Stream Bathymetric Surveying
Specializing in environmental mapping, AFFILIATED RESEARCHERS provides accurate, GPS surveys of water depth, water surface, and streambed sub-bottom contours in riverine environments. AFFILIATED RESEARCHERS trained staff utilizes HYPACK and other hydrographic software, and an onboard computer to interface RTK-GPS data with either single-beam or multi-beam sonar data.
Accurate water depth measurements are collected and correlated to respective centimeter accurate, real-time GPS positions. These depth-position data sets are continuously recorded onto an onboard computer while navigating the survey vessel along a GPS gridline course.
HYPACK, AutoCAD, and other hydrographic software are used to develop the data sets into accurate water-depth and sub-bottom “contours”, and enable these hydrographic contours to be accurately portrayed on project aerial photography or other databases.
Centimeter accurate GPS positions are collected along the wetted-edge of the stream to determine shoreline boundaries at given flows. Fluctuating water elevations are obtained at centimeter accuracies during the survey, and later developed with the deliverables as an important additional hydrology parameter.
In certain projects such as dredging applications where sediment thickness needs to be determined, a dual-frequency echo sounder can be used to collect sub-bottom (sediment thickness) depths concurrently while water depth data are collected.
Accurate, full format, scaled survey drawings are provided, to include cross-section views, 3-D views, and staged water and sediment volume computations.
Hydrographic surveys and sub-bottom profiling are valuable tools for resource management of riverine environments. These services provide an accurate and reliable method of measuring baseline conditions, monitoring seasonal sediment transport, quantifying fish habitat at various flows, and/or calibrating of an ongoing hydrology model.