rules can easily be added to the knowledge base to extend the prototype range of applications. This study thus provides a framework for building operational support tools from various types of existing engineering guidelines

Development of Computer Simulation Model for Urban Region Using Xp-Swmm in Savannah, Georgia

The objective of this thesis was to determine if it is possible to create, calibrate, and validate a computer simulation model given a limited amount of measured data. In June 1999, significant flooding was experienced throughout the Casey Canal North drainage basin in Savannah, Georgia. Time-depth rainfall data from a single gage was recorded for this event, along with peak water surface elevations throughout the basin. The computer model chosen for this application was XP-SWMM, which was approved by the Federal Emergency Management Agency to simulate both one dimensional and two dimensional hydraulic models. XP-SWMM was chosen due to its ability to dynamically link the subsurface drainage system with the overland flow experienced during significant rainfall events. The measured peak water surface elevation data was divided into two, with one dataset used to calibrate the model and the second used for model verification. The model calibration was completed by manually adjusting certain hydrologic model parameters within an acceptable range in order to match field observed peak water surface elevations. The model evaluation showed that the peak water surface elevations estimated by the model matched the levels observed in the field and that inundated road intersections observed during the flooding event were correctly predicted by the model

Metodología de calibración 2D de modelos hidromorfológicos con alta variabilidad morfológica: caso de estudio: Río Meta, Colombia

Esta investigación desarrollo una metodología de calibración basada en el manejo eficiente de los parámetros utilizando diseño de experimentos. Esta metodología es capaz de realizar una calibración de modelos hidromorfológicos 2D con alta variabilidad morfológica. Como parte de la metodología se propuso criterios de simplificación que permitieran una reducción de los parámetros de calibración previa al diseño experimental. Asimismo se definieron indicadores de ajuste sensibles a las variaciones de los parámetros de calibración. La metodología se aplicó exitosamente al caso de estudio del río Meta, Colombia. En este caso los parámetros de calibración fueron: el coeficiente de rugosidad (Chezy), la ecuación de transporte de sedimentos, • Factor de Carga de Lecho (Kb), Factor de Carga en Suspensión (Ks), Coeficiente de Pendiente Transversal (TSC) y Exponente de Pendiente Transversal (TSP). Como resultado de este proceso se obtuvo que las variaciones realizadas al Coeficiente de Pendiente Transversal (TSC) y Exponente de Pendiente Transversal (TSP) no fueran estadísticamente significativas para la calibración del modelo. El punto optimó encontrado para el modelo fue conseguido utilizado un C para el coeficiente de Chezy de 55, la ecuación de transporte de Van Rijn, un Ks=0.50 y un Kb=0.10. El un Indicador Global de Ajuste (IPA) de 0.8819, el cual es valor satisfactorio para los requerimientos y aplicaciones. Aunque los planteamientos y los parámetros de calibración descritos en la investigación están asociados a MIKE21C se espera que el la metodología pudiese ser aplicable a otros modelos numéricos hidromorfológicos.MaestríaMagister en Ingeniería Civi