Natural Resources Conservation Service Hydraulic Modeling Karl Visser

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Natural Resources Conservation Service Hydraulic Modeling Karl Visser, PE Ft Worth National Design, Construction

Natural Resources Conservation Service Hydraulic Modeling Karl Visser, PE Ft Worth National Design, Construction & Soil Mechanics Center

Current Modeling Projects What type of RAS modeling projects have you completed? What type

Current Modeling Projects What type of RAS modeling projects have you completed? What type of RAS modeling projects do you hope to complete? Nov 2016 Hydraulic Modeling 2

Modeling Purpose • Why are you hydraulic modeling this stream or floodplain? • What

Modeling Purpose • Why are you hydraulic modeling this stream or floodplain? • What is your ultimate design purpose? § § § Nov 2016 Inundated area Hazard class Design wse Velocity Shear stress Hydraulic Modeling 3

GIS • Data § Do you have statewide LIDAR? § LIDAR to cover your

GIS • Data § Do you have statewide LIDAR? § LIDAR to cover your projects? • DEM § Hydrologically enforced? § Water flow through or over bridges? Culverts? • User expertise § How much GIS capability/support do you have? § Are you willing to learn? Nov 2016 Hydraulic Modeling 4

Know your GIS data Z • Is xyz units consistent? § Meters/meters § Ft/ft/ft

Know your GIS data Z • Is xyz units consistent? § Meters/meters § Ft/ft/ft (state plane) x § Meter/meter/ft (some UTM) y • RAS Mapper will convert units § English SI § SI English Nov 2016 Hydraulic Modeling 5

Precision & Accuracy • How close do you need to be? +/- 0. 1

Precision & Accuracy • How close do you need to be? +/- 0. 1 ft? • Planning level vs final design Nov 2016 Hydraulic Modeling 6

Steady vs Hydrograph Steady flow 1 -D • No hydrograph needed Unsteady flow 2

Steady vs Hydrograph Steady flow 1 -D • No hydrograph needed Unsteady flow 2 -D • Eg. Dam breach hydrograph Nov 2016 Hydraulic Modeling 7

LIDAR vs Survey • What models does LIDAR work better? • What project does

LIDAR vs Survey • What models does LIDAR work better? • What project does 1 D field cross-sections more appropriate? Nov 2016 Hydraulic Modeling 8

Channel vs Floodplain • In-channel flow analysis § § Need full-depth channel data LIDAR

Channel vs Floodplain • In-channel flow analysis § § Need full-depth channel data LIDAR doesn’t penetrate water surface E. g. Stream restoration projects Any LIDAR data have full channel surface? • Floodplain analysis § Full depth channel data probably not needed § LIDAR surface – appropriate § E. g. Dam breach analysis Nov 2016 Hydraulic Modeling 9

Will I ever model 1 D again? 2 D is wonderful! • Bridges –

Will I ever model 1 D again? 2 D is wonderful! • Bridges – currently are 1 D only features Nov 2016 Hydraulic Modeling 10

Natural Resources Conservation Service END Richland Creek 113 2015 Nov 2016 Hydraulic Modeling 11

Natural Resources Conservation Service END Richland Creek 113 2015 Nov 2016 Hydraulic Modeling 11