Adjusted Unit Value Transfer as a Tool for Raising Awareness on Ecosystem Services Provided by Constructed Wetlands for Water Pollution Control: An Italian Case Study

Assessing nature-based solutions for transformative change

Green infrastructure preserves, enhances, or restores elements of a natural system to provide higher-quality, more resilient, and lower-cost infrastructure services. Ecosystem disaster prevention and mitigation is also one of the features of green infrastructure. It is thus expected to integrate gray and green infrastructure to achieve greater resilience and sustainability. While several concepts of integrated green and gray infrastructure (IGGI), or hybrid infrastructure, have been proposed at the landscape scale, hybrid possibilities could exist at the single structural element and material scales. This paper proposes three types of IGGI concepts that could be beneficial for gray engineers to implement green infrastructure in terms of the gray engineering perspectives (safety, serviceability, and durability), primarily focusing mainly on the scale of single- or multiple-structure scales smaller than landscape scale. By categorizing the past and feasible IGGI cases into three concepts, the performance requirements for each infrastructure (green or gray) will become apparent, accelerating the discussion to develop a performance curve model as an IGGI. Also, the work needed to realize IGGI is discussed, emphasizing the urgent need for gray engineers to understand the benefits of integrating green infrastructure into gray infrastructure and thus promote the implementation of IGGI.

Comparing green infrastructure as ecosystem-based disaster risk reduction with gray infrastructure in terms of costs and benefits under uncertainty: A theoretical approach

Adaptive pressure-driven multi-criteria spatial decision-making for a targeted placement of green and grey runoff control infrastructures

One of the pressing challenges we observe in fast expanding urban areas especially in Global South are linked to the retreat of nature, infrastructure development negatively impacting urban blue and green spaces (BGS), along with growing vulnerability due to climate change. With the rapid rate of urbanisation, there is growing interest in protecting BGS as important Nature based Solutions (NbS) by securing ecosystem services and refuge to biodiversity.Unlike energy and water efficiency, which yield clear financial benefits, ecological services and biodiversity co-benefits are often undervalued. This undervaluation reduces incentives for institutions to prioritize them. A promising NbS approach in fast sprawling urban areas is to implement biodiversity friendly practices in stable land-use areas such as large privately or publicly owned/managed campuses. There is evidence that a very large proportion of the country’s birds, bats and butterflies are reported to be found in educational campuses across India. While, there are evidence that these campuses help in mitigating heat stress besides sequestering carbon and helping in reducing urban risks due to lack of sufficient evidence, campus-based biodiversity conservation is likely to be seen as a co-benefit rather than a primary driver of impact. To fill the gap present stud we summarize evidence from across India and  bring in insights from two Indian urban educational campuses viz. National Environmental Engineering Research Institute, Nagpur and the Indian Institute for Human Settlements, Bengaluru.We use satellite derived land surface temperature (LST) to quantify and map negative temperature anomalies (cooling) with respect to spatial average in these campuses in years with different levels of summer temperature. Observations and measurements on biodiversity, ecosystem services including carbon sequestration, microclimate, and ground water from these campuses are linked to campus management including integration of blue, green and grey infrastructure.Several such campuses can include educational, governmental and defence establishments, multinational corporations as well as hospitality and other service providers can function as long term urban ecological observatories to understand the long-term impact and benefits of NbS apart being early warning networks for tracking environmental and ecological change across time and space, thereby enabling large areas as pivotal NbS at the city and country level. This improves the ease of implementation and have a positive impact on biodiversity, a key indicator of ecological health to promote ecosystem services, and also human health. We endorse urban campuses and their role as potential NbS by serving as catalysts for transformational urban development. This approach links biodiversity conservation with climate adaptation and deep de-carbonisation, crucial for sustainable economic development. A network of several campuses should be developed through the formulation and implementation of Ecosystem-based Adaptation (EbA) that focuses on climate action. Designating campuses under a new category of conservation area called other Effective Area-based Conservation Measures (OECM) will help emphasizing the relevance of campuses and, driving policy and investment changes for resilience building following NbS. An NbS roadmap leveraging the integration of blue, green, and grey infrastructure and emphasizing the concepts of co-existence with biodiversity and ecological restoration can emerge from campuses.

Systematic literature reviews provide the foundation for evidence-based research in a particular field of study. In this regard, the systematic review of the relationship between coastal management strategies and coastal infrastructure typologies provides an opportunity to benchmark local coastal adaptation policies against contemporary global practices, technologies, and sustainability. However, systematic reviews of coastal infrastructure in Ghana and West Africa at large are limited. To close this research gap, we conducted a systematic literature review of the global implementation of coastal management strategies and coastal infrastructure and provided a synopsis of coastal management in Ghana. To achieve this, we searched the Scopus Database for literature on coastal management approaches and infrastructure typologies. Forty-eight peer-reviewed publications met the inclusion criteria for full-text analysis. The results indicate a significant global shift from purely grey infrastructure toward integrating green and grey infrastructure. However, despite contemporary global advances, coastal infrastructure in developing contexts—particularly in Ghana—remains mostly static, using reactive, hold the line strategies, and grey infrastructure. As sea-level rise continues to intensify coastal hazards globally, increasing the demand for coastal protection, researching coastal management policies and coastal infrastructure is essential to support the hybridization of grey and green infrastructure and encourage transitions to adaptive coastal management instead of continuous coastal hardening using grey infrastructure.

Optimization and trade-off framework for coupled green-grey infrastructure considering environmental performance

Mountain ecosystem services affected by land use changes and hydrological control works in Mediterranean catchments

PurposeThis paper aims to advance the idea of sustainable flood reduction. Flood reduction through the use of the drainage system is considered an unsustainable approach that decreases the use of water. In contrast, the Water Sensitive City is a sustainable concept aimed at increasing the value of water for human needs and reduce flooding.Design/methodology/approachThe current approach of relying on drainage systems is ineffective and must be combined with green infrastructures to reduce flooding. Green infrastructures can increase infiltration rates or facilitate rain harvesting. The study developed four scenarios that combine green and grey infrastructures and used the Soil and Water Assessment Tool (SWAT) model to select the most effective scenario based on the remaining amount of flood volume in every scenario.FindingsGreen infrastructures that are related to increased infiltration and rain-harvesting instruments reduced flooding by 22.3 and 27.7 per cent, respectively. Furthermore, a combination of the two types of green infrastructures reduced flooding up to 45.5 per cent. Conversely, applying only grey infrastructures (by increasing drainage capacity) to reduce the flooding to zero is unfeasible, as this requires more than double the current capacity. Therefore, a combination of green and grey infrastructures can significantly reduce flooding in a water sensitive and feasible manner.Originality/valueApplying a combination of green and grey infrastructures is a new and effective approach to reduce flooding in the Kedurus Catchment Area.

Coastal zones are bearing the brunt of an increase in the likelihood of extreme events, coupled with sea-level rise (SLR). Conventionally, gray infrastructures, such as seawalls, have been constructed to reduce risks in limited coastal zone spaces. Nature-based approaches, known as green infrastructure, have been used in coastal defense, and their ecosystem-based disaster risk reduction functions (Eco-DRR) have received growing attention. However, both gray and green infrastructure alone have limitations in responding to an ongoing increase in the intensity and frequency of natural hazards. To overcome these issues, hybrid infrastructure, which combine gray and green components, is needed, and they have been receiving growing attention. Meanwhile, a large-scale coastal development requires stakeholder agreement; thus, it is imperative to understand people’s demands and build a consensus between municipalities and coastal citizens in coastal development for long-term resilience. The author administered the online survey across Japan, applying it to the choice experiment, and obtained 840 valid responses. Therefore, this paper clarified the heterogeneities in coastal people’s preferences for coastal ecosystem services provided by gray, green, and hybrid structures in intertidal zones in Japan, recognizing seawalls as gray and coastal pine forests as green infrastructure. Consequently, while coastal citizens acknowledged gray’s coastal defense function, the diverse perceptions toward seawalls for SLR preparation were notable as its scenarios became severe. Another remarkable finding is that nearly 60% of respondents preferred Eco-DRR functions provided by coastal forests with JPY 695 in willingness-to-pay for expanding 100 m in width, even though there are uncertainties in their performances.

The role of coastal blue carbon ecosystems in climate mitigation and adaptation efforts has been recognized. Blue carbon ecosystem functionality is one component of coastal nature-based or green–gray infrastructure multifunctionality, which includes contributions by nature to disaster risk reduction, infrastructure resilience, erosion control, land formation, and other ecosystem services. Here we review how green infrastructure and nature-based solutions in coastal and shallow nearshore areas can contribute to blue climate change mitigation and adaptation. We then summarize available coastal infrastructure types (green, gray, and green–gray hybrid) in terms of their inherent functions and potential co-benefits. We discuss technologies for integrating gray and green infrastructure and producing hybrid infrastructure to promote implementation of measures for both climate change and infrastructure development, although the best infrastructure type is dependent on the risks of a given time and locality. Collaboration among engineers, scientists, and economists who are interested in climate change or infrastructure and in emerging fields such as blue carbon and green infrastructure are needed to further enhance the implementation of multifunctional infrastructure, but the multifunctionality benefits should be quantified and monetized.

Non-Point Source Pollution (NPS) caused by polluted and untreated stormwater runoff discharging into water bodies has become a serious threat to the ecological environment. Green infrastructure and gray infrastructure are considered to be the main stormwater management measures, and the issue of their cost-effectiveness is a widespread concern for decision makers. Multi-objective optimization is one of the most reliable and commonly used approaches in solving cost-effectiveness issues. However, many studies optimized green and gray infrastructure under an invariant condition, and the additional benefits of green infrastructure were neglected. In this study, a simulation-optimization framework was developed by integrated Stormwater Management Model (SWMM) and Non-dominated Sorting Genetic Algorithm (NSGA-II) to optimize green and gray infrastructure for NPS control under future scenarios, and a realistic area of Sponge City in Nanchang, China, was used as a typical case. Different levels of additional benefits of green infrastructure were estimated in the optimizing process. The results demonstrated that green-gray infrastructure can produce a co-benefit if the green infrastructure have appropriate Value of Additional Benefits (VAB), otherwise, gray infrastructure will be a more cost-effectiveness measure. Moreover, gray infrastructure is more sensitive than green infrastructure and green-gray infrastructure under future scenarios. The findings of the study could help decision makers to develop suitable planning for NPS control based on investment cost and water quality objectives.

Development of hazard capacity factor design model for net-zero: Evaluation of the flood adaptation effects considering green - gray infrastructure interaction

Many older Midwestern cities of the United States are challenged by costly aging water infrastructure while working to revitalize urban areas. These cities developed much of their water infrastructure before the Clean Water Act became law and have struggled to mitigate contaminant loading to surface waters. An increasingly common approach to resolving these challenges is the integration of green infrastructure with gray infrastructure improvements to manage point and non-point source pollution. Stakeholder engagement and collaboration during green infrastructure planning can help address impairments and promote community involvement through the revitalization process. Mill Creek watershed in Cincinnati, OH, USA has seen improvement in watershed integrity indicators after being impaired for many decades by flashy hydrology, combined sewer overflows, and water quality degradation. A workshop was conducted to examine how integrated green and gray infrastructure has contributed to improvements in Mill Creek over the past several decades. This effort sought to examine internal and external factors that influence a multi-stakeholder watershed approach to planning, implementing, and evaluating green infrastructure techniques. Community investment and physical infrastructure, access to datasets, and skills and knowledge exchange were essential in improving use attainment in the Mill Creek. Strategic placement of green infrastructure has the potential to maximize water quality benefits and ecosystem services. However, green infrastructure deployment has been more opportunistic due to the diversity of stakeholder and decision maker interests. Future work should consider collaborative approaches to address scaling challenges and workforce development to maximize green infrastructure benefits.

The increase of greenhouse gases (GHG) emissions in the atmosphere due to human activities such as fossil fuel burning, deforestation and land-use changes, is causing increases in surface temperature. From the pre-industrial era to the current days, the carbon dioxide (CO₂) concentration has increased from 280 ppm to 398.17 ppm (NOAA, 2015) and according to the Intergovernmental Panel on Climate Change (IPCC, 2014) globally averaged combined land and ocean surface temperature data show a warming of 0.85°C per decade over the period 1880 to 2012. Under higher temperatures, the atmosphere has a higher capacity to hold water vapor (Horton et al, 2010), increasing the time interval between rain events and the magnitude of precipitation especially in extreme events. Thus, at higher temperatures the frequency at which precipitations occur tends to decrease while the intensity of such precipitations tends to increase. In the urban environment, where typically the majority of surfaces are impermeable, the impact of climate change tends to exacerbate the occurrence and the intensity of floods as well as droughts and heat waves. Within this context, there has been much discussion about strategies that could effectively help cities to reduce their CO₂ emissions to the atmosphere (mitigation strategies ) and to adapt to the impacts caused by climate change (adaptation strategies ). Regarding the impacts caused by urban floods, a decentralized approach, known as green infrastructure (GI) has been proposed as an alternative to the traditional concrete infrastructures (gray infrastructures [GR]). GI sustains, or attempts to replicate pre-development site hydrology in the post-development condition (Montalto, 2007), taking advantage of natural processes like infiltration, interception and evapotranspiration to manage stormwater (Davis et al, 2012). Beside capturing precipitation and reducing the amount of runoff that is convened to the sewer systems, GI can provide other benefits such as reduction of heat island effects, increased air and water quality, carbon sequestration, expansion of recreational spaces, increased habitat for flora and fauna among others (Wise et al, 2010). Because of their capacity to deliver multiple benefits, GI has been proposed as a sustainable alternative for cities to mitigate and adapt to climate change (Mason & Montalto, 2014; Union European, 2010). Several government grants have been launched recently to focus on the development, application and evaluation of methodologies for integrating GI into urban spaces as adaptation efforts to climate change (DOI, 2014; NOAA, 2014). Nevertheless, the body of literature that assesses GI as an effective strategy to help cities to build resilience to climate change remains small. For instance, the performance of designed urban green spaces under climate change is still poorly understood. In addition, the comparison between potential benefits of GI applied to urban watershed scale with the environmental costs associated with their installation and maintenance is still poorly supported by research (Pataki et al 2011). In order to better explore these research gaps, this thesis aims to evaluate GI as a means of reducing climate risks in the urban northeast environment. To reach out this main objective, we propose three different hypotheses: Hypothesis #1: Green infrastructure can reduce GHG emissions associated with urban drainage infrastructure · Compared to grey (stormwater management) infrastructure strategies, GI releases lesser GHG emissions over its entire useful life Hypothesis #2: GI can help cities adapt to extreme precipitation · GI facilities can significantly reduce urban runoff even during extreme precipitation Hypothesis #3: GI vegetation is not vulnerable to climate change, especially to floods and droughts · The risk of plant mortality within the expected envelope of climate variability (floods and droughts) is insignificant. The three hypotheses, as well as, a preliminary chapter that introduces the thesis topic, are presented separately in a scientific journal format. Chapter 1 reviews literature about the leading climate risks facing the Northeast Region (NE) of Unites States of America (USA), while provides an overview of the ongoing GI initiatives in the USA and their potential value for reducing vulnerability to the key climate risks faced by the urban northeast region. Chapter 2 addresses hypothesis #1 and includes a study conducted at the watershed scale level that used life cycle assessment techniques to compare the carbon footprint of a green and a grey strategy to reduce combined sewer overflow occurrence (CSO) in a highly urbanized watershed. Chapter 3 addresses hypothesis #2 via an investigation at the site scale that evaluated the performance of a bioretention installed in an urban watershed during extreme events including Hurricane Sandy and Hurricane Irene. Chapter 4 addresses hypothesis #3 and presents an experiment conducted in a greenhouse that evaluated the response of two species commonly used in vegetated GI sites to consecutive periods of floods and drought. This thesis finalizes with a general conclusion section for all the chapters.