Coastal and riverine shorelines are dynamic landscapes that change continually in response to environmental forces. The combination of static infrastructure with dynamic and diverse landscapes creates management challenges for navigation, storm damage reduction, and ecosystem health that are exacerbated during natural disasters. The U.S. Army Corps of Engineers (USACE) flood risk management (FRM) mission strives to reduce the nation's flood risk and increase resilience to disasters. FRM is inherently interdisciplinary, requiring accurate identification of environmental, physical, and infrastructure features that can reduce risk from flood and coastal storm disasters.

USACE has identified a number of research and development (R&D) opportunities that will help reduce disaster risks, including: identifying better technologies for hazard identification pre- and post-events; developing an interdisciplinary understanding of physical, chemical, and biological recovery processes that occur post-event; and providing shared and easily accessible, up-to-date data sets that can be utilized by flood and coastal storm modeling and predictive tools to inform emergency response.

Panel A shows the DTM (shaded presentation) of levees in a test area, and Panel B shows a comparison of profiles of the direct field survey (GNSS) and the DTM generated from a UAS. (Courtesy of Bakula et al. [2017])

Cost-efficient technology and methodology, such as the use of unmanned aircraft system (UAS) technology for accurate, detailed, and timely two-dimensional (2D) and three-dimensional (3D) monitoring of coastal and riverine landscapes, have the potential to address many of these goals. However, an important process in adapting new technologies is ensuring an understanding of existing methods, identifying gaps or shortcomings with current techniques, and then developing new approaches and providing guidance and insight on how new tools can address these gaps, as well as exploring potential future capabilities. To that end, the USACE Flood and Coastal Systems R&D Program (FCS) has initiated an effort focused on identifying and developing defendable and consistent UAS-based methodologies and data products that can seamlessly integrate with numerical models to improve quantification of the nation's flood risks to coastal and riverine shorelines, infrastructure, ecosystems, and communities.

Remotely sensed data provide spatial and temporal perspectives on ecological phenomena that would otherwise be difficult to study. Though traditional air- and space-borne systems provide many advantages, they are often constrained by cost; temporal, spatial, and spectral resolution; and cloud contamination. UASs are emerging as flexible platforms that, in many cases, overcome previous constraints and, therefore, have the potential to supplement or replace measurements acquired from other methods.

Major advantages of UASs can be found in the ability to operate in high-risk situations, in inaccessible areas, at low altitudes, and close to targets, all without endangering human life. Recent technological advances in UASs, including the miniaturization of components and improvements in electronics, navigation, and telemetry, have resulted in reduced costs and risks, increased efficiencies, and enhanced products and perspectives on projects. These UAS improvements have resulted in a growing service mechanism with widespread application across civil, military, and public sector uses.

Though remote sensing is not new to the USACE, advanced techniques have transformed ecological research by providing unique spatial and temporal perspectives on ecological phenomena and offer the potential for much higher resolution data at more frequent intervals, enabling scientists to more consistently examine a range of ecological systems. Environmental monitoring, especially to evaluate the success of large-or small-scale restoration projects, requires the ability to detect and map land surface attributes and landscape level characteristics over time and space.

The most practical method for these assessments is through high spatial resolution imagery (< 5 meter (m) spatial resolution), either from satellite or airborne platforms. Airborne systems have traditionally been considered the most available, versatile, and widely used means of acquiring remotely sensed data products. For decades, these data sources and products have been routinely used within the USACE for environmental mapping applications.

This work was done by Glenn M. Suir, Molly Reif, Shea Hammond, Sam Jackson, and Katherine Brodie for the Army Engineer Research and Development Center. For more information, download the Technical Support Package (free white paper) from the link below. ERDC-0013

This Brief includes a Technical Support Package (TSP).
Unmanned Aircraft Systems to Support Environmental Applications within USACE Civil Works

(reference ERDC-0013) is currently available for download from the TSP library.

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