GEOG 1 Lecture Notes - Lecture 11: Empty Spaces, Karst, Alluvium
Document Summary
A landscape is in a particular state of balance between uplift of land and erosion. They occur simultaneously but one force may be dominant at a particular time than the other. In mountainous regions, a stream may flow over precipieces, forming falls. The steep downhill gradient allows streams to flow rapidly, cutting narrow, v shaped channels in the rocks (erosional process are accelerated here). Over time, the streams wear out significantly enough for the falls to become rapids and the stream channel becomes incised below the height of the surrounding landforms. In humid areas, the effect of stream erosion is to round landforms. Streams flowing down moderate gradients tend to carve valleys that are wider than those in mountainous areas. Surrounding hills become rounded and valleys eventually become floodplains as they broaden and flatten. Streams work to widen the floodplain; their courses meander, constantly carving out new river channels.
