Suchergebnisse

The Lisbon metropolitan region has grown rapidly in population since 1970, due largely to the immigration of people from former Portuguese colonies in Africa and from rural areas of the country in pursuit of higher living standards. Much of this population growth was accommodated clustered high-rise apartment blocks (many unpermitted) in the region west of Lisbon, in the municipalities Oeiras, Cascais, Sintra, and Amadora. These developments were largely unplanned, often did not provide for sewage treatment, and lack adequate mass transit or urban amenities such as parks and other open spaces. Moreover, because the main transport axes run east-west, it is difficult for residents of these apartment blocks to go the relatively short distance southward to the coast (e.g., only 10 km from Cacém to the coast). This region is drained by a set of subparallel streams (each draining about 20-50 km2), flowing roughly north-south through deeply incised valleys to debouch into the Atlantic between Lisbon and Cascais. With rapid urbanization peak runoff has increased, resulting from larger impervious surfaces and sewage from illegal housing settlements. Many reaches have been canalized within concrete walls to increase flood capacity, eliminating physical habitat complexity, and reducing amenity and recreational values. However, the urbanization has occurred mostly on uplands, leaving the bottomlands of the incised stream valleys in many reaches surprisingly unaltered. For decades, these drainages were largely neglected, managed mostly to convey floodwaters, although in some reaches there was strong informal use of the stream corridor and floodplains (such as garden plots). The Water Framework Directive (WFD) adopted by the EU Parliament (2000), has motivated extension and improvement of the regional sewer network to improve water quality. The WFD requires that all water bodies in member states achieve 'Good Ecological Status' by 2015, defined in terms of hydromorphological, biological, and physico-chemical quality elements of stream reaches, based on characteristics documented at reference sites. Located 15 km west of Lisbon, Ribeira da Barcarena-Jardas drains a 35 km2 catchment, whose uppermost reaches are forested, but otherwise alternates between urbanization and remnant agricultural and open-space uses. With improved sewage treatment and water quality, there is strong potential to preserve and restore ecological functions, consistent with goals of 'good ecological status.' As illustrated by the successful urban stream project in Cacém, there is tremendous potential for the stream corridor to provide parkland for the dense urban settlements. Through GIS analysis of remotely-sensed data, and field surveys of water quality, habitat structure, riparian vegetation, and fish populations, an interdisciplinary workshop of graduate students from Berkeley and Lisbon analyzed potential opportunities to enhance ecological values and human access along the stream. Our analysis indicated that implementation of stormwater management strategies via relatively unobtrusive retrofits of small open bits of urban land and floodplain within the catchment could mitigate many of the negative hydrologic effects of urbanization. By virtue of its linear nature, the stream corridors could provide pedestrian and bicycle connections from population centers (now under-served by parklands) to cultural features and to coastal beaches and trails. A trail could inspire similar efforts on neighboring, parallel basins that have undergone similar urbanization pressures and face similar challenges in providing underserved urban populations with access to recreation and contact with nature.

Intro -- Foreword -- Acknowledgments -- Contents -- Biographies -- List of Figures -- Chapter 1: Introduction -- References -- Part I: Big River Basins -- Chapter 2: Managing Floods in Large River Basins in the USA: The Mississippi River -- 2.1 Introduction -- 2.1.1 The Mississippi River Basin -- 2.1.2 Flood Risk Management in the Mississippi: History and Governance -- 2.2 The 2011 Mississippi River Flood: What Worked -- 2.3 Land-Use Conflicts in Floodways of the Mississippi River System -- 2.3.1 Introduction -- 2.3.2 The Birds Point: New Madrid Floodway -- 2.3.3 The Atchafalaya Floodway System -- 2.3.4 Risk Perception and Implications for Floodway Operation -- 2.3.5 Conclusion -- 2.4 Mississippi River Navigation System: A Major Contributor to Flooding -- 2.4.1 Introduction -- 2.4.2 The Upper Mississippi River Navigation System -- 2.4.3 River Training Structures in the Middle Mississippi River -- 2.4.4 Scientific Consensus Regarding Effects of River Training Structures and the Agency Response -- 2.4.5 Conclusion and Recommendations -- 2.5 Floodplains: Meeting the Needs of People and Nature -- References -- Chapter 3: Managing Floods in Large River Basins in the USA: The Sacramento River -- 3.1 Introduction -- 3.1.1 The Sacramento River Basin -- 3.1.2 The Sacramento Valley: A Highly Engineered System -- 3.1.3 Flood Risk Management in California: Governance System -- 3.2 Managing Floods in the California Central Valley -- 3.2.1 State Plan of Flood Control -- 3.2.2 Standard Levee Design -- 3.2.3 Heightened Protection for Urban Areas -- 3.2.4 National Flood Insurance Program -- 3.2.5 The Flood of 1986 -- 3.2.6 The Flood of 1997 -- 3.2.7 2003 Paterno Decision -- 3.3 The Central Valley Flood Protection Plan -- 3.3.1 Central Valley Flood Protection Plan -- 3.3.2 Handbook for Local Communities -- 3.3.3 Building Code -- 3.3.4 Flood Risk Notification.

Abstract. In France, sirens have been the principal tool designated to alert the population in the case of danger. However, their efficacity has not been objectively tested. Using a geographical information system, questionnaires, and surveys, we analyzed (1) the spatial distribution of the siren network in relation to the covered population, the hazards threatening different areas, and the actual number of disasters that have occurred in the past, (2) the political dilemma of activating sirens, and (3) the population's trust in sirens, as well as its understanding of expected behavior in the case of an emergency. Results show that, with a few exceptions, siren coverage in France is primarily determined by population density, not by the expected hazards or the cumulative number of past disasters. Sirens are also rarely used by the authorities. However, surveyed members of the population identify sirens as the most effective alert system over other alternatives such as cell-phone-based alerting tools. In a "mock" emergency most members of the public did not know how to respond in the case of an emergency, and even most of those who correctly identified the appropriate response prior to the exercise did not react upon later hearing the siren. To improve the effectiveness of the French siren network, we recommend (1) relocating sirens to optimize their efficiency, (2) complementing the sound of sirens with a clear and unified message, (3) reorganizing the competencies to activate siren alerts, and finally (4) improving public education on different alert tools and expected behavior during an emergency.

Throughout the world there is increasing public awareness of the importance of sustainable water management to meet both growing human demands and ecosystem needs. Predictions of increased climate variability and indicators of ecological and water quality deterioration have made water management a salient political issue, particularly in arid climate regions such as western North America and the Iberian Peninsula. In recent years, substantial effort has been focused on adopting sustainable water use practices and mitigating the impacts to natural rivers and streams resulting from human activities. Yet the restoration of natural biological communities has been more difficult than anticipated. Our inability to effectively restore and protect rivers and groundwater sources are in part due to the scale of environmental damage inflicted upon them, but also are a consequence of the legal and institutional frameworks under which water is managed. Assessments of the current state of the world's water resources suggest that conventional approaches to water management will be inadequate to sustainably balance human and ecosystem needs into the future. Furthermore, as nations around the world struggle with water management challenges, there has been little explicit attempt for one region to learn from the experience of another in approaching common problems. The European Union's Water Framework Directive (WFD) defines a new strategy for meeting human water demands while protecting environmental functions and values and may be helpful in informing water management practices and policies in other regions of the world. In the report we explore how the management approach described under the WFD compares to the legal and institutional system of a California river basin, managed under distinctly different principles and objectives. Through a theoretical application of the WFD, we highlight the critical water management challenges of northern California's Russian River basin and use the Directive's approach to develop strategic recommendations for water management reform.

As urban waterfronts around the world de-industrialize, cities are increasingly capitalizing on these opportunities to provide open space and alternative commuting routes along riverbanks, bringing residents and visitors back to the waterfronts. Cairo has remarkable opportunities to reconnect its people with the river that was historically its heart. With a population of over eleven million, Cairo is one of the densest cities in the world. The urban population is underserved by parks and other public open space. The need for open space—and the compelling attraction of the wide river—is put in sharp focus by a common sight on Cairo's traffic snarled bridges: families set up chairs and picnic on the sidewalks, overlooking the river and enjoying the open space, seemingly oblivious to the honking traffic that crawls besides them. Most of the river banks are fenced off from public access, but those that are open to the public are heavily used by Cairenes of all ages and all walks of life. The potential for human use of the river banks as open-space is enormous. In an intensive workshop involving 23 students and seven faculty from Cairo University (CU), The American University in Cairo (AUC), and the University of California, Berkeley (UCB), interdisciplinary teams systematically inventoried existing conditions along a 12-km reach of the Nile from Maadi to Tahrir Square, recording river-bank relations, building heights and conditions, circulation, and land-use. Based on this field work the student teams identified specific opportunities and challenges for interventions along the Nile. The low, wide flood plains along much of the Nile bank have great potential to be reconfigured into accessible and active public spaces. It was also identified as a feasible route for a continuous pedestrian/bicycle trail. Air quality measurements along the river bank showed that particulate matter levels along the flood plain were on average 30% lower than street level measurements. The presence of historic landmarks and tourist attractions along the Nile provides significant opportunities for urban revitalization and economic development. The excellent views of the Nile and the Pyramids of Giza available at many waterfront locations provide a unique opportunity that interventions along the waterfront can capitalize on. While some stretches of the Corniche have wide sidewalks that can be redesigned to function better as public spaces, the Nile bank provides ample opportunities for ecological restoration at many places. The presence of vacant lots along the Corniche provides opportunities for strategic developments and also for better open space connectivity with the rest of the city. The visible public interest in the limited ferry routes along the river illustrates the potential the Nile holds to function as a significant public transportation corridor if the city is able to expand the existing ferry system. There are also significant challenges related to existence of incongruent public and private land-uses along the Nile Corniche. Appropriate institutional and regulatory frameworks would be required to ensure that proposals for public space restructuring are implemented and maintained well. Urban waste management is a significant concern in Cairo and the Nile waterfront is no exception. Building on the identified opportunities and challenges, workshop participants developed a strategic plan for a longitudinally continuous trail network along the Nile with lateral connectivity to important nodes in Cairo. They also developed detailed plans for the revitalization of two key zones (Athur El Nabi and Old Cairo). The workshop ended just one week before the streets of Cairo became the venue for historic political demonstrations that eventually resulted in major political changes. While there have been many past efforts to rehabilitate the city and 'plan' the future growth of Cairo, including the 'Cairo 2050 Vision Plan' (a multi-year planning effort initiated by the Egyptian government and undertaken by international consultants), none of these prior efforts have highlighted the potential to develop the Nilotic riverfront. In the wake of the January events, 'Cairo 2050' quickly became uncertain and outdated. However, the collaborative research and planning process undertaken here could serve as a model for future planning efforts that are more in-touch with local conditions and reflective of real needs of everyday Cairenes. The political changes of January 2011 highlighted public desires, expectations, and demands for major economic changes and improvements in living conditions. Thus, the concept of reconnecting Cairo's urban population with the Nile is unusually timely. Bringing the people to the river banks could significantly improve daily life for millions, and could contribute to democratization of society and strengthening of the social fabric.

In Mediterranean climates, mild year-round temperatures support comfortable human settlement with rich agricultural regions. The climate's long summer drought, seasonal river flow, high inter-annual variability in precipitation, and episodic floods threaten these settlements, leading to highly manipulated hydrologic systems. The degree of hydrological alteration and consequent ecological change is typically much greater in Mediterranean-climate rivers than humid-climate systems. Dams, diversions, irrigation channels, storage and distribution facilities simultaneously restrict flow regimes, support economic development and destroy the native biological communities in Mediterranean drainage basins. Overcoming the complex relationships among climate, economy and our entangled legal and political institutions challenge the restoration potential of Mediterranean-climate river systems worldwide.