CEE 795 Water Resources Modeling and GIS Lecture

CEE 795 Water Resources Modeling and GIS Lecture 8: Advanced Features in HEC-Geo. RAS March 6, 2006 Learning Objectives: • Utilize advanced features in HEC Geo-RAS Handouts: Assignments: Exercise #7

Advanced Features in HEC-Geo. RAS 1. 2. 3. 4. 5. 6. 7. Bridges/Culverts Ineffective Flow Areas Blocked obstructions Levees Inline Structures 2 Lateral Structure 1 Storage Areas 3 4 7 6 5

Advanced Features in HEC-Geo. RAS BRIDGES/CULVERTS (1) • Similar to a cross-section • Identifies stationing of bridge • Elevation of deck is based on TIN • Will need to add data in HEC-RAS

Advanced Features in HEC-Geo. RAS INEFFECTIVE FLOW AREAS (2) • Portions of floodplain that do not convey flow • “Dead” zones near bridges

Advanced Features in HEC-Geo. RAS BLOCKED OBSTRUCTIONS (3) • Parts of floodplains permanently remove from flow area • Encroachments entered as polygons similar to landuse • Example includes development along a river

Advanced Features in HEC-Geo. RAS LEVEE ALIGNMENT (4) • Linear feature that contains the flow • Levees are represented but also could be a road • One levee per bank • Once overtopped, the flow will go laterally 4

Advanced Features in HEC-Geo. RAS INLINE STRUCTURES (5) • Weirs and dams • Similar to a bridge • May need to adjust elevations depending on accuracy of TIN 6 5

Advanced Features in HEC-Geo. RAS LATERAL STRUCTURES (6) • Similar to weirs • Spillover flow from main channel • Parallel to river 6 5

Advanced Features in HEC-Geo. RAS STORAGE AREAS (7) • Receives flow from lateral structures • Floodplain detention storage • Connected with main channel using a lateral structure 6 5