River valley Flashcards
what is the rivers course
the path of a river as it flows downhill
what are the 3 courses of a river
-upper
-middle
-lower
what do rivers form as they flow downhill
channels and valleys
what does the long profile of a river tell you
how the gradient changes over different courses
what does the cross profile of a river show you
what a cross section of the river would look like
describe the upper course of a river
-steep
-v shaped valley
-steep sides
- narrow,shallow channel
describe the middle course of a river
-medium gradient
-gently, sloping valley sides
-wider deeper channel
describe the lower course of a river
-gentle gradient
-very wide
-very flat valley
-very wide deep channel
name the 2 types of erosion
lateral
vertical
what changes the cross profile of a river
vertical and lateral erosion
what’s vertical erosion
-deepens river valleys and makes the channels **v-shaped **
-dominant in upper course of river
-high turbulence causes rough rocks to be **scraped along river bed **causing intense downward erosion
what’s lateral erosion
-widens river valley and channel during formation of meanders
-dominant in middle and lower courses
what are 4processes of a river
-hydraulic action
-abrasion
-attrition
-solution
what’s hydraulic action
the force the water breaks rock particles away from the river channel
what’s hydraulic action
the force the water breaks rock particles away from the river channel