1 / 18

Understanding Rivers: The Key to Managing Floods

Delve into the importance of rivers, their drainage basins, patterns, and channels. Learn about sediment transport, velocity, and the impact of land use changes on river ecosystems. Explore Florida's river systems.

lorettaanderson
Download Presentation

Understanding Rivers: The Key to Managing Floods

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Rivers

  2. Why important? Flooding has tormented civilization for a long time.

  3. But… we continue to occupy low-lying regions adjacent to rivers.

  4. Must understand ENTIRE river system… not just the region occupied by water on most days.

  5. Drainage Basins: Where the water comes from.

  6. Drainage Patterns

  7. Basic Terminology: Flood plain -area adjacent to river channel Streams and Rivers • Runoff-portion of moving across the surface • Drainage basin -area drained by single stream • Slope-gradient of a stream (drop/unit of length) • Longitudinal profile -plot of elev. vs. length • Cross-section- profile across a stream valley • Plan view- two dimensions, map view • Base level- lowest level that a stream can erode its bed • Stream power = discharge X slope X unit weight of water

  8. Measuring and Calculating Discharge • Continuity Equation • Discharge Q= V x A or V x W x D  blackboard example of conservation of discharge • Reach -river area under study

  9. Channel Patterns Channel Patterns • Braided • Meandering • Point bars • Riffles and pools • Oxbows • Anastomosing • Multiple channels • Gulf Coast (Fl, La) Riverine environment--the river and adjacent floodplain

  10. Channel Patterns – Braided Rivers Nizina river, Alaska

  11. Channel Patterns – Meandering River (forms & processes)

  12. Avulsion – “permanent” change in a river’s course 1952 1988 McMurdo Basin, Columbia River, B.C.

  13. Sediments in Rivers • Competence-largest particle a stream can transport • Capacity-total load a stream can carry • Streams and Rivers • Transport of rock cycle • Erosion and sediments • Total load • Suspended load • Bed load • Dissolved load

  14. Competence Diagram

  15. Velocity/Shear Stress, Erosion, and Deposits • Alluvial fan-change in slope • Bajada -coalescing alluvial fans • Delta -form at the mouth of some rivers • Distributaries -streams that flow on deltas

  16. Effects of Land Use Change • Change in stream profiles • Development • Dam construction Modification of Continuity Equation • Q = C x i x A (C = Coefficient of infiltration; i =intensity of rainfall; A-area)

  17. Florida Rivers

  18. Florida Rivers

More Related