148 research outputs found

    Indexing floodplain effects for flood estimation

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    Combining flood estimation methodologies with hydraulic models to provide a detailed and spatially coherent representation of flood risk can be problematic. One potential difficulty is that of double-accounting the attenuating effect of floodplain storage. This occurs when effects are represented in both the flood frequency estimation of the flow and also in hydraulic modelling and can be particularly important in the context of the increasing desire to combine hydrological and hydraulic models in a manner that provides a detailed and spatially coherent representation of flood risk. This paper presents an empirically derived index that represents floodplain effects on flood magnitude. A HEC-RAS 1-D hydraulic model was used to generate downstream flow hydrographs in a generalised river reach for defined upstream hydrographs encompassing a range of flows and durations. Geometrical and resistance properties in the reach were systematically varied. Relative attenuations were determined by analysing differences in upstream and simulated downstream hydrographs. The index was derived by relating flood peak attenuations to the channel characteristics in each simulation in a multivariate regression analysis

    Agent-based modeling and simulation to assess flood preparedness and recovery of manufacturing small and medium-sized enterprises

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    Severe flooding has caused major damage and disruption to households, communities, businesses, and organizations in many parts of the world. In the United Kingdom (UK), flooding has been responsible for significant losses to the economy due to its impact on businesses, 99.9% of which are Small and Medium-sized Enterprises (SMEs). This paper reports on how agent-based modeling and simulation has been developed and used to assess the effectiveness of a range of physical/structural and social preparedness adaptation measures that can be implemented by manufacturing SMEs to reduce the impact of and expedite recovery from a major flood event. Results indicate the effectiveness of combinations of these adaptation measures in relation to a one in 1000 year flood event that has been modeled and simulated in a key industrial area of the UK which, in addition to having experienced severe flooding, has a high concentration of SMEs

    Building urban flood resilience with rainwater management

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    This is the final version.Urban stormwater is a significant hazard and a promising resource. Recent studies have highlighted that effective and smart rainwater management provides both flood and drought mitigation benefits through capturing extreme rainfall and contributing to water demands at the property scale [1], indicating opportunities to upscale benefits across urban areas. However, for stormwater management to reach this potential, planners must move away from ad-hoc and localised application towards integrated catchment-wide strategies, capable of delivering catchment-wide benefits. New planning methodologies are required to achieve this shift and key questions remain regarding how strategies could be applied to maximise flood resilience, supply augmentation and cost-effectiveness across urban scales. This study responds to these emerging challenges through assessing the potential benefits of catchment-scale rainwater management across the Pandon Dene surface water catchment in Newcastle-upon Tyne, NE England.Engineering and Physical Sciences Research Council (EPSRC

    ^{59}Co NMR evidence for charge ordering below T_{CO}\sim 51 K in Na_{0.5}CoO_2

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    The CoO2_{2} layers in sodium-cobaltates Nax_{x}CoO2_{2} may be viewed as a spin S=1/2S=1/2 triangular-lattice doped with charge carriers. The underlying physics of the cobaltates is very similar to that of the high TcT_{c} cuprates. We will present unequivocal 59^{59}Co NMR evidence that below TCO51KT_{CO}\sim51 K, the insulating ground state of the itinerant antiferromagnet Na0.5_{0.5}CoO2_{2} (TN86KT_{N}\sim 86 K) is induced by charge ordering.Comment: Phys. Rev. Lett. 100 (2008), in press. 4 figure

    The Influence of Floodplain Restoration on Flow and Sediment Dynamics in an Urban River

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    A study of floodplain sedimentation on a recently restored floodplain is presented. This study uses a two-dimensional hydro-morphodynamic model for predicting flow and suspended sediment dynamics in the downstream of Johnson Creek, the East Lents reach, where the bank of the river has been reconfigured to reconnect to a restored floodplain on a 0.26 km2 (26-ha) site. The simulation scenarios include event-based (10, 50, 100, and 500 year floods) deposition modelling of flood events and long-term modelling using the 64 historical flood events between 1941 and 2014. Simulation results showed that the restored floodplain significantly attenuates the upstream flood peak by up to 25% at the downstream. Results also indicated that approximately 20-30% of sediment from the upstream is deposited on the East Lents floodplain. Further, deposited sediment over the simulated period (1941-2014) is approximately 0.1% of the basin’s flood storage capacity, however the reduction in the storage does not offset the overall flood resilience impact of the flood basin. The sediment conservation at the East Lents flood basin as predicted by the model reduces the annual sediment loading of the Johnson Creek by 1% at the confluence with Willamette River, providing both water quality and flood resilience benefits further downstream

    Influence of Sea Surface Temperature on the Gonadal development of Sea urchin Temnopleurus toreumaticus from the Gulf of Mannar, South East Coast of India

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    This study was conducted for a 20 months period from October 2013 to May 2015 in Gulf of Mannar, south east coast of India. During the investigation the abiotic factors viz., Sea surface temperature (SST), Daylight photoperiod and atmospheric temperature data were collected from International comprehensive Ocean Atmospheric Database (ICOADS) and the reproductive cycle of the sea urchin was studied from the monthly sampling of sea urchin collected from Vedalai landing centre in Gulf of Mannar. The gonads were studied to calculate Gonad index as well histological to categories them into four different stages of the development and this data was compared with abiotic factors to study the influence of it on the reproductive behaviour of sea urchin. The data were analyzed statistically through Pearson correlation and it was found negative between mean monthly gonad index and day length photoperiod, as well as with SST. This clearly indicates that the gonadal development in sea urchin is very much influenced by these two abiotic factors; however other nutritional factors might play greater role in the development gonad

    Agent-based modelling and inundation prediction to enable the identification of businesses affected by flooding

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    Flooding continues to cause significant disruption to individuals, organisations and communities in many parts of the world. In terms of the impact on businesses in the United Kingdom (UK), flooding is responsible for the loss of millions of pounds to the economy. As part of a UK Engineering and Physical Sciences Research Council funded project on flood risk management, SESAME, research is being carried out with the aim of improving business response to and preparedness for flood events. To achieve this aim, one strand of the research is focused on establishing how agent-based modelling and simulation can be used to evaluate and improve business continuity. This paper reports on the development of the virtual geographic environment (VGE) component of an agent-based model and how this has been combined with inundation prediction to enable the identification of businesses affected by flooding in any urban area of the UK. The VGE has been developed to use layers from Ordnance Survey’s MasterMap, namely the Topography Layer, Integrated Transport Network Layer and Address Layer 2. Coupling the VGE with inundation prediction provides credibility in modelling flood events in any area of the UK. An initial case study is presented focusing on the Lower Don Valley region of Sheffield leading to the identification of businesses impacted by flooding based on a predicted inundation. Further work will focus on the development of agents to model and simulate businesses during and in the aftermath of flood events such that changes in their behaviours can be investigated leading to improved operational response and business continuity

    Flood risk management of a small urban river using a sustainable urban drainage system: Wortley Beck, Leeds, UK

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    This paper explores potential flood resilience approaches for the highly urbanised Wortley Beck river basin, south west of the City of Leeds, UK. Integrated 1D and 2D hydrodynamic modelling, using the ISIS and TUFLOW has been utilised to explore potential impact of SuDS on the flood hazard for three (1:15, 1:50 and 1:100) flood events. A direct rainfall runoff modelling approach has been employed to implicitly incorporate SuDS features within the case study region. Results indicate that SuDS reduce the flood hazard in downstream for all three (1:15, 1:50 and 1:100) flood events, with the effect more pronounced for the lowest rainfall (1:15) event
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