Water levels up- and downstream of dams are strongly affected by water levels in the reservoir as well as the discharge of the dam. To ensure that no harm comes to buildings, bridges or agricultural land it is important to ensure that the water level in the reservoir is adjusted to handle large floods. This report studies within what range the water level in the reservoir of the Yayangshan dam, located in Lixian River, can vary without causing any flooding downstream the dam or at the Old and New Babian Bridge located upstream the dam. By calculation of the designed flood, flood routing- and backwater computation, initial water level ranges in the reservoir have been set for the pre-flood, main flood and latter flood season for damages to be avoided. Due to the far distance between the dam site and the bridges, backwater effects had no influence on the limitations of the initial water level in the reservoir.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / In this article, a comparative analysis is performed between one-dimensional (HEC-RAS) and two-dimensional (IBER) models, in the evaluation of total scour in the pillars and abutments of a bridge. The case study is the Huallaga bridge, located in the San Martín region, Peru.Based on the geomorphological, hydrological and hydraulic data of the study area and after carrying out an analysis of the different equations for local, general scour; Numerical modeling was performed on the HEC-RAS and IBER software in order to calculate the depths of the scour.The following results were obtained: That in the local scour calculations, the scour depths were less with the 2D software, compared to the values obtained in the 1D software; while in general scour calculations, we obtain greater depths when modeling with 2D software, compared to the values obtained in 1D software

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Yes / The present study attempts to predict the reservoir sedimentation in 32 km region of the Tenryu River between the Hiraoka and Sakuma Dams in Japan. For numerical simulations of the reservoir sedimentation, the one-dimensional model of the Hydrologic Engineering Centre-River Analysis System (HEC-RAS) is used together with the inclusion of channel geometry, bed gradation curve, Exner-5 bed sorting mechanisms, fall velocity of the particle, and flow and sediment boundary conditions pertaining to modeling region. The modeling region of the Tenryu River is divided into 48 river stations with 47 reaches in the numerical simulations. The numerical model is calibrated using the available data for 48 years from 1957 to 2004. The formulae of sediment transport function, Manning’s roughness coefficient, computational increment and fall velocity have been identified for getting the best estimation of the Sakuma Dam reservoir sedimentation. Combination of obtained sensitive parameters and erodible limits of 2 m gave the best comparison with the measured bed profile. The computed results follow the trend of measured data with a small underestimation. Although Manning’s roughness coefficient has an effect on the sedimentation, no direct relation is found between the Manning’s roughness coefficient and reservoir sedimentation. It is found that the temperature of water has no effect on the reservoir sedimentation.

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A mesoscale evaluation is performed to determine the impacts of climate change on terrestrial hydrological components and the Net Irrigation Water Requirement (NIWR) throughout the Chesapeake Bay watershed in the mid-Atlantic region of the United States. The Noah-MP land surface model is calibrated and evaluated against the observed datasets of United States Geological Survey (USGS) streamflow gages, actual evapotranspiration from USGS Simplified Surface Energy Balance (SSEBop) Model and soil moisture from Soil Analysis Climate Network (SCAN). Six best performing Global Climate Models (GCM) based on Multivariate Adaptive Constructed Analogs (MACA) scheme are included for two future scenarios (RCP 4.5 and RCP 8.5), to assess the change in water balance components, change in NIWR for two dominant crops (corn and soybeans) and uncertainty in GCM projections. Using these long-term simulations, the flood inundation maps are developed for future scenarios along the Susquehanna River including the City of Harrisburg in Pennsylvania. The HEC-RAS 2D model is calibrated and evaluated against the high-water marks from major historical flood events and the stage-discharge relationship of the available USGS streamgages. Finally, the impacts of climate change are assessed on flood inundation depth and extent by comparing a 30-yr and 100-yr flood event based on the historical and future (scenario-based) peak discharge estimates at the USGS streamgages. Interestingly, flood inundation extent and severity predicted by the model along the Susquehanna River near Harrisburg is expected to rise in the future climate scenarios due to the greater frequency of extreme events increasing total precipitation. / Master of Science / Climate change is inevitable due to increased greenhouse gas emissions, with impacts varying in space and time significantly throughout the globe. The impacts are strongly driven by the change in precipitation and temperature which affect the control of the movement of water on the surface of the Earth. These changes in the water cycle require an understanding of hydrological components like streamflow, soil moisture, and evapotranspiration. Development of long-term climate models and computational hydrological models (based on mathematical equations and governed by laws of physics) has helped us in understanding this climate variability in space and time. This study performs a long-term simulation using the datasets from six different climate models to analyze the change in terrestrial hydrological components for the entire Chesapeake Bay watershed in the mid-Atlantic region of the United States. The simulations provide an understanding of the interplay between various land surface processes due to climate change and can help determine future water availability and consumption. To illustrate the usefulness of such long-term simulations, the crop water requirement is quantified for the dominant crops in Chesapeake Bay watershed to project water availability and support the development of mitigation strategies. Flood inundation maps are also developed for a section of Susquehanna River near the City of Harrisburg in south-central Pennsylvania using the streamflow from long-term simulations. The flood inundation depth and extent for major flood events such as Tropical Storm Agnes (1972) and Tropical Storm Lee (2011) are compared along the Susquehanna River, which can aid in managing flood operations, reduce the future flood damages and prioritize the mitigation efforts for endangered communities near the City of Harrisburg.

The diploma thesis deals with the design of the flood protection of the village Hrušky (Vyškov district). The hydraulic analysis of the water flow on the rivers Litava (river station km 19,460 - 20,928) and Rakovec (river station km 0,000 - 0,638) was done. The hydraulic analysis was performed on the Q5, Q20 and Q100 flows. For analysis was used a 2D numerical flow model in HEC-RAS 5.0.6. Based on results was designed a flood protection including a dry reservoir. The input data for the diploma thesis was the 2013 study „Litava II – přírodě blízká protipovodňová opatření a obnova přirozené hydromorfologie a retenční kapacity toku a nivy v úseku ř. km 16,0 (Újezd u Brna) až ř. km 24,0 (Slavkov u Brna)“. The diploma thesis was processed as a real project in the design office of Regioprojekt Brno, s.r.o.

Diploma thesis deal with revitalization Hartmanice river in district Svitavy. Section of interest is on 0,400 – 1,234 of river km. Part of this thesis is also rating current condition of stream and his vegetation accompaniment. Rating was made on base of reconnaissance terrain, my own measurement and photo documentation. In diploma thesis was design some revitalization steps: stabilization sink with wooden sills and stabilization slopes by using willow fences and similar precautions. There was designed total change of flow trend. Rating of current condition and condition of modified stream was made in software HEC-RAS.