Model Bathymetry Lake Travis: A Sinuous Reservoir Bridget Wadzuk March 29, 2001

Introduction Reservoir Characteristics Models CE-QUAL-W2 (COE) Segmented bathymetry ELCOM (Hodges/UWA) 3-D Cartesian grid bathymetry

Taken from CE-QUAL-W2 V3 User’s Manual

Problem Bathymetry from ArcView – Cartesian grid (plan view) Need to get into a format that is accepted by CE-QUAL-W2 (profile view) STRAIGHTENED BATHYMETRY

Theory Relation of physical and radial space 1:1 correspondence Radial lines Arc lengths

Easier Said… Choosing a grid Approach using Matlab Resolution over scale of Lake Travis Approach using Matlab Select points for centerline Spline points to a smooth curve Compute normal radial lines Check for crossing of radial lines Repeat process until no crossings Use intervals for bathymetry

Bathymetry (original)

Centerline Points

Radial Lines (1)

Radial Lines (2) Radius of Curvature, Ro Channel Width,  Normally, / Ro < 1 Ignore curvilinear term in sinuous systems Unacceptable, / Ro > 1 Thalweg must be adjusted

Radial Lines (3)

Straightened Bathymetry

Yet To Come Change approach to a GIS method Use a smaller, more concise area Lake LBJ Less computationally intensive