Dissertations / Theses: 'Rainfall intensity'

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Patron, Glenda G. "Joint probability distribution of rainfall intensity and duration." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06232009-063226/.

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Mongwa, Themba. "Rainfall intensity, kinetic energy and erosivity of individual rainfall events on the island of Mauritius." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/452.

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On most tropical volcanic islands the risk for soil erosion is enhanced due to a complex topography, high intensity rainfall and the exploitation of land for agriculture. Mauritius is a typical maritime tropical volcanic island with a distinct elevated interior. Rainfall is dominated by tropical weather systems and trade winds and the island is under intensive cultivation. Rainfall depth, duration, intensity, kinetic energy and erosivity were analysed for 385 erosive rainfall events at five locations over a five year period (2004 to 2008) on the island of Mauritius. Two stations located on the west coast and three stations sited on the Central Plateau above 550 m a.s.l. are used to provide detailed rainfall data at six minute intervals. Erosive storm events, defined here as a total rainfall exceeding 12.5 mm and a maximum 6-minute intensity exceeding 25 mm/hour, are found to differ markedly between the coastal lowlands and the elevated interior with regards to the frequency, the total rainfall generated, the duration, total kinetic energy and total erosivity of individual events. However, mean kinetic energy, mean and maximum rainfall erosivity (EI30) and maximum intensities (I30) from individual erosive events do not show this distinct differentiation. Erosivity measured during summer exceeds that recorded in winter, but the data indicate that large percentages of winter rainfall on Mauritius are defined as erosive and non-tropical cyclone rainfall can pose a substantial erosion risk. In this maritime tropical environment with its elevated interior, soil erosion risk occurs from storm scale to synoptic scale rainfall events and extreme events generate the bulk of the erosivity. Findings show that using rainfall records at an event scale within soil erosion risk assessments on tropical islands with a complex topography will increase the effectiveness of erosivity estimates

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Eckersten, Sofia. "Updating Rainfall Intensity-Duration-Frequency Curves in Sweden Accounting for the Observed Increase in Rainfall Extremes." Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-283714.

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Increased extreme precipitation has been documented in many regions around the world, in- cluding central and northern Europe. Global warming increases average temperature, which in turn enhances atmospheric water holding capacity. These changes are believed to increase the frequency and/or intensity of extreme precipitation events. In determining the design storm, or a worst probable storm, for infrastructure design and failure risk assessment, experts commonly assume that statistics of extreme precipitation do not change significantly over time. This so- called notion of stationarity assumes that the statistics of future extreme precipitation events will be similar to those of historical observations. This study investigates the consequences of using a stationary assumption as well as the alternative: a non-stationary framework that con- siders temporal changes in statistics of extremes. Here we evaluate stationary and non-stationary return levels for 10-year to 50-year extreme precipitation events for different durations (1-day, 2-day, ..., 7-day precipitation events), based on the observed daily precipitation from Sweden. Non-stationary frequency analysis is only considered for stations with statistically significant trends over the past 50 years at 95% confidence (i.e., 15 to 39 % out of 139 stations, depend- ing on duration, 1-day, 2-day, ..., 7-day). We estimate non-stationary return levels using the General Extreme Value distribution with time-dependent parameters, inferred using a Bayesian approach. The estimated return levels are then compared in terms of duration, recurrence in- terval and location. The results indicate that a stationary assumption might, when a significant trend exists, underestimate extreme precipitation return levels by up to 40 % in Sweden. This report highlights the importance of considering better methods for estimating the recurrence in- terval of extreme events in a changing climate. This is particularly important for infrastructure design and risk reduction.
Ökad extrem nederbörd har dokumenterats globalt, däribland centrala och norra Europa. Den globala uppvärmningen medför en förhöjd medeltemperatur vilket i sin tur ökar avdunstning av vatten från ytor samt atmosfärens förmåga att hålla vatten. Dessa förändringar tros kunna öka och intensifiera nederbörd. Vid bestämning av dimensionerande nederbördsintensiteter för byggnationsprojekt antas idag att frekvensen och storleken av extrem nederbörd inte kommer att förändras i framtiden (stationäritet), vilket i praktiken innebär ingen förändring i klimatet. Den här studien syftar till att undersöka effekten av en icke-stationärt antagande vid skattning av dimensionerande nederbördsintensitet. Icke-stationära och stationära nerderbördsintensiteter föråterkomsttider mellan 10 och 100år bestämdes utifrån daglig och flerdaglig svensk nederbörds- data. Nederbördintensiteterna bestämdes med extremvärdesanalys i mjukvaran NEVA, där den generella extremvärdesfördelningen anpassades till årlig maximum nederbörd på platser i Sverige som påvisade en ökande trend under de senaste 50åren (15% till 39 % utav 139 stationer, beroende på varaktighet). De dimensionerande nederbördsintensiteterna jämfördes sedan med avseende på varaktighet, återkomsttid och plats. Resultaten indikerade på att ett stationärt antagande riskerar att underskatta dimensionerande nederbördsintensiteter för en viss återkomsttid med upp till 40 %. Detta indikerar att antagandet om icke-stationäritet har större betydelse för olika platser i Sverige, vilket skulle kunna ge viktig information vid bestämning av dimensionerande regnintensiteter.

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Clothiaux, John D. "Verification of rain-flow reconstructions of a variable amplitude load history." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-11072008-063531/.

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5

Castillo, Jean M. "Duration-rainfall intensity equations : study of IDF curves using local precipitation data /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1203570521&sid=23&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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Michaud, Aubert Raymond. "Soil erodibility indices for Southern Quebec soils derived under variable intensity rainfall simulation." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66178.

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7

NHAT, Le Minh. "Development of Intensity-Duration-Frequency Relationships Based on Scaling Characteristics of Rainfall Extremes." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/124493.

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West, Derek A. "The use of satellite microwave rainfall measurements to predict eastern North Pacific tropical cyclone intensity." The Ohio State University, 1998. http://catalog.hathitrust.org/api/volumes/oclc/41553838.html.

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Mayeux, Brian Clifford, and Brian Clifford Mayeux. "The relative importance of rainfall intensity versus saturated hydraulic conductivity for runoff modeling of semi-arid watersheds." Thesis, The University of Arizona, 1995. http://hdl.handle.net/10150/626771.

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When using distributed rainfall runoff models in order to simulate the runoff volume and time distribution, one faces the problem of how to represent the spatial distribution of rainfall intensity and soil characteristics when the actual continuous distributions are unknown. There are two objectives for this thesis. The first is to investigate, for semi-arid regions, how the scale of rainfall intensity and soil features affects the simulation of rainfall excess and which is of more importance. The second is to utilize probability distribution theory to develop a scheme which represents both the spatial distribution of rainfall intensi ty and the saturated hydraulic conductivity (Ks) in order to accurately simulate the true runoff for semi-arid regions when knowing limited statistical information (mean and variance) on each feature (rainfall intensity and Ks). All conclusions made are assuming that they hold for semi-arid regions only and the· assumed true watershed output is the model simulation which uses the finest resolution for soil features, vegetation, and rainfall intensity. Furthermore, the model used for this study provided very accurate simulations of the actual streamflow for the watershed used (Walnut Gulch). It was found that, when using real data for rainfall and soils, the spatial distribution for rainfall intensity is more important to represent than that of soil features with respect to accurately reproducing the assumed true streamflow. However, when using synthetic data generated from probability distributions, it was found that, for semi-arid regions, the spatial distribution of Ks was of more importance. Hence, certain conclusions concerning which is more important to spatially characterize with respect to accurately simulating streamflow can be different, depending upon if one uses synthetic data versus real data. The lognormal distribution was found to produce an excellent fit to the Ks data and the exponential distribution was found to produce an excellent fit to the spatial rainfall intensity distribution. However, this goodness-of-fit (for rainfall) can be dependent upon time and/or the amount of localization which the storm possesses. The rainfall parameters for the probability distributions of rainfall intensity were assumed to change with time but were not related at all to location within the watershed. When using the probability distributions to characterize the spatial rainfall intensity and Ks distributions, it was found that characterizing the Ks distribution provided more accurate simulations than characterizing the rainfall intensity distribution. It was also found that spatially characterizing both rainfall intensity and Ks simultaneously provided more accurate simulations than just representing one and not the other.

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McNear, Veronica Ann. "Low-level convergence and its role in convective intensity and frequency over the Houston lightning and rainfall anomaly." Texas A&M University, 2003. http://hdl.handle.net/1969.1/6005.

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An increase in the amount of lightning and rainfall over the Houston area, compared to the surrounding rural areas, has been well documented in previous studies. The placement of a Shared Mobile Atmospheric Research and Teaching Radar (SMART-R) in the Houston area during the summer season of 2005 presented a unique opportunity to investigate the role of boundary-layer convergence in modulating convective frequency and intensity and, thereby, likely causing the rainfall and lightning anomalies. The role of the urban heat island (UHI) and the sea-breeze, as a source of low-level convergence leading to enhanced convection over Houston, was examined. Hourly average dual-Doppler wind and convergence maps were created on 1 X 1 km grids for an eleven-week period. By using these images along with average lightning, rainfall, and reflectivity for a large Houston-centered domain, it was possible to discern a correlation between low-level convergence and convection. Also, past findings of enhancement in lightning and rainfall over Houston and downwind of Houston were validated. High convergence levels for the Houston area in the mid-morning were followed closely by a peak in convection in the early afternoon. The enhancement of rainfall and lightning over and downwind of downtown was found to be primarily from a large increase in frequency of deep convective events when compared to the surrounding domain. Also, it was found that UHI, rather than sea-breeze, was likely the primary causative mechanism in the development of convection over the Houston area because of the lack of deep convection in areas equally affected by the sea-breeze and the timing of the convection compared to time of peak sea-breeze. An area of weaker enhancement south of Houston, not discussed in previous studies, was found to be present, possibly from the interactions between the bay-breeze off of the Galveston Bay and the seabreeze.

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Cooley, Alexis Kirsten. "Detecting Change in Rainstorm Properties from 1977-2016 and Associated Future Flood Risks in Portland, Oregon." PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/3889.

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In response to increased greenhouse gases and global temperatures, changes to the hydrologic cycle are projected to occur and new precipitation characteristics are expected to emerge. The study of these characteristics is facilitated by common indices to measure precipitation and temperature developed by the Expert Team on Climate Change Detection and Indices (ETCCDI). These indices can be used to describe the likely consequences of climate change such as increased daily precipitation intensity (SDII) and heavier rainfall events (R95p). This study calculates a subset of these indices from observed and modelled precipitation data in Portland, Oregon. Five rainfall gages from a high resolution rain gage network and projections from three downscaled global climate models including CanESM2, CESM1, CNRM-CM5 are used to calculate precipitation indices. Mann-Kendall's tau is used to detect monotonic trends in indices. The observational record is compared with models for the historic period (1977-2005) and these past trends are compared with projected future trends (2006-2100). The influence of study unit on trend detection is analyzed by computing trends at the annual and monthly scale. Study unit is shown to be important for trend detection. When the annual study unit is used, projected future trends towards increased precipitation intensity and event volumes are not observed in the historic data. However, when analyzed with a monthly study unit, trends towards increased precipitation intensity and event volumes are observed in the historic data. These trends are shown to be important for Portland area flooding, as precipitation indices are shown to significantly correlate with 40 maximum peak flow events that occurred during the period of study.

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Llabrés, Brustenga Alba. "Intensity-Duration-Frequency of Rainfall in Catalunya. Maximum Expected Precipitation and IDF Relationships at High Temporal and Spatial Resolution." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/668777.

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Intensity - Duration - Frequency (IDF) relationships of extreme precipitation events are of high interest in hydrology. The building of infrastructure or designation of flood zone need, as groundwork, the recurrence intervals at which extreme episodes of rainfall can occur, i.e., the maximum intensities that can be expected for a given duration and return period. In this project 2,142 series of daily rainfall data were analysed and quality controlled after the design of a new specific procedure. The newly proposed quality control is able to classify available rainfall series according to their quality and, using this information, performs a relative comparison with nearby measures to attain a quality category for each daily value (in this project 14,144,395 measures were checked and 74% of them were considered reliable). Afterwards, climatic homogeneity of a selection of series was checked and 163 daily rainfall data series of high quality data in the temporal period 1942-2016 and uniformly distributed over the territory of Catalonia were used in the obtainment of Intensity-Duration-Frequency relationships. The obtainment of IDF was achieved by a temporal monofractal downscaling methodology implemented on a grid of high spatial resolution (1 km x 1 km) of maximum expected intensity in 24 hours. The spatial grid of maximum expected intensity in 24 hours at several return periods (2, 5, 10, 20, 50, 100, 200 and 500 years) was obtained from annual maximum precipitation in one day after correcting daily measures with an empirical factor thoroughly analysed in the scope of the project. The monofractal downscaling methodology was implemented after the obtainment of a single scaling exponent at the 163 selected locations; the scaling exponent was studied in relation to geographical and climatic characteristics of the study area. The final results of IDF relationships are provided as a set of maps that display the maximum expected intensity at a selection of durations (daily and subdaily, namely: 1h, 6h, 12h, 24h and 48h) and for a selection of return periods. The results are of high spatial resolution as they are obtained in a spatial grid of 1 km x 1 km. The results also have high temporal resolution as the intensity - frequency relationship can be calculated at any duration at the locations of the grid nodes using the provided empirical scaling exponent with validity as long as the duration ranges between 1 hour and 15 days.
Les relacions d’Intensitat-Duració-Freqüència (IDF) d’episodis de pluja extrems són de gran interès en hidrologia on es necessita, com a base, els intervals de recurrència en què es donen les precipitacions extremes, és a dir, la intensitat màxima que es pot esperar per una durada i període de retorn determinats. En aquest projecte, es van analitzar 2.142 sèries de precipitació mitjançant un nou control de qualitat especialment dissenyat per a aquestes dades. El control de qualitat proposat és capaç de classificar les sèries de precipitació disponibles segons la qualitat de les dades i, utilitzant aquesta informació, fa una comparació relativa amb mesures properes per assignar una categoria a cada un dels valors diaris (es van analitzar 14.144.395 mesures i un 74% d’elles es consideren bones). També es va realitzar un control d’homogeneïtat climàtica d’una selecció de les sèries disponibles. Per obtenir la relació IDF es va fer una selecció de 163 sèries de precipitació diària de bona qualitat en el període 1942-2016 i uniformement distribuïdes pel territori de Catalunya. Les relacions IDF es van obtenir amb un mètode monofractal de downscaling temporal implementat en un grid d’alta resolució espacial (1 km x 1 km) de la intensitat màxima esperada en 24 hores. Aquest grid espacial per diversos períodes de retorn (2, 5, 10, 20, 50, 100, 200 i 500 anys) es va obtenir a partir de les sèries anuals de màxims de precipitació diària després de corregir les mesures amb un factor de correcció empíric detingudament analitzat dins del projecte. El downscaling temporal monofractal es va implementar havent obtingut un únic exponent d’escala per cada una de les 163 localitats seleccionades; l’exponent d’escala va ser àmpliament estudiat en relació amb les característiques geogràfiques i climàtiques de l’àrea d’estudi. Els resultats finals de les relacions IDF es proporcionen en un conjunt de mapes que mostren la precipitació màxima esperada a una selecció de durades (diàries i subdiàries: 1h, 6h, 12h, 24h i 48h) i per una selecció de períodes de retorn. Els resultats són d’alta resolució espacial perquè s’obtenen en un grid de 1 km x 1 km. Els resultats també són d’alta resolució temporal perquè la relació entre intensitat i freqüència es pot calcular per qualsevol durada en els nodes del grid utilitzant l’exponent d’escala proporcionat (que té validesa entre 1 hora i 15 dies).
La relación de Intensidad-Duración-Frecuencia (IDF) de episodios extremos de lluvia es de gran interés en hidrología, donde se necesitan, como base, los intervalos de recurrencia de precipitaciones extremas, por lo tanto, la intensidad máxima esperada en una duración y período de retorno determinados. En este proyecto, se analizaron 2.142 series de precipitación por medio de un nuevo control de calidad especialmente diseñado para estos datos. El control de calidad propuesto es capaz de clasificar las series de precipitación disponibles según la calidad de los datos y, usando esta información, compara relativamente con medidas cercanas para asignar una categoría a cada valor diario (se analizaron 14.144.395 medidas y un 74% de ellas se consideraron buenas). También se realizó un control de homogeneidad climática de las series disponibles. Para obtener la relación IDF se seleccionaron 163 series de precipitación diaria de buena calidad en el período 1942-2016, uniformemente distribuidas por el territorio de Cataluña. La relación IDF se obtuvo con un método monofractal de downscaling temporal implementado en un grid de alta resolución espacial (1 km x 1 km) de intensidad máxima esperada en 24 horas. Este grid espacial para diferentes períodos de retorno (2, 5, 10, 20, 50, 100, 200 y 500 años) se construyó a partir de las series anuales de máxima precipitación diaria después de corregir las medidas con un factor de corrección empírico detenidamente analizado dentro del proyecto. El downscaling temporal monofractal se implementó tras la obtención de un único exponente de escala para cada una de las 163 localidades seleccionadas; el exponente de escala fue ampliamente estudiado en relación con las características geográficas y climáticas del área de estudio. Los resultados finales de la relación IDF se proporcionan en un conjunto de mapas que muestran la precipitación máxima esperada en una selección de duraciones (diarias y subdiarias: 1h, 6h, 12h, 24h y 48h) y para una selección de períodos de retorno. Los resultados son de alta resolución espacial porque se obtienen en un grid de 1km x 1km. Los resultados también son de alta resolución temporal porque la relación entre intensidad y frecuencia se puede calcular para cualquier duración en los nodos del grid usando el exponente de escala proporcionado (valido entre 1 hora y 15 días).

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Tao, Cheng. "Climatology of overshootings in tropical cyclones and their roles in tropical cyclone intensity changes using TRMM data." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2457.

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The climatology of overshooting convection in tropical cyclones (TCs) is examined using Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). The percentage of TC convective systems with overshooting convection is highest over the North Indian Ocean basin, while the northwest Pacific basin contains the highest population of both TC convective systems and convection with overshooting tops. Convective systems in the inner core region are more capable of penetrating 14 km and the associated overshooting convection are featured with much stronger overshooting properties compared with those in the inner rainband and outer rainband regions. In the inner core region of TCs, convection associated with precipitating systems of higher intensity and intensification rates has a larger probability of containing overshooting tops. To identify the relative importance of shallow/moderate versus deep/very deep convection in the rapid intensification (RI) of TCs, four types of precipitation-convection are defined based on the 20 dBZ radar echo height (Z20dBZ). Distributions of four types of precipitation-convection, and their contributions to total volumetric rain and total latent heating are quantified. It is shown that RI is closely associated with increased and widespread shallow precipitation around the storm center, while moderately deep and very deep convection (or overshooting convection) does not increase until in the middle of RI. This is further confirmed by the study of rainfall and convection evolution with respect to the timeline of RI events. Statistically, the onset of RI follows a significant increase in the areal coverage of rainfall, shallow precipitation, and cyan of 37 GHz color composites upshear-left, which in turn could be used as potential parameters to forecast RI. Very deep convection is most frequent 12-24 hours before RI onset and concentrates upshear-left, but it quickly decreases in the following 24 hours. The percent occurrence of very deep convection is less than 1% for RI storms. The tilt of vortex is large prior to, and near the RI onset, but rapidly decreases in the middle of RI, suggesting that the vertical alignment is a result instead of a trigger of RI.

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Bobe, Bedadi Woreka. "Evaluation of soil erosion in the Harerge region of Ethiopia using soil loss models, rainfall simulation and field trails." Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-08022004-141533.

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Zhang, Jie, and s3069216@student rmit edu au. "A laboratory scale study of infiltration from Pervious Pavements." RMIT University. Civil, Environmental and Chemical Engineering, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070125.164003.

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Increased urbanization causes pervious greenfields to be converted to impervious areas increasing stormwater runoff. Most of the urban floods occur because existing drainage systems are unable to handle peak flows during rainfall events. During a storm event, flood runoff will carry contaminants to receiving waters such as rivers and creeks. Engineers and scientists have combined their knowledge to introduce innovative thinking to manage the quality of urban runoff and harvest stormwater for productive purposes. The introduction of pervious pavements addresses all the principles in Water Sensitive Urban Design. A pervious pavement is a load bearing pavement structure that is permeable to water. The pervious layer sits on the top of a reservoir storage layer. Pervious pavements reduce the flood peak as well as improve the quality of stormwater at source before it is transported to receiving waters or reused productively. To be accepted as a viable solution, understanding of the influence of design parameters on the infiltration rate (both from the bedding and the sub-base) as well as strength of the pavement requires to be established. The design of a particular pavement will need to be customized for different properties of sub layer materials present in different sites. In addition, the designs will have to meet local government stormwater discharge standards. The design of drainage systems underneath pervious pavements will need to be based on the permeability of the whole pervious system. The objectives of the research project are to: Understand the factors influencing infiltration capacities and percolation rates through the pervious surface as well as the whole pavement structure including the bedding and the sub-base using a laboratory experimental setup. Obtain relationships between rainfall intensity, infiltration rate and runoff quantity based on the sub-grade material using a computational model to assist the design of pervious pavements. A laboratory scale pavement was constructed to develop relationships between the surface runoff and the infiltration volume from a pervious pavement with an Eco-Pavement surface. 2 to 5mm crushed gravel and 5 to 20mm open graded gravel were chosen as the bedding and sub-base material. Initial tests such as dry and wet density, crushing values, hydraulic conductivity, California Bearing Ratio tests for aggregate material were conducted before designing and constructing the pavement model. A rainfall simulator with evenly spaced 24 sprays was set up above the pervious pavement surface. The thesis presents design aspects of the laboratory scale pavement and the tests carried out in designing the pavement and the experimental procedure. The Green and Ampt model parameters to calculate infiltration were obtained from the laboratory test results from aggregate properties. Runoff results obtained from rainfall simulator tests were compared with the Green and Ampt infiltration model results to demonstrate that the Green and Ampt parameters could be successfully calculated from aggregate properties. The final infiltration rate and the cumulative infiltration volume of water were independent of the rainfall intensity once the surface is saturated. The model parameters were shown to be insensitive to the final infiltration capacity and to the total amount of infiltrated water. The Green and Ampt infiltration parameters are the most important parameters in designing pervious pavements using the PCSWMMPP model. The PCSWMMPP model is a Canadian model built specially for designing pervious pavements. This is independent of the type of sub-grade (sand or clay) determining whether the water is diverted to the urban drainage system (clay sub-grade) or deep percolation into the groundwater system (sand sub-grade). The percolation parameter in Darcy's law is important only if the infiltrated water recharges the groundwater. However, this parameter is also insensitive to the final discharge through the subgrade to the groundwater. The study concludes by presenting the design characteristics influencing runoff from a pervious pavement depending on the rainfall intensity, pavement structure and sub-grade material and a step-by step actions to follow in the design.

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Choi, Daniel Mintae. "Rainfall intensity and soil erosion by water : limitations of current erosion models and implications for erosion model-based studies under future climates." Thesis, University of Oxford, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604890.

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Existing simulation studies of the effects of future climate change upon erosion indicate that, under land usages that leave the soil unprotected, even minor increases in rainfall amounts are likely to result in disproportionately large increases in erosion, but commonly make the simplifying assumption that distributions of future rainfall intensities remain unchanged from the present. This research aims to determine implications of rainfall -intensity changes on soil erosion using computerised models. Thus, this thesis is a step towards the ultimate goal of predicting future rates of soil erosion caused by future rainfall intensity changes. Three soil erosion models, WEPP, EUROSEM, and RillGrow are employed to investigate impacts of various rainfall intensities on runoff and soil loss rates. Two extreme daily rainfall events in summer and autumn are subjectively selected from the tipping-bucket rainfall data, and runoff and soil losses are simulated using three erosion models. Estimated runoff and soil loss rates with high resolution rainfall data are greater than those with low temporal resolution rainfall data. Within-Storm Intensity Patterns (WSIPs) affect soil erosion amount, although runoff was not much affected. An additional daily rainfall event with Within-Storm Gaps (WSGs) is also selected to investigate effects of WSG removals on soil erosion. For a given amount of rainfall, events with constant low intensity (constant WSIP) produced dramatically less erosion: thus it appears that assuming a constant (or averaged) intensity throughout a storm does not provide a good representation of a real rainfall with its continuously varying intensity. Analyses of outputs from WEPP simulations revealed a problem that WEPP modifies original rainfall intensity and, thus, simulates erroneous runoff and erosion rates. Future soil erosion rates are estimated using WEPP and CLIGEN data. 30 year-long weather is generated by CLIGEN. Likely future rainfall frequency and intensity are anticipated by changing the mean maximum 30 minutes peak intensity also known as MX.SP. No fu ture rainfall amount change is assumed. WEPP simulation results suggest that where mean maximum 30-min peak intensity of the wet months increases soil erosion increases at a greater rate than runoff. This research assists in improving the performance of erosion models with respect to changes of rainfall intensity by highlighting where current problem exists. In conclusion, greater knowledge found here will, once future changes in rainfall intensity become better known and appropriate rainfall data become available, improve our ability to estimate future rates of erosion.

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Jobin, Erik. "An Urban Rainfall Storm Flood Severity Index." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24124.

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Extreme rainfall statistics are important for the design and management of the water resource infrastructure. The standard approach for extreme rainfall event severity assessment is the Intensity-Duration-Frequency (IDF) method. However, this approach does not consider the spatial context of rainfall and consequently does not properly describe rainfall storm severity, nor rarity. This study provides a critical account of the current standard practice and presents an approach that takes into consideration both the spatial context of rainfall storms, and indirectly incorporates runoff to produce a representative approach to assessing urban rainfall storm severity in terms of flood potential. A stepwise regression analysis was performed on a dataset of individual rainfall storm characteristics to best represent documented basement floodings in the City of Edmonton. Finally, the urban rainfall storm flood severity index was shown to be most representative of the documented basement floodings' severity when compared to that of the IDF method.

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Loganbill, Andrew Wood. "Post-fire Response of Little Creek Watershed: Evaluation of Change in Sediment Production and Suspended Sediment Transport." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1028.

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The Little Creek watershed was assessed to identify changes in event-based suspended sediment export and determine the factors contributing to sediment production the first year following the Lockheed Fire in 2009. The amount and volume of near-stream sediment sources were found to decrease, while an increase in hillslope sediment production was documented. High intensity, short duration rainfall (up to 87 mm/hr for 10 minute duration) initiated extensive rilling and minor channel-derived debris torrents originating from the upper south facing slopes. Rainfall simulations, hillslope erosion plots, and soil infiltration tests indicated that fire produced soil water repellency, the lack of ground cover, steep slopes, and high soil burn severity were the most influential factors contributing to hillslope erosion. Contrary to results reported in other western U.S. studies, regression analyses determined that the effect of fire significantly decreased suspended sediment concentrations with higher flows at North Fork and Upper North Fork monitoring stations. The effect of the fire did not produce increases in stormflow volumes and event sediment load, likely due to the fact near-stream sediment contribution was minimal and the majority of hillslope-derived sediment sources were not hydrologically connected. This study provides valuable information for landowners and land managers to understand how a coastal redwood dominated watershed responds to wildfire and prepare post-fire mitigation efforts following future wildfires.

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Montebeller, Claudinei Antonio. "Influência dos perfis de precipitação nas perdas de solo e água." Universidade Federal de Viçosa, 2009. http://locus.ufv.br/handle/123456789/661.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
Rainfall is considered the main climatic factor related to the degradation of agricultural lands, and among their characteristics the intensity stands out as the main conditioning factor of the erosive process. The present work had the objective of evaluating the influence of different precipitation profiles in the soil and water losses. Four precipitation profiles were considered: exponential negative, forwarded double exponential, delayed double exponential and a profile with constant intensity, being the total applied depth of 55 mm and duration of 30 min. The simulator was installed in an experimental area with Inceptsol. The treatments consisted in the simulation of the four precipitation profiles in conditions of bare soil, applied three times in 24 h-intervals, characterizing three initial conditions of soil moisture: low, medium and high. Thus the treatments were defined based on the combination of the precipitation profiles and the conditions of initial soil moisture, using six replications. It was used a completely randomized design, and the water and soil losses data were submitted to the analysis of variance (ANOVA) and the Tukey's test (5%). During the first application, which consisted in the simulation of rains in soils with low initial moisture there was not superficial runoff, consequently there was not soil loss. In the second application, where the soils were with intermediate initial moisture, differences among the treatments were not obtained due to the high variability observed. In the third application, statistically significant differences among the treatments were found for soils with conditions of high moisture. The largest losses of water and soil were obtained with the negative exponential profile, followed by the delayed, forwarded and constant profiles. Therefore, it was possible to conclude that there was influence of the precipitation profiles on the soil and water losses, however only for the treatments with soils of high moisture.
A precipitação é considerada o principal fator climático relacionado à degradação de terras agrícolas e, entre suas características, a intensidade se destaca como o principal fator condicionador do processo erosivo. O presente trabalho teve por objetivo avaliar a influência de diferentes perfis de precipitação nas perdas de solo e água. Foram definidos quatro perfis de precipitação: exponencial negativo, duplo exponencial adiantado, duplo exponencial atrasado e um perfil com intensidade constante, que foram aplicados por meio de um simulador de chuvas, sendo uma lâmina total de 55 mm e duração de 30 min comum a todos os perfis. O simulador foi instalado em uma área experimental cujo solo foi classificado como Cambissolo Háplico. Os tratamentos consistiram na simulação dos quatro perfis de precipitação em condições de solo descoberto, aplicados por três vezes em intervalos de 24 h, caracterizando três condições iniciais de umidade do solo: baixa, intermediária e alta. Assim, os tratamentos foram definidos pela combinação dos perfis de precipitação e das condições de umidade inicial do solo, sendo realizadas para cada um deles seis repetições. O delineamento experimental utilizado foi o inteiramente casualizado (DIC) e os totais de perdas de água e solo submetidos à análise de variância (ANOVA) e ao teste de Tukey (5%). Durante a primeira aplicação, que consistiu na simulação de chuvas em solos com baixa umidade inicial, não houve escoamento superficial e, consequentemente, não ocorreram perdas de solo. Na segunda aplicação, condição em que os solos se encontravam com umidade inicial intermediária, não foram obtidas diferenças estatisticamente significativas entre os tratamentos devido à alta variabilidade observada. Na terceira aplicação foram encontradas diferenças estatisticamente significativas entre os tratamentos, para solos com condições de umidade próxima à saturação. As maiores perdas de água e de solo foram obtidas para o perfil exponencial negativo, seguido pelos perfis duplo exponencial atrasado, adiantado e o constante. Assim, foi possível concluir que houve influência dos perfis de precipitação nas perdas de solo e água, porém apenas para os tratamentos com umidade do solo próxima a saturação.

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Bazzano, Marcos Gabriel Peñalva. "Erosividade, coeficiente de chuva, padrões e período de retorno das chuvas de Quaraí e Rio Grande, RS." Universidade Federal de Santa Maria, 2005. http://repositorio.ufsm.br/handle/1/5489.

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The rainfall specifics characteristics vary from one region to another. The knowledge of the rainfall potential to cause erosion is necessary to plan agricultural and civil engineering activities. For Quarai and Rio Grande (RS, Brazil), were determined the rainfall erosivity and its relationship with precipitation and rainfall coefficient, rainfall patterns and rainfall return period. Were used rainfall data charts of 38 years of Quarai (1966-2003) and 23 years of Rio Grande (1957, 1959-1978 e 1980-1981). For each erosive rainfall were separated the segments of the rainfall chart with the same intensity and the data registered in worksheet. With the software Chuveros were estimated the mean monthly and annual rainfall erosivity, the EI30 index in the International System of Units and the rainfall patterns. The mean monthly values of precipitation and erosivity index were expressed as percentages of the mean annual values of precipitation and erosivity index, respectively, to obtain the curve of accumulated distribution of precipitation and erosivity index in function of time. The rainfall coefficient (Rc) was calculated. Were performed Pearson correlations and linear regressions between the erosivity index EI30 and the mean annual values of precipitation and rainfall coefficient.. The rainfall return period were calculated for 2, 5, 10, 20, 50 e 100 years. The mean annual values of EI30 for Quarai and Rio Grande were 9292.1 e 5135.0 MJ mm ha-1 h-1 ano-1, respectively. Were obtained the equations EI30 = -754.37 + 13.50 p (r2 = 0.85) e EI30 = - 47.35 + 82.72 Rc (r2 = 0.84) for Quarai. For Rio Grande the equations were not significant. In relation to the total of the rainfalls studied for each place, 44.3% of the number and 90.4% of the volume were erosive in Quarai, and 32.6% of the number and 99.3% of the volume were erosive in Rio Grande. The method of extreme distribution type I was adequate for obtaining the curves of intensity-duration-frequency. The rainfall return periods may be calculated by the equations using the values of the parameters found, or by the figures of intensity-durationfrequency.
As características específicas das chuvas variam de uma região a outra. O conhecimento da potencialidade das chuvas em causar erosão é necessário para planejar atividades agrícolas e de engenharia civil. Para as localidades de Quarai e Rio Grande (RS), foram determinados a erosividade da chuva e a relação com a precipitação e o coeficiente de chuva, os padrões da chuva e o período de retorno da chuva. Utilizaram-se dados pluviográficos de 38 anos de Quarai (1966-2003) e 23 anos de Rio Grande (1957, 1959-1978 e 1980-1981). Para cada chuva erosiva foram separados os segmentos do pluviograma com a mesma intensidade e registrados os dados em planilha. Com o programa Chuveros foram calculadas a erosividade mensal, anual e média das chuvas pelo índice EI30 no Sistema Internacional de Unidades e os padrões de chuva. Os valores médios mensais da precipitação e do índice de erosividade foram expressos como percentagens do valor médio anual da precipitação e do índice de erosividade respectivamente, para obter a curva de distribuição acumulada da precipitação e do índice de erosividade em função do tempo. O coeficiente de chuva (Rc) foi calculado. Foram realizadas correlações de Pearson e regressões lineares simples entre o índice de erosividade EI30 e os valores médios anuais de precipitação e de coeficiente de chuva. O período de retorno foi calculado para 2, 5, 10, 20, 50 e 100 anos. Os valores médios anuais de EI30 para Quarai e Rio Grande foram 9292,1 e 5135,0 MJ mm ha-1 h-1 ano-1, respectivamente. Para Quarai, obtiveram-se as equações EI30 = -754,37 + 13,50 p (r2 = 0,85) e EI30 = -47,35 + 82,72 Rc (r2 = 0,84). Para Rio Grande as equações não foram significativas. Em relação ao total das chuvas estudadas em cada localidade, 44,3% do número e 90,4% do volume foram erosivas em Quarai, e 32,6% do número e 99,3% do volume foram erosivas em Rio Grande. O método da distribuição extrema tipo I foi adequado para obter as curvas de intensidade duração-freqüência. Os períodos de retorno da chuva podem ser calculados através das equações utilizando os valores dos parâmetros achados, ou pelos gráficos das curvas de intensidade-duração-freqüência.

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21

Garcia, Joema Ferreira da Costa. "An?lise da precipita??o no semi-?rido potiguar." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15980.

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The semiarid rainfall regime is northeastern Brazil is highly variable. Climate processes associated with rainfall are complex and their effects may represent extreme situations of drought or floods, which can have adverse effects on society and the environment. The regional economy has a significant agricultural component, which is strongly influenced by weather conditions. Maximum precipitation analysis is traditionally performed using the intensity-duration-frequency (IDF) probabilistic approach. Results from such analysis are typically used in engineering projects involving hydraulic structures such as drainage network systems and road structures. On the other hand, precipitation data analysis may require the adoption of some kind of event identification criteria. The minimum inter-event duration (IMEE) is one of the most used criteria. This study aims to analyze the effect of the IMEE on the obtained rain event properties. For this purpose, a nine-year precipitation time series (2002- 2011) was used. This data was obtained from an automatic raingauge station, installed in an environmentally protected area, Ecological Serid? Station. The results showed that adopted IMEE values has an important effect on the number of events, duration, event height, mean rainfall rate and mean inter-event duration. Furthermore, a higher occurrence of extreme events was observed for small IMEE values. Most events showed average rainfall intensity higher than 2 mm.h-1 regardless of IMEE. The storm coefficient of advance was, in most cases, within the first quartile of the event, regardless of the IMEE value. Time series analysis using partial time series made it possible to adjust the IDF equations to local characteristics
O regime pluviom?trico no semi-?rido Nordestino ? altamente vari?vel. Os processos clim?ticos associados ?s precipita??es s?o complexos e seus efeitos podem representar situa??es limites de seca ou enchentes, os quais podem ter efeitos negativos para a sociedade e meio ambiente. A economia da regi?o, com forte componente agr?rio, ? fortemente impactada pelas condi??es clim?ticas. A an?lise de chuvas intensas ? feita tradicionalmente utilizando as equa??es tipo intensidadedura??o- freq??ncia (IDF). Os resultados obtidos nesses estudos s?o usados em projetos de engenharia envolvendo obras hidr?ulicas, tais como rede de drenagem e obras vi?rias. Por outro lado, a an?lise dos dados de precipita??o pode exigir a ado??o de algum tipo de crit?rio de identifica??o de eventos. Um dos crit?rios mais usados ? o intervalo m?nimo entre eventos (IMEE). Este estudo tem o objetivo de analisar o efeito do IMEE nas caracter?sticas dos eventos de precipita??o. Para isso, foi usada uma serie hist?rica de precipita??o com 9 anos de registros (2002-2011). Os dados foram registrados numa esta??o pluviogr?fica autom?tica instalada na Esta??o Ecol?gica do Serid?. Os resultados demonstraram que o valor do IMEE adotado tem um efeito importante no numero de eventos, dura??o, altura precipitada, intensidade m?dia e no intervalo m?dio entre eventos. Al?m disso, verificou-se uma maior ocorr?ncia de eventos extremos para pequenos valores de IMEE. A maioria dos eventos apresentou intensidade m?dia acima de 2 mm/h, independente do IMEE adotado. O coeficiente de avan?o da tormenta situou-se, na maioria dos casos, no primeiro quartil do evento, independente do valor do IMEE. A an?lise probabil?stica dos dados observados utilizando s?ries parciais possibilitou o ajuste de equa??es IDF caracter?sticas do local

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22

Bobe, Bedadi Woreka. "Evaluation of soil erosion in the Harerge region of Ethiopia using soil loss models, rainfall simulation and field trials." Thesis, University of Pretoria, 2004. http://hdl.handle.net/2263/26929.

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Accelerated soil erosion is one of the major threats to agricultural production in Ethiopia and the Harerge region is not exceptional. It is estimated that about 1.5 billion tones of soil is being eroded every year in Ethiopia. In the extreme cases, especially for the highlands, the rate of soil loss is estimated to reach up to 300 t ha-1yr-1 with an average of about 70 t ha -1yr-1 which is beyond any tolerable level. The government have made different attempts to avert the situation since 1975 through initiation of a massive program of soil conservation and rehabilitation of severely degraded lands. Despite considerable efforts, the achievements were far bellow expectations. This study was aimed at assessing the effect of some soil properties, rainfall intensity and slope gradients on surface sealing, soil erodibility, runoff and soil loss from selected sites in the Harerge region, eastern Ethiopia, using simulated rainfall. Soil loss was also estimated for the sites using Soil Loss Estimation Model for Southern Africa (SLEMSA) and the Universal soil Loss Equation (USLE). Moreover, the effectiveness of various rates and patterns of wheat residue mulching in controlling soil loss was also evaluated for one of the study sites, (i.e. Regosol of Alemaya University), under both rainfall simulation and field natural rainfall conditions. For most of the erosion parameters, the interaction among soil texture, slope gradient and rainfall intensity was significant. In general however, high rainfall intensity induced high runoff, sediment yield and splash. The effect of slope gradients on most of the erosion parameters was not significant as the slope length was too small to bring about a concentrated flow. The effect of soils dominated by any one of the three soil separates on the erosion parameters was largely dependent on rainfall intensity and slope gradient. The soils form the 15 different sites in Harerge showed different degrees of vulnerability to surface sealing, runoff and sediment yield. These differences were associated with various soil properties. Correlation of soil properties to the erosion parameters revealed that aggregate stability was the main factor that determined the susceptibility of soils to sealing, runoff and soil loss. This was in turn affected by organic carbon content, percent clay and exchangeable sodium percentage (ESP). Soils with relatively high ESP such as those at Babile (13.85) and Gelemso (7.18) were among the lowest in their aggregate stability (percent water stable aggregates of 0.25 –2.0mm diameter); and have highest runoff and sediment yield as compared to other soils in the study. Similarly, most of those soils with relatively low ESP, high organic carbon content (OC%) and high water stable aggregates such as Hamaressa, AU (Alemaya University) vertisol and AU regosol were among the least susceptible to sealing and interrill erosion. Nevertheless, some exceptions include soils like those of Hirna where high runoff was recorded whilst having relatively high OC%, low ESP and high water stable aggregates. Both the SLEMSA and USLE models were able to identify the erosion hazards for the study sites. Despite the differences in the procedures of the two models, significant correlation (r = 0.87) was observed between the values estimated by the two methods. Both models estimated higher soil loss for Gelemso, Babile, Karamara and Hamaressa. Soil loss was lower for Diredawa, AU-vertisol and AU-Alluvial all of which occur on a relatively low slope gradients. The high soil loss for Babile and Gelemso conforms with the relative soil erodibility values obtained under rainfall simulation suggesting that soil erodibility, among others, is the main factor contributing to high soil loss for these soils. The difference in the estimated soil losses for the different sites was a function of the interaction of the various factors involved. Though the laboratory soil erodibility values were low to medium for Hamaressa and Karamara, the estimated soil loss was higher owing to the field topographic situations such as high slope gradient. SLEMSA and USLE showed different degrees of sensitivities to their input variables for the conditions of the study sites. SLEMSA was highly sensitive to changes in rainfall kinetic energy (E) and soil erodibility (F) and less sensitive to the cover and slope length factors. The sensitivity of SLEMSA to changes in the cover factor was higher for areas having initially smaller percentage rainfall interception values. On the other hand, USLE was highly sensitive to slope gradient and less so to slope length as compared to the other input factors. The study on the various rates and application patterns of wheat residue on runoff and soil loss both in the laboratory rainfall simulation and under field natural rainfall conditions revealed that surface application of crop residue is more effective in reducing soil loss and runoff than incorporating the same amount of the residue into the soil. Likewise, for a particular residue application method, runoff and soil loss decreased with increasing application rate of the mulch. However, the difference was not significant between 4 Mg ha-1 and 8 Mg ha-1 wheat straw rates suggesting that the former can effectively control soil loss and can be used in areas where there is limitation of crop residues provided that other conditions are similar to that of the study site (AU Regosols). The effectiveness of lower rates of straw (i.e. less than 4 Mg ha-1 ) should also be studied. It should however be noted that the effectiveness of mulching in controlling soils loss and runoff could be different under various slope gradients, rainfall characteristics and cover types that were not covered in this study. Integrated soil and water conservation research is required to develop a comprehensive database for modelling various soil erosion parameters. Further research is therefore required on the effect of soil properties (with special emphasis to aggregate stability, clay mineralogy, exchangeable cations, soil texture and organic matter), types and rates of crop residues, cropping and tillage systems, mechanical and biological soil conservation measures on soil erosion and its conservation for a better estimation of the actual soil loss in the study sites. Copyright 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bobe, BW 2004, Evaluation of soil erosion in the Harerge region of Ethiopia using soil loss models, rainfall simulation and field trials, PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-08022004-141533 / >
Thesis (PhD (Soil Science))--University of Pretoria, 2004.
Plant Production and Soil Science
unrestricted

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Russell, Frances Marion. "Semi-permanent zones of radar radial shear within the planetary boundary layer : observations and effects on high intensity precipitation in the wider Auckland region, New Zealand : a thesis submitted to the Victoria University of Wellington in partial fulfilment of the requirements for the degree of Master of Science in Geophysics /." ResearchArchive@Victoria e-Thesis, 2009. http://hdl.handle.net/10063/1215.

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DI, NAPOLI MARIANO. "Spatial prediction of landslide susceptibility/intensity through advanced statistical approaches implementation: applications to the Cinque Terre (Eastern Liguria, Italy)." Doctoral thesis, Università degli studi di Genova, 2022. http://hdl.handle.net/11567/1076506.

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Landslides are frequently responsible for considerable huge economic losses and casualties in mountainous regions especially nowadays as development expands into unstable hillslope areas under the pressures of increasing population size and urbanization (Di Martire et al. 2012). People are not the only vulnerable targets of landslides. Indeed, mass movements can easily lay waste to everything in their path, threatening human properties, infrastructures and natural environments. Italy is severely affected by landslide phenomena and it is one of the most European countries affected by this kind of phenomena. In this framework, Italy is particularly concerned with forecasting landslide effects (Calcaterra et al. 2003b), in compliance with the National Law n. 267/98, enforced after the devastating landslide event of Sarno (Campania, Southern Italy). According to the latest Superior Institute for the Environmental Protection and Research (ISPRA, 2018) report on "hydrogeological instability" of 2018, it emerges that the population exposed to landslides risk is more than 5 million and in particular almost half-million falls into very high hazard zones. The slope stability can be compromised by both natural and human-caused changes in the environment. The main reasons can be summarised into heavy rainfalls, earthquakes, rapid snow-melts, slope cut due to erosions, and variation in groundwater levels for the natural cases whilst slopes steepening through construction, quarrying, building of houses, and farming along the foot of mountainous zone correspond to the human component. This Ph.D. thesis was carried out in the Liguria region, inside the Cinque Terre National Park. This area was chosen due to its abundance of different types of landslides and its geological, geomorphological and urban characteristics. The Cinque Terre area can be considered as one of the most representative examples of human-modified landscape. Starting from the early centuries of the Middle Ages, local farmers have almost completely modified the original slope topography through the construction of dry-stone walls, creating an outstanding terraced coastal landscape (Terranova 1984, 1989; Terranova et al. 2006; Brandolini 2017). This territory is extremely dynamic since it is characterized by a complex geological and geomorphological setting, where many surficial geomorphic processes coexist, along with peculiar weather conditions (Cevasco et al. 2015). For this reason, part of this research focused on analyzing the disaster that hit the Cinque Terre on October, 25th, 2011. Multiple landslides took place in this occasion, triggering almost simultaneously hundreds of shallow landslides in the time-lapse of 5-6 hours, causing 13 victims, and severe structural and economic damage (Cevasco et al. 2012; D’Amato Avanzi et al. 2013). Moreover, this artificial landscape experienced important land-use changes over the last century (Cevasco et al. 2014; Brandolini 2017), mostly related to the abandonment of agricultural activity. It is known that terraced landscapes, when no longer properly maintained, become more prone to erosion processes and mass movements (Lesschen et al. 2008; Brandolini et al. 2018a; Moreno-de-las-Heras et al. 2019; Seeger et al. 2019). Within the context of slope instability, the international community has been focusing for the last decade on recognising the landslide susceptibility/hazard of a given area of interest. Landslide susceptibility predicts "where" landslides are likely to occur, whereas, landslide hazard evaluates future spatial and temporal mass movement occurrence (Guzzetti et al., 1999). Although both definitions are incorrectly used as interchangeable. Such a recognition phase becomes crucial for land use planning activities aimed at the protection of people and infrastructures. In fact, only with proper risk assessment governments, regional institutions, and municipalities can prepare the appropriate countermeasures at different scales. Thus, landslide susceptibility is the keystone of a long chain of procedures that are actively implemented to manage landslide risk at all levels, especially in vulnerable areas such as Liguria. The methods implemented in this dissertation have the overall objective of evaluating advanced algorithms for modeling landslide susceptibility. The thesis has been structured in six chapters. The first chapter introduces and motivates the work conducted in the three years of the project by including information about the research objectives. The second chapter gives the basic concepts related to landslides, definition, classification and causes, landslide inventory, along with the derived products: susceptibility, hazard and risk zoning, with particular attention to the evaluation of landslide susceptibility. The objective of the third chapter is to define the different methodologies, algorithms and procedures applied during the research activity. The fourth chapter deals with the geographical, geological and geomorphological features of the study area. The fifth chapter provides information about the results of the applied methodologies to the study area: Machine Learning algorithms, runout method and Bayesian approach. Furthermore, critical discussions on the outcomes obtained are also described. The sixth chapter deals with the discussions and the conclusions of this research, critically analysing the role of such work in the general panorama of the scientific community and illustrating the possible future perspectives.

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Herůfek, Marek. "Vývoj metody pro hodnocení retenčních vlastností vegetačních střech." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240252.

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This diploma thesis deals with the development of methods for evaluating retention features of green roofs. For the purpose of this thesis, a rainfall simulator was designed and various types of precipitation were examined. The thesis is divided into two main parts: a theoretical part and a practical part. In the theoretical part, the importance of water retention on green roofs is discussed. In addition, a physical theory related to this topic is included and various rainfall simulators used for scientific experiments in the Czech Republic and abroad are described. The practical part deals with the measurement of droplet size and rainfall simulator design. In this part, the process of measuring the flow and the intensity of rainfall by using scales, flow meter and rain gauge is described. For this purpose, a datalogger was developed by the Faculty of Eletrical Engineering in Brno. Finally, the results are sumarized and recommendations on how to conduct the research in the future are provided.

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Melese, Victor. "Modélisation multi-échelle de l'aléa pluviométrique et incertitudes associées - Application à la région des Cévennes." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAU008/document.

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La thèse présentée s'intéresse à la modélisation de l'aléa pluviométrique dans la région du Sud-Est de la France centrée sur les Cévennes. Cette région connait régulièrement des crues rapides et très localisées appelées crues éclair qui ont des impacts socio-économiques considérables. Une mesure statistique de l'aléa est la fréquence d'occurrence ou, de manière équivalente, la période de retour. La pluie étant un phénomène qui s'accumule non uniformément dans le temps et dans l'espace, l'aléa pluviométrique est une variable multi-échelle. Cette thèse vise à en proposer une modélisation intégrée pour la région du Sud-Est de la France, c'est à dire valide pour le continuum d'échelles spatio-temporelles.La première partie de ces travaux permet de comprendre quel cadre d'inférence est le plus adapté à cette modélisation. La seconde partie propose un modèle permettant d'exprimer l'aléa pluviométrique sur le continuum d'échelles spatio-temporelles. Enfin, le troisième partie propose un cadre de quantification multi-échelle (en temps et en espace) de fréquence d'occurrence d'un événement pluviométrique donné ainsi que la quantification des incertitudes associées
This thesis aims at modelling the rainfall hazard in a mountainous region of southeastern France centered on the Cévennes massif. This region undergoes intense rainfall events leading to flash floods, which have considerable socio-economics impacts. A statistical measure of hazard is the frequency of occurrence, or equivalently the return period. Since rainfall accumulates in both time and space, rainfall hazard in a multi-scale variable. This thesis propose a generic framework for rainfall hazard modelling over the continuum of spatio-temporal scales.The first part of this work allows to determine which is the most relevant statistical framework. The second part proposes a multi scale modelling of rainfall hazard for the region. Finally, the third part allows the multi-scale quantification of the frequency of occurrence of a given storm and of the related uncertainties

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Santa, Cleiton Dalla. "PERDAS DE ÁGUA POR ESCOAMENTO SUPERFICIAL DE UM SOLO COM DIFERENTES NÍVEIS DE RESÍDUOS VEGETAIS E DECLIVIDADES DO TERRENO." Universidade Federal de Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/7526.

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The search for information and technology that can contribute for an adequate management of soil and water utilization has been in an increasing need, as their conservation is of great matter for a sustainable agriculture. The goal of the present work was determining and modelling the water losses through surface runoff, of a soil with different levels of crop residue and declivity, using simulated rainfall. The work was conducted inside an area for experiments of the Departamento de Engenharia Rural da UFSM, in four locations, which had slope of zero, 2.5, 5 e 8%, respectively. The design of the experiment was completely randomized, with three levels of crop residue of oat in the surface (0, 2.5 e 5 Mg ha-1) in three replicates. The parcels of the experiment of 0.5 m2 were delimited using galvanized metal sheets implanted in the soil with a gutter at the bottom, to collect the water of the surface runoff (measuring in 5 minutes intervals). The rainfall intensities of 30, 80 and 120 mm h-1 were applied using a rainfall simulator of multiple and oscillating nozzles, doing two simulations (Rainfall 1 and 2, applied alternately each day) in each slope for each intensity. For each simulated rainfall it was determined the starting time and the runoff rate, besides rain (amount, duration and intensity), initial humidity and soil saturation. For estimating the surface runoff, it was used the modified Smith model. The model parameters were adjusted through multivariate equations. In the Rainfall 1, with intensity of 30 mm h-1 there was no runoff for the zero slope, and for the remaining slopes, the runoff represented 1.0, 8.8 e 11.5% of the amount of rain applied. In the rainfalls with intensity of 80 and 120 mm h-1, the water losses through surface runoff represented about 59 and 53% of the amount of rain applied, respectively. In Rainfall 2, the water losses through surface runoff represented 33, 45 e 73%, of the amount applied, respectively, for the intensities of 30, 80 and 120 mm h-1. The presence of crop residue delays the start of surface runoff and reduces the surface runoff rate, for different rain intensities (30, 80 e 120 mm h-1) and slope steepness (zero, 2.5, 5 and 8%). The multivariate equations generated from the rain characteristics and soil humidity showed good precision in estimating the surface runoff rate and the starting time of the runoff.
A conservação da água e do solo constitui um aspecto de grande relevância para uma produção agrícola mais sustentável, assim, a busca de tecnologias e informações que contribuam para um adequado manejo do solo e o uso da água se faz cada vez mais necessária. O objetivo desse trabalho foi determinar e modelar as perdas de água por escoamento superficial, de um solo com diferentes níveis de resíduos vegetais na superfície e declividades do terreno, a partir de chuvas simuladas. O trabalho foi desenvolvido em área experimental do Departamento de Engenharia Rural da UFSM, em quatro locais, os quais possuíam declividades de zero, 2,5, 5 e 8%, respectivamente. O delineamento experimental utilizado foi o inteiramente casualizado, com três níveis de resíduos vegetais de aveia na superfície do solo (0, 2,5 e 5 Mg ha-1) em três repetições. As parcelas experimentais de 0,5m2 foram delimitadas por chapas metálicas galvanizadas cravadas no solo contendo na parte inferior uma calha coletora, para coletar a água do escoamento superficial (mensurado em intervalos de cinco minutos). A intensidade de precipitação de 30, 80 e 120 mm h-1 foram aplicadas utilizando um simulador de chuvas de bicos múltiplos e oscilantes, fazendo duas simulações (chuva 1 e 2, aplicados alternadamente, a cada dia) em cada declividade para cada intensidade. . Em cada intensidade de chuva simulada simulação foi determinado o tempo de início e a taxa de escoamento superficial, além da chuva (quantidade, duração e intensidade), umidade inicial e de saturação do solo. Utilizou-se o modelo modificado de Smith para estimativa do escoamento superficial. Os parâmetros do modelo foram ajustados através de equações multivariadas. Na chuva 1, intensidade de 30 mm h-1 não houve escoamento superficial na declividade zero, nas demais declividades, o escoamento superficial representou 1,0, 8,8 e 11,5%, da quantidade de chuva aplicada. Nas chuvas de intensidades de 80 e 120 mm h-1, as perdas de água por escoamento superficial representaram em média 59 e 53% da quantidade de chuva aplicada, respectivamente. Na chuva 2, as perdas de água por escoamento superficial representaram 33, 45 e 73%, da quantidade aplicada, respectivamente, para as intensidades de 30, 80 e 120 mm h-1. A presença de resíduo vegetal na superfície retarda o início do escoamento superficial e reduz a taxa de escoamento superficial constante, para diferentes intensidades de chuva (30, 80 e 120 mm h-1) e declividades do terreno (zero, 2,5, 5 e 8%). As equações multivariadas geradas a partir das características da chuva e do teor de umidade no solo apresentaram boa precisão na estimativa da taxa de escoamento superficial constante e o tempo de início do escoamento superficial.

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ARAÚJO, José Aécio Corrêa de. "Tipificação dos padrões de chuvas intensas em função do posicionamento da intensidade e fatores determinantes para o município de Barreiros do estado de Pernambuco." Universidade Federal Rural de Pernambuco, 2013. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5611.

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A subject that has aroused considerable interest in hydrometeorology and hydrology is the establishment of standards Rainstorm focusing on the positioning of the peaks over the duration of the events. We used rainfall data obtained in PCD located in the city of Barreiros in Meso coast of the state of Pernambuco, the period from 01/06/2000 (date of installation of PCD) to 31/12/2010. The methodology identified, besides the already known and referenced standards Advanced, Intermediate and Retarded, the following: Undefined and Multipico. Moreover, through the confrontation of heavy rainfall events identified with the stationary satellite images, the standards set were related to meteorological factors responsible and determinants thereof, giving bigger and better elements for aggregation of advantages in the provision of mitigation measures effects of weather forecasts and conditions within the modern view of weather. Therefore, the aim of this study was to indicate a form of rational presentation and unpublished patterns of heavy rainfall, providing subsidies to redirect the studies, with equanimity, and in accordance with the objectives which they propose, and additionally relate the patterns to weather systems that originate.
Um assunto que tem despertado bastante interesse na hidrometeorologia e hidrologia é o estabelecimento de padrões de chuvas intensas com enfoque no posicionamento dos picos ao longo da duração dos eventos. Foram usados os dados de precipitação obtidos na PCD localizada no município de Barreiros, na Mesorregião Litoral do Estado de Pernambuco, compreendendo o período de 01/06/2000 (data de instalação da PCD) a 31/12/2010. A metodologia aplicada permitiu identificar, além dos já conhecidos e referenciados padrões Avançado, Intermediário e Retardado, os seguintes: Indefinido e Multipico. Ademais, mediante a confrontação dos eventos de chuvas intensas identificados com as imagens fornecidas por satélites estacionários, os padrões estabelecidos foram relacionados com os fatores meteorológicos responsáveis e determinantes dos mesmos, conferindo maiores e melhores elementos para agregação de vantagens na provisão de medidas de mitigação dos efeitos e condições de previsões dentro da visão moderna de clima. Portanto, o objetivo do presente trabalho foi indicar uma forma de apresentação racional e inédita, dos padrões de chuvas intensas, proporcionando subsídios ao redirecionamento dos estudos, com equanimidade, e de conformidade com os objetivos a que se propõem, e, adicionalmente, relacionar os padrões aos sistemas meteorológicos que os originam.

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Shigaki, Francirose. "Transporte de fósforo na enxurrada superficial em função do tipo de fonte de P e intensidade das chuvas: Relevância à gerência ambiental em sistemas de produção brasileiros." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-09102006-145338/.

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Estima-se que a água potável no futuro será limitada devido a: (1) problemas ambientais, (2) aumento na demanda (a população mundial deve atingir 10,5 bilhões de habitantes em 2050); e (3) 60% do consumo mundial é baseado em recursos não renováveis. Conseqüentemente, é imperativo que os recursos de águas doces sejam cuidadosamente manejados para assegurar seu uso para as gerações futuras. Um dos principais problemas ambientais que limita o uso da água é a eutrofização, que pode ser acelerada por entradas de nitrogênio (N) e fósforo (P). Como resultado, a minimização das perdas de P para as águas é essencial para diminuição da incidência e severidade da eutrofização. Entretanto, suplementos adequados de P são necessários para produção de culturas de interesse econômico na maioria das vezes dependentes de suplementação adequada de P do solo. Sendo assim, o P é adicionado rotineiramente para melhores rendimentos de todas as culturas. A maioria dos fertilizantes fosfatados utilizados na agricultura são altamente solúveis em água, afim de fornecer P prontamente disponível para absorção das plantas. Entretanto, uma alta proporção desse fósforo aplicado torna-se indisponível devido as reações químicas dos constituintes do solo (fixação). Fertilizantes fosfatados com alta solubilidade em água tendem a dissolver-se rapidamente, disponibilizando P para as plantas em estágios iniciais, mais o P pode ser fixado pelas partículas do solo ou lavados do solo durante a enxurrada. O Brasil possui poucas informações nos impactos da agricultura na qualidade da água. Sendo assim, um levantamento foi conduzido utilizando-se dados de 1993 a 2003 que avaliou o desenvolvimento e mudanças nos sistemas de produção que podem afetar a futura qualidade da água, e como estas podem ser manejadas. Esse levantamento mostrou que o recente desenvolvimento dos sistemas produtores em certas regiões no Brasil (principalmente no Sul), tem o potencial de acumular grandes quantidades de P que podem se tornar fontes para a enxurrada e danificar recursos de águas regionais. Alguns estudos mostram que o potencial do fósforo dissolvido reativo (PDR) no transporte da enxurrada superficial é maior quando fertilizantes high-grade, com alta solubilidade em água (ex. superfosfato triplo) é aplicado, comparando-se com fertilizantes com baixa solubilidade em água (ex. fosfato diamônico). Entretanto, poucos estudos tem comparado o efeito de fertilizantes fosfatados como rocha fosfatadas e superfosfatos, variando em na solubilidade de P (1,5 a 85% de fósforo solúvel em água, respectivamente) no movimento do P na enxurrada superficial. Estudos de enxurrada em campo e em laboratório foram conduzidos utilizando-se 4 fontes de P variando na solubilidade em água, com três intensidades de chuva para avaliar seus efeitos no transporte de P. Os resultados mostraram que enquanto o P na enxurrada foi maior após a aplicação do superfosfato triplo, uma contínua liberação de P proveniente das fontes menos solúveis (ex. low-grade superfosfato simples e rocha fosfatada da Carolina do Norte) pode ser um risco a longo prazo no enriquecimento de P na enxurrada. Opções de manejo para a minimização dos ricos para a agricultura brasileira são sugeridos.
It has been estimated that potable water will be limited in the future due to: (1) environmental problems, (2) increased demand (world population may reach 10.5 billion by year 2050 before starting to decrease), and (3) 60% of world consumption is based on underground non-renewable resources. Consequently, it is imperative that these fresh water resources are carefully managed to ensure their use for future generations. One of the main environmental problems limits water use is eutrophication, which can be accelerated by increased inputs of nitrogen (N) and particularly phosphorus (P) to these waters. As a result, minimizing P loss to fresh waters is essential to decreasing the incidence and severity of eutrophication. However, adequate P supplies are also necessary for economic crop production that are most of the times dependent on the adequate supply of P from the soil. Thus, P is routinely added for optimum yields of all crops. Most of the P fertilizers utilized in agriculture are highly water soluble, in order to readily supply P in an available form for crop to take up. However, a high proportion of the P applied becomes plant unavailable due to chemical reactions with soil constituents (fixation). Phosphate fertilizers with high water solubility tend to dissolve rapidly, providing P to the plants at early stages, but P can be fixed by soil particles or be washed off the soil during rainfall induced runoff. Brazil has little information on the impacts of agriculture on water quality. Thus, a survey was conducted using a data base from 1993 to 2003 to evaluate the development and changes in the Brazilian production systems that can affect future water quality and how it can be managed. This survey showed that the recent development of farming systems in certain regions of Brazil (mainly south), has the potential to accumulate large amounts of P that may become sources to runoff and impair regional water resources. Some studies have shown the potential for dissolved reactive P (DRP) transport in surface runoff is greater when high-grade fertilizers, with high water soluble P (e.g., triple superphosphates) are compared with lower P solubility fertilizers are applied (e.g., diammonium phosphate). However, few studies have compared the effect of P fertilizers, such as rock phosphate and superphosphates, varying in P solubility (1.5 to 85% water soluble P, respectively) on P movement in surface runoff. Outdoor and indoor runoff studies were conducted using four sources of P varying in water soluble P and three rainfall intensities to evaluate their effect on P transport. Results showed that while P runoff was greatest after triplesuperphosphate application, continued release of P from less soluble sources (e.g., low-grade superphosphate and North Carolina Rock Phosphate) may pose a long-term risk to runoff P enrichment. Management options to minimize this risk for Brazilian agriculture are suggested.

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Karlsson, Johan, and Hannes Öckerman. "Föroreningar från gata till å : Utvärdering av beräkningsmetod för föroreningsbelastningfrån dagvatten genom en fallstudie i Uppsala." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-277033.

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Vi lever i ett samhälle med pågående urbanisering. Nyexploateringar och förtätningar istadsmiljöer bidrar till minskad infiltration och evapotranspiration samt ökad ytavrinning avregn- och smältvatten; så kallat dagvatten. Det är viktigt att kvantifiera denna diffusaföroreningskälla i urbana miljöer då bland annat näringsämnen och tungmetaller transporterasmed dagvattnet, vilket bidrar till försämrad status i recipienter. Enföroreningsbelastningsmodell för näringsämnen i dagvatten på nationell nivå används avSvenska miljöemissionsdata (SMED). Beräkningsmetoden använder empiriskt framtagnaavrinningskoefficienter och belastningsschabloner som varierar beroende påmarkanvändningsslag. Flödesproportionell provtagning av totalhalter kväve, fosfor, bly, koppar, zink, kadmium ochsuspenderad substans genomfördes under nio veckor i ett av Uppsalas störstadagvattenavrinningsområden. Syftet var att kvantifiera områdets föroreningsbelastning för attutvärdera och föreslå förbättringar till SMED:s beräkningsmetod som enligt tidigare studierhar stora osäkerheter, men även för att ge underlag till placering av eventuella reningsåtgärderi området. Provtagningen kompletterades med en modellutvärdering där beräkningsmetodenskänslighet med avseende på markanvändning och inkludering av basflöde testades. Även enmer fysikaliskt förankrad modell för näringsämnestransport i naturliga avrinningsområdenanvändes i modellutvärderingen. Resultaten visade att bly, koppar och zink transporteras till Fyrisån i koncentrationer somöverskrider föreslagna regionala riktvärden för dagvatten. För koppar och zink är även dentotala belastningen på recipient högre än tidigare modellerade värden. Då tungmetaller, menäven fosfor, till stor del transporteras i partikulär form bör en eventuell reningsåtgärd iavrinningsområdet fokusera på att avskilja partikulärt material. Åtgärden bör även placerasuppströms industrin GE Healthcare Bio-Sciences AB där föroreningskoncentrationerna spädsut genom att stora volymer kyl- och regenereringsvatten tillförs dagvattennätet. Vidare visade modellutvärderingen att när SMED:s beräkningsmetod applicerades på detstuderade avrinningsområdet överskattades volymavrinningen från dagvattnet jämfört medprovtagningsresultaten medan medelkoncentrationen för kväve underskattades. För fosfor gavprovtagningsresultaten och beräkningsmetoden samstämmiga svar. Sammantagetöverskattade modellen fosforbelastningen något men underskattade kvävebelastningen. Förkväve har basflödet visat sig stå för en betydande del av belastningen och bör därför iframtiden inkluderas i SMED:s beräkningsmetod. Även den markanvändningskarta somanvänds i metoden bör bytas ut på grund av dess inaktualitet samt att modellutvärderingenvisade relativt stora känsligheter i resultaten för ändring i markanvändning.
We live in a society with an ongoing urbanization. New development projects anddensifications in urban areas contribute to reduced infiltration and evapotranspiration and anincreased surface runoff from rain and melt water, i.e. stormwater. It is essential to quantifythis diffuse source of pollution in urban environments since nutrients, heavy metals and otherpollutants, are transported by the stormwater and contribute to recipient degradation. Anutrient pollution load model in stormwater is used by Swedish environmental emission data(SMED) on a national level. The SMED computational method utilizes empirical runoffcoefficients and standard concentrations, which vary depending on the catchment land-use. Flow proportional sampling of total concentrations of nitrogen, phosphorus, lead, copper,zinc, cadmium and suspended solids was conducted during nine weeks in one of the largeststormwater catchments in Uppsala city, Sweden. The study aimed at quantifying the pollutionload of the catchment in order to evaluate and suggest improvements to the SMEDcomputational method, which contains large uncertainties according to previous studies.Furthermore, the study aimed at providing a basis for potential treatment measures in thecatchment. The sampling was complemented with a model evaluation where the sensitivity ofthe computational method was tested with respect to land-use input and the inclusion ofbaseflow. The model evaluation also included a comparison with a more physically basedmodel for nutrient transport in natural catchments. The results revealed that lead, copper and zinc are discharged into the Fyris River inconcentrations exceeding proposed regional guideline values. For copper and zinc the totalpollution loads on the recipient are higher than previously modeled values. As heavy metalsand phosphorus are transported largely in particulate form the potential treatment measureshould have the ability to effectively separate particulate matter from the stormwater matrix.Due to emissions of large volumes of cooling and regeneration water from the industry GEHealthcare Bio-Sciences AB, the stormwater pollutants are diluted. The treatment measureshould therefore be placed upstream from the industry. When applying the SMED computational method on the studied catchment, the modeloverestimated the runoff volume from stormwater compared to the sampling results, while theaverage nitrogen concentration was underestimated. Regarding phosphorus concentrations,the model and the sampling results concurred relatively well. This resulted in a higherphosphorus, but lower nitrogen, pollution load predicted by the model. It can partly beattributed the fact that baseflow transport of nitrogen is a significant part of the total pollutionload, and should thus be included in the SMED computational method in future calculations.Another model improvement would be to replace the outdated land-use map currently beingused in the method as the model evaluation indicated a relatively large sensitivity in theresults with regards to alterations in the land-use type input.

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Dorneles, Viviane Rodrigues. "Análise de chuvas intensas com abordagem de dados pluviográficos e pluviométricos." Universidade Federal de Pelotas, 2017. http://guaiaca.ufpel.edu.br:8080/handle/prefix/4118.

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O conhecimento do comportamento dos eventos extremos de precipitação e consequentes vazões observadas é de extrema importância para desenvolvimento de projetos de obras hidráulicas, tais como, drenagem agrícola, vertedouros de barragens, bueiros e drenagem urbana, canais de terraço, entre outros. Considerando a esparsa rede de monitoramento de vazão, disponibilizada no território brasileiro, é possível realizar a análise da vazão de projeto, quando não se tem dados históricos de vazão, por estudo de chuvas intensas. A dissertação, desenvolvida no curso de mestrado, no Programa de Pós-Graduação em Manejo e Conservação do Solo e da Água, foi elaborada a partir da pesquisa de chuvas intensas no município de Pelotas/RS, sendo composta por dois artigos científicos. Os artigos divididos em 1 e 2, foram realizados mediante a análise de registros pluviográficos e dados pluviométricos, respectivamente. Objetivou-se com este estudo determinar as equações intensidade-duração-frequência, do município de Pelotas/RS, utilizando a metodologia de interpretação e análise de pluviogramas e desagregação de chuvas diárias, bem como, comparar as estimativas das intensidades de precipitação por meio da aplicação da equação utilizada atualmente no município. Para isso, foram utilizados dados pertencentes à Estação Agroclimatológica mantida pela Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) e pela Universidade Federal de Pelotas (UFPel), compondo 34 anos de séries históricas (1982 a 2015), utilizando-se as metodologias anteriormente mencionadas. As séries históricas foram submetidas à análise estatística a fim de identificar o modelo probabilístico teórico que representasse melhor o ajuste aos dados, e o método empírico de análise dos dados, por se ter disponíveis 34 anos de dados. As equações intensidade-duração-frequência obtidas pela análise de registros pluviográficos e dados pluviométricos, bem como, a pela metodologia híbrida (empírico) e convencional (teórico) permitem o cálculo das intensidades máximas de precipitação, para as durações de chuva de 5 até 1440 min, nos períodos de retorno de 2 a 100 anos.
Knowledge of the behavior of the extreme events of precipitation and consequent observed flows is of extreme importance for the development of projects of hydraulic works, such as agricultural drainage, spillways of dams, culverts and urban drainage, terrace channels, among others. Considering the sparse flow monitoring network available in the Brazilian territory, it is possible to carry out the analysis of the project flow, when there is no historical flow data, due to the study of heavy rains. The dissertation, developed in the master's degree program in the Postgraduate Program in Soil and Water Management and Conservation, was elaborated based on intense rainfall research in the city of Pelotas, Rio Grande do Sul, Brazil, and was composed of two scientific articles. The articles divided into 1 and 2, were carried out through the analysis of pluviographic records and rainfall data, respectively. The objective of this study was to determine the intensity-duration-frequency equations of the municipality of Pelotas / RS, using the methodology of interpretation and analysis of pluviograms and disaggregation of daily rains, as well as to compare the estimates of precipitation intensities by means of Application of the equation currently used in the municipality. For this purpose, data from the Agroclimatological Station maintained by the Brazilian Agricultural Research Company (EMBRAPA) and the Federal University of Pelotas (UFPel) were used, composing 34 years of historical series (1982 to 2015) using the aforementioned methodologies. The historical series were submitted to statistical analysis in order to identify the theoretical probabilistic model that best represented the adjustment to the data, and the empirical method of data analysis, because 34 years of data were available. The intensity-duration-frequency equations obtained by the analysis of pluviometric and rainfall data, as well as by the hybrid (empirical) and conventional (theoretical) methods allow the calculation of the maximum precipitation intensities for rainfall durations from 5 to 1440 Min, in the return periods of 2 to 100 years.

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Blumenthal, Barbara. "Nederbördsintensitet och andra faktorer som påverkar skyfallsskador." Licentiate thesis, Karlstads universitet, Centrum för klimat och säkerhet (from 2013), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-70173.

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I Sverige inträffar många skyfall och intensiva regn under sommarmånaderna. Det finns inga uppenbara geografiska mönster, vilket är en skillnad gentemot älv- eller sjööversvämningar där det vanligtvis är känt vilka områden som kan komma att översvämmas vid en viss vattennivå eller ett visst vattenflöde. För individer och samhällsaktörer innebär en skyfallshändelse i många fall en stor överraskning då skyfall utvecklas snabbt och dagens meteorologiska prognossystem i stort inte lyckas att prognosticera extrema regn korrekt med avseende på mängd, tid och plats. Vädervarningar kommer med kort varsel eller uteblir helt. Konsekvenserna av intensiv nederbörd och skyfall är främst översvämningar och erosionsskador på byggnader och infrastruktur, men även störningar och avbrott i olika samhällsfunktioner som kan påverka samhället och individer utanför det drabbade området. I denna avhandling har 15 år av försäkringsskadedata använts för att undersöka samband mellan nederbördsintensitet och skyfallsskador. Även påverkan av andra faktorer som topografi, bebyggelse och socioekonomiska aspekter har undersökts. Resultaten visar att regnintensitet under ett 60 minuters intervall i kombination med korta perioder av extrem intensitet, tillsammans med topografiska faktorer spelar en betydande roll vid uppkomsten av skador.

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Parracho, Sandro Castanho. "Interações sobre a pluviosidade em encostas de clima tropical úmido e os movimentos de massa: o caso de sub-bacias do Alto Rio São João - RJ." Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4250.

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Cada vez são mais comuns problemas relacionados a movimentos de massa nas encostas de clima tropical no Estado do Rio de Janeiro, especialmente na Serra do Mar, provocados por acumulados pluviométricos intensos. A ocupação humana desordenada de áreas sensíveis a tais processos geomorfológicos, bem como as condicionantes geológicas, geomorfológicas, pedológicas e de uso e cobertura do solo são apontadas como fatores cruciais na explicação desses processos. O maior conhecimento da dinâmica pluviométrica bem como suas interações com tais aspectos físicos ligados ao relevo parece ser a chave dessa maior compreensão desses fenômenos. Assim foram realizadas pesquisas relacionadas aos volumes e intensidades das chuvas na região do Alto Curso do Rio São João, bem como uma análise dos movimentos de massa identificados através de imagens de satélite e in loco, como forma de fornecer subsídios à melhor gestão do espaço dessas regiões montanhosa estão vulneráveis a movimentos de massa. A correlação entre os acumulados e a intensidade pluviométrica com fenômenos climáticos de escala global, como El Niño e La Niña também foi contemplada nessa pesquisa, mostrando uma relação mais alta com relação à intensidade da chuva mensal para anos de El Niño e para anos de La Niña uma reduzida ocorrência dessas intensidades pluviométricas. Os estudos revelaram que os tipos de solos e sua cobertura e uso têm uma grande influência na deflagração de movimentos de massa. Foram observados um número reduzido de movimentos de massa em áreas naturais e uma maior proporção desses movimentos em áreas utilizadas para a atividade da pecuária na região. Grande parte dos movimentos de massa ocorreram em áreas de Cambissolos (áreas mais elevadas) e Latossolos (áreas de encostas em menores altitudes). Ambos os solos são mais espessos do que os encontrados em áreas mais declivosas, apresentando maior acúmulo de materiais a serem mobilizados durante grandes acumulados pluviométricos, gerando movimentos de massa. A análise mostrou também que áreas mais chuvosas e com maior ocorrência de acumulados pluviométricos extremos, acima de 100 mm/dia e acima de 30mm/mês concentraram um número maior de movimentos de massa, como a região mais próxima da estação de Quartéis (porção leste). Por outro lado áreas bastante elevadas, com altas declividades, porém com predomínio de Mata Atlântica e áreas com solos menos espessos, como os Neossolos Litólicos, se mostraram com um número reduzido desses processos. Enfim esse estudo mostrou a necessidade de se gerir melhor os espaços dessas áreas sensíveis sob o ponto de vista geomorfológico, até por que são áreas na periferia de regiões densamente habitadas e cujas demandas tendem a se tornar cada vez mais marcantes, o que pode gerar problemas locais, atingindo sua população e economia, com sérias conseqüências para o ambiente.
Are increasingly common problems related to mass movements on the slopes of tropical climate in the State of Rio de Janeiro, especially in the Serra do Mar, caused by intense rainfall accumulated. The disorganized human occupation of sensitive areas such geomorphological processes and the geological conditions, geomorphology, soil and use and land cover are cited as crucial factors in explaining these processes. The understanding of rainfall dynamics as well as their interactions with such physical aspects related to the relief seems to be the key to this greater understanding of these phenomena. So were performed research related to volume and intensity of rainfall in the Upper St. John River Course, as well as an analysis of mass movements identified through satellite imagery and on-site as a way to provide subsidies to better management of these space mountainous regions as vulnerable to mass movements. The correlation between rainfall intensity and accumulated with global-scale climatic phenomena like El Niño and La Niña was also considered in this study, showing a higher ratio with respect to the intensity of monthly rainfall for El Niño years and La Niña years a reduced occurrence of rainfall intensities. Studies have shown that the types of soils and their cover and land use have a great influence on outbreaks of mass movements. We observed a small number of mass movements in natural areas and a higher proportion of these movements in areas used for livestock activity in the region. Most mass movements occurred in areas of Cambisols (higher areas) and Oxisols (slopes in areas of lower altitudes). Both soils are thicker than those found in hilly areas, with higher accumulation of materials to be deployed during large accumulated rainfall, generating mass movements. The analysis also showed that areas with increased wet and accumulated occurrence of precipitation extreme excess of 100 mm/day and above 30mm/month concentrated a larger number of mass movements, as the region closest to the station Quartéis (East portion).On the other hand very high areas with steep slopes, but with a predominance of Atlantic Forest and areas with thinner soils, such as Entisols, were with a small number of these processes. Finally this study showed the need to better manage these areas, sensitive areas under the geomorphological point of view, even for areas that are on the outskirts of densely populated and whose demands tend to become increasingly salient, which can cause problems locations, reaching its population and economy, with serious consequences for the environment

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34

Turčenko, Sandra. "Paviršinių nuotekų Vilniaus mieste užterštumo tyrimai." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100701_091557-21888.

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Magistriniame moksliniame tiriamajame darbe „Paviršinių nuotekų Vilniaus mieste užterštumo tyrimai“ buvo apžvelgta mokslinė – techninė literatūra, kurioje aprašoma paviršinių nuotekų užterštumo skendinčiosiomis medžiagomis kaita lietaus metu. Literatūroje taip pat išanalizuotas pirmojo teršalų antplūdžio reiškinys, t.y., kuomet po tam tikro sausojo periodo, lyjant lietui, urbanizuotoje teritorijoje susiformuoja ypač užterštos pirmosios paviršinių nuotekų porcijos. Ištyrus pirmojo teršalų antplūdžio reiškinio dėsningumą, patikimumą ir universalumą, galima būtų šias žinias panaudoti valytino paviršinių nuotekų kiekio nustatymui. Žinodami, kad didžioji dalis miesto teršalų transportuojama lietaus pradžioje, o likusioji dalis neturi reikšmingos įtakos upių ekosistemoms, valymo įrenginius galėtume projektuoti taip, kad į juos nukreiptume tik pirmąsias paviršinių nuotekų porcijas. Tai suteiktų galimybę efektyviau ir ekonomiškiau tvarkyti paviršines nuotekas. Šiame tiriamajame darbe atsitiktiniu būdu tyrimo objektu buvo pasirinkti Vilniaus miesto šiaurinės dalies vienas didžiausių (Verkių g. Nr. 1) ir vienas mažiausių (Sporto g. Nr. 2) paviršinių nuotekų surinkimo baseinų išleistuvai. Tyrimų rezultatai parodė, kad paviršinių nuotekų debito bei skendinčiųjų medžiagų koncentracijos kaita priklauso nuo urbanizuotos teritorijos baseino charakteristikų, nuo tinklo akumuliacinių savybių, nuo lietaus intensyvumo bei nuo sausojo periodo. ... [toliau žr. visą tekstą]
This work of scientific research named „The research of the pollution of storm water runoff in Vilnius city“ overlooks the fluctuation of concentration of suspended solids in a storm water runoff. There was also the concept of the first flush phenomenon investigated, which means, that the store of pollutants that had accumulated on paved surface in dry weather are quickly washed off during the beginning of the storm. Investigation of the first flush phenomenon consistent reliability and universality would help to determine the amount of storm water runoff that needs to be purified. Knowing that most of the urban pollutant load is transported in the beginning of a storm and the rest of storm water runoff do not have a significant impact on river ecosystem, water treatment facilities could be designed so that they accept only the first portions of the storm water runoff. In this case, a much smaller volume of runoff storage would be needed to treat and remove urban pollutants. This would allow more efficient and economical control of storm water runoff. The study areas where selected to be the representative drainage basin for a large (Verkių g. Nr1) and small (Sporto g. Nr.2) commercial-residential district. Research results showed that storm water runoff flow and suspended solids concentration change depends on the characteristics of the urban catchment’s area, also from the network storage properties and from the intensity of rainfall... [to full text]

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35

Foldyna, David. "Začlenění tramvajové tratě s vegetačním krytem do veřejného prostoru města Brna." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409755.

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This diploma thesis deals with problematics of tram tracks with vegetation cover. The research part of the work contains the overview of currently used systems of green tram tracks in Europe and their advantages and disadvantages with respect to sustainability of a vegetation cover. 3 different variations of a green tram track at a particular location in Brno at Nové Sady street are compared in the second part of the thesis. The low maintenance vegetation and intesively planted vegetation are compared from both financial and ecological points of view. Life cycle costs analysis and multicriterial analysis were used for the comparison.

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36

Lin, Chia-Yu, and 林珈伃. "Rainfall intensity- duration -frequency analysis and rainfall intensity characteristicsof induced inclinometer displacement at Huafan University Campus." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/dgdsum.

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碩士
華梵大學
環境與防災設計學系碩士班
107
Huafan University is located in the Ta-Lun Shan area of Shih ding District, New Taipei City. It is about 430 meters to 570 meters above sea level. There is a weather station on the campus to measure the rainfall and temperature data. For slope disaster prevention there are SAA (Shape Accel Array) observation instruments to monitor slope displacement. The area of Huafan University is listed in the landslide-landslip geologically sensitive area by the Central Geological Survey. The analysis of slope displacement is more important. This study is separated into two parts. First is to analysis the characteristic of different duration rainfall intensity–duration-frequency Curve (IDF) in Huafan University, and second is to induce rainfall with tilting displacement greater than 0.5mm. The first part selects the date from 2004 to 2017 of Huafan weather station, and selects the annual maximum rainfall data from 5 minutes to 1 hour called short duration and 1 hour to 48 hours called long duration. By frequency analysis, the most suitable theoretical probability distribution is obtained, the short duration IDF and the long duration IDF are established. It is known from the study that the long duration IDF formula estimates the short duration rainfall intensity value, which is overestimated, especially when the rainfall duration is 5 minutes. The data of four days cumulative rainfall amount greater then 100mm are used to as the background value of the second part of the analysis. The second part is to select the data with the daily displacement greater than 0.5mm from SAA for the number SIS-11A and the four-day cumulative greater than 100mm, and calculate the average rainfall intensity value in two different ways. The first type is the day when the displacement occurs, as the first day, and continues to calculate forward. The second type is the three days before the tilting displacement day as the first day, and then continues to calculate backwards. Will these two methods are compared to the background values. The rainfall intensity during typhoon is widely distributed on one day and two days. The daily rainfall intensity falls between 1 (mm/day) and 305 (mm/day). The distribution of rainfall intensity on the three days and four days is concentrated. The rainfall intensity falls between 47 (mm/day) and 147 (mm/day), while the rainfall intensity of the southwest monsoon affects the four days rainfall intensity from 28 (mm/day) to 85 (mm/day). The four days rainfall intensity falls from 25 (mm/day) to 55 (mm/day). It has probability to occur tilting displacement greater than 0.5 mm when rainfall intensity is small. Keywords： Frequency Analysis、IDF、Shape Accel Array、Tilting Displacement

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37

Hung, Ging-Fu, and 洪菁甫. "Rainfall Intensity - Duration - Frequency Analysis in Taiwan." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/99382868401122179053.

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碩士
國立臺灣大學
農業工程學系
82
The data files of rainfall including the weather stations of CentralWeather Bureau, Taiwan Provincial Water Conservancy Bureau, and Taiwan Electric Power Company were collected and analysed in order todevelop the relations among rainfall intensity , duration and frequency for Taiwan area. The annual maximum serious is used for selection of rainfall in frequency analysis. The criteria for selection of weather stations is those have record length longer than ten years. In this research, 167 stations were chosen, which include 21 stations from Central Weather Bureau, 96 stations from Taiwan Provincial Water Conservancy Bureau, and 50 stations from Taiwan Eletric Power Company. Frequency analysis was done for a total of 167 stations based on Pearson Type of III distribution . The results from frequency analysis is used as the source data for developing rainfall intensity , duration and frequency relations. Then, multiple regression is applied to estimate the coefficients of Rainfall Intensity - Duraion - Frequency formula. The regression is based on the source data from frequency analysis corresponding return period and duration. In order to improve the accuracy of Rainfall Intensity - Duration - Frequency formula, The rainfall duration was divided into long duration and short duration. The long duration is five to seventy - two hours, and the short duration is ten minutes to five hours. The established regional Rainall Intensity - Duration - Frequency relationship for Taiwan has been preliminarily verified and shown applicable in planning and design of hydraulic works.

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38

Keim, Richard F. "Attenuation of rainfall intensity by forest canopies /." 2003. http://hdl.handle.net/1957/9697.

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39

Doong, Dong-Jiing, and 董東璟. "A STUDY ON NONPARAMETRIC REGIONAL RAINFALL INTENSITY FORMULA." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/45180950173394190449.

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碩士
國立成功大學
水利及海洋工程學系
84
Regional maximum rainfall intensity-duration frequency (IDF) curvesor formula have been widely used for estimating the design rainfall atungauged sites. This study used 1~24 hours rainfall annual maximumseries, which collected from 38 recording raingauges over northernTaiwan, to develop regional IDF formula. Before that, the frequencyanalysis at site was first studied. Historical recorded data was applied tocompare the performance of traditional parametric methods andnonparametric frequency analysis, which utilized Gauss distribution asKernel function and the least square cross validation method to calculatesmoothing factor. The comparisons show that the nonparametricfrequency has better performance based on Chi- square test, KS test andRMSE as criteria. Moreover, the comparison was further investigated interms of Monte Carlo and Resampling simulation techniques. The resultsimply that nonparametric frequency analysis have less variation for largereturn periods when the sample is relative small.This study further developed regional IDF based on the analysis ofnonparametric frequency analysis. The station-year method was applied topool nondimension rainfall intensity data in a homogeneous region, whichwas classified by Yu and Chen (1996). The average of daily annualmaximum rainfall was found to be suitable chosen as an index in regionalIDF formula. The simulation results show that the regional IDF formulahas less than 20% absolution error. The vertifiation results from sevenstations further concluded that the formulas can be reasonably applied tothe non-recording raingauges or ungauges sites.

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40

Wu, Min-fon, and 吳明峰. "Interrill erosion and its relationship with rainfall intensity." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/19598636673867764286.

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41

Chen, Chia Jung, and 陳嘉榮. "STUDY ON REGIONAL RAINFALL INTENSITY－DURATION－FREQUENCY RELATIONSHIP." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/32888100794513284002.

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42

Chuang, Li-Rung, and 莊麗蓉. "Regionalization of Dimensionless Rainfall Intensity Formulas for Short Duration." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/38027094263303362567.

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碩士
國立成功大學
水利及海洋工程學系碩博士班
94
The debris-flow often comes up in the mountain region of Taiwan after the 921 earthquake, and it is found that the rainfall intensity which were estimated in the debris-flow site obviously differ from the observation befor the earthquake. In recent years, the precipitations which are caused by typhoons constantly exceed the 100-year rainfall return period. In this study, the extreme rainfall intensity data (~2004) are collated to analyze its space and temporal characteristics in Taiwan. The purpose of this thesis is to discuss the rainfall intensity formulas which are generally used in Taiwan. 　　The precipitations are surveyed from 144 recording stations of Water Resources Agency and Taiwan Power Company, and different characteristics in temporal and space scales are indicated here. The rainfall intensity plotted in double log chart shows different characteristics in the long-duration rainfall scale and short-duration rainfall scale. The Horner IDF equations and the dimensionless IDF formulas, which are divided by 90 minutes rainfall duration, are calculated respectively in this study and the modified IDF equations reveal that they can increase the accuracy of the designed rainfall intensity. 　　Regional IDF formulas of short duration rainfall in Taiwan are further developed for using in ungauged area. Several tools including Principal Component Analysis, Cluster Analysis, and Geographic Information System are used here to decide hydraulic homogeneous regions. The Taiwan area is divided into 7 hydraulic homogeneous regions and the regional IDF equations of each region are also established. Finally, a geographic inquiring system is developed here to provide users inquire about all kinds of parameters of IDF formulas in this study.

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43

Lu, Shu-hsuan, and 盧書炫. "A Study on Regionalization of Short-Duration Rainfall Intensity." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/31048927030549729745.

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碩士
國立成功大學
水利及海洋工程學系碩博士班
95
Regional analysis is an important tool of hydrologic planning and design in ungauged areas. Small watersheds are usually ungauged and short-duration need design rainfall of short rainfall duration. Therefore, it is essential to investigate regionalization of the short-duration rainfall intensity formula for gauged and ungauged areas. This study is to develop a regional rainfall intensity formula for short durations that are herein defined as rainfall duration less than and equal to 90 minutes. 144 recording raingauges provide the data in this work. Two cluster analysis methods (two-stage clustering and self-organizing map) were adopted for homogeneous classification based on 11 variables of rainfall and topographic characteristics. Results show that longitude and latitude can improve the spatial pattern of homogeneous regions. Elevation is an effective variable to discriminate the rainfall characteristic between mountain and plain, indicating topographic characteristics is an important variable for homogeneous classification. Comparison of two cluster methods shows that the two-stage clustering has better results for homogeneous classification than self-organizing map, although both methods result in similar clusters. Consequently, four homogeneous regions are delineated. Regional short-duration rainfall intensity formula pertaining to four homogeneous regions are developed using the dimensionless intensity-duration-frequency (IDF) formula. Those proposed regional IDF formula are compared with previous study. The comparison demonstrated that the regional IDF formula in this study has more accurate in estimating short-duration design rainfall.

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44

CHENG, SHI-CHI, and 陳世墀. "Studies on the characteristics of one-day rainfall and one-hour rainfall intensity in Taiwan." Thesis, 1987. http://ndltd.ncl.edu.tw/handle/6m9j9s.

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45

ZHANG, YI-XIN, and 張宜信. "Raindrop size distribution of natural rainfall in Taipei area and its relationship with rainfall intensity." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/63111958664489437033.

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46

Chang, Hung-Yang, and 張紘揚. "Landslide Susceptibility Analysis Using Hourly Estimated Rainfall Intensity and Accumulated Rainfall with the Kriging Method." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5k5jay.

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碩士
國立中興大學
水土保持學系所
106
Precipitation is often regarded as a triggering factor in a rainfall-induced landslide susceptibility analysis, and maximum rainfall intensity is often used one. When most scholars apply geostatistics such as Kriging to estimate this factor, they input the maximum rainfall intensity that each rainfall station has recorded in the duration of the research event into the location of each rainfall station, which means all of these maximum rainfall intensities are considered to be recorded at the same time. However, these maximum rainfall intensities are seldom recorded in each rainfall station at the same time because of the nonuniformity of precipitation distribution in time-space. If we do a landslide susceptibility analysis by the foregoing way, it is bound to differ from the actual situation. This study estimate two types of the maximum rainfall intensity factor in the Chenyoulan watershed based on the environmental conditions caused by typhoon Morakot using kriging. The first type of the factor is to estimate it by the foregoing way; the second type of it is to estimate the rainfall intensity of each unit of analysis hourly, and we take the maximum one as the maximum rainfall intensity factor of the unit of analysis. Afterwards, we use receiver operating characteristic curve to do rainfall-induced landslide susceptibility analyses and compare the differences between the two types of maximum rainfall intensity factor. The area under the curve of receiver operating characteristic produced by the maximum rainfall intensity factor estimated by the foregoing way is 0.581 and its accuracy is 57%; the area under the curve of receiver operating characteristic produced by the maximum rainfall intensity factor estimated by the hourly-estimated way is 0.619 and its accuracy is 60%. So do rainfall-induced landslide susceptibility analyses by the maximum rainfall intensity factor estimated by the hourly-estimated way is surely better. This study also estimates accumulated rainfall factor by accumulate rainfall of the whole duration of typhoon Morakot and accumulate rainfall from the beginning to the hours of the maximum rainfall intensity factor estimated by the hourly-estimated way happened continuously. Afterwards, we use receiver operating characteristic curve to do rainfall-induced landslide susceptibility analyses and compare the differences between different types of accumulated rainfall factor, and the results show that there has none obvious difference. Finally, this study divides units of analysis into two groups by median of height of all units and do landslide susceptibility analyses individually, and the results show that overall, the accuracy can be promoted.

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47

Wu, Pei-Ju, and 吳佩儒. "Revision of rainfall erosivity map in Taiwan and simplified estimation of maximum 30-min rainfall intensity." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/70861502276129185295.

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碩士
國立中興大學
土木工程學系所
103
Taiwan’s geographical feature is unique. It is located on convergent boundary of the Eurasian plate and the Philippine plate, towering central Mountains stretching from north to south. Hillslope area is more than flatlands with special geological structures are developed such as faults, folds and joints, so the land is fractal and earthquakes occur frequently. The climate of Taiwan belongs to monsoon climate zone with abundant amount of rainfall. In particular, high intensity rainfall induced by monsoon and typhoons, leading to serious soil erosion in catchments. In order to reasonably estimate the amount of soil erosion of catchments in Taiwan with USLE, RUSLE and TUSLE equation, it is necessary to revise the rainfall erosion index (R) for different regional districts. This study divided Taiwan into 10 climate regions. Forty years (1975~2014) of raw rainfall recording sheets, hourly and daily rainfall recordings were collected for 10 stations, including 9 stations of Central Weather Bureau and Lien-Hua Chi of Taiwan Forestry Research Institute Analysis of the maximum 30-min rainfall intensity (I30) and the maximum hourly rainfall intensity (I60) for the rainfall events indicated that I30 and I60 are highly correlated. However, it was also has significant regional, monsoon climate and typhoon route effects. The second objective of this study is to revise the rainfall erosivity map. The relationships between recent annual rainfall and annual rainfall erosion index derived from data for 2001 to 2014 and 10 representative stations were applied in each district of the Central Weather Bureau and Water Resources Agency for 339 precipitation recording stations. The annual rainfall and the average erosion index were 2573 mm and 1302 (100ft-tonsin/achryr), respectively in Taiwan (the maximum value for the United States is 550 100ft-tonsin/achryr), indicating Taiwan is abundant of rainfall with high rainfall erosivity. In addition, the annual rainfall variability in recent years tends is higher than that in previous years (1975 to 2000), which was mainly caused by the impact of climate change. Finally, the annual rainfall erosivity map in Taiwan was revised, which can be used for the soil and water conservation planning and the catchment sediment soil loss estimation.

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Wu, Shiang-Jen, and 吳祥禎. "A Study on Rainfall intensity-Duation-Frequency Analysis in Taiwan." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/18433594853272823005.

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碩士
國立交通大學
土木工程學系
84
The purpose of this study is to identify appropriate probability distributions for the annual maximum precipitation of various duration at ninety-two recording rain gauging stations in Taiwan .The method used in the frequency analysis is the L-moment method along with various goodness-of-fit procedures. Also, this study aims at developing a non- dimensional rainfall intensity-duration-frequency (IDF) equations based on a rainfall intensity with 25-year return period and 1-hour duration.To enhance the accuracy of the regional analysis, the cluster analysis was applied using the parameter in the IDF equation and geographical coordinates of each station. It is found the 92 raingage stations can be clustered separated by into two areas separated by the line connecting ({EMBED Equation |} E , {EMBED Equation |} N) and ({EMBED Equation |} E , {EMBED Equation |}N), as the demarcation.In the regional analysis, empirical relationships for each groupwere developed to relate each parameter in the IDF equation to the mean annual precipitation and elevation. The regional equations for the parameters in the IDF equation can be used to estimate extreme precipitation characteristics at locations where there is no precipitation record.

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49

WU, HUNG-YI, and 吳宏義. "The Research of Roof Drainage Capacity Influenced by Rainfall Intensity." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/04910616069887508429.

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碩士
中國科技大學
建築研究所
101
Global climate such as temperature and rainfall has been changed due to the global warming, and it has affected human’s life in every aspect. Especially Taiwan is surrounded by ocean which is easily impacted by the environment and the weather. Besides, Taiwan is mainly affected by the introduction of strong high southerly flow which is leaded from Pacific high pressure and the heavy rainfall from typhoons during June to October. These situations usually make water accumulate on the roof easily and cause leakage problems. This study is aimed at the plane roof and structural steel slanted roof drainage problems in Taiwanese metropolitan area through the discussion of actual cases. Regarding to the weather, this study collected the raining data from Taipei and Keelung weather stations during 1971 to 2012, by Extreme-Value type Ⅰ distribution and Log-Pearson type Ⅲ distribution to estimate the recurrence interval of 10-minute maximum precipitation of 5-year interval was around 22.30~22.34mm for Taipei and 22.59~23.41mm for Keelung. Regarding to roof drainage, this study measured the drainage ability of commercially available tall roof drain, commercially available plane roof drain and diameter D56mm roof drain through miniature open flume experiment. Through the result of experimental observation, we could see when water depth was 8cm, the drain cover of weephole affected the drainage around 15% ~ 20%. Also, by increasing sluice gradient to 1/100 to raise the drainage to 10%~30%. The rainfall intensity in Taiwan has been increasing, however, there is no explicit regulation for the rain drainage of rooftop. This study is to provide the reference for drain piping of roof for future building construction and roof waterproofing construction by discussing the rain drainage of building’s roof. Key words: Plane Roof, Steel Slanted Roof, Rainfall Intensity

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50

Lin, Chin-Sheng, and 林金聲. "A Study on Regional Rainfall Intensity Formula Based on Scaling Theory." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/77289365977893199944.

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碩士
國立成功大學
水利及海洋工程學系
88
The study attempts to develop regional IDF formulas for ungauged site based on “scaling” theory. As the network of non-recording raingauge has better spatial distribution, the mean value of annual 1-day maximum series was used as index to develop regional IDF. Forty-six recording raingauges over northern Taiwan provide the data set. The temporal scaling properties of annual maximum series for various rainfall durations were first investigated. Three scaling homogeneous rainfall regions were classified by different scaling regimes. That could respond the influence of climate and topography on rainfall characteristic over this area. The study further combined the simple scaling hypothesis with Gumbel distribution to develop the IDF scaling formulas. The results concluded that the proposed IDF scaling formulas has reasonable simulation of IDF relationship for rainfall duration from 20 min to 24hr. For estimating the design storm at ungauged sites, this study further developed regional IDF for various scaling regimes, in which the parameters of IDF scaling formulas can be regionalized based on the regression relationship between scale exponent and the average of daily annual maximum rainfall. The simulation results show that the regional IDF scaling formulas has reasonable performance.

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Dissertations / Theses on the topic 'Rainfall intensity'

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