37,404 research outputs found
When ENSO Reigns, It Pours: Climate Forecasts in Flood Planning
Get PDFRecent scientific and technical advances have increased the potential use of longterm seasonal climate forecasts for improving water resource management. This paper examines the role that forecasts, in particular those based on the El Nino-Southern Oscillation (ENSO) cycle, can play in flood planning in the Pacific Northwest. While strong evidence of an association between ENSO signals and flooding in the region exists, this association is open to more than one interpretation depending on: a) the metric used to test the strength of the association; b) the definition of critical flood events; c) site-specific features of watersheds; and d) the characteristics of flood management institutions. A better understanding and appreciation of such ambiguities, both institutional and statistical, is needed to facilitate the use of climate forecast information for flood planning and response.Flooding, Climate, ENSO, Water Resources Planning, Water Policy, Water Management
Evaluation of Urban Polder Drainage System performance in Jakarta. Case Study Kelapa gading Area
No full textKelapa Gading area is located in the plains of North Jakarta about 6 km from the coastline of Jakarta Bay. Kelapa Gading area covers 1288 ha it consists of three large compartments and next to that the Kodamar Unit separated system from Kelapa Gading excess water of the area is discharged to Sunter river and Pertukangan River. The area is regularly flooded, especially during the wet season. Kelapa Gading area is in particular facing flood problem since Jakarta __ the capital city of Indonesia __ became the primary growth machine of the nation. Among others, this has resulted in suburbanization in Jakarta’s neighbouring regions. Land subsidence, which occurs due to huge groundwater extraction, and climate change are also contributing to flooding problem due to hydrologic changes that alter the magnitude and frequency of peak flows and sea level rise. Four main objectives are the basis for this research. First is describing the existing urban drainage and flood protection systems in Kelapa Gading area and other satellite cities (JABODETABEK). Second is analysing the possible impacts of land subsidence and sea level rise on inundated area. Next are some measures that would have to be taken into consideration in order to reduce the flooded area and provide adequate urban drainage and flood protection especially when the impacts of land subsidence and sea level rise are taken into account. The structural measures were studied by considering hydrologic and hydraulic conditions and by carrying out hydrodynamic modelling (DUFLOW) as tools for decision support which may evaluate options in developing urban drainage and flood protection scenarios for Kelapa Gading area based on a design rainfall with a chance of occurrence of 4% per year or the return period of 25 years. Scenarios on the improvement of the macro urban drainage system and the selected river basin were developed as follows: Scenario 1. The existing urban drainage was considered as one system with the sedimentation in the urban canal system. This represents the existing condition and has been used as the basic case; Scenario 2. Similar with the first scenario 1 but the designed urban canal profiles are used; Scenario 3. Each compartment is considered as a single polder; Scenario 4. To analyse the effect of land subsidence and sea level rise. In this case 1.25 m of land subsidence and 0.15 m of sea level rise will be considered for the 25 years time interval; The results indicate that due to lower topographic conditions in adjacent area caused by land subsidence and sea level rise, a combine system consisting of gravity drainage and pumping are primed to meet the future conditions of drainage system and flood protection in the future in Kelapa Gading area. Therefore an urban polder with its properties is proposed to be constructed
Risk based life-cycle planning for flood-resilient critical infrastructure
No full textThe paper presents a risk assessment model, developed in the project oVERFLOw and further implemented in the project CROSScade, for determining the direct and indirect impacts of flooding hazards. As a consequence of flooding, transport infrastructure and flood protection systems can be significantly damaged and cause cascading effects on other infrastructure. To achieve flood resilient infrastructure, it is necessary to assess the vulnerability of critical assets in the affected area. The model uses novel vulnerability assessment methods for embankments and bridges exposed to different flood hazard scenarios allowing the asset owners to understand risk and performance of their infrastructure. Scarce financial resources are allocated on the critical assets allowing significant cost savings and avoiding the waste of non-renewable resources in strengthening large sections which have sufficient resilience. The consequence analysis is based on an improved quantification model for direct and indirect impacts of different flood hazard scenarios used for risk mapping of the affected area.Geo-engineerin
Understanding defence failures and coastal flood events: a case study approach
No full textExtreme sea level events are a current global threat, whilst sea-level rise (SLR) and climate change over the 21st century will increase the frequency and severity of flooding in most coastal regions. Numerical model simulations can help to understand and predict coastal floods (e.g. flood mapping and forecasting) but in comparison to flood sources (waves and water levels) coastal flood pathways (defence failures and inundation) are presently less integrated within these models. This thesis develops and demonstrates a methodology to rapidly simulate and understand the consequences of coastal flood events, with an emphasis upon regions where the risks of flooding are not well understood and could change quickly with SLR. The Solent on the south coast of England is the case study, and is prone to frequent flooding. This region is currently differentiated from the UK east and west coasts by experiencing smaller storm surges, and is characterised by undefended sections of shoreline and small floodplains. Within the Solent is Portsmouth, a city of national flood significance (only London and Hull contain more people considered at risk of coastal flooding in the UK). However, life threatening floods have not occurred in living memory. An integrated modelling approach is developed, coupling loads and defence failures with two-dimensional simulations of floodplain inundation. Observations collated from a real storm surge and flood event are shown to generate a validation data set, which indicates that this model can predict floodplain water levels to a good level of accuracy, whilst highlighting implications of such data collection. Solent-wide analysis includes simulations of hypothetical coastal flood events based upon scenarios that cover the full range of coastal loadings (realistic waves and water levels) and defence failures (overflow, outflanking, overtopping and breaching). More detailed case-studies are also applied at two sites within the region (including Portsmouth). This analysis generates peak flood water depths and an overview of impacts across this spectrum of possible floods.This research improves the existing knowledge of coastal flooding in the case study, and highlights a number of generic concepts that should be applied to others. For example the combination of flood simulation methods with real flood event analysis is essential for optimising the interpretation of model outputs whilst supporting inferences about flood consequences associated with extreme loading events (including how these may change with SLR). Simple methods estimated that >24,000 properties are within a 1 in 200 year flood event outline; and incorporating defence failures, flood dynamics, validation and detailed case studies substantially refine the assessment of places likely to experience damages. Breach defence failures generate the worst flood impacts, although in the Solent this failure mechanism is presently less of a threat than outflanking, overflow and wave overtopping. The modelling system includes easily interpreted outputs, whilst being computationally fast; therefore with potential applications including supporting land-use and defence planning, and real-time flood forecasting and warning
Risk based inspection of flood defence dams: An application to grass revetments
No full textIn The Netherlands, inspection and maintenance are essential for maintaining stringent flood protection standards. Flood defences are assessed every 12 years to ensure they meet their risk-based safety standards,which are given as legally-binding maximum failure probabilities. Between assessments, flood defence managers are subject to risk-maintenance requirements: they must ensure that the failure probability of the defence does not increase in excess of its safety standard. However, there is no prescribed methodology to meet this requirement. In the study presented here, we developed a method which enables flood defence managers to derive inspection strategies using visual inspection data that will allow them to meet their risk-maintenance requirements.We applied the method to the assessment of grass revetments on the outer slope of the Oesterdam, one of the dams of the Dutch Delta Works. The application illustrates how – using visual inspection data, degradation information, and a failure mechanism model – inspection intervals can be derived that will ensure the risk-maintenance requirements are met.Accepted Author ManuscriptHydraulic Structures and Flood Ris
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Integrating flood management and agri-environment through washland creation in the UK.
Get PDFIn many river floodplains in the UK there has been a long history of flood
defence, land reclamation and water regime management for farming. In recent
years, changing policies with respect to farming, environment and flood
management are encouraging a re-appraisal of land use in rural areas. In
particular, there is scope to develop, through the use of appropriate
promotional mechanisms, washland areas which will simultaneously accommodate
winter inundation, support extensive farming methods, deliver environmental
benefits, and do this in a way which can underpin the rural economy. This paper
explores the feasibility of flood storage and washland creation, the likely
economic impacts (on the agricultural sector) of this type of development, and
the financial and institutional mechanisms required to achieve implementation.
The outcome is the identification and assessment of a washland package within
the UK agri-environment framework. However, given the diversity of circumstance
and practice, it is suggested that a range of options, and not just those
associated with management agreements and annual payments, is used for the
management and administration of washland areas
A framework for assessing information quality in asset management of flood defences
No full textFor asset management of flood defences a pivotal aspect is the quality and accessibility of available data and information. In the management of flood defences inThe Netherlands, safety assessments are conducted every twelve years. To assure the quality and consistency of these safety assessments, flood defence engineers have to make use of a comprehensive toolbox and a set of guidelines (WBI 2017). The safety assessment is one of the main starting points for the different asset management processes such as day-to-day maintenance and reinforcement/reconstruction. However, there is no clear method available to assess whether the underlying information is sufficient as a basis for decision making. In this study a framework has been developed that consists of methods for an assessment of the quality of information, an assessment of the use and accessibility of information, and a rational framework for assessing the costs and benefits of obtaining additional information. Whereas many frameworks for information management start from the information itself, here the starting point is the extent to which the behavior of a flood defence is understood, in relation to the decision or management process considered. The applicability of the framework is illustrated using various cases and has been tested in multiple workshops with experts in the field.Hydraulic Structures and Flood Ris
International dairy product aid & trade 1960s~1990s: focusing on the EU and India in operation flood
Get PDFThis thesis investigates the interrelationship between dairy aid and trade. After WW-II US dairy aid contributed to rises in consumption and sales in the Pacific; US domestic politics and Cold War strategy influenced aid programmes. Similarly, when dairy surpluses in the EEC (also known as the EC; currently the EU) coincided with shortages in India in the 1960s, the EEC sought to: maintain the CAP status quo, dispose of its "Butter Mountain", and earn political cachet such as the US enjoyed via PL 480 food aid - while assisting India. Proceeds from "monetised" EEC butter oil and milk powder donations were to be invested in Indian dairy infrastructure. As the largest Asian country with a "dairy culture", India was a suitable setting for Operation Flood (OF), the world's largest dairy development programme ca. 1970- 1996. Because so much debate on aid, trade and development can be illustrated by OF, this thesis chose India as its case study. Claims that dairying could benefit women and minorities attracted World Bank loans, but subjected OF to virulent charges of unmet goals. Worse, warned OF detractors, India could become permanently dependent on Europe’s lactic largess. OF officials countered that they were successfully carrying out their original mission to improve the dairy marketing system of India. Thesis maps and charts based on the Agrostat-PC database (FAQ) show India increased dairy production and consumption significantly during OF. As some comparable countries declined, India moved toward self-sufficiency and status as the world's number two milk producer. Proper pricing by Indian authorities ensured that dairy aid was not a long-term disincentive to farmers and, in the end, increased dairy autonomy. Prospects for "replication" of Operation Flood are limited by a lack of settings suitable for such programmes, and by reduced stocks available for aid. But dairy aid will have a continued role in emergency aid, and in structural adjustment in those poor countries whose food security declines as GATTAVTO liberalises international agricultural trade
Letter from W.H. Grattan Flood to Hagan
No full textHolograph letter from W.H. Grattan Flood, Rosemount, Enniscorthy (County Wexford), to Hagan. Enclosing his new hymn to 'Christ Our King' (printed hymn sheet with music by Grattan Flood, organist at Enniscorthy Cathedral). It has already proved very popular. Mentioning Fr. Pat Murphy's re-election at the Mission House, and Fr. Dan Quigley's promotion to Rosslare. Speaking of his sons, one in St. Peter's College, one a bank clerk in Sligo. According to rumour, the cardinalate goes to Dublin, Dr. McRory is appointed to Armagh, and 'the Rt. Rev. Mgr. J.H.' (Hagan) will be coadjutor of Ossory. Also stating that he has contributed to the new Grove's Dictionary of music and musicians
Alaskan Author and Historian Dan O'Neill
No full textDan O'Neill has become a living legend in Alaska. He is the author of The Firecracker Boys: H-Bombs, Inupiat Eskimos, and the Roots of the Environmental Movement; A Land Gone Lonesome: An Inland Voyage Along the Yukon River; The Last Giant of Beringia: The Mystery of the Bering Land Bridge, and recently Stubborn Gal: The True Story of an Undefeated Sled Dog Racer, a children's book published by the University of Alaska Press. Dan came to Alaska in 1975 and has done a variety of things including dog mushing, trapping, hunting, working in construction, and on the pipeline. As research associate at the UAF Oral History program, he produced radio and television documentaries for public broadcasting, and for several years he wrote a column of political opinion for the Fairbanks Daily News-Miner
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