Development and Evaluation of a Dynamic Moving Storm (DMS) Builder

Abstract:

The University of Texas at Arlington (UTA) developed a design rainfall generator - Dynamic Moving Storm (DMS). DMS is a unique tool because it accounts for three major factors of real rainfall events simultaneously that other tools do not: (1) spatial variability, (2) temporal variability, and (3) directional movement. The rainfall intensity distribution with a storm is normally referred to spatial variability factor. The DMS builder takes in account storm sizes, shapes, and orientations (for non-circular storms) within the spatial variability module. Given rainfall intensity within the storm always varies with respect of time, the builder has a capability of specifying temporal distributions of rainfall intensities following linear or exponential patterns. To represent the dynamic motions of real storms, the researchers at UTA developed a movement module into DMS to handle combinations of accelerations, decelerations, pause and turns. Typically, an idealized storm generated by DMS can be presented as a circular shape in 2-D and conic shape in 3-D views. While it moves across a watershed, the rainfall pattern within the storm follows a certain temporal pattern. Once various combinations of spatial, temporal, and movement factors are input into the DMS builder, it can generate corresponding elliptical-shaped rainfall contours with rainfall hyetographs for each subbasin of a particular watershed. The resulted rainfall information can then be fed into hydrologic models to evaluate the spatiotemporal impacts for any watersheds. This paper demonstrates a case study using DMS builder to access the vulnerability for the Brays Bayou watershed in Houston, Texas.