| Creation of accurate and coherent surface models is vital to the effective planning and construction of flood control and hurricane protection projects. Typically, topographic surface models are synthesized from Delaunay triangulations or interpolated raster grids. Although these techniques are adequate in most general situations, they do not effectively address the specific case where topographic data is available only as cross-section and profile centerline data, such as the elevation sampling produced by traditional hydrographic surveys.;The hydraulic spline algorithm was developed to generate irregular two-dimensional channel grids from hydrographic cross-sections at any desired resolution. Hydraulic spline output grids can be easily merged with datasets of higher resolution, such as LIDAR data, to build a complete model of channel geometry and overbank topography.;In testing, the hydraulic spline algorithm faithfully reproduces elevations of known input cross-section points where they exist, while generating a smooth transition between known cross-sections. The algorithm performs particularly well compared to traditional techniques with respect to aesthetics and accuracy when input data is sparse. These qualities make the hydraulic spline an ideal choice for practical applications where available data may be limited due to historic or budgetary reasons.;Keywords - spline, LIDAR, interpolation, surface, triangulation, river... |
