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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Evaluating Changes in Terrestrial Hydrological Components Due to Climate Change in the Chesapeake Bay Watershed

Modi, Parthkumar Ashishbhai 09 June 2020 (has links)
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.
112

Numerical modeling of the Sakuma Dam reservoir sedimentation

Hanmaiahgari, P.R., Gompa, N.R., Pal, D., Pu, Jaan H. 16 January 2018 (has links)
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.
113

Architecture et mission pédagogique : regards sur le campus de l'Université de Montréal et de l'école des HEC à l'ère d'une société de la connaissance

Antonat, Dan 11 1900 (has links)
Toutes les photos présentes dans ce mémoire (sauf indication contraire) ont été réalisées par Dan Antonat (c). / À l’ère de la société de la connaissance, l’éducation supérieure occupe une place prépondérante dans le monde et les universités sont des acteurs de premier ordre. La connaissance, à travers l’innovation qu’elle permet, est devenue un élément central du processus de production et l’on parle désormais d’une économie du savoir, qui serait porteuse d’un ensemble de changements qui affectent la société sur différents plans. Le mode de fonctionnement traditionnel des universités n’y échappe pas et connaît plusieurs renouveaux. Les NTIC ont fait évoluer les manières d'enseigner et de faire de la recherche et l’on parle aujourd’hui d’un nouveau type de relations inédites entre les universités, l'État et le secteur de l’industrie. Après avoir passé en revue l’ensemble de ces changements, nous proposons d'explorer l'impact de toutes ces transformations sur le développement physique des universités à travers l’étude du projet de construction du futur campus de l'Université de Montréal à Outremont et de l'École des HEC Montréal. Nous analysons dans notre étude l'influence de ces changements sur l'organisation physique des universités et sur l'architecture des bâtiments. / In the era of the knowledge society characterized by the importance of constant innovation, various dimensions of social life are going through notable renewals. The New Technologies of Information and Communication (NTIC) are offering a large panel of new possibilities that affects the traditional mode of operating of various institutions. In this context, Universities become fundamental actor, by contributing to the high education of the population through their activities of teaching and research. It seems that the traditional mission of universities is going through major changes. Lots of new possibilities permit by the NTIC affects the traditional way of teaching and doing research and we also talk about new kind of unprecedented relations between universities, state and the industry. We offer to explore the impact of all these changes on the physical development of universities through a look at a case study of the campus of Université de Montréal and the business school of HEC Montreal. Our work discuss about the influence of these changes in the physical organization of the university, more specifically on the architecture of the buildings. Through a look at the project of construction of a new campus situated at Outremont, we have attended to study actual tendencies and concerns about university buildings. We then attended to analyse the impacts of these developments on the organisation of universities buildings through a study of the architectural features of the new school of HEC Montréal.
114

Architecture et mission pédagogique : regards sur le campus de l'Université de Montréal et de l'école des HEC à l'ère d'une société de la connaissance

Antonat, Dan 11 1900 (has links)
À l’ère de la société de la connaissance, l’éducation supérieure occupe une place prépondérante dans le monde et les universités sont des acteurs de premier ordre. La connaissance, à travers l’innovation qu’elle permet, est devenue un élément central du processus de production et l’on parle désormais d’une économie du savoir, qui serait porteuse d’un ensemble de changements qui affectent la société sur différents plans. Le mode de fonctionnement traditionnel des universités n’y échappe pas et connaît plusieurs renouveaux. Les NTIC ont fait évoluer les manières d'enseigner et de faire de la recherche et l’on parle aujourd’hui d’un nouveau type de relations inédites entre les universités, l'État et le secteur de l’industrie. Après avoir passé en revue l’ensemble de ces changements, nous proposons d'explorer l'impact de toutes ces transformations sur le développement physique des universités à travers l’étude du projet de construction du futur campus de l'Université de Montréal à Outremont et de l'École des HEC Montréal. Nous analysons dans notre étude l'influence de ces changements sur l'organisation physique des universités et sur l'architecture des bâtiments. / In the era of the knowledge society characterized by the importance of constant innovation, various dimensions of social life are going through notable renewals. The New Technologies of Information and Communication (NTIC) are offering a large panel of new possibilities that affects the traditional mode of operating of various institutions. In this context, Universities become fundamental actor, by contributing to the high education of the population through their activities of teaching and research. It seems that the traditional mission of universities is going through major changes. Lots of new possibilities permit by the NTIC affects the traditional way of teaching and doing research and we also talk about new kind of unprecedented relations between universities, state and the industry. We offer to explore the impact of all these changes on the physical development of universities through a look at a case study of the campus of Université de Montréal and the business school of HEC Montreal. Our work discuss about the influence of these changes in the physical organization of the university, more specifically on the architecture of the buildings. Through a look at the project of construction of a new campus situated at Outremont, we have attended to study actual tendencies and concerns about university buildings. We then attended to analyse the impacts of these developments on the organisation of universities buildings through a study of the architectural features of the new school of HEC Montréal. / Toutes les photos présentes dans ce mémoire (sauf indication contraire) ont été réalisées par Dan Antonat (c).
115

Rainfall-runoff modeling in arid areas

Abushandi, Eyad 27 May 2011 (has links) (PDF)
The Wadi Dhuliel catchment/ North east Jordan, as any other arid area has distinctive hydrological features with limited water resources. The hydrological regime is characterized by high variability of temporal and spatial rainfall distributions, flash floods, absence of base flow, and high rates of evapotranspiration. The aim of this Ph.D. thesis was to apply lumped and distributed models to simulate stream flow in the Wadi Dhuliel arid catchment. Intensive research was done to estimate the spatial and temporal rainfall distributions using remote sensing. Because most rainfall-runoff models were undertaken for other climatic zones, an attempt was made to study limitations and challenges and improve rainfall-runoff modeling in arid areas in general and for the Wadi Dhuliel in particular. The thesis is divided into three hierarchically ordered research topics. In the first part and research paper, the metric conceptual IHACRES model was applied to daily and storm events time scales, including data from 19 runoff events during the period 1986-1992. The IHACRES model was extended for snowfall in order to cope with such extreme events. The performance of the IHACRES model on daily data was rather poor while the performance on the storm events scale shows a good agreement between observed and simulated streamflow. The modeled outputs were expected to be sensitive when the observed flood was relatively small. The optimum parameter values were influenced by the length of a time series used for calibration and event specific changes. In the second research paper, the Global Satellite Mapping of Precipitation (GSMaP_MVK+) dataset was used to evaluate the precipitation rates over the Wadi Dhuliel arid catchment for the period from January 2003 to March 2008. Due to the scarcity of the ground rain gauge network, the detailed structure of the rainfall distribution was inadequate, so an independent from interpolation techniques was used. Three meteorological stations and six rain gauges were used to adjust and compare with GSMaP_MVK+ estimates. Comparisons between GSMaP_MVK+ measurements and ground rain gauge records show distinct regions of correlation, as well as areas where GSMaP_MVK+ systematically over- and underestimated ground rain gauge records. A multiple linear regression (MLR) model was used to derive the relationship between rainfall and GSMaP_MVK+ in conjunction with temperature, relative humidity, and wind speed. The MLR equations were defined for the three meteorological stations. The ‘best’ fit of the MLR model for each station was chosen and used to interpolate a multiscale temporal and spatial distribution. Results show that the rainfall distribution over the Wadi Dhuliel is characterized by clear west-east and north-south gradients. Estimates from the monthly MLR model were more reliable than estimates obtained using daily data. The adjusted GSMaP_MVK+ dataset performed well in capturing the spatial patterns of the rainfall at monthly and annual time scales, while daily estimation showed some weakness for light and moderate storms. In the third research paper, the HEC-HMS and IHACRES rainfall runoff models were applied to simulate a single streamflow event in the Wadi Dhuliel catchment that occurred in 30-31.01.2008. Both models are considered suitable for arid conditions. The HEC-HMS model application was done in conjunction with the HEC-GeoHMS extension in ArcView 3.3. Streamflow estimation was performed on hourly data. The aim of this study was to develop a new framework of rainfall-runoff model applications in arid catchment by integrating a re-adjusted satellite derived rainfall dataset (GSMaP_MVK+) to determine the location of the rainfall storm. Each model has its own input data sets. HEC-HMS input data include soil type, land use/land cover map, and slope map. IHACRES input data sets include hourly rainfall and temperature. The model was calibrated and validated using observed stream flow data collected from Al-Za’atari discharge station. IHACRES shows some weaknesses, while the flow comparison between the calibrated streamflow results agrees well with the observed streamflow data of the HEC-HMS model. The Nash-Sutcliffe efficiency (Ef) for both models was 0.51, and 0.88 respectively. The application of HEC-HMS model in this study is considered to be satisfactory.
116

Návrh a posouzení suché nádrže a protipovodňové ochrany / Design of small reservoirs and flood protection

Pikna, Martin January 2019 (has links)
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.
117

Revitalizace vybraného úseku toku Hartmanického potoka / Revitalization of the selected section of river "Hartmanický potok"

Samková, Aneta January 2017 (has links)
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.
118

Rainfall-runoff modeling in arid areas

Abushandi, Eyad 08 April 2011 (has links)
The Wadi Dhuliel catchment/ North east Jordan, as any other arid area has distinctive hydrological features with limited water resources. The hydrological regime is characterized by high variability of temporal and spatial rainfall distributions, flash floods, absence of base flow, and high rates of evapotranspiration. The aim of this Ph.D. thesis was to apply lumped and distributed models to simulate stream flow in the Wadi Dhuliel arid catchment. Intensive research was done to estimate the spatial and temporal rainfall distributions using remote sensing. Because most rainfall-runoff models were undertaken for other climatic zones, an attempt was made to study limitations and challenges and improve rainfall-runoff modeling in arid areas in general and for the Wadi Dhuliel in particular. The thesis is divided into three hierarchically ordered research topics. In the first part and research paper, the metric conceptual IHACRES model was applied to daily and storm events time scales, including data from 19 runoff events during the period 1986-1992. The IHACRES model was extended for snowfall in order to cope with such extreme events. The performance of the IHACRES model on daily data was rather poor while the performance on the storm events scale shows a good agreement between observed and simulated streamflow. The modeled outputs were expected to be sensitive when the observed flood was relatively small. The optimum parameter values were influenced by the length of a time series used for calibration and event specific changes. In the second research paper, the Global Satellite Mapping of Precipitation (GSMaP_MVK+) dataset was used to evaluate the precipitation rates over the Wadi Dhuliel arid catchment for the period from January 2003 to March 2008. Due to the scarcity of the ground rain gauge network, the detailed structure of the rainfall distribution was inadequate, so an independent from interpolation techniques was used. Three meteorological stations and six rain gauges were used to adjust and compare with GSMaP_MVK+ estimates. Comparisons between GSMaP_MVK+ measurements and ground rain gauge records show distinct regions of correlation, as well as areas where GSMaP_MVK+ systematically over- and underestimated ground rain gauge records. A multiple linear regression (MLR) model was used to derive the relationship between rainfall and GSMaP_MVK+ in conjunction with temperature, relative humidity, and wind speed. The MLR equations were defined for the three meteorological stations. The ‘best’ fit of the MLR model for each station was chosen and used to interpolate a multiscale temporal and spatial distribution. Results show that the rainfall distribution over the Wadi Dhuliel is characterized by clear west-east and north-south gradients. Estimates from the monthly MLR model were more reliable than estimates obtained using daily data. The adjusted GSMaP_MVK+ dataset performed well in capturing the spatial patterns of the rainfall at monthly and annual time scales, while daily estimation showed some weakness for light and moderate storms. In the third research paper, the HEC-HMS and IHACRES rainfall runoff models were applied to simulate a single streamflow event in the Wadi Dhuliel catchment that occurred in 30-31.01.2008. Both models are considered suitable for arid conditions. The HEC-HMS model application was done in conjunction with the HEC-GeoHMS extension in ArcView 3.3. Streamflow estimation was performed on hourly data. The aim of this study was to develop a new framework of rainfall-runoff model applications in arid catchment by integrating a re-adjusted satellite derived rainfall dataset (GSMaP_MVK+) to determine the location of the rainfall storm. Each model has its own input data sets. HEC-HMS input data include soil type, land use/land cover map, and slope map. IHACRES input data sets include hourly rainfall and temperature. The model was calibrated and validated using observed stream flow data collected from Al-Za’atari discharge station. IHACRES shows some weaknesses, while the flow comparison between the calibrated streamflow results agrees well with the observed streamflow data of the HEC-HMS model. The Nash-Sutcliffe efficiency (Ef) for both models was 0.51, and 0.88 respectively. The application of HEC-HMS model in this study is considered to be satisfactory.
119

Posouzení možností zvýšení protipovodňové ochrany obce / Assessment of the Options of Increased the Flood Protection

Adam, Karel January 2012 (has links)
The work deals with the assessment of the stream Chribska Kamenice current state in the village Vsemily urban area. The aim of the project is the assessment of capacity and the current state of the stream-bed. Based on an assessment measure there has been designed the improvement suggestion of the current state and flood protection increasing in close neighbourhood.
120

Skyfall i Sala : En skyfallskartering i HEC-RAS

Källbom, Jacob January 2023 (has links)
När klimatet i Sverige blir varmare ökar både förekomsten och omfattningen av intensiva skyfall. Dessa kan leda till stora konsekvenser lokalt för drabbade samhällen. Omfattande översvämningar, skadade fastigheter, erosionsskador och hindrad framkomlighet är några av de potentiella följderna. Ett första steg för att öka beredskapen för skyfall är att göra en skyfallskartering där ett nederbördstillfälle med skyfallskaraktär läggs in i en hydraulisk modell över ett område. Modellen visar sedan områden som riskerar att drabbas av översvämningar samt vilken väg som ytavrinningen tar under förloppet. I detta arbete har en sådan modell gjorts över Sala stad. Skyfallsmodellen skapades i programmet HEC-RAS och för att simulera infiltrationen användes metoden SCS curve number. SCS curve number metoden uppskattar infiltration baserat på markanvändning och jordart. Typregnet valdes till 100 års återkomsttid och modellerades som ett CDS-regn med varaktighet sex timmar och klimatfaktor 1,3. Ett avdrag på nederbördsmängden gjordes även för dagvattennätets kapacitet. Resultatet blev att flertalet områden i Sala kan drabbas av potentiellt stora vattendjup. De största problemområdena identifierades till bebyggelsen mellan Ringgatan och Östra Tulegatan söder om centrala Sala samt området kring Pråmån uppströms Jakob Mats kvarn. Då infiltrationsmetoden SCS curve number är baserad på empiriska data gjordes en känslighetsanalys på infiltrationsparametrarna. Det som undersöktes var påverkan på total andel infiltrerad nederbörd och översvämningarnas utbredning. Tre olika scenarion baserat på osäkerheten i curve number-talet användes samt ett scenario utan infiltration i modellen. Skillnaden i total översvämmad yta med ett djup större än 0,1 m mellan scenariot med högst infiltration och scenariot med lägst infiltration var i modellen totalt 9,1 procentenheter. I det scenario där ingen infiltration modellerades drabbades flertalet nya fastigheter och infrastruktur av översvämning vilket visar på infiltrationens betydelse för riskbedömningen vid en skyfallskartering. Totalt infiltrerade 30 % av nederbörden i modellen vid scenariot med lägst infiltration, 49 % av nederbörden vid scenariot med direkta litteraturvärden för curve number- talet och 66 % av nederbörden i scenariot med högst infiltration. Eftersom infiltrationen mellan scenarierna til hög grad berodde på hur jordarterna klassades i modellen är det dock svårt att dra en generell slutsats om vilket infiltrationsscenario som är bäst lämpat att använda vid skyfall. / As the climate becomes warmer in Sweden the frequency and extent of cloudbursts are expected to rise. When these rain events occurs in populated areas the consequences can be severe for the local community with extensive flooding leading to for example damaged properties, erosion and obstructions of traffic. One step to increase the awareness of these risks is to do a cloudbust mapping were a rain with cloudburst extent is modelled hydraulically. Areas that are at risk of flooding during the rain event and flow paths for the surface runoff can be assessed from the model. In this thesis such a model was created for the town of Sala. The cloudbust model was made using the software HEC-RAS and to simulate infiltration the method SCS curve number was implemented. The rain event was modeled as a Chicago design storm with a return period of 100 years, total duration of six hours and a climate factor of 1,3. The results were that several areas in Sala were at risk of flooding. Two main areas with risk of major flooding extents were located to just south of central Sala between Ringgatan and Östra Tulegatan and adjacent to Pråmån upstream of Jakob Mats kvarn. Because of uncertainties in the SCS curve number model and due to the fact that it is based on empirical data a sensitivity analysis was also done on the infiltration parameters. For the sensitivity analysis four different scenarios were used. One scenario had no modeled infiltration and the three other scenarios were based of error estimations of the curve number parameter called antecedent runoff conditions. The difference in flooding extent with a depth greater than 0,1 m in the model between the scenario with high infiltration and the scenario with low infiltration was 9,1 percentage points. Several new properties and infrastructure were affected in the scenario when no infiltration was used. In total 30% of the precipitation infiltrated in the model in the scenario with low infiltration, 49% infiltrated in the scenario with literature values for the curve number value, and 66% of the precipitation infiltrated in the scenario with high infiltration. Since the infiltration is highly dependent on the classification of the soils in the model no overall conclusion could be drawn on which infiltration scenario that is best suited for a cloudburst model in general when the SCS curve number method is used to model infiltration.

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