Field assessment of engineered bioretention as microplastics sink through site characterization and hydrologic modeling.

Green stormwater infrastructure (GSI) practices like bioretention are considered a sink for microplastics washed in from urbanized land uses-land covers, and thereby regulating the environmental dispersion of microplastics. However, the capacity of GSI in microplastic sequestration remain unclear. This work investigated the spatial distributions of microplastics within bioretention cells and their soils, concentration in the GSI groundwater monitoring well, and the overall potential of GSI as a sink for microplastics.

Urbanization drives convergence in soil profile texture and carbon content.

Urban development has driven extensive modification of the global landscape. This shift in land use and land cover alters ecological functioning, and thereby affects sustainable management agendas. Urbanization fundamentally reshapes the soils that underlay landscapes, and throughout the soil profile, extends impacts of urbanization far below the landscape surface.

An analytical approach to ascertain saturation-excess versus infiltration-excess overland flow in urban and reference landscapes.

Uncontrolled overland flow drives flooding, erosion, and contaminant transport, with the severity of these outcomes often amplified in urban areas. In pervious media such as urban soils, overland flow is initiated via either infiltration-excess (where precipitation rate exceeds infiltration capacity) or saturation-excess (when precipitation volume exceeds soil profile storage) mechanisms. These processes call for different management strategies, making it important for municipalities to discern between them.

Full Water-Cycle Monitoring in an Urban Catchment Reveals Unexpected Water Transfers (Detroit MI, USA).

A goal in urban water management is to reduce the volume of stormwater runoff in urban systems and the effect of combined sewer overflows into receiving waters. Effective management of stormwater runoff in urban systems requires an accounting of various components of the urban water balance. To that end, precipitation, evapotranspiration, sewer flow, and groundwater in a 3.

The Hydrologic Role of Urban Green Space in Mitigating Flooding (Luohe, China).

Even if urban catchments are adequately drained by sewer infrastructures, flooding hotspots develop where ongoing development and poor coordination among utilities conspire with land use and land cover, drainage, and rainfall. We combined spatially explicit land use/land cover data from Luohe City (central China) with soil hydrology (as measured, green space hydraulic conductivity), topography, and observed chronic flooding to analyze the relationships between spatial patterns in pervious surface and flooding. When compared to spatial-structural metrics of land use/cover where flooding was commonly observed, we found that some areas expected to remain dry (given soil and elevation characteristics) still experienced localized flooding, indicating hotspots with overwhelmed sewer infrastructure and a lack of pervious surfaces to effectively infiltrate and drain rainfall.

Widespread loss of intermediate soil horizons in urban landscapes.

Soils support terrestrial ecosystem function and therefore are critical urban infrastructure for generating ecosystem services. Urbanization processes modify ecosystem function by changing the layers of soils identified as soil horizons. Soil horizons are integrative proxies for suites of soil properties and as such can be used as an observable unit to track modifications within soil profiles.

Agroecology for the Shrinking City.

Many cities are experiencing long-term declines in population and economic activity. As a result, frameworks for urban sustainability need to address the unique challenges and opportunities of such shrinking cities. Shrinking, particularly in the U.

Street-level emissions of methane and nitrous oxide from the wastewater collection system in Cincinnati, Ohio.

Recent studies have indicated that urban streets can be hotspots for emissions of methane (CH) from leaky natural gas lines, particularly in cities with older natural gas distribution systems. The objective of the current study was to determine whether leaking sewer pipes could also be a source of street-level CH as well as nitrous oxide (NO) in Cincinnati, Ohio, a city with a relatively new gas pipeline network. To do this, we measured the carbon (δC) and hydrogen (δH) stable isotopic composition of CH to distinguish between biogenic CH from sewer gas and thermogenic CH from leaking natural gas pipelines and measured CH and NO flux rates and concentrations at sites from a previous study of street-level CH enhancements (77 out of 104 sites) as well as additional sites found through surveying sewer grates and utility manholes (27 out of 104 sites).

Factors Contributing to the Hydrologic Effectiveness of a Rain Garden Network (Cincinnati OH USA).

Infiltrative rain gardens can add retention capacity to sewersheds, yet factors contributing to their capacity for detention and redistribution of stormwater runoff are dynamic and often unverified. Over a four-year period, we tracked whole-system water fluxes in a two-tier rain garden network and assessed near-surface hydrology and soil development across construction and operational phases. The monitoring data provided a quantitative basis for determining effectiveness of this stormwater control measure.

The role of trees in urban stormwater management.

Urban impervious surfaces convert precipitation to stormwater runoff, which causes water quality and quantity problems. While traditional stormwater management has relied on gray infrastructure such as piped conveyances to collect and convey stormwater to wastewater treatment facilities or into surface waters, cities are exploring green infrastructure to manage stormwater at its source. Decentralized green infrastructure leverages the capabilities of soil and vegetation to infiltrate, redistribute, and otherwise store stormwater volume, with the potential to realize ancillary environmental, social, and economic benefits.

A tale of two rain gardens: Barriers and bridges to adaptive management of urban stormwater in Cleveland, Ohio.

Green infrastructure installations such as rain gardens and bioswales are increasingly regarded as viable tools to mitigate stormwater runoff at the parcel level. The use of adaptive management to implement and monitor green infrastructure projects as experimental attempts to manage stormwater has not been adequately explored as a way to optimize green infrastructure performance or increase social and political acceptance. Efforts to improve stormwater management through green infrastructure suffer from the complexity of overlapping jurisdictional boundaries, as well as interacting social and political forces that dictate the flow, consumption, conservation and disposal of urban wastewater flows.

Ecology for the Shrinking City.

This article brings together the concepts of shrinking cities-the hundreds of cities worldwide experiencing long-term population loss-and ecology for the city. Ecology for the city is the application of a social-ecological understanding to shaping urban form and function along sustainable trajectories. Ecology for the shrinking city therefore acknowledges that urban transformations to sustainable trajectories may be quite different in shrinking cities as compared with growing cities.

Assessment of regional variation in streamflow responses to urbanization and the persistence of physiography.

Aquatic ecosystems are sensitive to the modification of hydrologic regimes, experiencing declines in stream health as the streamflow regime is altered during urbanization. This study uses streamflow records to quantify the type and magnitude of hydrologic changes across urbanization gradients in nine U.S.

Modeling the hydrologic and economic efficacy of stormwater utility credit programs for US single family residences.

As regulatory pressure to reduce the environmental impact of urban stormwater intensifies, US municipalities increasingly seek a dedicated source of funding for stormwater programs, such as a stormwater utility. In rare instances, single family residences are eligible for utility discounts for installing green infrastructure. This study examined the hydrologic and economic efficacy of four such programs at the parcel scale: Cleveland (OH), Portland (OR), Fort Myers (FL), and Lynchburg (VA).

How much is enough? Minimal responses of water quality and stream biota to partial retrofit stormwater management in a suburban neighborhood.

Decentralized stormwater management approaches (e.g., biofiltration swales, pervious pavement, green roofs, rain gardens) that capture, detain, infiltrate, and filter runoff are now commonly used to minimize the impacts of stormwater runoff from impervious surfaces on aquatic ecosystems.

Impediments and solutions to sustainable, watershed-scale urban stormwater management: lessons from Australia and the United States.

In urban and suburban areas, stormwater runoff is a primary stressor on surface waters. Conventional urban stormwater drainage systems often route runoff directly to streams and rivers, thus exacerbating pollutant inputs and hydrologic disturbance, and resulting in the degradation of ecosystem structure and function. Decentralized stormwater management tools, such as low impact development (LID) or water sensitive urban design (WSUD), may offer a more sustainable solution to stormwater management if implemented at a watershed scale.

Earthworm additions affect leachate production and nitrogen losses in typical midwestern agroecosystems.

Earthworms affect soil structure and the movement of agrochemicals. Yet, there have been few field-scale studies that quantify the effect of earthworms on dissolved nitrogen fluxes in agroecosystems. We investigated the influence of semi-annual earthworm additions on leachate production and quality in different row crop agroecosystems.