Talking about the weather seems to be more than just a pastime in East Africa these days. Dust is filling the air and has completely engulfed the Rift Valley. A thick layer of brownish orange haze blurs the horizon. Tsavo and Amboseli are parched and praying for wet season to commence, but areas surrounding Kisumu are experience a different phenomena - too much rain. Luckily, the Serengeti seems to be between extremes, receiving the best weather in the region; A consistent amount of rainfall in the areas where it is needed most.
The lack of precipitation across several nations including Ethiopia, Kenya, Uganda, and Tanzania is a direct link to food security issues. Most affected are the pastoralists who depend on their goats and cattle for their livelihood. Stories of drought are dominating headlines and claiming the lives of cattle and wildlife in several areas. The long rains that typically dominate April and May failed entirely in some regions leaving dry, desolate conditions. Croplands are lacking any agricultural production forcing several human settlements into starvation. The World Food Program has estimated that 23 million people are in need of emergency food relief. Human conflict has increased in areas of northern Uganda and Kenya where locals are combating for natural resources.
Despite the desolate conditions in these other areas, the Serengeti has seen and still is receiving adequate rainfall. The drought has severely hit areas east of the park such as Loliondo and Ngorongoro, sending herdsmen 200km in search of water for their livestock. However, the Serengeti Ecosystem has been receiving more rainfall than average, markedly in the west towards Lake Victoria.
The weather in the Serengeti and much of East Africa used to be much more predictable. The Inter Tropical Convergence Zone can likely be given credit for that. When the trade winds meet twice a year, large low-pressure systems emerge over the Indian Ocean and we experience the long and short rains. In addition the vast expanse of Lake Victoria in the west of the park brings local rain to the west and north of the Serengeti. These two forces characterise our seasons and in the past have come and gone around the same time each year. However, we are now experiencing longer wet seasons, but with less concentrated downpours and wetter dry seasons. The November-December “short rains” are commencing in October and often lasting until the New Year. The “long rains” are often late and at times seem to end early.
We received plenty of precipitation earlier this year that allowed the wildebeest to follow their normal migratory route from southern Tanzania through Seronera and north into the Masai Mara. The animals typically return back through the Western Corridor and continue south beginning in late November to December. However, due to exceptional rains in the west at the beginning of October they were already present across the Western Corridor – something I haven’t witnessed in thirty years. Their presence seemed so foreign that I circled the area with the aircraft trying to comprehend whether the resident population had skyrocketed or if the migration had truly already begun its trip back south. The west is dotted with a few hundred thousand wildebeest leaving no doubt that part of the migration has returned.
From Seronera, dark storm clouds and heavy rains have been visible towards the west over the past few weeks. They have resulted in exceptional grass growth likely enticing the migration to return back to Tanzania early and providing a boost for all the resident grazers. The lack of precipitation earlier this year in northern Serengeti is perhaps also influencing the animals’ early departure from the north.
We have been given warning that the meteorological phenomenon, El Niño, is due to hit with brute force this year. Though it normally brings the short rains in November and December, it passes by casually. Rumor has it, that this year, El Niño will hit like it did in 1998. In 1998 El Niño created a mass of flooding across East Africa, including the Serengeti Ecosystem. Visitors were unable to leave or enter Seronera; Both cars and planes did not attempt travel on the water-soaked landscape for an entire week. Even the FZS office in Seronera seemed to be sitting in a swampland, not in the bush. Forecasters are predicting a similar occurrence this year bringing the potential to revive croplands, but also the potential for severe flooding.
Apart from calculations related directly to El Niño, future predictions on climate change estimate that areas in Tanzania will see an increase in rainfall over the next eighty years.
The Climate Wizard, a project of the Nature Conservancy, has pinpointed the Serengeti Ecosystem as an area that can expect an increase in rainfall from 88mm to 350mm/year. Likewise, the whole of Tanzania is estimated to see increases from -34mm to 87mm across the country.
However, other studies by Mark Ritchi from the Serengeti Biocomplexity Project suggest lower and less predictable rainfall in the Serengeti due to warming of the Indian Ocean and Lake Victoria.
The climatic situation in the Serengeti in the last few years was characterized by:
• Wet season rainfall is becoming increasingly variable and unpredictable
• Dry season rainfall has increased on average and in variability
• Years of consecutive dry or wet dry seasons have increased throughout the last century
• Length of wet season increasing, but intensity is decreasing
Rain drives everything – not just in the Serengeti where 2 Million wild animals depend on it - but all over Africa where the mostly rural population is at the mercy of enough rains for their survival. Rain and water I believe will be the most crucial factors for conservation and development in Africa in the future. No doubt it will be the talk of the town for years to come.
UPDATE, 17th October: I just returned from a flight to Arusha and Nairobi. Eastern Kenia and North East Tanzania have finally received good rains in the last two days. It looks as the rainy season has started. The poor Masai in Loliondo will have to suffer a bit longer. It always takes time for the winds with the rains from the Indian Ocean to reach further west. The spell of the drought however seems broken.
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