Cost Effective Evacuation Mapping: DSS-WISE? vs. HEC-RAS 2D; When to go the Extra Mile

摘要

Many dams have evacuation maps that are outdated and inadequate by today's standards. Many of the maps are black and white and use poor quality basemaps like low-resolution USGS Topographic Quadrangles or old aerial imagery, and some of the maps have hand drawn features. A majority of dam breach modeling was completed using standard dam breach and hydraulic modeling software that was available during the early 1990s. While most of the modeling was accomplished through sound practices and techniques, there are several instances where the available technology was inadequate in accurately defining the extent of flooding. Our experience is that DSS-WISE has many benefits compared to conventional HEC-RAS modeling. DSS-WISE is simple to use compared to HEC-RAS 2D. It provides the user with a report of the simulation run, along with digital products that can be used on different platforms. HEC-RAS 2D can be more complicated and time consuming when setting up a simulation run, but the user can input higher quality data when it's available, and HEC-RAS 2D can deliver more detailed results. So, when do you need to go that extra mile and use HEC-RAS 2D, or some other form of 2D modeling software? In this article, we provide examples of how the Montana DNRC Dam Safety Program has taken advantage of 1D and 2D modeling software to help the owners of small dams by providing them with better, more up-to-date evacuation maps for their Emergency Action Plans.