Hydrographs are a compulsory part of most AS geography courses. They may appear in skills questions, and your understanding of them may also be tested in questions about flooding. This Building on the Basics column summarises the basic knowledge of hydrographs that you need and builds on this by applying the key geographical ideas of variability and interrelationships to the topic.
A hydrograph is a graphical representation of how a river’s discharge varies over time at a given point in its course. Skills questions in exams may present a hydrograph and ask you to describe its main features, so it is important to be familiar with the components of the hydrograph (Figure 1) and to use the appropriate terminology (see the Glossary). It is also important to interpret rather than just ‘lift’ data. For example in Figure 1 the peak discharge is almost 3.5 times the base flow. Discussing relative values is preferable to simply stating the values. Reference to the lag time is also important — it should be calculated and stated.
Your organisation does not have access to this article.
Sign up today to give your students the edge they need to achieve their best grades with subject expertise
Subscribe
