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In class activity Put name on back of sheet. Define drainage basin Area that contributes water to the trunk stream. Sepa...

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In class activity Put name on back of sheet. Define drainage basin Area that contributes water to the trunk stream. Separated from other drainage basins by drainage divides, such as the continental divide List controls of erosion Gradient Discharge Channel shape, roughness What are the types of floods? Riverine: slow and flash Coastal: storm surge, high tide, rainfall, river contribution Catastrophic: river dammed by natural causes, dam washout, tsunami How are floods described? Feet above flood stage Recurrence interval: ‘100 year flood’ has a 1% chance of occurring in any year Cubic measure (feet or meters) per second To describe the recurrence interval as a 50-year flood, what does this mean? A 50 year flood has a 2% chance of occurring in any given year Determined by dating materials that are deposited at a certain level and finding average amount of time between those deposits

How are stream channels in headwaters different from downstream areas? Increase in discharge downstream: increases capacity Decrease in gradient: reduces competence Increase in channel size Describe depositional environments of rivers Point bar deposits in meandering systems Alluvium deposited on the inside of meander curves Channel bars in braided systems Mobile alluvial deposits in systems with large amount of unconsolidated material and variable amount of water Common in glacial and desert areas Deltas where river enters standing body of water: ocean or lake Set of distributaries deliver sediment to standing water Shift over time because the sediment clogs distributary