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Using LiDAR for Engineering Applications Conservation Our Purpose, Our Passion Slide 2 Objectives Identify some engineering applications Present an Overview for Breach Routing Review a Breach Routing Case Study Slide 3 Using LiDAR Applications include design and planning of physical land modifications or mitigations LiDAR is suitable for planning and in some cases even final design or aspects of final design. Applicability depends on degree of accuracy required. Hydraulic and Hydrology Modeling, Farm Field Terracing Systems, Irrigation Systems, Floodwater Retarding Structures, Grade Stabilization Structures, Water Supply Structures, etc. Slide 4 Surface Modeling Stage Storage Earthfill & Excavation Quantities Slide 5 Hydrology Modeling Delineation of Watersheds and Water Flow Paths Slide 6 More Modeling Identify and map Flood Frequencies Identify and map hazard areas downstream of structures Slide 7 Inundation Boundary Mapping Slide 8 Small Structure Case Study Breach Routing a Small Structure to Identify hazards downstream Three data sets: Traditional Survey ESRI TIN from LiDAR ESRI TIN from USGS DEM Accuracy required, Budget, Time Constraints Slide 9 Slide 10 Traditional Process Using Total Station or Survey Grade GPS a survey crew would gather data at each cross section in the field Downloaded with CAD Copied & Entered into Hec-RAS Slide 11 LiDAR Process Using a ESRI TIN developed from LiDAR Extract Valley Cross Sections with Hec- GeoRAS & ArcGIS Immediate file import into Hec-Ras Slide 12 Hec-GeoRas Pre-Ras Slide 13 USGS DEM Process Same as LiDAR, except extracting data from the USGS DEM dataset Slide 14 Slide 15 Survey Data Analysis Kept all factors the same, except the differences in the two data sets Cut cross sections exactly at the same spot Utilized the same mannings N values Hec-Ras Steady State analysis run with TR- 20 flood routing Slide 16 Slide 17 Slide 18 Slide 19 Slide 20 Site H-39a Results Trimble GPS Survey; overtopped Hwy YY by 1.6 LiDAR Survey; overtopped Hwy YY by 1.0 Slide 21 Hec-GeoRas Post-RAS Slide 22 Reference Links Hec-Ras: http://www.hec.usace.army.mil/software/hec-ras/ Hec-GeoRas: http://www.hec.usace.army.mil/software/hec-ras/hec-georas.html TR-60: http://www.info.usda.gov/CED/ftp/CED/TR_210_60_Second_Edition.pdf TR-20: http://www.wcc.nrcs.usda.gov/hydro/hydro-tools-models-tr20.html Ag. Research Service http://www.ars.usda.gov/main/site_main.htm?modecode=62-17-10-00 Slide 23 Helping People Help the Land The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.