Perspectivas positivas y negativas de la maternidad adolescente

The question addressed here is if the IFRM plan for Dordrecht comprises integrated outputs: in objectives, and across spatial and temporal scales.

Integration across spatial scales is central to the MLS strategy and IFRM plan. The flood hazard can only be reduced at a national level, as it can be caused inter alia by a storm surge at the North Sea (downstream) and peak discharge in the rivers (upstream). The flood hazards were taken as a starting point for the IFRM plan for Dordrecht. On the regional scale, in this case the Island of Dordrecht that includes the dyke ring area and the unembanked areas, the flooding system has been designed to be ‘self-reliant’ in case of a flood. Evacuation of the entire population from the island was not considered feasible, or effective (see: sub- section on system analysis). Self-reliance was, therefore, selected as a central concept that aimed to strengthen and align the capacity of organizations, communities and individuals each operating at different spatial scales, to cope with and recover from an extreme flood event (i.e. above the current protection standard). Measures that contribute to increased self-reliance comprise the realization of a ‘delta dyke’ and compartmentalizing the dyke ring area into three subdivisions by using the existing regional dykes (see Fig. 3.1). The northeast part of the dyke ring is to be made virtually unbreachable (100 times lower probability of failure than for the current design standard) by heightening and/or widening the dyke sections. This allows for overtopping of the levees with flood water, rather than breaching, and thus reduces the potential consequences of a flood event. The three compartments allow for a differentiation of flood risk and specific strategies for each compartment. The south ‘compartment 3’ consists mainly of agricultural land where the consequences of a flood would be lower than in the 2 north compartments. Compartment 3 will have a lower protection standard and further urban development there is to be avoided. The northwest ‘compartment 2’, that has a higher individual flood risk, could be evacuated to the northeast ‘compartment 1’ in case it is threatened by a levee breach. These measures also provide opportunities for effective measures at the local, neighbourhood scale that are proposed to further reduce the consequences of flooding and enable the functioning of the socio-economic system during and after a flood event, such as: individual protection of critical infrastructure networks (e.g., energy supply) and nodes (e.g., hospitals); creation of safe havens or shelters; elevated access and egress routes within and between compartments and neighbourhoods; flood proof planning and building of public spaces and buildings; and improved risk and crisis communication.

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Figure 3.1. Illustration of the IFRM plan for the Island of Dordrecht.

The fine black line indicates the dyke ring, with a virtually unbreachable delta dyke in the North East that merely allows for overtopping of floodwater; and the compartmentalizing of the dyke ring area into three subdivisions by secondary dykes (grey lines) allowing for differentiation of flood risk and specific strategies. No further development is allowed in compartment 3. 65% of Inhabitants of compartment 2 can be evacuated to compartment 1 prior to a flood event. And shelters are to be created in compartment 1

Integration across temporal scales is inherent to the self-reliance strategy and is

included in the FRM plan in two ways: to deal with various potential futures and for a flexible implementation strategy over time. Firstly, the plan is robust and flexible for various potential long-term futures, taking a range of climate and socio-economic scenarios into account. As self-reliance increases the capacity to cope with and recover from an extreme flood event, it is less dependent on a design standard for the dyke protection system that is designed to handle an expected return period and future climate scenarios. For example, the entire dyke ring, with the exception of dyke section 13 (Voorstraat), has been designed with a residual height in order to accommodate climate change and sea level rise under the projected KNMI climate change scenarios for 2100 (Van den Hurk et al.,

Process design and management for integrated flood risk management:

exploring the Multi Layer Safety approach for Dordrecht, The Netherlands

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2006). The Voorstraat, which is the primary dyke through the historical inner city, is not high enough to withstand higher water levels than those accounted for by the current design standard. This dyke section is difficult to heighten without affecting cultural heritage buildings (Gersonius et al., 2012). However, it is virtually unbreakable because of its very flat inner slope and stone cover. For this dyke section the IFRM plan proposes the construction of dry-canals behind the dyke to accommodate floodwater in case overtopping and overflow occurs more frequently in the future as expected due to climate change. Secondly, the investment planning for the proposed measures is optimised over time to reduce investment costs by exploiting the many opportunities for mainstreaming and integrating flood risk management into sectoral policies, planning frameworks, and 'normal' investment and renovation cycles. The construction of the delta dyke is to be combined with already envisaged dyke reinforcement projects, such as for the dyke section at Kop van het Land in the East. Several schools have been selected to serve as shelters to receive evacuees in times of emergency. When regular renovations to these schools are scheduled, they will be adapted to additional requirements for a shelter where opportune. The (Wieldrechtste) Zeedijk, a regional dyke separating the urbanised areas in the north from agricultural and natural areas in the south, is to be strengthened to add additional protection to the urbanised north. This strengthening is to be combined with envisaged nature development along the dyke that will be designed to break flood waves, in addition to enriching the landscape. Incremental investments over time, as proposed by the IFRM plan, provide the flexibility to adjust the implementation and timing of measures based on new insights, e.g. from updated climate and socio-economic scenarios.

Integration in objectives is a direct consequence of the three-layered MLS approach

that aims for multiple flood risk objectives by reducing probability and consequences of floods, but has also been achieved by incorporating socio- economic objectives. The dyke reinforcement planned in the East of the Island is to be combined with nature development on the riverside of the dyke. The dyke reinforcement in the West supports the redevelopment of an industrial area that is intersected by the dyke, providing a safe elevated transport route. The Stadswerven, an unembanked old industrial area in the North of the island is being redeveloped into a residential and commercial area. Spatial and financial objectives have prevailed in the related master planning, but flood risk was used as a design variable. The masterplan includes lower lying, attractive water-rich areas to appeal to potential house buyers. The public spaces and dwellings are flood-proofed by elevated construction, dry-proof building design or by selection of materials, pavements and vegetation. Transport infrastructures are also

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elevated so that they can serve as escape routes for evacuation. The construction of dry-canals to guide floodwater overtopping De Voorstraat dyke, requires integration of these flows into planning and maintenance of public roads in the embanked polder area. Regional businesses have been invited to explore business opportunities related to the implementation of the IFRM plan in Dordrecht so as to support economic development and also any exploitation potential internationally. Examples include: advanced sensors and ICT systems for flood monitoring and management; engineering and construction of delta dykes and flood proof dwellings.