Landform Geography Fluvial Landforms
Stream Gradation Streams evolve to carry just the amount of sediment produced by their drainage basin
Meandering Stream Stream carrying mostly suspended load usually has deep channel curving side-to-side
Evolution of a Graded Stream Base Level – lowest level at which a stream can erode its channel bed – can rise & fall with changes in sea or land level
Niagara Falls Upstream (Lake Erie) 571 ft elev Downstream (Lake Ontario) 243 ft elev Has retreated almost 7 miles in past 12,000 yrs
Development of Graded Stream with Wide Floodplain
Development of Graded Stream with Wide Floodplain
Stream Meandering
Oxbow Lake
Floodplain Features
Alluvial Fans Created by alluvial aggradation in areas of high relief where bedload- dominated streams flow out of mts onto plain – stream sweeps side to side over time, making fan shape – most common in desert climates
Common Drainage Pattern Types
Drainage Density Total length of all streams Drainage Density = Area of drainage basin
Stream Ordering Represents stream size Smallest streams in basin order 1 – order rises when 2 streams of same order come together at confluence
Hydraulic Variables
Mississippi River Floods - 1993