Lauren E. McPhillips

Infrastructures as socio-eco-technical systems: Five considerations for interdisciplinary dialogue

Infrastructure plays a key role in 21st century sustainability challenges related to burgeoning populations, increasing material and energy demand, environmental change, and shifts in social values. Social and political controversy over infrastructure decision making will continue to intensify without robust interdisciplinary and intersectoral dialogue over national-scale and local-scale infrastructure trajectories. Alongside large investments in physical and social systems, the infrastructure community—including planners, engineers, public works specialists, financiers, and sustainability scientists—needs to articulate a 21st century vision addressing the interrelated technological, social, and environmental dimensions of infrastructure systems. Such a vision needs to address existing systems in the industrialized world and new systems in countries seeking to improve human welfare through infrastructure development. Infrastructure systems—discussed here as primarily those integrating the built environment (Jones et al. 2001; Pulselli et al. 2007), transportation (Greene and Wegener 1997), power generation and distribution (Jacobson and Delucchi 2009), food production and processing (Food and Agriculture Organization of the United Nations 2011), manufacturing (Jovane et al. 2008), water delivery (Gleick 2003; Muller et al. 2015; Palmer et al. 2015), and waste treatment (Melosi 2008)—underpin the unprecedented material wealth of contemporary human society. These technological systems have developed alongside extensive social infrastructure including specialized knowledge and expertise housed in institutions, informal knowledge systems of operation and maintenance, and a broader system of governance and regulatory politics setting budgetary priorities, policy directions, and regulatory certainty. In combination with these policy processes, user behavior and demographic change influence the demand and maintenance costs for infrastructure services, both of which have an identified overall investment need of

Nutrient Cycling in Grassed Roadside Ditches and Lawns in a Suburban Watershed.

3.6 trillion (ASCE 2013),

Methane Emission in a Specific Riparian-Zone Sediment Decreased with Bioelectrochemical Manipulation and Corresponded to the Microbial Community Dynamics

2 trillion of which is needed by 2027 (ASCE 2017). Because infrastructure relies on environmental inputs to function, channels and protects society from environmental forces, and impacts environmental systems, attitudes about technology and appropriate human–nature relationships set the goals for long-term infrastructure sustainability. They do so through both a social willingness to pay for infrastructure systems and a social consciousness of and desire for specific types of systems. Shifting environmental conditions, including climatic changes and dispersed atmospheric pollutants, are exacerbated by the externalities of present infrastructure systems and the technologies they support. The extent of these shifts is rarely apparent until systems become overwhelmed (Gross 2010; Perrow 1999). For example, in the case of Hurricane Sandy, siloed system management created unforeseen vulnerabilities propagating through critical infrastructure systems (Klinenberg 2013, Comes and Van de Walle 2014), serving as an example of cascading failure (Rinaldi et al. 2001), as well as affecting system restoration (Sharkey et al. 2015). At the same time, infrastructure systems and the technologies and behaviors they enable serve as sources of risks and costs to public and environmental health; 8 of 10 people now live in urban areas with excessive air pollution primarily due to transport, manufacturing, and energy generation (WHO 2016). How has contemporary infrastructure practice come to this point? The modern infrastructure ideal of large, networked systems such as power generation, information technology, and transport (Dueñas-Osorio et al. 2007; Haimes and Jiang 2001;

Nutrient Leaching and Greenhouse Gas Emissions in Grassed Detention and Bioretention Stormwater Basins

Roadside ditches are ubiquitous in developed landscapes. They are designed to route water from roads for safety, with little consideration of water quality or biogeochemical implications in ditch design and minimal data on environmental impacts. We hypothesize that periodic saturation and nutrient influxes may make roadside ditches hotspots for nitrogen (N) removal via denitrification as well as biological production of the greenhouse gases (GHGs) nitrous oxide (NO), methane (CH), and carbon dioxide (CO). Research sites included 12 grassed ditches and adjacent lawns with varying fertilization in a suburban watershed in central New York, where lawns represented a reference with similar soils as ditches but differing hydrology. We measured potential denitrification using the denitrification enzyme assay in fall 2014 and GHG fluxes using in situ static chambers between summer 2014 and 2015, including sample events after storms. Potential denitrification in ditches was significantly higher than in lawns, and rates were comparable to those in stream riparian areas, features traditionally viewed as denitrification hotspots. Ditches had higher rates of CH emissions, particularly sites that were wettest. Lawns were hotspots for NO and CO respiratory emissions, which were driven by nutrient availability and fertilizer application. Extrapolating up to the watershed, ditches have the potential to remove substantial N loads via denitrification if managed optimally. Ditch GHG emissions extrapolated across the watershed were minimal given their much smaller area compared with lawns, which were the greater contributor of GHGs. These findings suggest that roadside ditches may offer new management opportunities for mitigating nonpoint source N pollution in residential watersheds.

Defining Extreme Events: A Cross‐Disciplinary Review

Dissimilatory metal-reducing bacteria are widespread in terrestrial ecosystems, especially in anaerobic soils and sediments. Thermodynamically, dissimilatory metal reduction is more favorable than sulfate reduction and methanogenesis but less favorable than denitrification and aerobic respiration. It is critical to understand the complex relationships, including the absence or presence of terminal electron acceptors, that govern microbial competition and coexistence in anaerobic soils and sediments, because subsurface microbial processes can effect greenhouse gas emissions from soils, possibly resulting in impacts at the global scale. Here, we elucidated the effect of an inexhaustible, ferrous-iron and humic-substance mimicking terminal electron acceptor by deploying potentiostatically poised electrodes in the sediment of a very specific stream riparian zone in Upstate New York state. At two sites within the same stream riparian zone during the course of 6 weeks in the spring of 2013, we measured CH4 and N2/N2O emissions from soil chambers containing either poised or unpoised electrodes, and we harvested biofilms from the electrodes to quantify microbial community dynamics. At the upstream site, which had a lower vegetation cover and highest soil temperatures, the poised electrodes inhibited CH4 emissions by ∼45% (when normalized to remove temporal effects). CH4 emissions were not significantly impacted at the downstream site. N2/N2O emissions were generally low at both sites and were not impacted by poised electrodes. We did not find a direct link between bioelectrochemical treatment and microbial community membership; however, we did find a correspondence between environment/function and microbial community dynamics.

Temporal Evolution of Green Stormwater Infrastructure Strategies in Three US Cities

AbstractNutrient cycling was compared in a grassed detention basin and a bioretention basin was amended with compost, mulch, and diverse plantings. The authors monitored dissolved nutrients in basi...

Hydrogeomorphology of the Hyporheic Zone: Stream Solute and Fine Particle Interactions With a Dynamic Streambed

Extreme events are of interest worldwide given their potential for substantial impacts on social, ecological, and technical systems. Many climate-related extreme events are increasing in frequency and/or magnitude due to anthropogenic climate change, and there is increased potential for impacts due to the location of urbanization and the expansion of urban centers and infrastructures. Many disciplines are engaged in research and management of these events. However, a lack of coherence exists in what constitutes and defines an extreme event across these fields, which impedes our ability to holistically understand and manage these events. Here, we review 10 years of academic literature and use text analysis to elucidate how six major disciplines--climatology, earth sciences, ecology, engineering, hydrology, and social sciences--define and communicate extreme events. Our results highlight critical disciplinary differences in the language used to communicate extreme events. Additionally, we found a wide range in definitions and thresholds, with more than half of examined papers not providing an explicit definition, and disagreement over whether impacts are included in the definition. We urge distinction between extreme events and their impacts, so that we can better assess when responses to extreme events have actually enhanced resilience. Additionally, we suggest that all researchers and managers of extreme events be more explicit in their definition of such events as well as be more cognizant of how they are communicating extreme events. We believe clearer and more consistent definitions and communication can support transdisciplinary understanding and management of extreme events.

Thresholds of flow-induced bed disturbances and their effects on stream metabolism in an agricultural river

Over the last several decades, interest in green stormwater infrastructure (GSI) has rapidly increased, particularly given its potential to provide stormwater management in conjunction with other ecosystem services and co-benefits such as urban heat island mitigation or habitat provision. Here we explore the implementation of GSI in three US cities – Baltimore (Maryland), Phoenix (Arizona), and Portland (Oregon). We examine the trends in GSI construction over several decades, highlighting changes in implementation rates and GSI types with concurrent regulatory and economic changes. Additionally, we discuss the implications of these GSI portfolios for ecosystem service delivery in urban areas. Results indicate that Portland’s quantity of GSI is approximately ten times greater than the quantity of GSI in Phoenix or Baltimore. However, Baltimore has the most diverse portfolio of GSI types. In Phoenix, regional stormwater policies focused on flood control have led to retention basins being the dominant GSI type for decades. In contrast, Portland and Baltimore both have had substantial changes in their GSI portfolios over time, with transitions from detention or retention basins and underground facilities towards filters, infiltration facilities, and swales. These changes favor increased water quality function as well as provision of other ecosystem services. Additionally, we find evidence that each city followed a different GSI implementation pathway, with Portland’s combined sewer overflow program influencing initial development of GSI, while state legislation and regional water quality pressures played a major role in Baltimore’s GSI development. By studying the evolution of GSI in these different cities, we can see the variability in stormwater management trajectories and how they manifest in different suites of benefits. We hope that continued research of GSI implementation and performance will identify opportunities for future improvement of these infrastructures.