Abstract

Sediment Deposition in Cochiti Reservoir and the Rio Grande, NM
Track: Water Resources
Authors: Nathan Kempf, John Peterson, Daniel Paulsen

Since completion of Cochiti Dam in 1975, sediment has accumulated within Cochiti Reservoir and the Rio Grande. Historical aerial photography was georeferenced with ground coordinates to prepare a DTM of pre-dam conditions. Recent aerial photography and bathymetry was georeferenced to prepare a recent DTM. Comparison of these DTM's shows quantity and spatial distribution of sediment deposition. Temporal DTM's yield comparative analysis of reservoir storage capacity; sediment volume and distribution; river baseline elevation change; cross section profiles; forecasting of sediment inflow and life expectancy of Cochiti Reservoir. In 2011, wildfire ravaged the watershed. Heavy rains flushed sediment & debris into the river & reservoir; compounding the effect of previous sediment deposition. Digital aerial photography and LiDAR of the fire and flooded canyons was acquired. Examples of stereo photography, DTM, and bathymetry will be displayed in 3D to visualize this phenomenon. A description of data compilation, analysis and ArcGIS input is given.