Download or read book Issues of 2-D Modeling for Flood Mapping written by Devinder Singh Dhillon and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical modeling is the standard tool in determining floodplain areas for engineering and insurance purposes. For many years one-dimensional (1-D) models have been primarily used for these purposes, with HEC-RAS arguably the most widely used 1-D model. Relatively robust guidelines and specifications, as well as an industry standard of practice, currently exists for 1-D models. While 1-D models are relatively simple to apply and rather inexpensive to develop, they are based on several assumptions that do not always hold true in overbank flooded conditions. These shortcoming are particularly significant for models intended to simulate flow over levees or in very flat areas, such as the Central Valley of California.In recent years, 2-D models have been used as an additional tool in floodplain mapping to allow for more detailed analyses. Unfortunately, the assumptions behind these 2-D models are not fully understood by all users. 2-D models are even less understood by decision and policy makers. The Federal Emergency Agency (FEMA) has recognized the need for greater understanding and improved guidelines for applying 2-D models in flood studies and intends to widely disseminate the advantages and limitations of 2-D models examined. This work develops a) a literature review of 2-D modeling use for floodplain mapping; b) presents the Blue Ribbon Panel's (BRP's) results of the 46 issues; c) develop a question form for 2-D software vendors; and d) produce written guidelines that address limitations and capabilities of 2-D models to help practitioners, decision and policy makers use 2-D models more effectively.The decision on model complexity and dimensionality for a given case, can be based on two main ideas: a) the goal of the analysis, and b) the modeler. Thus, the steps to consider when facing a modeling task should be: a) define the goal of the study; b) select the adequate modeler for the task; c) chose the right tool for the goal of the study and the modeler; and d) perform the study considering all conditions.