{"id":735,"date":"2026-08-24T08:01:01","date_gmt":"2026-08-24T08:01:01","guid":{"rendered":"https:\/\/laoearth.com\/portfolio-item\/river-cross-section-and-profile-survey\/"},"modified":"2026-10-05T09:41:56","modified_gmt":"2026-10-05T09:41:56","slug":"river-cross-section-and-profile-survey","status":"publish","type":"portfolio","link":"https:\/\/laoearth.com\/lo\/portfolio-item\/river-cross-section-and-profile-survey\/","title":{"rendered":"River Cross Section and Profile Survey"},"content":{"rendered":"

River Cross-Section & Longitudinal Profile Survey<\/h1>\n

Bathymetric & River Profile Survey<\/h2>\n

LaoEarth conducts professional river cross-section, longitudinal profile and bathymetric surveys<\/strong> to accurately measure river geometry, water depth and bed elevations.<\/p>\n

The survey combines CHCNAV GNSS RTK positioning, echo-sounder technology, hydrographic survey software and elevation control<\/strong> to produce accurate digital profiles of river channels and underwater terrain.<\/p>\n

These surveys provide essential data for bridge and infrastructure design, hydraulic modelling, flood studies, river management, dredging, erosion assessment and water-resource development<\/strong>.<\/p>\n

Survey Methodology<\/h2>\n

River cross-sections are established at predetermined intervals, typically approximately 5\u201310 metres apart<\/strong>, depending on the project requirements, river geometry and survey objectives.<\/p>\n

Each cross-section is surveyed systematically from one riverbank to the other to capture:<\/p>\n

    \n
  • Riverbank positions<\/li>\n
  • Water-surface elevation<\/li>\n
  • River-bed elevation<\/li>\n
  • Water depth<\/li>\n
  • Channel width<\/li>\n
  • Cross-sectional geometry<\/li>\n
  • Longitudinal river profile<\/li>\n<\/ul>\n

    GNSS RTK Positioning & Survey Control<\/h2>\n

    CHCNAV GNSS RTK equipment<\/strong> is used to establish accurate horizontal positioning for the survey.<\/p>\n

    A GNSS reference station is installed at a suitable known or established control point onshore, where the surrounding environment provides clear satellite visibility and reliable communication with the survey rover.<\/p>\n

    The GNSS rover is installed on the survey boat and provides real-time positioning during the bathymetric survey.<\/p>\n

    The reference and rover receivers simultaneously observe common GNSS satellite signals. Differential correction information is transmitted from the reference station to the rover through the data link, allowing the position of the survey boat and each sounding point to be determined accurately in real time.<\/p>\n

    Bathymetric Depth Measurement<\/h2>\n

    Water depths are measured using a CHCNAV Echo Sounder D390<\/strong>.<\/p>\n

    The echo sounder transducer and GNSS rover antenna are positioned with a known and consistent horizontal relationship, allowing the measured water depth to be accurately associated with the corresponding geographic coordinate.<\/p>\n

    The echo sounder continuously records depth measurements and transfers the data electronically to the onboard survey computer for processing and integration with the GNSS positioning data.<\/p>\n

    This produces a synchronized dataset containing:<\/p>\n

    Easting + Northing + Water Depth + Water-Surface Elevation<\/strong><\/p>\n

    which can subsequently be used to calculate the elevation of the riverbed.<\/p>\n

     <\/p>\n

    Our recent survey on River Cross Section and Profile Survey<\/strong><\/p>\n\n\t\t\t