剥蚀作用.PPT

* Part 2 Quit ? Oxford University Press 2006 Landforms and exogenetic processes 2 Landforms and exogenetic processes 2.1 When will a river appear? Exogenetic processes What are exogenetic processes? Besides endogenetic processes, are there any other processes that shape the earth? What are exogenetic processes? What are exogenetic processes? Exogenetic processes are the processes generated by agents, such as _______, ______ and ____. rivers wind ice They bring down materials from mountains which fill the valleys. Let’s take rivers as an example. What are exogenetic processes? The two main processes are: Denudation Deposition Weathering Mass wasting Erosion Transportation Deposition Before studying the exogenetic processes that the river produces, let’s see how water moves on the earth! Where does the water mainly store on the earth? In what ways does water move on our earth? Atmosphere Rivers/ lakes Vegetation Ocean Soil/ rocks Evaporation Evaporation Transpiration Evapotranspiration Condensation Precipitation Precipitation Surface run-off Infiltration Subsurface run-off In what ways does water move on our earth? Through the water cycle, water moves on our earth. Let’s look at it in detail. Unsaturated rock and soil Water table Saturated rock Impermeable rock Precipitation Interception by vegetation In what ways does water move on our earth? Stem flow Drip flow Evaporation Transpiration Precipitation Overland flow Channel flow Surface run-off Evaporation In what ways does water move on our earth? Unsaturated rock and soil Water table Saturated rock Impermeable rock Surface storage Infiltration Soil moisture storage Ground water storage Percolation Throughflow Base flow Subsurface run-off Absorption Evaporation In what ways does water move on our earth? What can we find in a river basin? What is a river basin? River basin is an area drained by a main river with its ___________ and _____________. tributaries distributaries Can you identify different features i