The table below shows rainfall data collected for a drought study in northern Nigeria. A farming cooperative compared the wet-season total with the long-ter...
Question 1 Report
The table below shows rainfall data collected for a drought study in northern Nigeria. A farming cooperative compared the wet-season total with the long-term mean before deciding how much millet seed to distribute. The data were shared with students completing a fieldwork enquiry into the effects of unreliable rainfall on rural livelihoods.
| Year | Wet-season rainfall (mm) | Number of days with rain |
|---|---|---|
| Long-term mean | 640 | 48 |
| 2023 | 590 | 43 |
| 2024 | 405 | 27 |
(a) State the wet-season rainfall shown for 2024. [1]
(b) Calculate the difference between the long-term mean rainfall and the 2024 rainfall. Show your working. [2]
(c) Explain two likely impacts of the 2024 rainfall data on millet farmers. [2]
After an offshore earthquake near the island of Seram, a tsunami warning centre issued messages to villages on the coast. Fig. 1 is a diagram used in a community meeting. It shows how waves change as they travel from deep water towards a beach. The map reference for the school evacuation point was printed on each warning card, and students practised the route during a fieldwork exercise.
(a) State the natural event that can trigger a tsunami. [1]
(b) Describe one change to the tsunami wave shown as it enters shallow water. [2]
(c) Suggest two actions villagers should take after receiving an official tsunami warning. [2]
Answer Details
Drought study
(a) Wet-season rainfall in 2024 was 405 mm. [1]
(b)
\[640\text{ mm}-405\text{ mm}=235\text{ mm}\]
The 2024 rainfall was 235 mm below the long-term mean. [2]
(c) Less rainfall means less water is available for millet growth, so crops may fail or produce lower yields. This can reduce the food farmers have to eat or sell and lower household income. Reduced water for livestock grazing or drinking is another valid impact. [2]
Tsunami warning
(a) A tsunami can be triggered by an undersea earthquake. [1]
(b) As the wave enters shallow water, its height increases. Its wavelength decreases, so waves become closer together, and its speed also decreases. [2]
(c) Villagers should move to higher ground and move inland away from the coast. Following the signed evacuation route, taking emergency supplies if safe, and not returning until authorities say it is safe are also valid. [2]
Download The App On Google Playstore
Everything you need to excel in your exams
