A GIS framework for describing river channel bathymetry

Detailed bathymetry data are collected on short reaches and are usually not available for the entire stream network at a regional scale. By using the field data collected for a reach along the Brazos River in Texas, a geographic information system (GIS) framework for describing river channel bathymetry at regional-scale is presented. The framework is based on deriving relationships among different channel characteristics such as the channel planform, the thalweg location, and the cross-sections. Thus, using only the channel planform, in conjunction with the derived relationships, it is possible to create a three-dimensional mesh that comprises a series of cross-sections and profile-lines (lines parallel to the flow). The three-dimensional mesh provides a mean surface for the channel bed. The suitability of this approach is verified by it applying to a short reach upstream of the study area to create a three-dimensional channel description.