AQA AS Geography Unit 1 – GEOG1 Physical and Human Geography 70% of AS, 35% of A Level 2 hour exam 120 marks Short and essay questions Physical Topics: Rivers, Floods and Management Cold Environments Unit 2 – GEOG2 Geographical Skills 30% of AS, 15% of A Level 1 hour exam 50 marks Structured skills and generic fieldwork questions. Google ‘AQA A-Level Geography’ then click on specification

Drainage Basin Hydrological Cycle and the Water Cycle Specification Focus: The drainage basin hydrological cycle and the water cycle. Learning Outcomes: be able to describe the key features of the DBHC and define the key processes explain the spatial and temporal variations that exist and explain how human activities can affect processes in the cycle. explain the water balance graph.

Systems Theory IsolatedClosedOpen

The Global Hydrological Cycle There is a fixed amount of water circulating in our atmosphere and on its surface. There are no exchanges outside the earth and its atmosphere. It is therefore a CLOSED SYSTEM, which means that there are no INPUTS or OUTPUTS of water but only of energy. Water is continuously cycled between the oceans, the land, and the atmosphere as the GLOBAL HYDROLOGICAL CYCLE.

Precipitation Can you construct your own drainage basin hydrological cycle? Infiltration Percolation Interception Throughflow Stemflow Use the cards to construct your own version of the DBHC. Draw arrows between the cards to show how they are linked. You must be able to justify why you put each card in a particular place. When you’re done colour code each card to show if it’s an input, store, transfer or output. End!

Copy and complete the following paragraphs into your notes: The drainage basin (or catchment) is the area of land drained by a __________ and ___ ___________. An imaginary line called the __________ separates one drainage basin from another. This follows a ridge of highland; any rain falling on the other side of the ridge will flow into another river in the adjacent drainage basin. The drainage basin hydrological cycle is the part of the hydrological cycle that occurs within a _______ _______. Unlike the hydrological cycle it is a closed/open system. The DBHC is made up of ______, ______ and ______, which can vary greatly over ________ and ________.

Dynamic Equilibrium Inputs = Outputs ‘Dynamic Equilibrium’ e.g. more rainfall leads to greater discharge Negative Feedback Loop – changes are addressed to led back to the original state. Positive feedback loop – changes not addressed; system unable to find redress.

Water Budget Equation P = Q + E +/- change in storage P= precipitation Q= runoff E= evapotranspiration

The Water Budget Graph

Use table below to draw a water budget graph for a river in the UK. Colour code it and set it out like the one on page 4. MonthJanFebMarAprMayJunJulAugSepOctNovDec Precipitation (mm) Evapotranspiration (mm) Add the following statements to the right place on your graph: 1)Rainfall in excess of evapotranspiration 2)The villagers are on flood alert and begin to put the sandbags out 3)Margret despairs – her plants are wilting and the lawn is looking brown. 4)Rooftops can be seen at the bottom of a reservoir 5)Soil water starts to be utilised

Questions What do the terms – water surplus, soil moisture, soil moisture utilisation, soil moisture recharge and field capacity mean? In which months is there a water surplus? Why is there soil moisture recharge in the autumn/winter? Why is a water deficit not usually reached in the UK? In what area of the world is a water deficit likely to be reached? Describe at least two paths in the DBHC that water could use to flow from an input to an output. Explain how different paths might exist depending on whether the environmental conditions were a) extremely hot and dry b) very cold Explain at what point will field capacity be attained?

What could I be asked in the exam? Give a detailed definition of any of the key words in the DBHC Fill in gaps on a diagram of the DBHC Explain how human activities could modify the DBHC

Drainage Basin Hydrological Cycle and the Water Cycle Specification Focus: The drainage basin hydrological cycle and the water cycle. Learning Outcomes: be able to describe the key features of the DBHC and define the key processes explain the spatial and temporal variations that exist and explain how human activities can effect processes in the cycle. explain the water balance graph.

Homework Write a definition for the list of keywords on Moodle Answer any unfinished class questions (available on Moodle) Due Wednesday