1. Access Geography Unit 3 Lesson 2 Hydrology

5. The energy balance

9. 4. Distribution: Water Stores

11. Before we can understand the Hydrological cycle we need to understand a little about weather

12. So it is hotter at the equator but why???

13. Where on earth receives the most year round sunshine to provide good growing conditions? 1) Distance the sun’s rays have to travel through the atmosphere Equator Sun Rays Longer Distance Shorter Distance

14. 2) The curvature of the earth

15. 3) The sun´s rays have to travel through thicker atmosphere at the poles Thinner atmosphere Thicker atmosphere

16. What causes it to rain? 1) The sun heats up the sea. This causes water to be evaporated (made into a gas called water vapour). 2) The warm air full of water vapour rises high into the sky. Because it is so warm it is very light, that’s why it rises. 3) The higher up the air gets, the colder it gets as well. This makes the water vapour condense (turn back to liquid) and form clouds. 4) These clouds eventually drop all of the water in them as rain. This type of rain is called CONVECTIONAL rain

17. The UK is affected by a number of different air masses. Air masses are huge blocks of air at different temperatures. Some of the air masses are warm and some of the air masses are cold .

18. But air masses at different temperatures DO NOT like one another so they won’t mix together. Birmingham is affected by cold air coming down from the north and warm air coming up from the south. The junction between these two different air masses is called a front so when they cause it to rain it is called FRONTAL RAIN .

19. But if they won’t mix, what happens when they meet?

20. Its fair to assume then, that the final type of rainfall will also follow the same process. But what is it that is causing the air to rise? A FEW CLUES Name: RELIEF rainfall

21. Meet Reggie, the RELIEF RAIN raindrop Reggie is a gas flying in the air (water vapour) but when he meets a hill he has to climb over it. It gets very cold near the top of the hill as he is so high and Reggie changes from a gas to a liquid and settles into some clouds (condensation). When lots of Reggie’s friends arrive in the cloud it is too cramped to stay so some of them fall back to earth as relief rainfall (precipitation).

22. The Hydrological Cycle

23. Hydrological Cycle Matching Resurgence Overland Flow (surface runoff Ground water flow Infiltration Surface water storage Percolation Transpiration Isolation Precipitation Atmospheric Store Snowmelt Saturated zone (aquifer) evaporation Soil moisture Ocean store Base flow Atmospheric condensation Water table Volcanic water Ice cap storage Human activities Interception Stream runoff Impervious bedrock Reabsorbed by plants