Leveraging ancillary benefits from urban greenspace - a case study of St. Louis, Missouri
Urban greenspace and green infrastructure are often cited for their many ecosystem services and benefits including stormwater management. However, the localized nature and limited range of effects of these benefits and the type of greenspace and green infrastructure, make planning and placement critical components to selecting for and maximizing desired benefits. Here, the authors test a framework to demonstrate a practical approach to simultaneously manage excess stormwater and maximize distribution of ecosystem services to underserved areas using spatial analysis. St. Louis was subdivided using census block polygons and polygons identified have combined sewer systems with high aggregate annual discharge. Additionally, indicators representing social, economic, and environmental characteristics, which have demonstrated effects from greenspace, were mapped to identify spatial distribution and overlap. The analysis identified one polygon that could promote multiple desired ecosystem services, while reducing annual discharge into combined sewers, and provide these services to an underserved demographic.
Modeling radionuclide transport in urban overland flow: a case study
This paper presents a case study demonstrating the process used to develop an overland flow model of radionuclide transport following an aerosol deposition from a hypothetical radiological dispersal device explosion. The process included the integration of digital elevation, building, and land cover information with hydrologic information from a calibrated Stormwater Management Model (SWMM) model. The overland flow model was used to explore the impact of washoff parameter selection and different storm events on radionuclide transport in surface flow. The range of washoff parameters used in the literature resulted in over a 7 times difference in radionuclide washoff, from a small surface removal to nearly full removal. The overland flow model illuminated the primary pathways of contaminant transport, a potentially useful tool that informs emergency response, planning, and remediation activities.
Calibrated methodology for assessing climate change adaptation costs for urban drainage systems
Changes in precipitation patterns associated with climate change may pose significant challenges for storm water management systems across the U.S. In particular, adapting these systems to more intense rainfall events will require significant investment, though no method currently exists for estimating the costs of these investments on a national scale. To support assessment of these costs at the national level, this paper presents a reduced-form approach for estimating changes in normalized flood depth (the volume of node flooding normalized by the area of the catchment) and the associated costs of flood prevention. This reduced form approach is calibrated to results generated by the U.S. Environmental Protection Agency's Storm Water Management Model (SWMM) for city-wide or neighborhood-level catchments in seven cities across the U.S. Estimates derived from this approach represent a reasonable approximation of storm water management adaptation costs and exhibit no systematic bias relative to results derived from SWMM.
Water safety plans for water supply utilities in China, Cuba, France, Morocco and Spain: costs, benefits, and enabling environment elements
Water Safety Plans (WSPs) are a management tool to identify and prioritize risks and implement appropriate control measures throughout the water supply chain, from catchment to consumer. WSPs have been implemented in over 90 countries; yet, costs, benefits and the enabling environment elements necessary for WSP implementation are under-studied. To better understand these factors, we conducted interviews with WSP implementation management teams from 20 private urban water utilities in China, Cuba, France, Morocco and Spain in 2014. Collectively, these utilities serve 10.6 million consumers and supply over 2.2 million m/day of water to consumers. Time for WSP implementation to achieve certification averaged 13 months. The main startup cost was staff time, averaging 16.2 full-time equivalent person-months. Additional costs, averaging €16,777, were for training staff, hiring consultants, purchasing equipment, and certifying WSPs. Benefits commonly reported included improved hazard control, treatment practices, record keeping, and client and health agency confidence.
