Managing water resources for the future is challenging, given the wide range of climatic and hydrological uncertainty. To support decision makers in formulating robust adaptation plans and finding their way through the broad range of available climate data and models, decision scaling was introduced: an approach for bottom-up climate vulnerability assessments, informed by Global Climate Models (GCMs). This study aims to improve decision scaling as developed by Brown et al. (2012) by introducing three recent advances in climate adaptation and uncertainty science.

First, the concept of environmental flows (eflows) was adopted to represent the local ecology and variable hydrology with a broad range of indicators for evaluating the impact of climate change. Second, the GCM weighting strategy of Knutti et al. (2017) was applied to account for model performance and interdependency when estimating the plausibility of future climate conditions. Lastly, climate stress testing was not only done for annual average climate changes, but also for a prolonged dry season to represent the interannually variable character of climate change. The potential application of the novel decision scaling approach was illustrated through a case study of the Mokolo River. This river is situated in the South African Waterberg Biosphere Reserve, which faces competing water demands from tourism, industry, agriculture, and ecology under a changing climate.

It was found that the additions contribute to decision scaling, as eflows indicators introduced the climate impact on multiple flow components, which provides extra information on the climate vulnerability of the river during different flow conditions. In Waterberg, low and average flow conditions were found similarly sensitive to climate change. Moreover, GCM weighting increased the range of temperature uncertainty and showed high weights for both wet and dry GCM projections, which emphasizes the need for robust climate adaptation in Waterberg. Next, the additional stress test showed that prolonging the dry season by one month influences flows throughout the following year, especially in the posterior months. In this way, understanding the impact of plausible characteristics of future climate was improved.

Finally, this study revealed that local activities, such as groundwater extractions and land use changes, and available knowledge challenges the application of decision scaling to a real case study as it requires models and quantification of indicators. Therefore, carefully matching models, performance indicators, local concerns and knowledge are required for formulating climate adaptation strategies with decision scaling.

To encourage climateadaptive building in the Netherlands the Covenant ClimateAdaptive Building (CKAB) was developed by a consortium of stakeholders (Convenant klimaatadaptief bouwen in ZuidHolland, 2018). This nonbinding agreement proposed standards for six (climate) aspects in order to adapt the Netherlands to a changing climate. These standards were first applied in pilots in Haarlemmermeer, Utrecht, Rotterdam (Vlot et al., 2021) and in Dordrecht, where the new residential area of Amstelwijck was planned. Implementing climateadaptive measures ánd standards is yet an innovative process and iterative learning is required to improve this process. We want to know what role standards played in selecting climateadaptive measures in Dordrecht and what result they achieved. This study focused on three climate aspects specifically: heat stress, pluvial flooding and droughts. The case study in Dordrecht was evaluated by means of a stateoftheart hydrological model, UrbanWB. Urban plans of Amstelwijck provided the basis to research applicability of this model as a design and assessment tool (i). The goal of this method was to improve the integral understanding of the complexity and interrelations of a (hydrological) system for designers and policymakers, which would allow them to make better choices. Additionally, this same model was used to assess uncertainty in design, engineering and climate (ii). A quantification was made for the relative relevance of design choices, such as decreasing paved surfaces, local conditions, such as soil type or drainage velocities, and climate change, with increased evaporation, precipitation and extremes. Additionally, CKAB standards and the process of applying them in Amstelwijck was researched (iii). Two groups of stakeholders, goal oriented (Municipality of Dordrecht, WSHD & hired staff) and user oriented (project developers & hired staff), were identified and these groups were interviewed with the goal of learning what kind of standards encourage climate adaptation and finding where barriers or enablers exist. This was done with the help of the concept of user centred design (Long et al., 2016), inspiring the stakeholder groups and a division into standards focused on goals or means, and the concepts of principle/rulebased approach (Nakpodia et al., 2016) and creative freedom/specification (Frei and Di Marzo Serugendo, 2011). With this research it could be concluded that UrbanWB can help designers by providing arguments for design choices, which was mentioned as an enabler in interviews. The model touched on interconnectivity between different climate aspects and five model indicators were identified to compare the performance of different plans. For assessment purposes no major improvements were made yet compared to models commonly employed, except that this method offers potential for a tool, which is easytoadopt. By verification with other models this should become more clear. The model architecture was found to be less suitable for assessing urban plans on heat stress and to a lesser extent drought, but proved valuable for pluvial flooding. On uncertainty three important notions were made: climate change is a significant uncertainty; local conditions are decisive for the ’robustness’, ability to perform under different conditions, of an urban system; design choices can have large effects on the hydrology of the system, some are effective enough to deal with climate change. The type of soil was found to be a decisive factor for every climate aspect. It is reaffirmed in interviews and focus groups that local conditions could be listed as a possible theme in the process of climate adaptation. In working with CKAB standards for the first two parts of this research ideas about the way of description, direction and commitment of standards were already formed, but the interview analysis affirmed and strengthened this view. Ideal standards should be specific, focused on goals and rulebased, but principles are leading and exceptions should be allowed to ensure creative freedom, which is important in an innovative process. Designers, policy makers and engineers could apply the methodology used in this study to promote climate adaptation and deal with the uncertainty brought by climate change. The results of this research emphasized the importance of integral thinking in design and lawmaking, since this provides more insight and argumentation for selecting climateadaptive measures A perception that standards should be focused on goals instead of means is crucial to directing urban developments.

Sustainable Urban Drainage Systems (SUDS) are useful tools to manage rainwater and reduce pollutants in urban environments. Their use, as sustainable solutions, can mitigate the effects of climate change and urbanization. The existence of different definitions of performance is one reason for delaying more implementation of SUDS. Deciding on the Key Performance Indicators (KPIs) is one of the objectives of this thesis. WaterStreet, the chosen study area, is a living lab that permits the implementation, presentation, and testing of newly designed SUDS with the goal of facilitating their entrance into the market. WaterStreet could benefit from using sensors to provide the KPIs and other indicators of performance, but the sensors already implemented do not achieve that objective fully. So, the objective of this thesis is, to develop a comprehensive set of KPIs that describe the performance of SUDS and propose a monitoring network to measure the performance of SUDS implemented in WaterStreet.
To achieve that objective, information on the study area’s characteristics, like soil types, design of SUDS, and groundwater levels were gathered to find how water flows in, out, and around the study area including the SUDS. Additionally, the key stakeholders were determined with a stakeholder analysis, and literature was researched on the important indicators used to reflect the performance of SUDS for water quality and quantity. Interviews were performed to include the view of the key stakeholders on the indicators found in the literature. The two approaches explained above provide the data that need to be monitored on WaterStreet. Criteria for the quality of data that would be provided by the sensors are set, before concluding on suggestions. The suggested sensors and their limitations are based on results of published studies and reports.
Based on the findings of this thesis a distinction between the Key Performance Indicators (KPIs) and Indicators of Performance (IP) is made. In the first category, the indicators of overflowing volume, duration, and frequency are included along with rainfall and overflow from upstream drainage areas. In the second category the indicators, infiltration in the soil and through the first layer of SUDS, and storage in the soil and system are included. Both categories of indicators are suggested to be monitored in the study area of WaterStreet to increase the value of WaterStreet as a living lab. Indicators for water quality are not concluded due to the lack of information on the existing pollutants and their removal and remobilization mechanisms. Reduction of Total Suspended Solids (TSS) and Total Phosphorus (TP) are two possible indicators that are also considered as a proxy in Germany. Changes in pH and temperature are two indirect indicators that are found to affect the reduction and remobilization mechanisms and are therefore important to consider as well.
An acoustic disdrometer to measure rainfall, a sonar pulse sensor to measure groundwater levels, divers in an observation pipe in the system to measure the water level in the system and the infiltration in the soil, and lastly divers in a controlled volume downstream of the SUDS to measure the overflowing water downstream the SUDS, were the proposed sensors. The disdrometer and two of the sonar pulse sensors are already installed on WaterStreet while it is suggested to put divers in the individual systems and two more sonar pulse sensors. For the indicators, overflowing water from upstream and the rate of water entering the SUDS research on the runoff coefficient and the use of water balance are suggested, respectively.
An important consideration in this thesis is the characterization of hydraulic isolation from the top and bottom of the system, allowing the interpretation of the data from monitoring, to represent only one system’s response. Suggestions to include a controlled volume to capture the overflow downstream of the SUDS and a drainpipe to ensure a drainage depth of 0.5 m, are made, to help ensure hydraulic isolation from top and bottom respectively. Based on this study, only half of the systems placed on WaterStreet are isolated, not considering the possibility that the groundwater table can get even higher resulting in even fewer systems isolated. Additionally, from analyzing the hydraulic response on the SUDS in WaterStreet, it was concluded that all 5 studied systems out of 8 total were being over-dimensioned, meaning that the storage in the SUDS would not be full even with rainfall of once in 100 years. From the same analysis, it was also concluded that the infiltration through the first layer is the prevalent overflowing mechanism of 3 out of 4 studies SUDS. Both the previous findings are important to realize a hydraulic response to rainfall proportionally to real implementations. This is an essential consideration from living labs because they try to bring lab and real implementation closer. Lastly, pollutants to be used as KPIs for water quality performance of SUDS should be researched more based on the principle of not shifting problems downstream.

The Netherlands is world famous when it comes to coastal defence. The world is always changing, therefore the Netherlands, together with many countries, has to adapt constantly to the climate. This constant change means that in particular the coastline of the Netherlands requires extra attention because of the uncertainty of sea level rise. The Dutch coastline is protected by means of a static approach. However the intention for the future is to apply an adaptable design to better handle sea level rise. This report focuses on a method that uses a dynamic approach with the aim of keeping the Netherlands protected against rising sea levels that are uncertain. This dynamic approach consist of several pathways that each consist of different actions. With the help of evaluation-criteria, the pathways in the dynamic approach are evaluated. The outcome of this evaluation is described and recommendations for future research are given.

The report focuses on keeping the coastline of the south-west of the Netherlands protected against the uncertainty of the rising sea. This will be done with the help of a dynamic approach. First, an area analysis was carried out to find out what aspects should be given the most attention. After that, the method of DAPP is used to function as a dynamic approach. This Dynamic Adaptive Pathway Policy is then used to implement the different pathways in a structured way. These pathways are made up of different actions. These actions are existing plans presented by Deltares and they form a big list. Not all plans do function properly in order to function as a flood protection and so a selection method is used to extract the right plans out of this list. The requirements that are used to select the right plans have its main focus on protecting the hinterland against sea level rise, storm surge and wave load. The extracted plans that function as an action are implemented in the different pathways of the DAPP. To evaluate these pathways, evaluation-criteria are used in a Multi Criteria Analysis. These criteria are extracted from sources like a stakeholder analysis, old and new watermasters and a brainstorm session with the group members who act through their own accumulated expertise. The extracted criteria in combination with determined weighting factors are placed in a Multi Criteria Analysis after which the pathways have been assessed individually. This evaluation process led to some pathways being iterated to a different shape for the final design of the DAPP.

From the project can be concluded that the DAPP approach works well to combine different static plans into a comprehensive mitigation strategy. Secondly the evaluation criteria can be successfully derived from the old and new watermasters. The old watermasters already have one or more of their plans implemented. The new watermasters, are working on flood protection plans for the future in their daily life and have a lot of experience in the current engineering field. From the stakeholder analyses, the criteria can also be derived but than from the perspective of a variety of stakeholders. Thirdly, organizing criteria using a PESTLE (Political, Economic, Social, Technological, Environmental) and objectives tree has significant benefits for determining weighting factors. At last, it can be concluded that the main requirements used in this project are a good starting point, but they are only focused on reducing the flood risk (only technology). To select plans on a wider perspective(also Political, Economic, Social, Legal and Environmental), it is recommended to take a closer look to requirements from that perspectives. Advised is to consult experts in those fields to help with that.