Lake Chad used to be one of the biggest lakes in the world, but its volume has been reduced to a tenth of what it was in the 1960s. The way this lake has dried up has become a symbol of climate change in action. It's true that the lake's water level has always changed, but this hasn't diminished the major changes to the lifestyle of the inhabitants of the lake's shoreline. Yet, as demonstrated by a French-Nigerian team including the IRD1, lake dwellers have made the best of these changes to their environment. Formerly fishermen or herdsmen, they have become farmers, often growing for export. The land that was part of the lake has made it possible for them to develop highly productive crops such as corn, rice and cowpea. In the valley of the Komadugu Yobe River in Niger, they have even commenced the intensive farming of peppers, which is highly lucrative although risky.
Rewatering the lake, as proposed by the Ubangi5 international project, would cause upheaval once again to the farming system, particularly if the yearly rise and fall in lake water levels were to cease.
Lying in the midst of the Sahelian band, Lake Chad is a vital water resource for fishermen, herdsmen and farmers from the four countries along its shoreline: Niger, Nigeria, Chad and Cameroon. The lake has undergone major changes in recent decades. Half a century ago, it was virtually an inland sea with an area of 20,000 km². Recurring droughts in the 1970s and 1980s caused it to dry up quickly and shrank its area to around 2,000 km², which of course affected the lake people
A French-Nigerian team including the IRD1 studied the major changes to lifestyles that have occurred around Lake Chad in recent decades. The results demonstrate to what extent Sahelian societies have been able to adapt to a major environmental shift. Using an interdisciplinary approach, agronomists, anthropologists, geographers and hydrologists looked especially at changes in the production methods around Bosso in Niger, a small town which previously was located at the fork of the Komadugu River and the lake. When Lake Chad was at high water mark, up until the
1970s, the inhabitants mainly fished -- and this provided both food and significant income from the export of smoked or dried fish.
...have become intensive farmers
The water levels of the lake have always fluctuated2, as previous paleo-climatic studies have shown. As a result, the shoreline people have developed a significant capacity to adapt, alternating between fishing, which was highly profitable, and raising various crops through the use of sophisticated irrigation techniques. Since the fall in water levels from 1970 to 2000, the newly revealed shoreline of Lake Chad has become the breadbasket of the region. The now dry northern basin of Lake Chad, in particular, has been transformed into many grain-growing polders3 in the shallows amidst the dunes. For, as the lake water recedes, the inhabitants make use of the fertile moist soil to plant corn, cowpea4, rice, sorghum and the like, which grow without the need for irrigation or fertiliser; and they have cut back on growing millet on the lakeshore, which requires rain water and has become especially uncertain.
Peppers for export
Another money-making crop has been added to these: peppers. Mainly for export to Nigeria, the intensive farming of peppers along the Komadugu Yobe River was first begun as a local initiative in the 1960s and then developed with the encouragement of government authorities, NGOs and development programmes. This single-crop farming is lucrative but also risky as the initial cost of investing in the inputs -- fertiliser, pesticides, irrigation pump fuel -- is high. In terms of the functioning of society, it also causes inequality between men and women and between poorer farmers who have to borrow in the beginning of the season and sell their crop quickly at low prices and the wealthier farmers who can store their crops and take advantage of changes in market prices.
A climate-controlled lake
Changes in the level and the area of Lake Chad have become a well-known phenomenon since the 1960s, mainly because of work done by IRD hydrologists. The depth of the lake is slight, around two metres on average, so it acts as an evaporation machine and the water loss is very significant. About 80 % of the lake's water volume comes from the Chari River and its tributary the Logone, both of which spring from the central African mountains in the south-east and which supply water to the south basin of the lake. The water crosses the great barrier of vegetation and sand which divides the lake in two only in years of significant rainfall, when it floods the north basin -- the only side of the lake to which Niger has access. The Komadugu Yobe River itself provides only 4 % of the lake water, with the rest mainly coming from rainfall.
The rural communities have long since adapted to the fluctuations in the level of Lake Chad -- which can change by the year, from year to year and from decade to decade -- by switching occupations. High water times were favourable for fishing and soil renewal while low water periods meant the ability to plant on the polders. The present study concluded that, in contrast to what was generally thought, the system of switching between crop growing and foraging, which has come into play in recent decades, actually works quite well. The main concern for the future of this profitable farming lies in the project to shift water from the Ubangi5 to the Chari: by moving water into Lake Chad to keep a 'level lake', this system could prevent the lake from rising and falling significantly and thus produce a profound effect on the current farming methods and lifestyles of inhabitants.
1. These studies were carried out with researchers from the CNRS and the Universities of Niamey, Maradi and Tahoua in Niger.
2. The lake's current status is that known as 'small Chad', along the lines of what was noted at the beginning of the 20th century, with several separate basins.
3. Polders are dried shore areas below sea level, with the water removed usually artificially. In this case, the term polder designates dried-up areas of the basin floors between the dunes of Lake Chad.
4. Cowpea is a bean-like vegetable whose seeds are a foodstuff.
5. The Ubangi is the main tributary of the Congo River. By running water off from it towards the Chari, Lake Chad would receive additional water over and above the current flow from the Chari.
The above post is reprinted from materials provided by Institut de Recherche pour le Développement (IRD). The original item was written by Gaëlle Courcoux. Note: Content may be edited for style and length.
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