UPSC Prelims 2022 Q23: West African Lake Turned Desert — Explained
Which one of the following lakes of West Africa has become dry and turned into a desert?
- Lake Victoria
- Lake Faguibine
- Lake Oguta
- Lake Volta
Answer: (b) Lake Faguibine
Statement-wise explanation
- a: incorrect — Lake Victoria is in East Africa, not West Africa. Uganda, Kenya and Tanzania share it. It is Africa's largest lake, at about 68,800 sq km, and the main reservoir of the White Nile. It has not dried up.
- b: correct — Lake Faguibine lies west of Timbuktu in northern Mali. It sits at the end of a chain of basins that fill when the Niger River floods. In 1974 it covered about 590 sq km and was one of the largest lakes in West Africa. Lower rainfall began drying it in the late 1980s. By the late 1990s fishing, farming and herding there had become impractical. Normal rainfall returned after 2000, but the lake stayed nearly dry (NASA Earth Observatory).
- c: incorrect — Oguta Lake is in Imo State, in humid south-eastern Nigeria. Alluvium dammed the lower Njaba River to form it. It is the largest natural freshwater lake in south-eastern Nigeria, and it was named a Ramsar site (No. 1757) in 2008. It still holds water and supplies the town.
- d: incorrect — Lake Volta in Ghana is a man-made reservoir, formed when the Akosombo Dam closed the Volta River in the 1960s. At about 8,502 sq km, it is Africa's largest artificial lake by surface area. It still feeds a major hydropower plant and has not dried up.
How to eliminate
Location removes one option and the lake's nature removes another. Lake Victoria is in East Africa, not West Africa, so it is out at once. Lake Volta is the famous Akosombo Dam reservoir in Ghana, and a working hydropower reservoir has not 'turned into a desert'. That leaves Lake Oguta and Lake Faguibine. Here basic map sense helps: Oguta lies in the wet, forested south of Nigeria, near the Niger delta, where a lake is unlikely to turn into desert. Faguibine lies near Timbuktu, on the Sahel–Sahara edge, where droughts and blowing sand are common. To be sure, remember one fact: Lake Faguibine is in Mali, near Timbuktu, on the Niger flood system, and it has been almost dry since the late 1980s.
Know more
Why Lake Faguibine dried up
Faguibine is the last and largest lake in a chain of basins north of the Niger River, west of Timbuktu. It has no steady inflow. It fills only when the Niger floods strongly enough to push water through narrow channels into the basins. That makes it very sensitive to rainfall in the Niger basin.
- Drought: Rainfall fell in the Sahel from the 1970s, and from the late 1980s the lake steadily dried. UNEP records earlier complete dry-outs in 1914, 1924 and 1944.
- Silted channels: Sand blown in from the desert filled the channels that link the lakes to the Niger. When rain returned after 2000, floodwater could no longer reach the lake.
- Human pressure: UNEP links heavier use of land, water and vegetation, along with prolonged drought, to desertification around the lake. Fishing, farming and herding collapsed, and people migrated away. UNEP backed a project to clear the channels and re-flood about 600 sq km.
This is a textbook case of desertification: land in a dryland losing its productivity through climate swings plus human activity. It happens on desert margins such as the Sahel, not in the desert core.
| Lake | Country / region | Type | Status |
|---|---|---|---|
| Faguibine | Mali (Sahel, West Africa) | Natural, fed by Niger floods | Nearly dry since late 1980s |
| Oguta | Imo State, Nigeria | Natural, alluvium-dammed | Holds water; Ramsar site (2008) |
| Volta | Ghana | Artificial (Akosombo Dam) | Largest man-made lake in Africa by area |
| Victoria | Uganda, Kenya, Tanzania (East Africa) | Natural, Africa's largest lake | Source of the White Nile |
Another Sahel lake, Lake Chad, has shrunk greatly since the 1960s and is often asked alongside Faguibine.
NCERT Concepts to Revise
- Sahel: Knowing where the semi-arid Sahel belt runs helps you judge which West African lake sits on the desert margin.
- Lake Victoria: Placing Lake Victoria correctly on the map tells you whether it fits the question's 'West Africa' label.