After
enjoying the video, now a bit more facts about the lake Chad. I found some
information on the official Lake Chad Basin Commission website. I will give you
a brief summary.
The lake
Chad basin is located in the north of the Sahara in the so-called sahelian
zone. It covers four different climate zones with a high variability in
rainfall. The more north you go, the fewer rainfall you will see. The Amount of
rain varies between 100mm per year in the north to 1500mm in the south of the
basin. But more important for the rainfall is the location of the ITCZ (Inter
Tropical Convergence Zone), which can bring on the one hand a dry season, up to
8 month, or on the other hand a wet season with a few rainy days.
Notwithstanding these extreme weather situations, the biggest problem is the
high potential evapotranspiration, which is annually higher than the actual
rainfall. So on a long term, the lake will run dry, even without a human
overuse or fail management of the water.
How
dramatic the drying of the lake actually is, you can see in the following
picture, which I found in a paper from the LCBC “Saving lake Chad” 2008.
Figure 3: LCBC “Saving lake Chad” 2008
To give you
some more facts, the lake shrank from 25.000km2 in the 1960s to less than
1.200km2 today. In the 19th century, when the Europeans first
discovered the lake, it was one of the biggest lakes in the world. Even before,
the biggest estimate size of the lake was about 300.000km2 – 400.000km2. (Terra-Online)
It looks
like; the reason for the drying lake is just because of the absolute water
scarcity in this area, but many people are also blaming the climate change. In
particular the involved local people, I found an interview with the Executive
Secretary of the Lake Chad Basin Commission, Engr. Sanusi Imran Abdullahi. He
is mainly blaming the climate change and especially all the countries, which
have driven and still driving it. Therefore, he changed the discussion/problem
from a just natural/absolute to a political one. I think mainly to raise a
local problem to a global one and to get more attention, which is in this case,
at my opinion, absolutely right.
At the
moment there are many projects to save the lake. In particular, driven from the
riparian states, Cameroun, Libya, Niger, Nigeria, Central African Republic and
Chad. Together they form the Lake Chad Basin Commission (LCBC). What kind of projects
and how they going to achieve them, will be the topic of my next post.
Very shocked by how much surface water in Lake Chad has gone for over the last few decades. It reminded me of the Aral Sea where the huge lake has gone under significant decline in water level as a result of intensive agricultural activities like production of cotton. I'm just wondering how the surface water of Lake Chad interacts with groundwater because I think Lake Chad Basin itself is famous for being one of the largest sedimentary aquifers (perhaps relevant to this topic: http://www.cblt.org/en/sustainable-management-water-resources-lake-chad-basin-bgr-module-advice-groundwater-ressources-lake) . I am very looking forward to reading more about the management of this transboundary resources in your next blog! :)
AntwortenLöschenYeah the Aral Lake is quite similar. I will try to find something concerning the groundwater maybe in my next post. But it is just one of the largest "closed" sedimentary groundwater basins, which mainly discribes, accoring to my understanding, the size of the whole basin and not the amount of groundwater. So I'm not quite sure, how important groundwater in this area really is. But I will check it. :)
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