159 research outputs found

    High resolution mapping of Puget Sound shorelines

    Get PDF
    In an effort to collect high-resolution baseline coastal topographic data of beaches and bluffs around the Puget Sound and Strait of Juan de Fuca, the Washington State Department of Ecology Coastal Monitoring & Analysis Program (CMAP) conducted a series of boat-based lidar surveys in October 2013, May through September 2015, and May 2016 at a total of 16 sites spanning 220 km of shoreline and over two dozen drift cells. The drift cells were selected based on a rigorous and systematic geospatial analysis of bluff-backed beaches for their potential for significant bluff sediment supply to intact shorelines identified as having a relative abundance of habitat for forage fish, eelgrass, herring, shellfish, and geoduck, as well as having previous investments in beach restoration projects, and potential for future shoreline armoring and habitat loss based on population growth scenarios. As such, the surveyed drift cells are top candidates for implementing drift cell-scale protection and restoration strategies. The boat-based lidar and GPS topography data were used to produce 0.5-m digital elevation models (DEMs) for the beaches and bluffs at each of the survey sites. These DEMs provide the opportunity to inventory and characterize the shoreline landscape that affects nearshore ecosystem services such as feeder bluff activity, beach slope and width, and the position, length, and elevation of armoring relative to the backshore. Boat-based lidar provides an advantageous point of view of the bluff face, resulting in high resolution data which is needed to gain insight into bluff failure and erosion mechanisms and corresponding sediment transport processes. In addition, it successfully collects data under overhanging vegetation and overwater structures. Repeat surveys in the future would enable change analyses for quantifying bluff sediment supply, changes in marine riparian vegetation, and a better understanding of the linkages between physical and ecological processes

    Puget Sound shoreline inventory and assessment using boat-based lidar

    Get PDF
    Boat-based lidar of Puget Sound shorelines collected by the Washington State Department of Ecology are developed to provide a comprehensive inventory, classification, and analyses of site conditions and variability. For example, quantitative metrics of shoreline characteristics are derived from DEMs such as bluff crest height, bluff slope, bluff toe elevation, beach slope, and shoreline armoring elevations. These metrics can then be compiled and compared within and among drift cells to determine regional variability such as differences between updrift and downdrift beaches and the effect of fetch, orientation, and other exposure variables. Certain features can also be correlated to characterize how the shoreline landscape may be affecting nearshore ecosystem services. For example, variability and gradients in beach slope and width may be correlated to proximity to feeder bluff activity and the position, length, and elevation of armoring relative to the shoreline and backshore. Upland development and shoreline modification may be correlated to the amount of overhanging vegetation, large woody debris, or beach wrack, and these findings can be compared to conditions at undeveloped shorelines. Details in the lidar point clouds, such as intensity values, can help identify groundwater seepage and potential bluff failure and erosion mechanisms. The complementary photos to the lidar point clouds provide additional documentation of bluff geology, stratigraphy, groundwater flow, and other characteristics to help assess relative bluff stability

    Evaluating methods to obtain high resolution nearshore bathymetry and coastal topography for Puget Sound

    Get PDF
    The Washington State Department of Ecology Coastal Monitoring & Analysis Program performed a coastal topographic and bathymetric survey of Port Gamble Bay between March 9 and March 28, 2014. Boat-based topographic lidar was collected along the shoreline of the bay and multibeam bathymetric sonar was collected throughout the bay to obtain a seamless topographic-bathymetric surface with complete coverage of Port Gamble Bay. The survey was performed with a R2Sonic 2022 multibeam echosounder, an Optech ILRIS-HD-ER mobile laser scanner, and an Applanix POS MV 320 v5 receiving real-time kinematic positioning corrections. The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) performed a topographic and bathymetric lidar survey of Port Gamble Bay on September 4, 2014. The Coastal Zone Mapping and Imaging Lidar (CZMIL) system was used to obtain seamless coastal topographic-bathymetric coastal intertidal and nearshore coverage of Port Gamble Bay. The bathymetric depth coverage is limited to laser extinction, which is determined by water clarity. The availability of these two datasets provides the unique opportunity to compare data between high-resolution boat-based lidar and multibeam systems and the state-of-the-art airborne topo-bathy lidar system and also assess detection and resolution of specific features throughout a range of water depths across the nearshore important to habitat and restoration efforts. This effort provides a detailed comparison of coverage and resolution of nearshore features and will help clarify differences between these capabilities to aid in planning complementary efforts in coastal zone mapping and monitoring

    Behaviour and performance of a dynamic cobble berm revetment during a spring tidal cycle in North Cove, Washington State, USA

    Get PDF
    In many places, sandy coastlines and their associated assets are at high risk of erosion and flooding, with this risk increasing under climate change and sea level rise. In this context, dynamic cobble berm revetments represent a potentially sustainable protection technique to armour sandy beaches, reduce wave runup and protect the hinterland against wave attack. However, the behaviour and performance of such structures is not well understood. The dynamic cobble berm revetment located in North Cove, WA, USA, was monitored over a spring tidal cycle in January 2019. A representative 60 m alongshore section was monitored over 10 days using 2D laser scanner (lidar) measurements, GPS ground elevation surveys, Radio Frequency Identification of individual cobbles and revetment thickness measurements. These data were used together to assess the dynamic behaviour and functionality of the revetment throughout the experiment. Over the course of the experiment, the surface elevation changed by up to ±0.5 m, and the revetment volume reduced by an average 0.67 m3/m. These changes were found to be caused by relatively large significant wave height and high water levels. The revetment demonstrated a dynamic stability and the capacity to quickly reshape under changing hydrodynamic conditions. The instrumented cobbles were transported along and cross-shore and accumulated at the toe of the revetment, but were never transported seaward of the toe. The revetment also managed to recover some of the lost volume under moderate wave conditions. The revetment behaviour was found to be influenced by variation in the cobble-sand matrix. The underlying sand dynamics – i.e., accumulation or removal of sand within the cobbles – were found to govern the overall volume changes and were important to the overall stability of the revetment. Seven possible transport regimes were identified, and a model of the internal sand dynamics was developed. During the spring tidal cycle measured here, the revetment protected the sand scarp immediately landward and prevented flooding of the hinterland, while armouring the underlying sand. Over time, renourishment will likely be required due to longshore sediment transport, and preliminary guidelines for this and other aspects of design are suggested.</p

    Swash-by-swash morphology change on a dynamic cobble berm revetment:High-resolution cross-shore measurements

    Get PDF
    Dynamic cobble berm revetments are a promising soft engineering technique capable of protecting sandy coastlines by armouring the sand and dissipating wave energy to protect the hinterland against wave attack. They also form composite beaches as they are essentially mimicking natural composite beach structure and behaviour. This type of coastal protections and beaches have recently been investigated, and this led to a better understanding of their overall behaviour under varying water levels and wave conditions. However, the short-term dynamics of the swash zone (where all bed changes occur) has never been studied at high-resolution, and this is needed to fully understand the underlying dynamics of such structures and relate it to observed processes at larger scale. To do so, the revetment at North Cove (WA, USA) was monitored for a nine-day period in January 2019 over a spring tidal cycle and with offshore significant wave height reaching 6 m. A 2-D lidar was used to survey a cross-shore profile of the revetment, and record all surface changes and interaction with swashes at high spatial (0.1 m) and temporal (swash-by-swash) resolution. The revetment was found to rapidly reshape under these energetic conditions, but reached a relatively stable state during the rising tide. The analysis of bed-level changes and net cross-shore mass fluxes over the revetment showed that revetment changes are mainly driven by very small events, with some rare large bed-level changes of a magnitude comparable to the median cobble diameter. The distribution of event mass fluxes nearly balanced out over the duration of a tide, meaning that positive and negative fluxes tended to be symmetrical. Furthermore, measured net fluxes magnitude were 18 times smaller than the absolute fluxes, which demonstrated the dynamic stability of the revetment as substantial movement occur on a wave-by-wave timescale but these balance out over time. The analysis of swash revealed that the revetment section where the swash reaches a maximum depth between 0.15 and 0.45 m undergoes the more extreme fluxes. Swashes deeper than 0.45 m only occurred in zones inundated more than 50% of the time, and smaller extreme fluxes were measured over the revetment section where these deep swashes were recorded. Bed level change oscillations over the revetment were observed, and the cross shore limit of these was correlated with the mean wave period at the toe of the revetment. Overall, the water depth at the toe of the revetment was identified as the key parameter to describe the energy reaching the revetment. This study enables the morphodynamics of dynamic revetment, observed in previous lab and field studies, to be explained at the swash scale, and brought new information on the sediment dynamics of composite beaches and dynamic revetments. These findings allow to suggest some generic guidance for dynamic cobble berm revetment design. Finally, the results are compared to a similar study on sandy beaches.</p

    Swash-by-swash morphology change on a dynamic cobble berm revetment:High-resolution cross-shore measurements

    Get PDF
    Dynamic cobble berm revetments are a promising soft engineering technique capable of protecting sandy coastlines by armouring the sand and dissipating wave energy to protect the hinterland against wave attack. They also form composite beaches as they are essentially mimicking natural composite beach structure and behaviour. This type of coastal protections and beaches have recently been investigated, and this led to a better understanding of their overall behaviour under varying water levels and wave conditions. However, the short-term dynamics of the swash zone (where all bed changes occur) has never been studied at high-resolution, and this is needed to fully understand the underlying dynamics of such structures and relate it to observed processes at larger scale. To do so, the revetment at North Cove (WA, USA) was monitored for a nine-day period in January 2019 over a spring tidal cycle and with offshore significant wave height reaching 6 m. A 2-D lidar was used to survey a cross-shore profile of the revetment, and record all surface changes and interaction with swashes at high spatial (0.1 m) and temporal (swash-by-swash) resolution. The revetment was found to rapidly reshape under these energetic conditions, but reached a relatively stable state during the rising tide. The analysis of bed-level changes and net cross-shore mass fluxes over the revetment showed that revetment changes are mainly driven by very small events, with some rare large bed-level changes of a magnitude comparable to the median cobble diameter. The distribution of event mass fluxes nearly balanced out over the duration of a tide, meaning that positive and negative fluxes tended to be symmetrical. Furthermore, measured net fluxes magnitude were 18 times smaller than the absolute fluxes, which demonstrated the dynamic stability of the revetment as substantial movement occur on a wave-by-wave timescale but these balance out over time. The analysis of swash revealed that the revetment section where the swash reaches a maximum depth between 0.15 and 0.45 m undergoes the more extreme fluxes. Swashes deeper than 0.45 m only occurred in zones inundated more than 50% of the time, and smaller extreme fluxes were measured over the revetment section where these deep swashes were recorded. Bed level change oscillations over the revetment were observed, and the cross shore limit of these was correlated with the mean wave period at the toe of the revetment. Overall, the water depth at the toe of the revetment was identified as the key parameter to describe the energy reaching the revetment. This study enables the morphodynamics of dynamic revetment, observed in previous lab and field studies, to be explained at the swash scale, and brought new information on the sediment dynamics of composite beaches and dynamic revetments. These findings allow to suggest some generic guidance for dynamic cobble berm revetment design. Finally, the results are compared to a similar study on sandy beaches.</p

    Delivery of adjuvant chemotherapy (AC) to veterans with resected colon cancer

    Get PDF
    Patients with incomplete administration of AC for colon cancer (CC) likely experience inferior survival while oxaliplatin- and capecitabine-containing AC may not improve survival for older patients. The influence on AC completion of age, other baseline patient characteristics, or regimen characteristics is unknown. We evaluated the association of baseline characteristics and planned AC regimen with AC delivery in resected CC patients

    Assessing bulkhead removal and shoreline restoration using boat-based lidar

    Get PDF
    The Washington State Department of Ecology performed before and after boat-based lidar surveys of a shoreline restoration project involving the removal of ~800 feet of armoring from the base of a historic feeder bluff at Edgewater Beach, along Eld Inlet in South Puget Sound. As part of the restoration project, 700 feet of bulkheads, two rock revetments, a large wood and rock groin, and several large boulders were removed or realigned from the site in fall 2016. Removal of the armoring is expected to reconnect the historic feeder bluff at the updrift end of the project site with the adjacent beaches, restoring nearshore habitat and sediment supply to the drift cell. This poster will present an assessment of geomorphological changes to the beach and bluff associated with the bulkhead removal, and the opportunity to utilize this monitoring technology for documenting the physical processes and habitat functions restored through projects of this type

    Toward criteria for pragmatic measurement in implementation research and practice: a stakeholder-driven approach using concept mapping

    Get PDF
    Background: Advancing implementation research and practice requires valid and reliable measures of implementation determinants, mechanisms, processes, strategies, and outcomes. However, researchers and implementation stakeholders are unlikely to use measures if they are not also pragmatic. The purpose of this study was to establish a stakeholder-driven conceptualization of the domains that comprise the pragmatic measure construct. It built upon a systematic review of the literature and semi-structured stakeholder interviews that generated 47 criteria for pragmatic measures, and aimed to further refine that set of criteria by identifying conceptually distinct categories of the pragmatic measure construct and providing quantitative ratings of the criteria’s clarity and importance. Methods: Twenty-four stakeholders with expertise in implementation practice completed a concept mapping activity wherein they organized the initial list of 47 criteria into conceptually distinct categories and rated their clarity and importance. Multidimensional scaling, hierarchical cluster analysis, and descriptive statistics were used to analyze the data. Findings: The 47 criteria were meaningfully grouped into four distinct categories: (1) acceptable, (2) compatible, (3) easy, and (4) useful. Average ratings of clarity and importance at the category and individual criteria level will be presented. Conclusions: This study advances the field of implementation science and practice by providing clear and conceptually distinct domains of the pragmatic measure construct. Next steps will include a Delphi process to develop consensus on the most important criteria and the development of quantifiable pragmatic rating criteria that can be used to assess measures
    • …
    corecore