Triggered by recent flood catastrophes and increasing concerns about climate change, scientists as well as policy-makers increasingly call for making long-term water policies to enable a transformation towards flood resilience. A key question is how to make these long-term policies adaptive so that they are able to deal with uncertainties and changing circumstances. The paper proposes three conditions for making long-term water policies adaptive, which are then used to evaluate a new Dutch water policy approach called 'Adaptive Delta Management'. Analysing this national policy approach and its translation to the Rotterdam region reveals that Dutch policy-makers are torn between adaptability and the urge to control. Reflecting on this dilemma, the paper suggests a stronger focus on monitoring and learning to strengthen the adaptability of long-term water policies. Moreover, increasing the adaptive capacity of society also requires a stronger engagement with local stakeholders including citizens and businesses.
Floods can be approached at a given location with two different concepts in mind: defending against floods or adapting to floods (Saurí-Pujol et al., 2001) (further, the option of mitigation exists, but this is a rather long-term and large-scale approach). First, resistance-based flood protection is the traditional approach to flood risk; second is resilience, which is linked with the concept of flood risk management. Flood protection usually requires dykes, technical flood protection measures, and strong water management institutions with technical skills; resilient flood risk management asks for comprehensive and integrative concepts, encompassing many stakeholders and asking for collaboration at various levels. The advantage of resistance-oriented flood protection is that it facilitates using protected land efficiently without the necessity of making compromises because of the flood risk. However, this approach has boundaries and constraints when flood risk increases, protection measures fail, or extreme floods occur. Thus, complementary resilient flood risk management is necessary, which comes with costs for adaptation and compromises for land use, but allows for coping much better with the management of increasing risk and extreme events because it reduces vulnerabilities.
As a consequence of climate change and urbanization, many cities will have to deal with more flooding and extreme heat stress. This paper presents a framework to maximize the effectiveness of Nature-Based Solutions (NBS) for flood risk reduction and thermal comfort enhancement. The framework involves an assessment of hazards with the use of models and field measurements. It also detects suitable implementation sites for NBS and quantifies their effectiveness for thermal comfort enhancement and flood risk reduction. The framework was applied in a densely urbanized study area, for which different small-scale urban NBS and their potential locations for implementation were assessed. The overall results show that the most effective performance in terms of flood mitigation and thermal comfort enhancement is likely achieved by applying a range of different measures at different locations. Therefore, the work presented here shows the potential of the framework to achieve an effective combination of measures and their locations, which was demonstrated on the case of the Sukhumvit area in Bangkok (Thailand). This can be particularly suitable for assessing and planning flood mitigation measures in combination with heat stress reduction.
Restoring rivers with an integrated approach that combines water safety, nature development and gravel mining remains a challenge. Also for the Grensmaas, the most southern trajectory of the Dutch main river Maas, that crosses the border with Belgium in the south of Limburg. The first plans (“Plan Ooievaar”) were already developed in the 1980s and were highly innovative and controversial, as they were based on the idea of using nature-based solutions combined with social-economic development. Severe floodings in 1993 and 1995 came as a shock and accelerated the process to implement the associated measures. To address the multifunctionality of the river, the Grensmaas consortium was set up by public and private parties (the largest public-private partnership ever formed in the Netherlands) to have an effective, scalable and socially accepted project. However, despite the shared long term vision and the further development of plans during the process it was hard to satisfy all the goals in the long run. While stakeholders agreed on the long-term goal, the path towards that goal remains disputed and depends on the perceived status quo and urgency of the problem. Moreover, internal and external pressures and disturbances like climate change or the economic crisis influenced perception and economic conditions of stakeholders differently. In this research we will identify relevant system-processes connected to the implementation of nature-based solutions through the lens of social-ecological resilience. This knowledge will be used to co-create management plans that effectively improve the long-term resilience of the Dutch main water systems.
INXCES will use and enhance innovative 3D terrain analysis and visualization technology coupled with state-of-the-art satellite remote sensing to develop cost-effective risk assessment tools for urban flooding, aquifer recharge, ground stability and subsidence. INXCES will develop quick scan tools that will help decision makers and other actors to improve the understanding of urban and peri-urban terrains and identify options for cost effective implementation of water management solutions that reduce the negative impacts of extreme events, maximize beneficial uses of rainwater and stormwater for small to intermediate events and provide long-term resilience in light of future climate changes. The INXCES approach optimizes the multiple benefits of urban ecosystems, thereby stimulating widespread implementation of nature-based solutions on the urban catchment scale.INXCES will develop new innovative technological methods for risk assessment and mitigation of extreme hydroclimatic events and optimization of urban water-dependent ecosystem services at the catchment level, for a spectrum of rainfall events. It is widely acknowledged that extreme events such as floods and droughts are an increasing challenge, particularly in urban areas. The frequency and intensity of floods and droughts pose challenges for economic and social development, negatively affecting the quality of life of urban populations. Prevention and mitigation of the consequences of hydroclimatic extreme events are dependent on the time scale. Floods are typically a consequence of intense rainfall events with short duration. In relation to prolonged droughts however, a much slower timescale needs to be considered, connected to groundwater level reductions, desiccation and negative consequences for growing conditions and potential ground – and building stability.INXCES will take a holistic spatial and temporal approach to the urban water balance at a catchment scale and perform technical-scientific research to assess, mitigate and build resilience in cities against extreme hydroclimatic events with nature-based solutions.INXCES will use and enhance innovative 3D terrain analysis and visualization technology coupled with state-of-the-art satellite remote sensing to develop cost-effective risk assessment tools for urban flooding, aquifer recharge, ground stability and subsidence. INXCES will develop quick scan tools that will help decision makers and other actors to improve the understanding of urban and peri-urban terrains and identify options for cost effective implementation of water management solutions that reduce the negative impacts of extreme events, maximize beneficial uses of rainwater and stormwater for small to intermediate events and provide long-term resilience in light of future climate changes. The INXCES approach optimizes the multiple benefits of urban ecosystems, thereby stimulating widespread implementation of nature-based solutions on the urban catchment scale.
