Shoreline Situation Reports (SSR) were first generated by VIMS in the 1970's to report the condition and status of the shore lands. The SSR series were published in hardcopy on a county by county basis for each Tidewater Virginia localities. The reports were intended to assist planners, managers, and regulators in decisions pertaining to management of coastal areas and natural resources therein. This Shoreline Inventory report continues a process which updates and expands the earlier reports. Data collected reports conditions surveyed in the immediate riparian zone, the bank, and along the shoreline.
To inventory Virginia's tidal shoreline conditions.
There are three shapefiles that are part of the 2009 City of Newport News Shoreline Inventory database: nnews_lubc, nnews_astru, nnews_sstru. Nnews_lubc (land use and bank cover for the City of Newport News) is a linear shapefile containing data about land use, bank height, bank cover, erosion, Phragmites australis, marsh, and beach status along the shoreline. Nnews_sstru (City of Newport News shoreline structures) is a linear shapefile delineating hard structures in place at the shoreline (bulkhead, breakwater,miscellaneous, dilapidated bulkhead, riprap, jetty, marina, marsh toe revetment, seawall, shipyard, groinfields). Nnews_astru (City of Newport News structures) is a point shapefile with locations of docks, ramps, dilapidated docks, outfalls and boathouses. The attributes of these three shapefiles are explained in the Entity and Attribute Information section below.
ground condition at time of survey
These data should not be used for jurisdictional permit determinations beyond providing general shoreline condition or status information. These data have not been surveyed to property boundaries.
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Chain-node topology present. Linear coverages were built for lines and point coverages were built for points.
All shoreline of the City of Newport News that has a minimum depth of 2 feet at mean low water was surveyed. Some shorelines are coded remotely if access was restricted due to depth upriver of the James River Bridge . Downriver of bridge was coded remotely.
Shoreline structures were recorded with a GPS unit as the boat moved along the shoreline. Data was transferred from the GPS boat track to an existing digital shoreline coverage by projecting data to the shoreline at a 90 degree angle from the boat track. Rectified digital orthophoto quads were used as a background coverage to aid in data positioning. Dock and boathouse point data were aligned with docks on the images. Land use features were placed along the shore so changes in land use were coincident with changes illustrated in the imagery. Positional accuracy for data that has been corrected with imagery is .3 meters (equivalent to image resolution). Data not visable on the imagery (bulkheads, riprap, etc.) has a positional accuracy of 11 meters. Accuracy was determined by comparing digitally processed data locations to onsite GPS ground surveys collected at random.
Imagery (2007) serves as a background in the map portfolio. Imagery is used to update land use and structure data as well as to remotely code areas not previously surveyed in the field. The VBMP shoreline was also used and adjusted using the imagery where needed.
Data was collected by a two-person field crew (one person collecting land use and bank condition data and one boat operator also collecting shoreline features) using two hand-held Trimble GeoExplorers GPS Units, while navigating along the shoreline. A data dictionary designed for the inventory was installed on each GPS Unit. One data collector records natural features including land use, bank height, presence of marsh or beach, and shoreline stability. A second person collects data on the hardened structures: riprap, bulkheads, docks, boatramps, etc. Point features (docks, boathouses, ramps) were surveyed with a six second observation recorded at 1 reading/second. Linear features were surveyed kinematically at a rate of one observation every 3 seconds.
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Data from the GPS units were postprocessed on a PC with Trimble Pathfinder Office software. Postprocessing includes differential correction using base station data collected at the VIMS laboratory. Corrected data is converted to shapefiles for further processing.
In the ArcMap environment, boat-track arcs were manually shifted to the base shoreline (VBMP). Arcs were split and moved to locations on the shoreline perpendicular to the original locations on the boat-track. Shoreline arc segments were coded, and the shapefiles were visually checked for attribute accuracy between coded shoreline and boat-track data.
In ArcMap, boat-track points were manually shifted to the base shoreline (VBMP). Points were moved to locations on the shoreline perpendicular to the original locations on the boat-track. Points were coded and the access structure (astru) was visually checked for attribute accuracy between coded shoreline and boat-track data.
Land use, dock, and boathouse locations were digitally checked and repositioned if necessary with VBMP imagery displayed as a background coverage. This was done using ArcMap capabilities. Areas inaccessible by boat due to low tide were coded based on features observed on the imagery. The "remote" coded areas were given the item REMOTE = "yes" to distinquish them from GPS collected data.
A portfolio containing fourteen 1:12,000 scale plates was created for the City of Newport News. Each plate shows four maps: riparian land use, bank conditions, shoreline features, and natural buffers. VBMP (2007) imagery is displayed in the background to provide users with additional information.
Internal feature number.
ESRI
Feature geometry.
ESRI
current land use: bare, commercial, forest, grass, industrial, multifamily dwelling, military, paved, scrub-shrub, single family dwelling
condition of bank face: high, low, undercut
presence or absence
presence or absence
bank height (in feet) from the toe to the edge of the fastland: 0-5, 5-10, 10-30, >30
vegetative coverage of the bank: total, partial or bare
coded in the lab using background imagery
date of data capture
presence or absence
same as height
same as cover
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