{
    "tag": 12802,
    "title": "SOCAL_BIASVALUES - Southern California Shoreline Bias Values",
    "pubdate": "2006",
    "sername": null,
    "series_name": null,
    "issue": "2006-1251",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/pcmsc\/SeriesReports\/OFR\/OFR_2016-1251\/socal_biasvalues.shp.faq.html",
    "format": null,
    "email": null,
    "descript": "The USGS has produced a comprehensive database of digital vector shorelines by compiling shoreline positions from pre-existing historical shoreline databases and by generating historical and modern shoreline data.  Shorelines are compiled by state and generally correspond to one of four time periods: 1800s, 1920s-1930s, 1970s, and 1998-2002.  These shorelines were used to calculate long-term and short-term change rates in a GIS using the Digital Shoreline Analysis System (DSAS) version 3.0; An ArcGIS extension for calculating shoreline change: U.S. Geological Survey Open-File Report 2005-1304, Thieler, E.R., Himmelstoss, E.A., Zichichi, J.L., and Miller, T.M. Shoreline vectors derived from historic sources (first three time periods) represent the high water line (HWL) at the time of the survey, whereas modern shorelines (final time period) represent the mean high water line (MHW). Changing the shoreline definition from a proxy-based physical feature that is uncontrolled in terms of an elevation datum (HWL) to a datum-based shoreline defined by an elevation contour (MHW) has important implications with regard to inferred changes in shoreline position and calculated rates of change. This proxy-datum offset is particularly important when averaging shoreline change rates alongshore. Since the proxy-datum offset is a bias, virtually always acting in the same direction, the error associated with the apparent shoreline change rate shift does not cancel during averaging and it is important to quantify the bias in order to account for the rate shift. The shoreline change rates presented in this report have been calculated by accounting for the proxy-datum bias.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Hapke, Cheryl J.",
            "role": "Author"
        },
        {
            "name": "Reid, David",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "2047",
            "name": "beach nourishment",
            "scope": "Transfer of sand from offshore areas to resupply beach areas that have been eroded."
        },
        {
            "thcode": 2,
            "code": "1799",
            "name": "coastal processes",
            "scope": "Processes unique to coastal areas including longshore transport, beach erosion, storm surge, shoreline change, delta formation, barrier island migration, beach stabilization by vegetation"
        },
        {
            "thcode": 2,
            "code": "353",
            "name": "erosion",
            "scope": "The process whereby materials of the earth's crust are loosened, dissolved, or worn away and simultaneously moved from one place to another."
        },
        {
            "thcode": 2,
            "code": "648",
            "name": "lidar",
            "scope": "Light detection and ranging, an airborne, spaceborne or ground-based laser-ranging technique commonly used for acquiring high-resolution topographic data."
        },
        {
            "thcode": 2,
            "code": "2072",
            "name": "shoreline accretion",
            "scope": "Seaward migration of the shoreline resulting from the addition of earth materials."
        },
        {
            "thcode": 15,
            "code": "007",
            "name": "environment",
            "scope": "Environmental resources, protection and conservation, for example environmental pollution, waste storage and treatment, environmental impact assessment, monitoring environmental risk, nature reserves, landscape, water quality, air quality, environmental modeling"
        },
        {
            "thcode": 15,
            "code": "008",
            "name": "geoscientificInformation",
            "scope": "Information pertaining to earth sciences, for example geophysical features and processes, geology, minerals, sciences dealing with the composition, structure and origin of the earth's rocks, risks of earthquakes, volcanic activity, landslides, gravity information, soils, permafrost, hydrogeology, groundwater, erosion"
        },
        {
            "thcode": 61,
            "code": "14",
            "name": "coastal processes",
            "scope": "oceanographic and geologic processes that cause changes to the shoreline and coastal zone."
        },
        {
            "thcode": 61,
            "code": "57",
            "name": "effects of coastal change",
            "scope": "changes in coastal processes, landscapes, and ecosystems."
        },
        {
            "thcode": 61,
            "code": "68",
            "name": "shoreline accretion",
            "scope": "seaward migration of the shoreline resulting from the addition of earth materials."
        },
        {
            "thcode": 61,
            "code": "69",
            "name": "shoreline erosion",
            "scope": "landward migration of the shoreline resulting from the removal of earth materials."
        },
        {
            "thcode": 62,
            "code": "GC-045",
            "name": "Continental\/Island Shore Complex",
            "scope": "Physiographic Setting: This feature includes the land-water interface zone and contains geoforms across a diversity of scales. ..."
        }
    ],
    "place_term": [],
    "image": [],
    "fan": []
}