Lake Chad straddles four countries: Chad with the largest surface area of the lake, Niger, Nigeria and Cameroon. Believed by geologists to have been formed 50,000 years ago, as an inland fresh water sea of 2 million square km, it has been shrinking ever since. Its most recent massive shrinking was during the 1968-1973 drought period. However, there have also been periods when it expanded.
The Lake Chad basin is an important ecosystem, with approximately 20 million people believed to be relying on it and competing with the natural fauna and flora for its waters and soils. Of great concern is that this once massive inland sea is literally disappearing, and could be non-existent in the next twenty years.
Knowing the cause of its shrinking and that of other fast disappearing lakes, could be crucial in arresting the extinction of the world’s internal water bodies, and thereby stabilizing the earth’s ecosystem. So, the most important question now is: what is causing Lake Chad and others to shrink? There are a number of reasons for lake Chad’s seasonal fluctuations over the years, and its current rapid shrinkage.
The first possible cause of Lake Chad’s rapid reduction is global warming and climatic change. There has been overwhelming evidence in recent years, that the atmospheric temperatures around the earth have gone up by several degrees, causing ice-melts in the polar regions, desertification in tropical climates, milder winters in temperate regions and evaporation of internal water surfaces. The area around Lake Chad has in recent years seen reduction of rainfall , thereby causing the volumes of Lake Chad’s river tributaries to fall.
Lake Chad is also situated right at the southern tip of the great Sahara desert, whose expansion southwards is estimated at 48 km every year. The Sahara, the hottest place on earth with temperatures reaching 57 degrees Celsius, causes rapid evaporation of water. At that rate of its extension, lakes that are in danger of extinction include Lakes Kyoga(Uganda), Lake Tana(Ethiopia), Lake Turkana and Victoria(both in Kenya). Other drainage systems on its path stand very little chance of survival. Global warming and climate change, have been given various interpretations, but the major culprit has been man’s rapid industrialization which produces huge emissions of CO2. The CO2 emissions create greenhouse effects on the atmosphere which raise atmospheric temperatures. There has never been more urgent need than now to cut down these emissions to save natural phenomena like Lakes.
Apart from creating greenhouse effects on the atmosphere, man also stands accused for other malpractices that endanger the ecosystem. The recent population increase around Lake Chad, and the indiscriminate exploitation of its water resources have been a danger to its very survival. Kamadougou-Yobe, one of Lake Chad’s tributaries, though seasonal has been dammed and this has tremendously reduced its spillage into the latter. Diversion of the Chari-Longone river, an important Chad feeder, for irrigation purposes has also affected it further. Effects of over-exploitation of water resources has seen the reduction of Aral sea, once the fourth largest inland body of water in the world. Aral sea, which serves both Uzbekistan and Kazakhstan, among other nearby countries, has its water volume reduced because its two important tributaries-Amudarya and Syrdarya- are being irrigated by Turkmenistan, Tajikstan and Kyrgyztan. Massive irrigation of these two rivers is threatening the existence Aral sea. Unless a coordinated agreement is reached among these countries Aral sea faces extinction.
It is apparent that man’s activities have a direct effect on climate change and on the earth’s natural resources such as lakes and rivers . Whereas climate change and global warming may have other causes, natural phenomena like water resources must still be safeguarded for posterity. The exploitation of the river Nile , for instance, has recently been a subject of much interest. The Lake Victoria, the source of the Nile is also rapidly shrinking and its waters getting more polluted, due to industrialization and trawling.
A well-coordinated and concerted effort in tackling these human malpractices, could ensure the preservation of Lake Chad and other shrinking lakes.
Bibliogaphy:
http://www.scientificamerican.com/article.cfm?id=reclaiming-the-aral-sea
http://www.unep.org/dewa/Africa/publications/AEO-2/content/085.htm
http://www.fao.org/landandwater/aglw/webpub/lakevic/lakevic4.htm
