Climate change and urbanization will increase the frequency and magnitude of urban flooding and water quality problems in many regions of the world. In coastal and delta areas like The Netherlands and the Philippines, where urbanization is often high, there has been an increase in the adoption of sustainable urban drainage systems (SUDS). SUDS are installed around the world with the expectation to reduce urban flooding and reduce the pollution impact on receiving waters. Most cities in Asia are starting to implement SUDS as their strategy to make their cities sustainable and resilient.The combination of SUDS with appropriate wastewater treatment and management systems have the potential to be multifunctional in alleviating flood run-off, improving water quality, alleviating heat stress and as a source for reusing the stormwater and wastewater.Since the earliest SUDS are implemented in Europe decades ago it is advised to use the lessons learnt in this process. International knowledge exchange is promoted in projects as IWASTO where several organisations from the Philippines and The Netherlands join forces on a specific region as the Pateros riverin Manila with the aim to minimise the pollution impact on this receiving water. The first findings of this project related to storm water and wastewater management are presented in this paper. In this stage of the project high level support models that map the challenges in the city (such as flooding and heatstress) arevaluable tools for implementing cost effective sustainable drainage for improving water quality.
DOCUMENT
Storm sewers are known to significantly contribute to annual pollutant loads to receiving water bodies. The storm sewers of the city of Almere discharge the stormwater of 1384 ha of impervious area via 700 storm sewer outfalls (SSOs) to the local receiving water system. This water system suffers from eutrophication and long term build-up of pollutant levels in the sediment bed. In order to be able to select the most effective stormwater management strategy, the municipality of Almere and Water Authority Zuiderzeeland have launched a 2 year extensive monitoring project to measure the stormwater quality and the potential impact of source control and end of pipe measures to decrease the emission via SSOs. Source control measures, such as removal of illicit connections and increasing the cleaning frequency of gully pots showed to be most effective. The potential impact of end of pipesolutions based on settling showed to be very limited due to the low settleability of solids in the storm water of Almere at the SSOs.
DOCUMENT
Urban green and shading are adaptation measures that reduce urban heat. This is evident from meteorological measurements and investigations with surveys and has been described in many papers (e.g. Klemm et al., 2015). The cooling effect of these adaptation measures is reflected by lower air temperatures and an improved thermal comfort. Shading and urban green are also experienced as cooler than impervious urban spaces without vegetation or shading. However, the cooling effect of water bodies in cities, such as rivers, lakes, ponds, canals,fountains, is not clear yet (Steeneveld et al., 2014). Several studies show that the cooling effect of water bodies in cities is small, or can even be a source of heat during nighttime. The effect depends on the characteristics of the water body and the meteorological conditions. Nevertheless, water is often mentioned as an adaptation measure to reduce urban heat.To support urban professionals in designing cooler urban environments by using water bodies, we investigated in more detail how different water types in msterdam contribute to cooling the environment. During five summer days, we measured the cooling effect of five different water bodies: a pond, a fountain, a canal, and two rivers. We used measurements from mobile weather stations (air temperature, relative humidity, wind speed, global radiation and globe temperature) and collected almost 1000 surveys near the water bodies and a reference location. From these data, we could determine the effect of the water bodies on air temperature, thermal comfort and thermal sensation. The research question that we tried to answer with this study is: What is the cooling effect of different water types in the city of Amsterdam during hot days? The study has been carried out within the framework of a Dutch research project ‘Urban climate resilience – Turning climate adaptation into practice’ and supports urban professionals to decide on the right adaptation measures to reduce urban heat.
DOCUMENT
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.
