Search Results (16)

Climate change and extreme rainfall events pose great pressures on a city’s resilience to flooding and waterlogging. Designed as a kind of green infrastructure to manage stormwater, urban sponge parks (USPs) in China have been demonstrated to have ecological and societal benefits, while their landscape economic values lack evaluation. Taking the real-estate choices surrounding six USPs in China as an example, an evaluation framework integrating text mining with housing introduction documents and hedonic price model (HPM) regression with housing prices was constructed to combine the stated preferences and revealed preferences of citizens when purchasing properties. The main findings include the following: (1) USPs do contribute to property appreciation, especially in newer urban areas, although they are not as strong as location and property characteristic factors; (2) the extent of the influence of USPs on houses decreases as the distance increases, with a maximum radius of 3 km; (3) a USP’s effects vary according to the urban and environmental context, as HPM with GWR (R² ranges from 0.203 to 0.679) outperforms the OLS method (R² ranges from 0.149 to 0.491), which evokes the need for more affluent and detailed analyses in the future. This study demonstrates the economic benefits of USPs and provides an evaluation approach based on citizen science data, which could contribute to the policy-making of USPs in China and promote the implementation of Nature-based Solutions. Full article

Trees in urban environments play a crucial ecological role, helping to mitigate air pollution, reduce urban heat islands, improve stormwater drainage, and provide essential ecosystem services such as biodiversity conservation. Street trees, in particular, form an interconnected network within the urban fabric, offering the potential to link various green spaces across the city. Several cities have implemented dedicated Street Tree Master Plans (STMPs) to manage street trees effectively. A STMP thus serves as both a vital tool for the management and conservation of urban tree heritage and an opportunity to enhance public spaces and the quality of life for citizens. This case study of Rome (Italy) presents a particularly complex challenge, partly due to the city’s rich historical heritage, where street trees contribute to the identity of places and the urban environment in the context of climate change. The tree heritage of Rome requires ongoing maintenance, the improvement of growing conditions, the replacement of hazardous or aging trees along street rows, and the addition of new trees to enhance and diversify the urban tree population. Starting from a new census of street trees and a spatial analysis using GIS methodologies, this study examines the approach taken by Rome’s STMP. It focuses on the different strategies proposed for various types of streets, classified on the specific role that trees play in each context. Specifically, the plan offers a strategic vision for the city’s future, rooted in its urban form and supported by a methodological framework for planning interventions based on the current condition of tree cover. Drawing on insights from the STMP, the findings emphasize that any comprehensive renewal of street trees in large cities with historically significant and aesthetically rich landscapes must be guided by a strategic vision. In the discussion, a comparative analysis was conducted on different STMPs in various cities around the world, and we questioned how significantly historical and spatial considerations, which characterized the formation of Rome’s STMP, should be part of all STMPs. Full article

High-quality rainfall data are essential in many water management problems, including stormwater management, water resources management, and more. Due to the high spatial–temporal variations, rainfall measurement could be challenging and costly, especially in urban areas. This could be even more challenging in tropical regions with their typical short-duration and high-intensity rainfall events, as some of the undeveloped or developing countries in those regions lack a dense rain gauge network and have limited resources to use radar and satellite readings. Thus, exploring alternative rainfall estimation methods could be helpful to back up some shortcomings. Recently, a few studies have examined the utilisation of citizen science methods to collect rainfall data as a complement to the existing rain gauge networks. However, these attempts are in the early stages, and limited works have been published on improving the quality of such data. Therefore, this study focuses on image-based rainfall estimation with potential usage in citizen science. For this, a novel convolutional neural network (CNN) model is developed to predict rainfall intensity by processing the images captured by citizens (e.g., by smartphones or security cameras) in an urban area. The developed model is merely a complementary sensing tool (e.g., better spatial coverage) to the existing rain gauge network in an urban area and is not meant to replace it. This study also presents one of the most extensive datasets of rain image data ever published in the literature. The estimated rainfall data by the proposed CNN model of this study using images captured by surveillance cameras and smartphone cameras are compared with observed rainfall by a weather station and exhibit strong R² values of 0.955 and 0.840, respectively. Full article

Global extreme weather events such as rainstorms, floods and droughts have become increasingly frequent, posing significant threats to human beings worldwide. Green infrastructure has been implemented for decades to mitigate these issues. However, its widespread adoption in cities is still limited. A lack of sustainable funds was viewed as a great challenge for its widespread implementation. Many developed countries have practiced public participation and stormwater fee systems to mitigate these challenges. To assess the value that citizens place on the ecosystem benefits provided by urban green infrastructure is of great importance for increasing public participation and their willingness to pay. Thus, this paper aims to explore public preferences and their willingness to pay for the benefits of green infrastructure to support the construction and maintenance costs. A discrete choice experiment method was employed and five attributes were selected: reduction in run-off pollutant, degrees of ponding, plant type, planting aesthetics and the amount of payment. The Ngene1.2 software was used to generate a questionnaire, and data collected from the case cities, Xianyang and Xi’xian New Area, China, were analyzed using the mixed logit model. The results revealed that in Xianyang, the willingness to pay was not significantly associated with cognition, while in Xi’xian New Area, willingness to pay was positively related to cognition. Respondents exhibited a significant willingness to pay for green infrastructure to achieve reduced degrees of ponding in both cities, as well as improving planting aesthetics in Xi’xian New Area. Based on these findings, we conclude that government decision-makers should prioritize disseminating knowledge about green infrastructure to residents before implementing such projects in communities. The findings provide valuable insights into the potential economic value of urban green infrastructure and can guide policymakers and urban planners in making decisions regarding the design, implementation, and management of green infrastructure. This study contributes to the understanding of citizen perspectives and the economic evaluation of ecosystem services provided by urban green infrastructure. Full article

Green infrastructures deliver countless functions for counteracting climate change, air pollution, floods, and heat islands, contributing at the same time to water and carbon recycling as well as to renewable energies and feedstock provisioning. Properly addressing such environmental problems would require huge investments that could be decreased thanks to the further implementation of urban forests. Local administrations are designing participative projects to improve territories and their living conditions. The i-Tree Canopy modelling tool and the life cycle assessment method are jointly applied to evaluate the potential benefits of increasing tree coverage within the boundaries of the Metropolitan City of Naples, Southern Italy. Results highlighted that tree coverage could increase by about 2.4 million trees, thus generating 51% more benefits in pollutants removal, carbon sequestration and stormwater management. The benefits are also explored and confirmed by means of the life cycle assessment method. The potential tree cover is expected to provide a total annual economic benefit of USD 55 million, purchasing power parity value adjusted, representing USD 18 per citizen and USD 99,117 per square kilometre of implemented urban forest. These results can support a potential replication elsewhere and provide a reference for the sustainable improvement of cities by expanding urban green areas. Full article

Under a climate-change scenario, adaptation strategies to pluvial flood risk are crucial in urban and rural areas. Natural water retention measures are particularly helpful to manage runoff water, providing also additional co-benefits to the local population. However, the very limited knowledge of their benefits among citizens hinders their implementation, especially across southern European countries. Therefore, information and dissemination activities aimed at showing the benefits of these measures are particularly important to stimulate implementation by private citizens, although only a few studies have previously investigated their role. This paper considers some demonstrations of natural water retention measures—and the related information and dissemination activities to the local population—in northeastern Italy, explicitly including them as a driver in the Protection Motivation Theory framework. Through a direct survey of 219 households, it aims to quantitatively assess the impact on citizens’ willingness to implement natural water retention measures of the different levels of access to information provision, namely, the role played by active access through participation in the activities; passive access to available information; and no access. The results show that citizens’ willingness to implement the interventions on their properties is positively affected by their active access to information, thus highlighting the importance of high-quality information provision by public and private actors. Full article

Green stormwater infrastructure (GSI) has emerged as a promising decentralized management approach to urban stormwater challenges. A lack of data about GSI performance interferes with widespread adoption of GSI. A citizen science program that benefits researchers, lay scientists, and municipalities offers a way to provide these lacking data. We have developed an open-source, transferable green infrastructure rapid assessment (GIRA) protocol for studying the performance of GSI with citizen scientists. This protocol has been tested in six North American cities (New York City, Toronto, Vancouver, Chicago, San Francisco, and Buffalo). In this research we define the performance of GSI in varying geographic, climatic, and maintenance conditions with the intent to create technological, institutional, and management solutions to urban stormwater problems. The GIRA protocol was used by citizen scientists to assess the physical properties and capabilities of bioswales, while small, affordable Green Infrastructure Sensors Boxes (GIBoxes) were used to determine longer-term function across several rain events. Our results indicate that teams of citizen scientists can be effective for collecting and archiving widespread information on the post-installation function of GSI. The effort also showed that citizen scientists had changes in understanding of urban stormwater challenges and the role that GSI can play in solving these problems. We explore the multiple benefits to knowledge, participants, and municipal partners as a result of this research. Full article

Urban sustainability is most often measured using a series of social, economic, and ecological indicators. Assessment methods for urban sustainability typically factor in the ecological dimensions of greenspace, such as biodiversity maintenance, stormwater management, and/or air quality—yet indicator schemas that consider only the ecological dimensions largely overlook the social benefits of some types of urban greenspace, particularly community gardens and orchards. This article makes the case that the process of community formation and strengthening that occurs in shared growing spaces is an important element of urban sustainability in its own right. Based on 55 interviews of community garden advocates, policy-makers, and development professionals involved in urban agriculture planning, this article traces the widespread understanding among practitioners that shared growing spaces strengthen social as well as environmental sustainability, though the social benefits are often difficult to measure. The latter concern was most frequently expressed by urban agriculture advocates who, after involvement in the political process, perceived the need for such metrics in order to communicate persuasively with planners and policy makers. The social values of shared growing spaces, at once self-evident to garden advocates and difficult for them to demonstrate with quantitative data, may be theorized by drawing on insights from sociology: A truly sustainable city requires community coalescence among diverse citizens, and such community is fostered particularly well in shared growing spaces. Full article

Water-related green infrastructures (WrGIs), also known as blue infrastructures, and sustainable drainage systems (SuDSs) offer services such as stormwater runoff management, water purification, water storage at the intersection of the built environment, and natural systems by mimicking natural hydrological processes. While several papers document the reliability of such infrastructures in providing a variety of water-related services, few studies investigated the actual behaviour and the attitude of different stakeholders to understand the limitations and barriers in WrGIs/SuDSs implementation. In this paper, we investigated these issues by posing a set of questions to 71 qualified stakeholders in three Italian regions (Toscana, Liguria, and Sardegna) and one French region (Provence-Alpes-Côte d’Azur) in the northwestern Mediterranean. The results of the investigation largely show a lack of knowledge on these innovative solutions, although there is a general interest in their implementation both in the Italian and French regions. Barriers are also constituted by the scarcity of the demonstrators implemented, little knowledge on construction and maintenance costs, the absence of a proper regulatory framework, and of fiscal and financial incentives to support private citizens and companies. We finally suggest tools and soft measures that, in our opinion, may contribute to supporting the implementation of WrGIs/SuDSs, especially in view of adapting Mediterranean territories to the challenges posed by climate change. The results of our analyses may be reasonably up-scaled to the whole Mediterranean coastal region. Full article

This research presents a fully automated framework for runoff estimation, applied to Philadelphia, Pennsylvania, a major urban area. Trends in global urbanization are exacerbating stormwater runoff, making it an increasingly critical challenge in urban areas. Understanding the fine-scale spatial distribution of local flooding is difficult due to the complexity of the urban landscape and lack of measured data, but it is critical for urban management and development. A one-meter resolution Digital Elevation Model (DEM) was used in conjunction with a model developed by using ArcGIS Pro software to create urban micro-subbasins. The DEM was manipulated to account for roof drainage and stormwater infrastructure, such as inlets. The generated micro-subbasins paired with 24-h storm data with a 10-year return period taken from the National Resources Conservation Service (NRCS) for the Philadelphia area was used to estimate runoff. One-meter land-cover and land-use data were used to estimate pervious and impervious areas and the runoff coefficients for each subbasin. Peak runoff discharge and runoff depth for each subbasin were then estimated by the rational and modified rational methods and the NRCS method. The inundation depths from the NRCS method and the modified rational method models were compared and used to generate percent agreement, maximum, and average of inundation maps of Philadelphia. The outcome of this research provides a clear picture of the spatial likelihood of experiencing negative effects of excessive precipitation, useful for stormwater management agencies, city managers, and citizen. Full article

The persistence of urban floods and the inability of aging sewage infrastructure to deal with stormwater make sustainable urban drainage systems (SUDSs) one of the emerging paradigms in urban water management, in which stormwater is no longer a hazard but a resource. Although most of the global research has been done on the technical aspects of SUDSs, their social impacts are not always taken into consideration. The neighborhood scale that characterizes SUDSs creates a different governance system—compared to the old structures of flood risk management—characterized by decentralization practices and where communities gain a better position of negotiation and new responsibilities. The objective of this research is to recognize how the diverse stakeholders involved in SUDSs interact with each other and to look into the different levels of understanding SUDSs as a new alternative of stormwater infrastructure. In order to accomplish this task, the paper introduces the case of the neighborhood of Bon Pastor (Barcelona, Spain), which has gone through urban transformations over the past years, promoting the development of SUDSs in 2012. Empirical evidence was obtained from 10 semi-structured interviews with government, technicians, social organizations, and local community citizens as well as revision of existing policy documents and grey literature on SUDSs and historical documents on the development of the neighborhood. The results show how active the community was during the design process and afterward, as sustainability gradually became one of the main topics in the neighborhood to be incorporated in new developments. However, it also unveiled several issues related to maintenance and the ambiguity of the term SUDS for the different stakeholders involved. Full article

Water is a non substitutable resource and a social good, which governments must perforce provide to its citizens in the right quantity and quality. An integrated urban metabolism model is useful in understanding the status quo of an urban water and sanitation system. By defining and measuring the values of relevant hydrological performance indicators—deliverables of the model referred to—a thorough knowledge of the present performance and the gaps, which need to be plugged en route to a sustainable urban water infrastructure, can be obtained, as demonstrated in this paper. This then forms the bedrock for decision-making and policy formulation for change to be introduced top-down as well as advice, which would enable the much needed bottom-up support to policies. The authors have chosen Delhi as the case study city, but would like to point out that this application can be reproduced for any other town/city/region of the world. The water balance within the chosen system boundaries shows that the annual unutilized flows, amounting to 1443 million cubic meters, dominate the metabolic flows of water in Delhi, and the annual groundwater withdrawal, which exceeds 420 million cubic meters, is much greater than the recharge rate, resulting in a rapid depletion of the groundwater level. There is an urgent need thereby to improve the rate of infiltration of stormwater and reduce the rate of runoff by focusing on increasing the share of permeable surfaces in the city, as well as to consider the wastewater streams as potential sources of water, while not forgetting demand side of management measures, as the pressure on the urban water system in the city is likely to intensify with a combination of population growth, economic development, and climate change in the near future. The recommendations provided by the authors towards the end of the article, can, if suitable measures are undertaken and robust policies are implemented, result in Delhi’s enjoying a water surplus in the short term, and progressively attain complete sustainability with regard to the utilization of its water resources. Full article

Current and projected climate change in the Minnesota Lake Superior Coastal Area indicates an increase in frequency and intensity of extreme rainfall. One key outcome of this change is a subsequent potential increase in stormwater runoff, a concern exacerbated by the region’s shallow, often clay soils and exposed bedrock, along with highly impervious urban surfaces. This situation, coupled with public perception of climate change that is increasingly inclusive of severe weather, highlights an opportunity to apply green infrastructure to the challenge of stormwater management, referred to as green stormwater infrastructure. In addition to coordinated public action at local, state, and national levels, there is a role for the private landowner to participate in this form of climate adaptation. Private citizens have an opportunity to both protect their home and property while contributing to overall stormwater management for the community in which they live. Focus group research was conducted to better understand outreach and involve local residents in the creation of a tool to assist private green stormwater infrastructure efforts. Results of the focus group sessions were analyzed, and key themes emerged from the data to guide this process and support private home/landowner action. It is recommended that a fifth domain be added to the typology for public and private roles in climate adaptation, i.e. private adaptation for public and private benefit. Full article

As in other industrialized countries, many urban water social-ecological systems in the United States are characterized by frequent discharges of contaminated runoff, catastrophic flooding, and near-complete severance of the hydrologic cycle. Recent advancements in stormwater best management practices aim to push urban water social-ecological systems into a more sustainable regime that reconnects the hydrologic cycle and utilizes ecosystem services, such as infiltration and evapotranspiration, to improve the quality of urban and suburban water bodies. Collectively, these approaches are termed green infrastructure. As a decentralized approach, green infrastructure requires implementation on, as well as access to, property throughout a watershed, which poses particular governance challenges for watersheds where most land is held privately. We argue that green infrastructure on private property has a strong potential for creating a more sustainable regime through Citizen Stormwater Management, a participatory form of governance with strong citizen influence and engagement. We develop a classification scheme to assess policy instruments’ degree of government intervention, citizen participation, and engagement. The paper explores how various policy instruments encourage Citizen Stormwater Management across the United States on both public and private property. We then conduct a textual analysis of ten years of publicly available data from Onondaga County, New York (USA) to assess the implementation of applicable policy instruments. Findings indicate that incentive-based (carrots) along with outreach (sermon) policies can play an important role when regulatory instruments (sticks) are lacking. Full article

Urban stormwater infrastructure traditionally promoted conveyance. Cities are increasingly designing stormwater infrastructure that integrates both conveyance and infiltration in hybrid systems to achieve public health, safety, environmental, and social goals. In addition, cities face decisions about distribution of responsibilities for stormwater management and maintenance between institutions and landowners. Hybrid governance structures combine centralized and distributed management to facilitate planning, operations, funding, and maintenance. Effective governance in any management approach will require changes in the expertise of stormwater agencies. Recognizing the distinction between hybrid infrastructure and hybrid governance is important in long-term planning decisions for construction and management of stormwater systems. A framework is presented that relates the level and type of existing stormwater infrastructure with available capital, institutional development, and predominant citizen contributions. Cities with extensive existing infrastructure are increasingly integrating distributed, “green” approaches that promote infiltration, and must improve institutional expertise for governance decisions. For cities with little existing infrastructure, landowner management often dominates, especially when municipalities cannot keep pace with rapid growth. In between, rapidly industrializing cities are positioned to use growing capital resources to fund both conveyance and infiltration measures based on current design principles. For all cities, local management innovations, including decisions regarding public engagement, will be critical in shaping future urban stormwater systems. Full article