EBDUSA; A web-based county-level precipitation intensity-duration-frequency tool for the United States

Rainfall Intensity-Duration-Frequency (IDF) models have been developed at least since the 1970s. The IDF models are appealing to design engineers because they provide them with the ability to use a single equation to estimate rainfall intensity at any duration. The development of IDF models involves calculating the model's parameters by nding the best t of the model curve through an observed set of data points of rainfall depth/intensity. There are several IDF models documented in books and reports during years. In this research, the IDF model proposed by Texas Department of Transportation's Hydraulic Design Manual (TxDOT{HDM) is used to model precipitation frequency data and develop its ebd coe cients for most of the counties in the United States. Non-linear programming techniques are used to nd the best t of the IDF model. This thesis presents the ebd analysis R script that constructed for IDF model devel- opment. R is an open source, statistical programming language and software. This code uses a non-linear minimization approach through nlm package for IDF model development. A web{based application named EBDUSA is designed to deploy the developed ebd coe cients and perform the calculation of the intensity of a user-de ned duration. This thesis documents the EBDUSA web application development process along with its codes and scripts.