Nature Based Solutions for Urban Resilience: A Distinction Between No-Tech, Low-Tech and High-Tech Solutions

Abstract

Urbanization and extreme weather require smarter urban water management. Nature-based solutions (NBS) like vegetated roofs and city trees can contribute effectively to climate resilience and future proof urban water management. However, large scale implementation is limited due to a lack of knowledge among professionals on how to capture, store, and reuse water on-site. In this paper we advocate a classification into no-tech, low-tech, and high-tech green, thereby supporting urban designers to better utilize the ability of these green elements to effectively manage water flows in different urban settings. Here, “no tech” green is considered traditional urban green, handling (rain) water like nature would. “Low-tech” green (e.g., extensive Sedum roofs) are suitable for dense urban settings with limited demand for water management and ecosystem services. More developed “high-tech” green solutions have vegetation performing even beyond natural capacities, offering full water management control options and enable city planners, architects and landscape designers to enhance urban resilience and circularity without claiming valuable urban space. We elaborate our “tech NBS” approach for city trees and vegetated roofs thereby demonstrating the classification's added value for sustainable urban design. We conclude that specifying the demanded “no/low/high” -tech level of green infrastructure in urban design plans will help to yield the most of ecosystem services using appropriate levels of available technology.

Understanding the NEEDS for ACTING: An integrated framework for applying nature-based solutions in Brazil

“…Therefore, vulnerability, risk, multiple benefits, and resilience should be linked to the proposal of solutions (Dagenais et al 2016;Pappalardo et al 2017). In summary, the developed assessment for mapping and understanding the areas in need of changes, as well as the quantification of benefits, shows that NBS can deliver beyond the flood depth reduction, as it is routinely restricted in the hazards-tradition studies (Cutter et al 2008), and has the potential to strengthen environmental, social, and economic aspects of cities (Snep et al 2020).…”

Management of Urban Waters with Nature-Based Solutions in Circular Cities—Exemplified through Seven Urban Circularity Challenges

“…Rapid industrialisation and economic growth [5], as well as the generation of substantial amounts of industrial effluents, place a significant strain on limited water resources [6,7]. Climate change is expected to have a significant impact on the water cycle [8,9], resulting in issues in cities such as droughts, floods, water resource pollution, and heat waves [10,11]. Meanwhile, water in urban ecosystems, including wastewater, drinking water, stormwater, groundwater, surface waters, and a variety of urban ecosystems in which water plays a vital role, is currently not treated in a cyclical manner.…”

“…Thus, concepts such as treated effluent reuse in irrigation of commercial crops [15], local use of rainwater and greywater for toilet flushing, car-washing and garden irrigation [1,16] or separation of urine and faeces from greywater to maximise nutrient recovery [13,16] are gradually coming to the forefront of the discussion for a circular transition in the water sector. Cities all over the world must rethink and reinvent themselves as water-smart cities, shifting from drained to sponge cities, using reclaimed water and only draining surplus water as a last choice, while still generating chances to green the city and improve liveability [10]. More and more cities thereby consider nature-based solutions (NBS) an integral part of their water management plans.…”

“…Nika et al [1] reviewed assessment methodologies, tools and indicators with a focus on societal challenges. Snep et al [10] reviewed the different technological levels at which city trees and vegetated rooftops have been implemented. Mousavi et al [21] conducted a survey with Australian water professionals focused on the definition of NBS.…”

Improving energy efficiency of rental housing

“…Authors from the Netherlands: Van Hattum, Sabine Jansen, Saleh Mohammadi and Regina Boke write about alternative energy concepts [11]. Miguel Ángel Pardo examines the issue of effective water and energy resources management on the example of Spain cities [12].…”