Geology topics

Dianna M. Hogan

Publications and source records attributed to Dianna M. Hogan.

25 records · Page 2Linked to original sources

USGS2014

Effects of distributed and centralized stormwater best management practices and land cover on urban stream hydrology at the catchment scale

Urban stormwater runoff remains an important issue that causes local and regional-scale water quantity and quality issues. Stormwater best management practices (BMPs) have been widely used to mitigate runoff issues, traditionally in a centralized manner; however, problems associated with urban hydrology have remained. An emerging trend is implementation of BMPs in a distributed manner (multi-BMP treatment trains located on the landscape and integrated with urban design), but little catchment-scale performance of these systems have been reported to date. Here, stream hydrologic data (March, 2011–September, 2012) are evaluated in four catchments located in the Chesapeake Bay watershed: one utilizing distributed stormwater BMPs, two utilizing centralized stormwater BMPs, and a forested catchment serving as a reference. Among urban catchments with similar land cover, geology and BMP design standards (i.e. 100-year event), but contrasting placement of stormwater BMPs, distributed BMPs resulted in: significantly greater estimated baseflow, a higher minimum precipitation threshold for stream response and maximum discharge increases, better maximum discharge control for small precipitation events, and reduced runoff volume during an extreme (1000-year) precipitation event compared to centralized BMPs. For all catchments, greater forest land cover and less impervious cover appeared to be more important drivers than stormwater BMP spatial pattern, and caused lower total, stormflow, and baseflow runoff volume; lower maximum discharge during typical precipitation events; and lower runoff volume during an extreme precipitation event. Analysis of hydrologic field data in this study suggests that both the spatial distribution of stormwater BMPs and land cover are important for management of urban stormwater runoff. In particular, catchment-wide application of distributed BMPs improved stream hydrology compared to centralized BMPs, but not enough to fully replicate forested catchment stream hydrology. Integrated planning of stormwater management, protected riparian buffers and forest land cover with suburban development in the distributed-BMP catchment enabled multi-purpose use of land that provided esthetic value and green-space, community gathering points, and wildlife habitat in addition to hydrologic stormwater treatment.

Journal of Hydrology↗

USGS2014

Urban ecosystem services and decision making for a green Philadelphia

Traditional approaches to urban development often do not account for, or recognize, the role of ecosystem services and the benefits these services provide to the health and well-being of city residents. Without such accounting, urban ecosystem services are likely to be degraded over time, with negative consequences for the sustainability of cities and the well-being of their residents (Millennium Ecosystem Assessment, 2005; Hirsch, 2008). On May 23, 2013, the Spatial Integration Laboratory for Urban Systems (SILUS), a collaboration between the U.S. Geological Survey (USGS) Science and Decisions Center and the Wharton GIS Lab, convened a one-day symposium—Urban Ecosystem Services and Decision Making: A Green Philadelphia—at the University of Pennsylvania in Philadelphia, Pennsylvania, to examine the role of green infrastructure in the environmental, economic, and social well-being of cities. Cosponsored by the USGS and the Penn Institute for Urban Research (Penn IUR), the symposium brought together policymakers, practitioners, and researchers from a range of disciplines to advance a research agenda on the use of science in public decision making to inform investment in green infrastructure and ecosystem services in urban areas. The city of Philadelphia has recently implemented a program designed to sustain urban ecosystem services and advance the use of green infrastructure. In 2009, the Philadelphia Mayor’s Office of Sustainability launched its Greenworks plan, establishing a citywide sustainability strategy. Major contributions towards its goals are being implemented in coordination with the Philadelphia Water Department (PWD). The Green City, Clean Waters initiative, the city’s nationally recognized stormwater management plan, was signed into action with the U.S. Environmental Protection Agency (EPA) in April 2012. The plan outlines a 25-year strategy to use green infrastructure to protect and improve the city’s watershed. Widespread support for the plan marks a citywide effort to factor environmental quality concerns into the city’s strategic planning, choosing to replace expensive and aging grey infrastructure, with innovative and resilient green infrastructure. The symposium focused on these city of Philadelphia initiatives and also on two new Federal- local partnership programs: America’s Great Outdoors, initiated to promote conservation and recreation, and the Urban Waters Federal Partnership, a multiagency effort to reconnect urban communities to their waterways. A second goal of the symposium was to advance a research agenda on urban ecosystem services. While there has been considerable work on ecosystem services, the discussion of the benefits provided by urban ecosystems is not as developed. Benefits range from improved water and air quality to quality of life gains, including aesthetic and recreational considerations. There is also need for additional focused research toward furthering the understanding of the multiple indirect benefits provided by urban ecosystem services (Bolund and Hunhammar, 1999). Moreover, there is a need for a greater understanding of how best to inform local decision making in this area, as local decision makers in cities across the country are increasingly recognizing the importance of developing sustainability measures for their immediate and long-term planning (United States Conference of Mayors, 2005). Approaching these local and regional plans from a holistic perspective has become a guiding principle of sustainability and resiliency. Therefore, there is a need to better understand the gains that have been achieved and to advance a research agenda on ecosystem services going forward. The day’s program included presentations on greening initiatives from the Philadelphia’s Mayor’s Office of Sustainability, as well as discussion about using an urban ecosystem services framework to evaluate these initiatives. Panel sessions included discussion of the Green City, Clean Waters initiative; a dialogue about the management of urban trees and green space; and a conversation addressing the needs for future research.

Pennsylvania↗

USGS2013

Mitigating the effects of landscape development on streams in urbanizing watersheds

This collaborative study examined urbanization and impacts on area streams while using the best available sediment and erosion control (S&EC) practices in developing watersheds in Maryland, United States. During conversion of the agricultural and forested watersheds to urban land use, land surface topography was graded and vegetation was removed creating a high potential for sediment generation and release during storm events. The currently best available S&EC facilities were used during the development process to mitigate storm runoff water quality, quantity, and timing before entering area streams. Detailed Geographic Information System (GIS) maps were created to visualize changing land use and S&EC practices, five temporal collections of LiDAR (light detection and ranging) imagery were used to map the changing landscape topography, and streamflow, physical geomorphology, and habitat data were used to assess the ability of the S&EC facilities to protect receiving streams during development. Despite the use of the best available S&EC facilities, receiving streams experienced altered flow, geomorphology, and decreased biotic community health. These impacts on small streams during watershed development affect sediment and nutrient loads to larger downstream aquatic ecosystems such as the Chesapeake Bay.

Maryl↗

USGS2013

An integrated multi-criteria scenario evaluation web tool for participatory land-use planning in urbanized areas: The Ecosystem Portfolio Model

Land-use land-cover change is one of the most important and direct drivers of changes in ecosystem functions and services. Given the complexity of the decision-making, there is a need for Internet-based decision support systems with scenario evaluation capabilities to help planners, resource managers and communities visualize, compare and consider trade-offs among the many values at stake in land use planning. This article presents details on an Ecosystem Portfolio Model (EPM) prototype that integrates ecological, socio-economic information and associated values of relevance to decision-makers and stakeholders. The EPM uses a multi-criteria scenario evaluation framework, Geographic Information Systems (GIS) analysis and spatially-explicit land-use/land-cover change-sensitive models to characterize changes in important land-cover related ecosystem values related to ecosystem services and functions, land parcel prices, and community quality-of-life (QoL) metrics. Parameters in the underlying models can be modified through the interface, allowing users in a facilitated group setting to explore simultaneously issues of scientific uncertainty and divergence in the preferences of stakeholders. One application of the South Florida EPM prototype reported in this article shows the modeled changes (which are significant) in aggregate ecological value, landscape patterns and fragmentation, biodiversity potential and ecological restoration potential for current land uses compared to the 2050 land-use scenario. Ongoing refinements to EPM, and future work especially in regard to modifiable sea level rise scenarios are also discussed.

Environmental Modelling and Software↗

USGS2012

Effects of urban stormwater-management strategies on stream-water quantity and quality

Urbanization results in elevated stormwater runoff, greater and more intense streamflow, and increased delivery of pollutants to local streams and downstream aquatic systems such as the Chesapeake Bay. Stormwater Best Management Practices (BMPs) are used to mitigate these effects of urban land use by retaining large volumes of stormwater runoff (water quantity) and removing pollutants in the runoff (water quality). Current USGS research aims to understand how the spatial pattern and connectivity of stormwater BMPs affect water quantity and water quality in urban areas.

Fact Sheet↗

USGS2011

Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida

Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.

Florida↗

USGS2008

Management of Urban Stormwater Runoff in the Chesapeake Bay Watershed

Urban and suburban development is associated with elevated nutrients, sediment, and other pollutants in stormwater runoff, impacting the physical and environmental health of area streams and downstream water bodies such as the Chesapeake Bay. Stormwater management facilities, also known as Best Management Practices (BMPs), are increasingly being used in urban areas to replace functions, such as flood protection and water quality improvement, originally performed by wetlands and riparian areas. Scientists from the U.S. Geological Survey (USGS) have partnered with local, academic, and other Federal agency scientists to better understand the effectiveness of different stormwater management systems with respect to Chesapeake Bay health. Management of stormwater runoff is necessary in urban areas to address flooding and water quality concerns. Improving our understanding of what stormwater management actions may be best suited for different types of developed areas could help protect the environmental health of downstream water bodies that ultimately receive runoff from urban landscapes.

Fact Sheet↗