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HYDROGRAPH REVISION 1

This question type asks you to analyse the parts of the hydrograph in order to find out about the river basin and its reaction to a storm event.

Try this example from 2006.

First, look at the rainfall event itself.

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Now the discharge.

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What is the question?

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See the two graphs together-

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Hintsto follow

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What does this question need from you?

•Use technical terms as if you are comfortable with them.

•A description is needed- not too long-winded, but what you say must be accurate and meaningful to the question asked.

•Quote some data- not too much- and make sure it helps to illustrate the point you are making.

•Then try to give reasons for the changing levels.

You can of course mix up these four things- it may flow better if you do; but make sure they are all there before you finish the answer!

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Lag time of about 30 hours.

Steady river discharge at 0.8m until peak rainfall is reached, at start of 9th April.

Steep rising limb showing quick rising of river level to 2.8m during April 9th

into the 10th.

Fairly gentle return to base flow by end of April 13th.

description

Lag time

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explanation

Long response time because of infiltration-filling pore spaces in permeable/ porous soil or rock. Water in pores is called in storage.

Soil capacity reached by end April 8th, so then river rises fast due to storm flow-(throughflow, surface run-off, aka overland flow) as a steep rising limb.

Gentle recessional limb as rain drizzles for four days after peak, reaching the river as surface run-off.

Both description and explanation neededfor 6 marks.

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You should look up all the hydrograph past paper questions and see how to tackle them

using this one as a blue print!

Now let us look at a mapping river question.

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HYDROGRAPH REVISION 2

This question type asks you to analyse a map section of a river and its valley to identify river landforms

and/or

To find out about the land use around the river.

Try this example from 2007- the Worcester map.

Look it up in your booklet, and collect a map.

First, find the section of the river indicated. Do not look outside this section.

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a) Look for the PHYSICAL characteristics only of the river and its valley; do not include ANY man-made objects or land uses.

(The only exception could be if a river has a reservoir or other water feature in it that might affect the river itself; but then mention it only as an added extra!)

There are 14 possible marks here, and at least TEN possible features you could mention.

Giving a reference and a name for seven of them will get you full marks, as long as they are correct!

At least ONE reference MUST be a six figure one!

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Here are a list of ten- how many can you find and identify accurately? Are there any others?

1. meander 2. oxbow lake

3. pond 4. flat valley floor

5. wide flood plain 6. braiding

7. low channel gradient. 8. gentle valley sides

9. easterly river direction of flow

10. many tributaries- identify at least two

Note that the features you name MUST be found mainly- or more likely- in

the LOWER stage of a river. If there is a feature not normal for there,

do not use it!

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There is almost always a question asking to explain the formation of a river feature. Look back in the past papers to see which are the usual features asked about.

There might be a nasty one, not asked for before, so be prepared!

Meander incised meander

Waterfall River gorge

Levee delta

Braiding river terrace

Oxbow lake estuary/firth

Any others?

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Another question type asks you to describe the hydrological cycle.

This is often PART of a question.

The question here is looking to see if you can remember and include a lot of the more complex terms that you did not get in Intermediate,

so include them particularly!

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You are often expected to produce a diagram.

Firstly read the question carefully to see if you only need a diagram, or if they need text as well.

Do not duplicate the writing in both!

If you need both, the trick is to do good labels that explain what is going on in a concise way; this reduces the need to explain too much in the text.

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This diagram is in the SQA marking scheme as an example of an adequate diagram.

The labels are minimal- the text would need to include more detail!

You could add ADVECTION, THROUGHFLOW, STORAGE, INFILTRATION, INTERCEPTION

and some other terms, too.

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