7. a) What does a hydrologist do? b) What do you think the hydrologist is doing in the photograph? c) Why do you think it is important we understand how water gets into rivers? d) Compare what you see in the photograph with the river in the picture. e) Explain why you think hydrologists are excellent geographers.

a) A hydrologist studies water. Hydrologists investigate how water moves, is stored and changes in rivers, lakes, soils and underground rocks. They may measure river flow, groundwater levels, rainfall and flood risk.

b) The hydrologist is probably measuring or recording the river's water level and flow. The person may also be taking water samples or checking the river channel and its banks.

c) Understanding how water gets into rivers helps people predict floods and droughts, manage water supplies, protect ecosystems and reduce damage to homes and farmland.

d) The photograph shows a small, shallow river or stream with flowing water and a relatively narrow channel. The river in the picture is wider and appears to carry more water. Both are parts of the drainage system and both may receive water from tributaries, surface run-off and groundwater.

e) Hydrologists are excellent geographers because they study the relationship between water, land, weather, rocks, soils, plants and people. They collect field data, use maps and analyse how physical processes affect places and human activities.