Geopolitical history of the Lake Chad Basin
The history of Lake Chad is closely tied to the management of its natural resources (water fish, ...), a story replete with elements that reflect its uniqueness. In the days of the great empires (Kanem-Bornu, Baguirmi Waddai, Mandara, Sokoto ...) Lake Chad was an important trading centre between Central and Northern Africa.
The beginning of European explorations marked a milestone in this history. The British, French and German explorations attracted foreign lust to the lake. But faced with Rabah who had built an empire there, the matter proved more difficult than expected. In this light, a European coalition was set up. Once Rabah had been neutralised, the European powers proceeded to share the Lake Chad basin. Thus, the lake was opened up to navigation and became an international space with three (3) spheres of influence (British, French and German). But at the end of the First World War (1914-1918), France and Britain having vanquished Germany, divided the space into two (2), and began to push a colonial-style development model in the region.
Once the neighbouring African States of the basin had achieved independence in the 60s (Cameroon, Niger, Nigeria and Chad), they set up the LCBC in 1964. It marked the beginning of a new chapter in the history of the Chadian basin and in the management of Lake Chad’s natural resources.
History of the physical dynamics of Lake Chad
During the post-glacial periods, climatic conditions in the Sahara were much more clement than they are today. The actual desert did not have its current proportions, it was much smaller.
According to historians, the Sahara was largely covered by Mediterranean woody vegetation, particularly in the central massifs, which were surrounded by many lakes and dry grasslands. This state of affairs was more conducive to the proliferation of all kinds of wildlife and game.
Depending on the alternation of wet and dry phases, Lake Chad could stretch or retreat, but from 4000 BC. BC to date, the waters have shrunk at a fast pace, corresponding with the advent of aridity and desert encroachment with several origins.
Variations in Lake Chad, as shown in pictures below, indicate that many changes occurred on the following landmark dates:
- 50,000 B.C., the lake covered 2 million square kilometres;
- 20,000 B.C. , it disappeared completely due to the aridity of the tropics following the peak of glaciation;
- 9500 B.C., the Lake was swollen by rains pouring abundantly on the Tibesti massif, it has a depth of 15 m, before returning to the situation of around 9000 B.C.;
- 7000 B.C., it has a depth of 38 m, before returning to the current situation around 5500 BC. BC;
- 4000 B.C., it has a depth of 65 m, and eventually covers an area of over one million square kilometres, or several hundred times its current size before returning to the current situation around 2000 B.C.;
- 2000 B.C., the lake was then a genuine inland sea of Central Africa, which has desiccated and whose basin has filled up with sand;
- 1000 B.C., it has a depth of 17 m, before falling back to the current situation
- 1908, the lake was merely a wetland with two small basins to the north and south, and then its level increases;
- 1963 the Lake covers, according to sources, 22, 903 to 25 000 km2;
- 2001 its surface area shrinks to 4,000 km2;
- 2008, its dimensions are 30 by 40 km at the mouth of the Chari River - (Logone) with a surface area of 2500 km2. Lake Chad covers less than 10% of the area it occupied in 1960.
This situation has worsened due to: (i) increasingly scarce rainfall, (ii) severe droughts (1973, 1984 and 2008), and (iii) anthropogenic actions (deforestation, etc...).
Ironically, while the lake is under threat, its riparian populations seem to be opposed to its refilling. We are hereby referring to the LCBC flagship project, related to the Inter-basin Water Transfer Project (PTEIB). This may be explained by the fact that desiccation has exposed fertile lands from which they stand to gain significant income.
The Institutional history of the Lake Chad Basin Commission (LCBC) began with the four (4) riparian countries (Chad, Cameroon, Niger and Nigeria), when the Conventional Basin covered 430,000 km2. It was expanded to 970,000 square kilometres with the accession of the Central African Republic in 1994 as the fifth member country, and also taking into account the upstream areas formed by the Chari-Logone and Komadugu-Yobe active basins, followed by the accession of Libya in 2007.
Over a long time in history, the Lake Chad Basin appears to have been a key centre of trade between North and Central Africa. In less than a quarter of a century, new economic resources (industrial agricultural mining, etc..) are creating a new type of space differentiation, high population mobility and the emergence of intercommunity conflicts tied to these new dynamics.
The different states of Lake Chad as it has evolved over time
Following a long running debate, it was proven that a Mega-Lake Chad existed during the Quaternary period, measuring 340,000 km2 and up to 160 m deep, compared to only 3 m or even less currently.
According to Tilho (year), observations of the lake have recorded various levels:
- a "great Lake Chad" with 25,000 km2 of open water and a 284 m coast;
- a "medium Lake Chad," between 15,000 and 20,000 km2 of open water, corresponding to a coast of 282 m, forming one body or divided into two basins, which allows an archipelago of 2,000 islands to peek through. Its level varies by a 0.7 m margin between the high water (December-January) and the low water period (August);
- Finally, a "small Lake Chad", which is characterised by a coast of less than 280 m.
The natural hydrological balance of this "medium Lake Chad" relies on contributions derived principally from the Chari-Logone system (82.3%) and precipitation (14%). The small tributaries located west of the lake, which drain the Cameroonian and Nigerian sides of the basin, provide only 3.6%. Losses are caused by evaporation (95.5%) and infiltration (4.5%).
It should be noted here that the presence of shoals, the largest of which is called the Great Barrier Reef, compartmentalizes Lake Chad into several basins. The open waters extend over areas ranging from 1,500 to 14,000 km2, with their peripheral areas covering vast wetlands.
Lastly, Lake Chad follows an annual cycle. The beginning of the rainy season in the upper basin (May-June) gives rise to floods (August-September), which fill up Lake Chad (October-January) before evaporation associated with the end of the flow, leads to a drop in the water level. The contributions of the Chari-Logone system vary widely, from single to double inputs and sometimes more, similar to Sahelian rainfall.
Thus, Lake Chad’s rhythms vary greatly, depending on a host of factors such as: the timing and amount of rainfall in the Sudanian and Sahelian areas; the previous fill level, vegetation, etc. In conclusion, a difference of just a few dozen centimetres from one flood to another, results in several tens of thousands of acres being covered or uncovered, the coast retreating several kilometres, the islands being flooded.
The current Lake Chad is an ordinary "small Lake Chad", as it has been several times in the past. It has hardly witnessed any major changes since the beginning of the Sahelian drought of 70 years, except for minor seasonal and interannual fluctuations which are typical of its normal functioning.
After a decline in rainfall from 1968, the year 1973 dramatically introduced a cycle of drought. Very low flood levels led to the drying up of Lake Chad, including the entire north basin.
This paved the way for the germination of seeds which were previously buried in sediment and vegetation of a large part of Lake Chad’s surface area, whose outskirts were now covered by swamps of papyrus and reed-like grass. Lake Chad was then divided into two (2) or three (3) basins:
- one in the north-west, separated from the rest by the Great Barrier, which blocked the flow of water during low flood years;
- two (2) others in the south (across from the Chari delta) and in the east (Bol archipelago);
- the southern part which had the lowest variations in level and the freshest waters, receiving a constant and direct supply from the Chari. The northern part frequently dries up and has a higher salinity.
Since 1973, there have been few changes in the distribution of open water and vegetated wetlands.
Since 1984, aside from two (2) particularly dry years, contributions from the Chari-Logone system have remained in the range of 15 and 25 km3 annually (Lemoalle, 2003), which ensures the overall stability of the ecosystem at the level of the "small Lake Chad. "
In addition, much as elsewhere in the Sahel, there has been a slight increase in rainfall since the late 80s and mid-90s: the current period is less humid than the decades from the 1950s to 1960s, but less arid than the height of the droughts in the 1970-1980s. With the exceptional rainfalls of 2012, a change is expected, albeit a small one, in the configuration of Lake Chad.