Most dam break studies require complex numerical simulations and advanced knowledge in hydraulics. A number of programs are available to perform these simulations and the choice regarding the software to be used must be done within the resources available and the complexity of the problem to be addressed. It remains that this choice is also influenced by the experience and by the knowledge of the analyst. This study reports the simulations results of a comparative study performed for three (3) cases of varying complexity with the software NWS FLDWAV and HEC RAS. Thus, the rupture of a dam in a rectangular channel with uniform characteristics showed that both of the software allows obtaining almost identical results. The other two cases associated with the historical failure of Teton Dam (Idaho, United States) and the combined failure of Drummond and Rock Forest dams (Québec, Canada) showed significant differences in dam breach flow rates and maximum tailwater levels. A comparative analysis of the results leads to recommendations intended for users of these softwares.

Temporary Concrete Traffic Barriers (TCTBs) are essential in order to protect the traveling public and highway construction crews from accidents due to driver misfortune or negligence. In order for TCTBs to be installed, however, they must be successfully crash tested. Barrier height and drainage open space are key characteristics that influence this crash test rating. This is because an increase in height will insure that a vehicle will not over-top the barrier and a decrease in drainage open space will result in greater barrier mass, which will in turn resist larger impact forces. The factors that increase the crash worthiness of a barrier, however, lead to poor hydraulic performance. This then becomes a concern if barriers are placed in areas where they may adversely impact the local floodplain elevation. The objective of this research is the development of a hydraulic rating curve that describes the relationship between upstream energy head and the flow rate passing the barrier. To accomplish this objective, a three parameter model with three unknown coefficient terms was utilized. The model was then fit to experimentally obtained data, and a rating curve was developed. In addition, the effects of downstream submergence and clogging of the drainage opening, with respect to the rating curve, was also analyzed. Finally, a method for using this information in the hydraulic modeling software HEC-RAS was developed. / text

Currently the Iowa Flood Center (IFC) of the University of Iowa is working in conjunction with the Iowa Department of Natural Resources (IDNR) to create statewide floodplain maps. The IFC has set up a four year plan to construct flood inundation maps for 85 of the 99 counties within the state of Iowa, with the final goal of creating maps acceptable by FEMA. High resolution statewide LiDAR information provides a base dataset from which floodplain maps are produced. Stream centerline data is extracted from a DEM produced by the LiDAR dataset. The centerline information is used in both this project and as a replacement for the USGS NHD streamline for the state. Stream flow estimation for a range of annual exceedance discharges are produced through a USGS recommended combination of regional regression analysis weighted by gage influence. Water surface elevations are produced for each of the annual exceedance discharges through the use of a HEC-RAS one dimensional steady flow model. Flood boundaries are the final product created by HEC-GeoRAS though a comparison of a TIN produced from the water surface elevations and the ground surface DEM. Final FEMA acceptable DFIRM's are produce by the IDNR and submitted to FEMA for adoption into the NFIP.

The Iowa Flood Center (IFC), a unit of The University of Iowa's IIHR - Hydroscience & Engineering, and the Iowa Department of Natural Resources are developing a statewide floodplain boundary dataset to provide information that is critical to proper flood mitigation planning. During flooding, soil loss from agricultural land, in addition to inundation, can have a substantial economic impact on an agricultural state like Iowa. The ability to identify areas with a high potential to experience scour during flooding could assist farmers and land owners in making better land management decisions. Currently, the IFC statewide floodplain mapping program is creating annual exceedance probability floodplain data for all Iowa streams. The effort described herein has developed methods to take advantage of this large dataset, applying uniform open channel flow theory to spatially characterize scour potential using custom tools created with GIS model builder. The results of this thesis are being used by the Iowa Natural Heritage Foundation (INHF) and the IFC to develop a program through which certified crop consultants can help farmers make more informed land management decisions based on risk of flood related soil loss.

Many bridges are destroyed or completely failed during floods due to excessive scouring around bridge piers and abutments. Safe bridge design is based on joint consideration of structural, hydraulic, and geotechnical aspects. This study is concerned with the investigation of various types of countermeasures against scouring at bridge sites. The design criteria for various countermeasures are reviewed in terms of hydraulic, hydrologic, constructional, and economical requirements. (Conditions of applicability of these countermeasures are evaluated and designed for different return periods of flow, and hydroeconomic analyses are performed for Esenbosa Bridge). Based on the evaluation of the results of hydroeconomic analyses, combinations of rock riprap and grout filled bags are found to be appropriate measures for piers and abutments against scouring whereas vegetation is observed to be applicable for bank protection.

The diploma thesis deals with the proposal of flooded area on selected section 23,324-28,521 km of the Kyjovka river. Part of the thesis is about general issue of floods and flooded areas. In the practical part, the flooded area of the selected section of the Kyjovka river, with the help of AutoCAD and HEC-RAS programs, is designed. As a source for the proposal of flooded area served the data from The Morava River basin. The thesis is complemented by graphic attachment, photo documentation and drawings.

This thesis deals with the study of revitalization measures on upstream of the Svratka River, specifically near the village Herálec. The thesis also contains information about locality, bioregion and basin of Svratka River The main part of the paper examines the modified section Svratka. The goal of this work is to evaluate the current situation and then propose measures that would lead to the revitalization of Svratka River. When drafting work was also used hydrological program HEC-RAS and ATLAS DMT

This master thesis focus on determinig the flooding inundation of the selected area of Luzicka Nisa, flowing through the city Hradek nad Nisou. The work is based on the field survey and the information about the area, on this basis it describes the watched area in interaction for determing the flooding inundation. The thesis is split into the text summary and determing the flooding inundation of the selected part of the river Luzicka Nisa. The text summary sums up the problematic of flooding. It mentions the history, the prevention against flooding, the factors influencing their formation. The flood stages, the flooding inundation and the flood control plans. The second part focus on the determining the flooding inundation at the N year flows by using of the program HEC RAS 4.0 and the ArcGIS extension HEC-GeoRAS. The determined flooding inundation was modeled on the basis of the data of cross profiles, N year flows and water facilities and then exported on map data.

The thesis deals with a creation of a model that imitates a flood wave and determining the flooded area after the rupture of the earth dam situated on the water flow Bílá Desná in The Liberec Region. It is not only a fictitious demonstration, but the actual application of a real flow wave caused by the destruction of the hydraulic dam from 1916 till the present state of the territory. The used input data were obtained from the ČÚZK and the terrain measurements. These data were processed in several programs, namely: HEC-GeoRAS and HEC-RAS. From the results of the model was determined the flooded area during peak flow and a model that portrays the development of the flood wave on the designed flow section. The results of this study enable to sketch the event which could occur if the rupture of the hydraulic dam did not occur in the 1916, but nowadays.

My final thesis are focused on the field of flood protection and hydrodynamical modelling for the drainage area of the Jeptiška creek. The aim of my work is the evaluation of the status of the part of the watercourse (Jeptiška Creek between river km 0,0-2,5), the evaluation how hydraulic structures influence the streem and the analysis of foodplain areas for the selected floods. Floodplain areas and flood hazard areas are, as result of former steps, determined in Městec Králové. The hydrodynamical model (using HEC-RAS model application) is compiled, flood plain areas are docomented using GIS.