No description available.

No description available.

Dagens dagvattenhantering i urbana områden är inte hållbar vilket resulterar i översvämningar, förfallav naturen och hälsoproblem. Fortsatt urbanisering och klimatförändringar påverkar systemet negativtoch kräver en brådskande förändring. Ett alternativ till traditionell dagvattenhantering är naturligalösningar, NBS, definierat som inspiration och användandet av naturen för att hanterasamhällsproblem. Det kan ge resilienta och adaptiva lösningar som främjar biologisk mångfald,människors välbefinnande, ett lovande alternativ för att tackla de här problemen. NBS är dock förenatmed osäkerheter såsom kunskapsbrister kring prestanda, underhåll och möjliga negativakonsekvenser. Även om NBS kan anses vara en hållbar lösning är den inte frekvent implementerad iurbana områden. Den här uppsatsen använder fallstudien Årstafältet för att samla och analysera föroch nackdelar av NBS och traditionella dagvattenlösningar. Med hjälp av intervjuer med inblandadeaktörer, plandokument, regleringar och en litteraturstudie visar resultatet att NBS kan ge ett resilient,flexibelt och kostnads-effektivt system med multipla fördelar vilket kan uppfylla t.ex. vattendirektivet(WFD), hållbarhetsmålen (SDGs) och miljömålen. Det traditionella systemet är en oelastisk lösninginkapabel att förebygga miljöförändringarna och med frekvent breddning av smutsigt dag- ochavloppsvatten. Systemet är sett som oförmögen att uppfylla mål kring biologisk mångfald, miljömåloch reningskrav och därav en ohållbar lösning. Existerande infrastruktur och ett välarbetat arbetssättgör att det traditionella systemet dock fortfarande förlitas på. Problem som identifierades med NBSvar kunskapsbrister, en ny process för att hantera dagvatten som inkluderar en omfattande inblandningav aktörer, övergångsbarriärer, oklarheter gällande ansvarsfördelning, brist på deltagande frånallmänheten, avsaknad av tekniskt vägledning, bristen och behovet av att kontrollera och mätalösningar samt beroendet av entusiastiska aktörer. / The current stormwater management in urban areas is not sustainable, resulting in frequent floodingevents, degeneration of the environment and human health issues. Increased urbanization and climatechange negatively impact the outcome and calls for an urgent change. An alternative to traditionalstormwater management is nature-based solution, NBS, broadly defined as the usage or inspiration ofnature to address societal challenges. It can provide resilient, adaptive solutions which promotebiodiversity and human well-being, a solution to address these challenges. NBS is however unitedwith uncertainties such as knowledge gaps of performance, maintenance, efficiency and potentialtradeoffs. Although NBS can be considered a sustainable solution, it is not widely adopted andimplemented in urban areas. This thesis uses the case study of Årstafältet project to identify andanalyze opportunities and challenges of NBS and conventional drainage system. Based on interviewswith involved actors, plans, regulation and a conceptual framework, the result shows that NBS canprovide a resilient, flexible and cost-effective system with multiple benefits which addresses allaspects of sustainability. It is widely supported by laws and policies, addressing the EU WaterFramework Directive (WFD), the Sustainable Development Goals (SDGs) and the EnvironmentalObjectives for example. The conventional drainage system is an inflexible system unable to mitigateclimate change, with frequent overflows (CSOs) of dirty storm and sewage water. It is unable toachieve biodiversity goals, environmental objectives and water quality targets and thus recognized asan unsustainable solution. With an existing infrastructure and an established way of managing theconventional drainage system, it is however still relied on. Identified challenges of NBS areknowledge gaps, a new management process with extensive stakeholder involvement, transitionbarriers, unclear division of responsibilities, lack of public participation and technical guidance, lackof and the need to monitor solutions and the dependence on enthusiastic actors.

Indiana University-Purdue University Indianapolis (IUPUI) / Although many studies have investigated the impact of tile drainage on nitrate and pesticide export from cropland to streams, little information is known about the primary hydrological controls of tile flow response to precipitation events and its impact on N, P and C transport in artificially drained landscapes of the US Midwest. This study investigated 1) the relationship between precipitation characteristics and tile flow response at a high temporal resolution during storms; 2) the relative importance of macropore and matrix flow in tile flow and in N, P and C transport to tile drains; and 3) the impact of storm characteristics in N, P and C fluxes/export rates. The study was conducted between April and June 2008, in an agricultural tile drained soybean field, representative of agro-ecosystems of the US Midwest near Indianapolis, IN. For the 8 storms analyzed, results showed that bulk precipitation amount was the best predictor of mean and maximum tile flow, time to peak and runoff ratio. The contribution of macropore flow to total flow increased with precipitation amount, representing between 11% and 50% of total drain flow, with peak contributions between 15% and 74% of flow. For large storms (> 6 cm rainfall), cations data indicated a dilution of groundwater with new water as discharge peaked. Although no clear indication of dilution was observed for smaller storms (< 4 cm rainfall), macropore flow still contributed between 11% and 17% of total flow. For large storms, the transport of dissolved organic carbon (DOC), total phosphorous (TP) and soluble reactive phosphorus (SRP) was found to be regulated mainly by macropore flow while nitrate transport was regulated mainly by matrix flow. For smaller storms, macropore flow dominated DOC and TP transport while SRP and nitrate transport was dominated by matrix flow. These results significantly increase our understanding of the hydrological functioning of tile drained fields and its interaction with N, P and C transport in spring, which is the time of the year during which most water and N losses from tile drains occur in the Midwest.

No description available.

No description available.

Draining the Everglades has been the central issue of southern Florida ever since the state was apnexed by the U.S. in .1845. Not until the twentieth century did water resource managers realize the detrimental repercussions of draining the Everglades. Now, south Florida finds itself in a state of crisis. In the aquifers and Lake Okeechobee water levels have dropped. Nutrient pollution has caused cattails to overrun the saw grass, from which the Everglades get there name. Continued development has placed more strain on the Everglades, and human water uses have often.been put under restraints due to lack of water. In order to understand the political and social priorities that guided the various water management agencies in the Everglades to this state of crisis, this research will review key events throughout the history of the Everglades, specifically analyzing what led to these events and how management reacted to them. This research will then analyze the priorities demonstrated through the various stages of water management in order to determine the presence of underlying social attitudes. Finally, this research will analyze the social attitudes as they pertain to water management in order to determine the presence of governing attitudes and paradigms, as well as implications of current attitudes on the future of the Everglades.

A cidade de Teresina, capital do estado do PiauÃ, à entrecortada pelos rios ParnaÃba e Poty, sendo o Ãltimo afluente ao primeiro, dentro da zona urbana de Teresina. O rio ParnaÃba controla uma bacia hidrogrÃfica de 237.000 km a montante de Teresina, enquanto que o rio Poty, controla uma bacia hidrogrÃfica de 51.400 kmÂ. A caracterÃstica hidrolÃgica principal das cheias nos rios ParnaÃba e Poty à que as enchentes do rio ParnaÃba sÃo passiveis de controle parcial a partir das comportas da Usina HidroelÃtrica (UHE) Boa EsperanÃa, ao passo que, tal controle inexiste para as cheias advindas da bacia do rio Poty. O presente estudo analisou a questÃo da interferÃncia das cheias do rio Poty com o sistema de microdrenagem formado pelas galerias urbanas transversais afluentes ao mesmo, constatando a possibilidade de afogamento e remanso do rio Poty sobre as galerias em determinadas condiÃÃes de cheias hidrolÃgicas. Foi analisado o caso da cheia do ano de 2009 no sistema de drenagem transversal ao rio Poty, que causou a inundaÃÃo de diversos bairros, em virtude do remanso decorrente da elevaÃÃo da cota do nÃvel d Ãgua do rio Poty acima da cota das geratrizes superiores das galerias transversais. Foi constatado que, em virtude das cotas de desague das galerias do bairro Primavera no rio Poty, as cheias deste rio com perÃodo de retorno bianual (TR = 2 anos), sÃo suficientes para promover o fluxo inverso no sistema de galerias e a inundaÃÃo de Ãreas urbanas conectadas. Conclui-se que hà necessidade de intervenÃÃes estruturais para solucionar este problema, a partir, ou do controle das cheias no rio Poty por meio de reservatÃrio de retenÃÃo, tal como a futura barragem Castelo do PiauÃ, ou a partir de emprego de bacias de detenÃÃo urbanas, comportas de marà e sistema de bombeamento das Ãguas pluviais das bacias interconectadas com o rio Poty. / The city of Teresina, Piauà state capital, is intersected by rivers ParnaÃba and Poty, the last tributary to the first, within the urban area of &#8203;&#8203;Teresina. The ParnaÃba River controls a watershed of 237,000 square kilometers upstream of Teresina, while the river Poty, controls a watershed of 51,400 kmÂ. The main hydrological characteristic of floods in the ParnaÃba and Poty rivers is that ParnaÃba River floods are likely to partial control from the gates of Hydroelectric Power Plant (HPP) Good Hope, whereas such control does not exist to floods arising from the Poty River basin. This study examined the question interference flooding of Poty river with minor drainage system formed by affluent urban galleries cross the same, noting the possibility of drowning and backwater Poty river on the galleries certain conditions of hydrological floods. Analyzed the case of the full 2009 in the transverse drainage system to Poty River, which caused the flood diverse neighborhoods, because of backwater due to the increase of share of the Poty river water level d greater than the level of the upper generating lines of the galleries cross. It was found that, because of desague quotas of galleries Spring neighborhood in Poty river, the floods of the river with two-year return period (TR = 2 years), are sufficient to promote the reverse flow in the gallery system and the Flood connected urban areas. It is concluded that there is need for structural measures to solve this problem, from, or control of Poty river floods through the sump, as a future dam Castle of PiauÃ, or from use of urban detention basins, locks tide and pumping system of rainwater in interconnected basins with the Poty River.

La constante de temps du débit de base (τ) représente le temps moyen pour que l'eau souterraine arrive à la rivière depuis la zone de recharge dans un bassin donné. C’est un élément clé pour simuler le débit de base dans les modèles simples des eaux souterraines, tels qu’ORCHIDEE. τ a été estimée à l’échelle globale à partir d’une solution de l’équation de Boussinesq pour les aquifères libres en pente. τ dépend de la porosité efficace, de la transmissivité, de la pente de l'aquifère et de la densité de drainage (δ). Calculées à partir de bases de données globales, les valeurs de τ sont surestimées par rapport à celles obtenues par analyse des courbes de récession. Une analyse de sensibilité a montré que la transmissivité et δ sont les principales sources d’incertitude de τ. L’extraction d’un nouveau réseau de drainage, qui dépend de la lithologie, du climat, de la pente et des δ observées, a permis d’obtenir des δ conformes aux valeurs observées aux échelles régionales et à la variabilité spatiale. L’utilisation de ces nouvelles δ et la combinaison de deux jeux de données de conductivité hydraulique pour le sol et l’aquifère a réduit τ de deux ordres de grandeur, mais les valeurs calculées restent surestimées. L’utilisation de τ dans le modèle de surface ORCHIDEE a montré une forte sensibilité du débit simulé à l’augmentation de τ, qui dégrade les débits simulés par rapport aux observations. Cette méthodologie nécessite des valeurs plus adaptées de transmissivité et porosité efficace par rapport aux jeux de données globaux actuellement disponibles pour obtenir des valeurs de τ plus proches de celles attendues et qui permettent de reproduire les débits observés. / The base flow time constant (τ) represents the mean amount of time the groundwater takes to reach the stream from the recharge zone in a given watershed. τ is a key element to simulate base flow in simple groundwater models as ORCHIDEE. τ was estimated at global scale based on a solution of the Boussinesq equation for unconfined sloping aquifers. τ depends on the effective porosity, transmissivity, aquifer slope, and drainage density (δ). When estimated from global available datasets, τ results are overestimated when compared to recession analysis results. A sensitivity analysis showed that transmissivity and δ are the main uncertainty sources of τ. A river network extraction based on lithology, climate, slope, and observed δ allowed to obtain δ values close to reference data and spatially variable at regional scale. The use of a new δ and the combination of two hydraulic conductivity datasets of soil and aquifer reduced τ of two orders of magnitude, however the values remained overestimated. The use of τ in ORCHIDEE land surface model showed a strong sensitivity of the river discharge buffer effect to τ, which worsen simulated river discharge when compared to observations. This methodology needs more adequate porosity and transmissivity values when compared to global available datasets that will result in close results to observed river discharge.

<p> Studies to date involving the network properties of drainage systems have been theoretical in nature; and the environmental implications of these network characteristics have not been exploited to the extent that would appear warranted. This situation exists due to the lack of an accurate data source. Many studies have recognized this. inadequacy of the conventional data sources to meet the necessary requirements of efficiency (in data production and handling), accuracy, consistency and uniformity. </p> <p> The present study demonstrates that high altitude, small scale colour infrared photography is capable of providing drainage network data that fulfill all these basic requirements. Data derived from the three drainage basins, mapped from a variety of data sources, demonstrate three important points. The level of detail obtained from the small scale colour infrared photography far exceeds that available from more traditional data sources. Secondly, these network data are statistica+ly consistent with the traditional data sources. Thirdly, the basin characteristics derived from the high altitude data source show a marked association with the known surficial environments and an expected variation from one surficial environment to another. </p> / Thesis / Master of Arts (MA)