Item talk:Q59757: Difference between revisions

{"@context": "https://schema.org", "@type": "CreativeWork", "additionalType": "USGS Numbered Series", "name": "Hydrographic survey of Chaktomuk, the confluence of the Mekong, Tonl\u00e9 Sap, and Bassac Rivers near Phnom Penh, Cambodia, 2012", "identifier": [{"@type": "PropertyValue", "propertyID": "USGS Publications Warehouse IndexID", "value": "sir20145227", "url": "https://pubs.usgs.gov/publication/sir20145227"}, {"@type": "PropertyValue", "propertyID": "USGS Publications Warehouse Internal ID", "value": 70135681}, {"@type": "PropertyValue", "propertyID": "DOI", "value": "10.3133/sir20145227", "url": "https://doi.org/10.3133/sir20145227"}], "inLanguage": "en", "isPartOf": [{"@type": "CreativeWorkSeries", "name": "Scientific Investigations Report"}], "datePublished": "2014", "dateModified": "2015-01-15", "abstract": "The U.S. Geological Survey, in cooperation with the U.S. Department of State, Mekong River Commission, Phnom Penh Autonomous Port, and the Cambodian Ministry of Water Resources and Meteorology, completed a hydrographic survey of Chaktomuk, which is the confluence of the Mekong, Tonl\u00e9 Sap (also spelled T\u00f4nl\u00e9 Sab), and Bassac Rivers near Phnom Penh, Cambodia. The hydrographic survey used a high-resolution multibeam echosounder mapping system to map the riverbed during April 21\u2013May 2, 2012.\nThe multibeam echosounder mapping system was made up of several components: A RESON Seabat\u2122 7125 multibeam echosounder, an inertial measurement unit and navigation unit, data collection computers, and a Real-Time Kinematic (RTK) Global Navigation Satellite System (GNSS) base station. The survey area was divided into six survey subreaches and each subreach was surveyed within 3 days along survey lines oriented parallel to the flow direction. Complete coverage of the riverbed was the operational objective; however, to obtain broad spatial coverage, gaps between parallel swaths were permitted, especially in wide, shallow areas where multibeam swath widths were narrow.\nThe survey was referenced to two existing bench marks with known geographic coordinates by establishing a GNSS base station on the bench marks each day and using real-time corrections from the base station to correct boat navigation data. The World Geodetic System of 1984 (WGS 84) ellipsoid was used during data collection to reference height, and data were adjusted to the local datum, Ha Tien 1960, during postprocessing.\nThe quality of hydrographic surveys was described by an uncertainty estimate called total propagated uncertainty (TPU). Calculations of TPU were completed for the hydrographic survey data resulting in the maximum TPU of 0.33 meters. The mean and median TPUs were 0.18 meters, and 99.9 percent of TPU values were less than 0.25 meters.\nDetailed hydrographic maps of Mekong, Tonl\u00e9 Sap, and Bassac Rivers showing the riverbed elevations surveyed April 21\u2013May 2, 2012, referenced to Ha Tien 1960 were produced. The surveyed area included a 2-km stretch of the Mekong River between the confluence with the Tonl\u00e9 Sap and Bassac Rivers, and extended 4 km upstream and 3.6 km downstream from the 2,000-m confluence stretch of the Mekong River. In addition, 0.7 km of the Bassac River downstream and 3.5 km of the Tonl\u00e9 Sap River (from the confluence to Chroy Changvar Bridge) upstream from their confluence with the Mekong River were surveyed. Riverbed features (such as dunes, shoals, and the effects of sediment mining, which were observed during data collection) are visible on the hydrographic maps. All surveys were completed at low annual water levels as referenced to nearby Mekong River Commission streamflow-gaging stations. Riverbed elevations surveyed ranged from 24.08 m below to 1.54 m above Ha Tien 1960.", "description": "vi, 23 p.", "publisher": {"@type": "Organization", "name": "U.S. Geological Survey"}, "author": [{"@type": "Person", "name": "Dietsch, Benjamin J. bdietsch@usgs.gov", "givenName": "Benjamin J.", "familyName": "Dietsch", "email": "bdietsch@usgs.gov", "identifier": {"@type": "PropertyValue", "propertyID": "ORCID", "value": "0000-0003-1090-409X", "url": "https://orcid.org/0000-0003-1090-409X"}, "affiliation": [{"@type": "Organization", "name": "Nebraska Water Science Center", "url": "https://www.usgs.gov/centers/nebraska-water-science-center"}]}, {"@type": "Person", "name": "Densmore, Brenda K. bdensmore@usgs.gov", "givenName": "Brenda K.", "familyName": "Densmore", "email": "bdensmore@usgs.gov", "identifier": {"@type": "PropertyValue", "propertyID": "ORCID", "value": "0000-0003-2429-638X", "url": "https://orcid.org/0000-0003-2429-638X"}, "affiliation": [{"@type": "Organization", "name": "Nebraska Water Science Center", "url": "https://www.usgs.gov/centers/nebraska-water-science-center"}]}, {"@type": "Person", "name": "Wilson, Richard C. wilson@usgs.gov", "givenName": "Richard C.", "familyName": "Wilson", "email": "wilson@usgs.gov", "affiliation": [{"@type": "Organization", "name": "Nebraska Water Science Center", "url": "https://www.usgs.gov/centers/nebraska-water-science-center"}]}], "funder": [{"@type": "Organization", "name": "Nebraska Water Science Center", "url": "https://www.usgs.gov/centers/nebraska-water-science-center"}], "spatialCoverage": [{"@type": "Place", "additionalType": "country", "name": "Cambodia", "url": "https://geonames.org/1831722"}, {"@type": "Place", "additionalType": "city", "name": "Phnom Penh", "url": "https://geonames.org/7150232"}, {"@type": "Place", "additionalType": "unknown", "name": "Bassac River"}, {"@type": "Place", "additionalType": "unknown", "name": "Chaktomuk"}, {"@type": "Place", "additionalType": "unknown", "name": "Mekong River"}, {"@type": "Place", "additionalType": "unknown", "name": "Tonl\u00e9 Sap River"}, {"@type": "Place", "geo": [{"@type": "GeoShape", "additionalProperty": {"@type": "PropertyValue", "name": "GeoJSON", "value": {"type": "FeatureCollection", "features": [{"type": "Feature", "properties": {}, "geometry": {"type": "Polygon", "coordinates": [[[103.64501953125, 10.914224006944366], [103.64501953125, 13.036669323115246], [105.8148193359375, 13.036669323115246], [105.8148193359375, 10.914224006944366], [103.64501953125, 10.914224006944366]]]}}]}}}, {"@type": "GeoCoordinates", "latitude": 11.975446665029809, "longitude": 104.72991943359374}]}]}