Natural disasters are becoming more common due to climate change and it is important to adapt the society and its infrastructure to withstand events such as extreme rainfall. Precipitation is an important climatic factor affecting the transport and annually generates the cost of millions in damages, over the past 40 years heavy rain has increased and will continue to increase in the future. The extreme rainfall that occurred in Kramfors municipality in September 2013 led to flooding and destroyed several roads, including highway 90, which recently both had been rebuilt and given a new stretch of road. Extreme rainfall had also occurred in the municipality earlier.   The aim of the thesis was to examine how the Swedish Transport Administration handles new knowledge gained after natural disasters and how this is used in the planning of new roads. From the aim of the study a case study was used as a method. Information was sought from reports, official documents and government investigations in order to see how the Swedish Transport Administration’s work looks like and to find studies about the incident on highway 90. There were also conducted interviews with informants within the Swedish Transport Administration to find out how the planning and investigation of roads looks like, and to get information about the work of national highway 90. Within the Swedish Transport Administration lessons are learned from natural disasters and events in the past, but learning is mainly individual - based and internally. There is no system in the Swedish Transport Administration to manage new information or collect past experiences. New knowledge and new conditions are used in the investigation and planning of roads, but depends on which people work with those. The planning of highway 90 follows the regulations and plans to be followed, but with additional information on past events and climate adaptation in those, the damages caused by the extreme rain on highway 90 could perhaps have been avoided. / Naturolyckor blir allt vanligare i samband med klimatförändringar och det är viktigt att anpassa samhället och dess infrastruktur för att motstå händelser som exempelvis skyfall. Nederbörd är en viktig klimatfaktor som påverkar transportsystemet och som årligen genererar i miljonbelopp i form av skador. Under de senaste 40 åren har andelen skyfall ökat och det kommer att öka mer i framtiden. Skyfallet som drabbade Kramfors kommun i september 2013 medförde översvämningar och flera förstörda vägar. Bland annat skadades riksväg 90 som nyligen både byggts om och fått en ny vägsträcka. Skyfall har också tidigare inträffat i kommunen.   Syftet med examensarbetet var att undersöka hur man på Trafikverket hanterar ny kunskap som man fått efter att naturolyckor inträffat och hur man använder denna vid planering av nya vägar. Utifrån syftet valdes fallstudien som metod. Information söktes från rapporter, myndighetsdokument och statliga utredningar för att kunna se hur Trafikverkets arbete ser ut och för att hitta utredningar runt händelsen på riksväg 90. Vidare utfördes intervjuer med informanter inom Trafikverket för att ta reda på hur arbetet med planering och utredning av vägar ser ut, samt för att få information runt arbetet med riksväg 90.   Inom Trafikverket dras lärdom av naturolyckor och tidigare händelser, men lärandet är främst personbaserat och internt. Det finns inget system inom Trafikverket för att hantera ny kunskap eller samla in tidigare erfarenheter. Ny kunskap och nya förutsättningar används vid utredning och planering av vägar, men det påverkas av vilka personer som genomför dessa. Planeringen av riksväg 90 gjordes i enighet med de regelverk och planer som ska följas, men med ytterligare information om tidigare händelser och klimatanpassning i dessa hade kanske de skadorna som uppkom vid skyfallet på riksväg 90 kunnat undvikas.

BARBIERI, Gláucia Miranda Lopes. Eventos de chuva extrema associados a sistemas atmosféricos de escala sinótica e escala local no Estado do Ceará. 2014. 290 f. Tese (Doutorado em geografia)- Universidade Federal do Ceará, Fortaleza-CE, 2014. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-10T19:30:39Z No. of bitstreams: 1 2014_tese_gmlbarbieri.pdf: 12147547 bytes, checksum: c42f0664749b1f74357068dfffe8c823 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-06-13T22:42:43Z (GMT) No. of bitstreams: 1 2014_tese_gmlbarbieri.pdf: 12147547 bytes, checksum: c42f0664749b1f74357068dfffe8c823 (MD5) / Made available in DSpace on 2016-06-13T22:42:43Z (GMT). No. of bitstreams: 1 2014_tese_gmlbarbieri.pdf: 12147547 bytes, checksum: c42f0664749b1f74357068dfffe8c823 (MD5) Previous issue date: 2014 / This research aimed to discover the frequency of extreme rainfall events, associated with synoptic scale weather systems and local scale acting on the state of Ceará, in the period 2000 to 2010 this period, it was observed that the years 2004 and 2009 was the year with the highest number of cases of extreme rainfall in Ceará. The synoptic analysis showed that the main weather systems that acted in Ceará were the ITCZ, LI, MCCs, CV and VCANs. In this period, it was observed that even in unfavorable conditions of the Atlantic Ocean (positive dipole) the ITCZ oscillated between Ecuador and northern NEB, favoring the formation of LI systems and MCCs on Ceará. The rain gauge stations with higher thresholds of heavy rain for the period January to December 2000 to 2010, were observed in the regions of the North Coast (Tour Cross), Jaguaribana region (post Fortescue), Central Region Hinterland/Inhamuns (post Tarrafas) and Cariri (post Granjeiro). Between the months of the rainy season from 2000 to 2010, it was found that the rainfall stations most affected by heavy rainfall events are located in the regions of Central Hinterland/Inhamuns, North Coast, Cariri Jaguaribana and Ibiapaba. The rainy season of 2009, was the hardest hit by heavy rain events, with 40 events in the North Coast, 48 in the Coast of Pecém, in Ibiapaba 41, 38 and 46 in Jaguaribana region in Central Hinterland/Inhamun. The methodology was based on classification thresholds to determine the rainfall intensity as well as the classification of intensity and frequency of extreme rainfall events and identification of weather systems associated with these events. The state of Ceará, in every year over the study period was hit by heavy rainfall events, regardless of the rainy season be rainy, very rainy or dry. These events are linked to climate dynamics, but on the other hand, poor socioeconomic conditions, the degree of degradation of natural systems amplifying the vulnerability, the use by the population of vulnerable natural areas devoid of means to cope with the negative manifestations of heavy rainfall events, contribute to enhance the performances of the consequences of extreme events. / A presente pesquisa buscou conhecer a frequência de eventos de chuva extrema, associados a sistemas atmosféricos de escala sinótica e escala local, atuantes sobre o estado do Ceará, no período de 2000 a 2010. Neste período, observou-se que os anos de 2004 e 2009 foram os anos com maior número de casos de chuvas extremas no Ceará. A análise sinótica, mostrou que os principais sistemas meteorológicos que atuaram no Ceará foram a ZCIT, LI, CCMs, CV e VCANs. Neste período, observou-se que mesmo em condições desfavoráveis do Oceano Atlântico (dipolo positivo) a ZCIT oscilou entre o Equador e o norte do NEB, favorecendo a formação dos sistemas LI e CCMs sobre o Ceará. Os postos pluviométricos com maiores limiares de chuva muito forte, para o período de janeiro a dezembro de 2000 a 2010, foram observados nas regiões do Litoral Norte (Posto de Cruz), região Jaguaribana (posto de Fortim), Região do Sertão Central/Inhamuns (posto de Tarrafas) e Cariri (posto de Granjeiro). Entre os meses do período chuvoso de 2000 a 2010, constatou-se que os postos pluviométricos mais atingidos por eventos de chuva extrema estão localizados nas regiões do Sertão Central/Inhamuns, Litoral Norte, Cariri, Jaguaribana e Ibiapaba. O período chuvoso do ano de 2009, foi o mais atingido por eventos de chuva muito forte, com 40 eventos no Litoral Norte, 48 no Litoral do Pecém, 41 na Ibiapaba, 38 na região Jaguaribana e 46 no Sertão Central/Inhamun A metodologia baseou-se em classificação de limiares para determinação da intensidade da chuva diária, bem como a classificação de intensidade e frequência de eventos de chuva extrema e identificação dos sistemas atmosféricos associados a esses eventos. O estado do Ceará, em todos os anos dentro do período estudado foi atingido por eventos de chuva extrema, independente do período da chuva ser chuvoso, muito chuvoso ou seco. Esses eventos estão associados a dinâmica do clima, mas por outro lado, a precariedade das condições socioeconômicas, o elevado grau de degradação dos sistemas amplificando a vulnerabilidade natural, o uso pela população dos espaços naturais mais vulneráveis desprovidos de meios para enfrentar as manifestações negativas dos eventos de chuva extrema, contribuem para intensificar as consequências das atuações dos eventos extremos.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A presente pesquisa buscou conhecer a frequÃncia de eventos de chuva extrema, associados a sistemas atmosfÃricos de escala sinÃtica e escala local, atuantes sobre o estado do CearÃ, no perÃodo de 2000 a 2010. Neste perÃodo, observou-se que os anos de 2004 e 2009 foram os anos com maior nÃmero de casos de chuvas extremas no CearÃ. A anÃlise sinÃtica, mostrou que os principais sistemas meteorolÃgicos que atuaram no Cearà foram a ZCIT, LI, CCMs, CV e VCANs. Neste perÃodo, observou-se que mesmo em condiÃÃes desfavorÃveis do Oceano AtlÃntico (dipolo positivo) a ZCIT oscilou entre o Equador e o norte do NEB, favorecendo a formaÃÃo dos sistemas LI e CCMs sobre o CearÃ. Os postos pluviomÃtricos com maiores limiares de chuva muito forte, para o perÃodo de janeiro a dezembro de 2000 a 2010, foram observados nas regiÃes do Litoral Norte (Posto de Cruz), regiÃo Jaguaribana (posto de Fortim), RegiÃo do SertÃo Central/Inhamuns (posto de Tarrafas) e Cariri (posto de Granjeiro). Entre os meses do perÃodo chuvoso de 2000 a 2010, constatou-se que os postos pluviomÃtricos mais atingidos por eventos de chuva extrema estÃo localizados nas regiÃes do SertÃo Central/Inhamuns, Litoral Norte, Cariri, Jaguaribana e Ibiapaba. O perÃodo chuvoso do ano de 2009, foi o mais atingido por eventos de chuva muito forte, com 40 eventos no Litoral Norte, 48 no Litoral do PecÃm, 41 na Ibiapaba, 38 na regiÃo Jaguaribana e 46 no SertÃo Central/Inhamun A metodologia baseou-se em classificaÃÃo de limiares para determinaÃÃo da intensidade da chuva diÃria, bem como a classificaÃÃo de intensidade e frequÃncia de eventos de chuva extrema e identificaÃÃo dos sistemas atmosfÃricos associados a esses eventos. O estado do CearÃ, em todos os anos dentro do perÃodo estudado foi atingido por eventos de chuva extrema, independente do perÃodo da chuva ser chuvoso, muito chuvoso ou seco. Esses eventos estÃo associados a dinÃmica do clima, mas por outro lado, a precariedade das condiÃÃes socioeconÃmicas, o elevado grau de degradaÃÃo dos sistemas amplificando a vulnerabilidade natural, o uso pela populaÃÃo dos espaÃos naturais mais vulnerÃveis desprovidos de meios para enfrentar as manifestaÃÃes negativas dos eventos de chuva extrema, contribuem para intensificar as consequÃncias das atuaÃÃes dos eventos extremos. / This research aimed to discover the frequency of extreme rainfall events, associated with synoptic scale weather systems and local scale acting on the state of CearÃ, in the period 2000 to 2010 this period, it was observed that the years 2004 and 2009 was the year with the highest number of cases of extreme rainfall in CearÃ. The synoptic analysis showed that the main weather systems that acted in Cearà were the ITCZ, LI, MCCs, CV and VCANs. In this period, it was observed that even in unfavorable conditions of the Atlantic Ocean (positive dipole) the ITCZ oscillated between Ecuador and northern NEB, favoring the formation of LI systems and MCCs on CearÃ. The rain gauge stations with higher thresholds of heavy rain for the period January to December 2000 to 2010, were observed in the regions of the North Coast (Tour Cross), Jaguaribana region (post Fortescue), Central Region Hinterland/Inhamuns (post Tarrafas) and Cariri (post Granjeiro). Between the months of the rainy season from 2000 to 2010, it was found that the rainfall stations most affected by heavy rainfall events are located in the regions of Central Hinterland/Inhamuns, North Coast, Cariri Jaguaribana and Ibiapaba. The rainy season of 2009, was the hardest hit by heavy rain events, with 40 events in the North Coast, 48 in the Coast of PecÃm, in Ibiapaba 41, 38 and 46 in Jaguaribana region in Central Hinterland/Inhamun. The methodology was based on classification thresholds to determine the rainfall intensity as well as the classification of intensity and frequency of extreme rainfall events and identification of weather systems associated with these events. The state of CearÃ, in every year over the study period was hit by heavy rainfall events, regardless of the rainy season be rainy, very rainy or dry. These events are linked to climate dynamics, but on the other hand, poor socioeconomic conditions, the degree of degradation of natural systems amplifying the vulnerability, the use by the population of vulnerable natural areas devoid of means to cope with the negative manifestations of heavy rainfall events, contribute to enhance the performances of the consequences of extreme events.

No verão do ano 2000, um evento extremo de chuva ocorreu em Campos do Jordão, causando deslizamento de encostas em vários pontos da área urbana, em bairros considerados de risco. Este evento provocou a morte de 10 pessoas e um saldo de aproximadamente 3000 desabrigados. Os impactos ambientais e sociais desse acontecimento foram catastróficos. A ocupação de encostas, de maneira geral, é feita de maneira desordenada onde se verifica a remoção da vegetação existente para a construção das moradias de baixo padrão, processo que altera a morfodinâmica local e traz implicações para a própria população.No caso específico de Campos do Jordão, houve um grande crescimento da ocupação das encostas entre os anos de 1986 e 2003, principalmente nas áreas com declividade superior a 45 áreas consideradas de alto risco para a construção de moradias mas que mesmo assim, são invadidas e ocupadas irregularmente. A partir do evento de chuvas/deslizamentos ocorrido no ano 2000, a Prefeitura Municipal de Campos do Jordão passou a intervir, de forma mais intensa e sistematizada, na busca de soluções para gestão das áreas de risco, por exemplo, com a aquisição de áreas para formação de loteamentos onde serão vendidos terrenos para as famílias que ocupam as áreas de risco muito alto. / On the 2000 Summer, an extreme rain event occurred in Campos do Jordão, causing landslide of the slopes in several points of the urban area in places considered on risk.This event causes the death of ten people an approximately 3000 (three thousand) homelesses. The social and environment impacts of this event were catastrophic. The occupation of the slopes, in general, is made in a disorganized way where it checked the removal of the existing vegetation for houses building, process that changes the morfodynamic local and brings implications to the own population. In the specific case of Campos do Jordão, there was a great increasing of the slopes occupation between 1986 and 2003, mainly in areas with superior slopes up 45 considered as high risk to the dweeling construction even so, are irregulary invaded and occupated. From the landslides/rain events onwards occurred on 2000, the Municipal Prefectures of Campos do Jordão, started to intervene on a systematic and intense way, in search of solutions for management of risk areas, for example, with the acquisition of areas to form portions that will be saled on pieces to the families that occup very high risk areas.

Increasing global mean temperature or global warming has the potential to affect the hydrologic cycle. In the 21st century, according to the UN Intergovernmental Panel on Climate Change (IPCC), alterations in the frequency and magnitude of high intensity rainfall events are very likely. Increasing trend of urbanization across the globe is also noticeable, simultaneously. These changes will have a great impact on water infrastructure as well as environment in urban areas. One of the impacts may be the increase in frequency and extent of flooding. India, in the recent years, has witnessed a number of urban floods that have resulted in huge economic losses, an instance being the flooding of Mumbai in July, 2005. To prevent catastrophic damages due to floods, it has become increasingly important to understand the likely changes in extreme rainfall in future, its effect on the urban drainage system, and the measures that can be taken to prevent or reduce the damage due to floods. Reliable estimation of future design rainfall intensity accounting for uncertainties due to climate change is an important research issue. In this context, rainfall intensity-duration-frequency (IDF) relationships are one of the most extensively used hydrologic tools in planning, design and operation of various drainage related infrastructures in urban areas. There is, thus, a need for a study that investigates the potential effects of climate change on IDF relationships. The main aim of the research reported in this thesis is to investigate the effect of climate change on Intensity-Duration-Frequency relationship in an urban area. The rainfall in Bangalore City is used as a case study to demonstrate the applications of the methodologies developed in the research Ahead of studying the future changes, it is essential to investigate the signature of changes in the observed hydrological and climatological data series. Initially, the yearly mean temperature records are studied to find out the signature of global warming. It is observed that the temperature of Bangalore City shows an evidence of warming trend at a statistical confidence level of 99.9 %, and that warming effect is visible in terms of increase of minimum temperature at a rate higher than that of maximum temperature. Interdependence studies between temperature and extreme rainfall reveal that up to a certain range, increase in temperature intensifies short term rainfall intensities at a rate more than the average rainfall. From these two findings, it is clear that short duration rainfall intensities may intensify in the future due to global warming and urban heat island effect. The possible urbanization signatures in the extreme rainfall in terms of intensification in the evening and weekends are also inferred, although inconclusively. The IDF relationships are developed with historical data and changes in the long term daily rainfall extreme characteristics are studied. Multidecedal oscillations in the daily rainfall extreme series are also examined. Further, non-parametric trend analyses of various indices of extreme rainfall are carried out to confirm that there is a trend of increase in extreme rainfall amount and frequency, and therefore it is essential to the study the effects of climate change on the IDF relationships of the Bangalore City. Estimation of future changes in rainfall at hydrological scale generally relies on simulations of future climate provided by Global Climate Models (GCMs). Due to spatial and temporal resolution mismatch, GCM results need to be downscaled to get the information at station scale and at time resolutions necessary in the context of urban flooding. The downscaling of extreme rainfall characteristics in an urban station scale pose the following challenges: (1) downscaling methodology should be efficient enough to simulate rainfall at the tail of rainfall distribution (e.g., annual maximum rainfall), (2) downscaling at hourly or up to a few minutes temporal resolution is required, and (3) various uncertainties such as GCM uncertainties, future scenario uncertainties and uncertainties due to various statistical methodologies need to be addressed. For overcoming the first challenge, a stochastic rainfall generator is developed for spatial downscaling of GCM precipitation flux information to station scale to get the daily annual maximum rainfall series (AMRS). Although Regional Climate Models (RCMs) are meant to simulate precipitation at regional scales, they fail to simulate extreme events accurately. Transfer function based methods and weather typing techniques are also generally inefficient in simulating the extreme events. Due to its stochastic nature, rainfall generator is better suited for extreme event generation. An algorithm for stochastic simulation of rainfall, which simulates both the mean and extreme rainfall satisfactorily, is developed in the thesis and used for future projection of rainfall by perturbing the parameters of the rainfall generator for the future time periods. In this study, instead of using the customary two states (rain/dry) Markov chain, a three state hybrid Markov chain is developed. The three states used in the Markov chain are: dry day, moderate rain day and heavy rain day. The model first decides whether a day is dry or rainy, like the traditional weather generator (WGEN) using two transition probabilities, probabilities of a rain day following a dry day (P01), and a rain day following a rain day (P11). Then, the state of a rain day is further classified as a moderate rain day or a heavy rain day. For this purpose, rainfall above 90th percentile value of the non-zero precipitation distribution is termed as a heavy rain day. The state of a day is assigned based on transition probabilities (probabilities of a rain day following a dry day (P01), and a rain day following a rain day (P11)) and a uniform random number. The rainfall amount is generated by Monte Carlo method for the moderate and heavy rain days separately. Two different gamma distributions are fitted for the moderate and heavy rain days. Segregating the rain days into two different classes improves the process of generation of extreme rainfall. For overcoming the second challenge, i.e. requirement of temporal scales, the daily scale IDF ordinates are disaggregated into hourly and sub-hourly durations. Disaggregating continuous rainfall time series at sub-hourly scale requires continuous rainfall data at a fine scale (15 minute), which is not available for most of the Indian rain gauge stations. Hence, scale invariance properties of extreme rainfall time series over various rainfall durations are investigated through scaling behavior of the non-central moments (NCMs) of generalized extreme value (GEV) distribution. The scale invariance properties of extreme rainfall time series are then used to disaggregate the distributional properties of daily rainfall to hourly and sub-hourly scale. Assuming the scaling relationships as stationary, future sub-hourly and hourly IDF relationships are developed. Uncertainties associated with the climate change impacts arise due to existence of several GCMs developed by different institutes across the globe, climate simulations available for different representative concentration pathway (RCP) scenarios, and the diverse statistical techniques available for downscaling. Downscaled output from a single GCM with a single emission scenario represents only a single trajectory of all possible future climate realizations and cannot be representative of the full extent of climate change. Therefore, a comprehensive assessment of future projections should use the collective information from an ensemble of GCM simulations. In this study, 26 different GCMs and 4 RCP scenarios are taken into account to come up with a range of IDF curves at different future time periods. Reliability ensemble averaging (REA) method is used for obtaining weighted average from the ensemble of projections. Scenario uncertainty is not addressed in this study. Two different downscaling techniques (viz., delta change and stochastic rainfall generator) are used to assess the uncertainty due to downscaling techniques. From the results, it can be concluded that the delta change method under-estimated the extreme rainfall compared to the rainfall generator approach. This study also confirms that the delta change method is not suitable for impact studies related to changes in extreme events, similar to some earlier studies. Thus, mean IDF relationships for three different future extreme events, similar to some earlier studies. Thus, mean IDF relationships for three different future periods and four RCP scenarios are simulated using rainfall generator, scaling GEV method, and REA method. The results suggest that the shorter duration rainfall will invigorate more due to climate change. The change is likely to be in the range of 20% to 80%, in the rainfall intensities across all durations. Finally, future projected rainfall intensities are used to investigate the possible impact of climate change in the existing drainage system of the Challaghatta valley in the Bangalore City by running the Storm Water Management Model (SWMM) for historical period, and the best and the worst case scenario for three future time period of 2021–2050, 2051–2080 and 2071–2100. The results indicate that the existing drainage is inadequate for current condition as well as for future scenarios. The number of nodes flooded will increase as the time period increases, and a huge change in runoff volume is projected. The modifications of the drainage system are suggested by providing storage pond for storing the excess high speed runoff in order to restrict the width of the drain The main research contribution of this thesis thus comes from an analysis of trends of extreme rainfall in an urban area followed by projecting changes in the IDF relationships under climate change scenarios and quantifying uncertainties in the projections.