Torrential Rains and Persistent Drought

Climate Change Devastates the Sahel

The Sahel is a region made increasingly arid by the encroaching desert and yet it must deal periodically with devastating floods. A double bind with many causes.

Niamey, 27 August 2020, Kirkissoye district
Boureima Hama/AFP

A man wading across an expanse of water carrying a mattress on his head. A woman piling onto a makeshift rowboat the pots and pans she has been able to rescue. Youths hastily trying to mount a sand dike in front of half-destroyed mud huts… For the past few years, these and similar pictures have become commonplace in the Sahel. Recently, on the social networks, we even saw an SUV dragged miraculously out of the water at the end of a cable while a crowd cheered.

At odds with what has been for years the region’s customary image—an increasingly parched savannah as the desert pursues its advance and where there is a penury of everything, especially water—the Sahel is now regularly devastated by severe flooding. Rainfall, vitally important for millions of farmers and livestock breeders, is not always impatiently awaited. Quite the contrary. In the bigger towns especially, everyone knows it will be coming sometime around the end of August or the beginning of September and will bring about huge rises in river levels and tragic flooding that will cause enormous damage and plunge thousands of families into mourning. “Every year it’s the same thing, there’s water everywhere. But what can we do?” Ali laments. He lives in Lamordé, a neighbourhood in Niamey, flooded again by the waters of the Niger at the beginning of September and who had to send his family to stay with friends while he cleaned his house.

From Niger to Sudan

The capital of Niger was especially hard hit this year. Several neighbourhoods were flooded, including those on the right bank where the university is located, when a dam burst under the pressure of the river water. By 7 September, the authorities had counted no less than 65 deaths (14 by drowning), 32,000 collapsed houses, some 330,000 homeless and thousands of acres of crops destroyed all over the country.

Another country that has greatly suffered this year is Sudan, where some hundreds have died, according to the UN Office for the Coordination of Humanitarian Affairs (OCHA). Nearly 71,000 houses were destroyed and over 720,000 people are homeless, victims of heavy rainfall (in the West) and the rise of the level of the Nile (in the East). In that country, where a state of national emergency has been declared for a period of three months, it is thought that these floods are the worst since 1946. The government has announced that the level of the Nile has reached 17.43 metres, the highest ever recorded in the last century.

Torrential rains have also fallen on Burkina Faso, where a state of national disaster was decreed on 9 September, when there had already been 13 dead; on Nigeria, where over 30 people died; on Chad, on Mauritania as well as on Senegal, where the capital, Dakar, was especially hard hit. In a single day, 5 September, more water fell on the city than during the three months of what is described as a “normal” rainy season. According to the OCHA, nearly 760,000 people have been affected by the flooding which has hit West Africa and a part of Central Africa over the past few weeks.

What shocked everyone ten years ago is no longer surprising today. “We finally got used to it,” observes our Ali, the Nigerien quoted earlier. “Today we’ve learned to live with it.” In 2019, torrential rains affected over a million people in eleven sub-Saharan countries. In most of the Sahelian countries, flooding has grown by leaps and bounds over the last few years, especially in the big cities: Niamey in 2010, 20121, 2013, 2016, 2017; Ouagadougou in 2009, 2012 and 2015…

On 1 September 2009, an unprecedented 263 millimetres of rain fell on the Burkinese capital in a matter of 12 hours. Eleven years later, the people of the city still remember that. The reservoirs overflowed. Forty-five districts were flooded and at least 125,000 people lost their homes. “My wife and I had only just time to scoop up our boy and run. It happened so quickly. The water rose by a metre and a half, the house collapsed,” a survivor named Antoine recounted a few years ago. He had been provided with downtown lodgings by the public authorities. On that same day, 1 September 2009, a very violent rainstorm hit northern Niger, in the middle of the desert, causing a big rise in the level of the wadi Teloua which flooded the city of Agadez causing enormous damage (3 dead, 80,000 homeless, devastated crops).

Global warming and population boom

How can we explain that water is causing so much damage in a region known to be beset by drought and threatened by the encroaching desert? Global warming immediately comes to mind. “Global warming is affecting West Africa more than other regions with a rise of 1.2° Celsius as against an average of 0.7° elsewhere. And the result seems to be an intensification of heavy rainfall episodes”, the French National Research Institute (IRD) observed in 2016. “These episodes are not more frequent than in the past but they are heavier”, says Luc Descroix, director of hydrological research at the IRD, a specialist on the Sahel. “Since 2005, we have established that rainfall in the Sahel is more intense than previously and we believe this is due to global warming. As elsewhere, the phenomenon is producing what are celled ‘extreme events’”.

“This intensification of the hydrological cycle is in keeping with the Claudius-Clapeyron theory, a warmer atmosphere containing more water vapour and thus becoming more explosive”, a group of French scientists wrote two years ago. “It has been observed in other parts of the world, but the Sahel seems to be the area of the African continent where it is most evident”. Thus, the populations of this region are subjected to something akin to double jeopardy. “This climate change has especially serious consequences […] the periods of drought are more severe making crops more uncertain […] and flooding more frequent.”

Degraded soil that can no longer absorb water

However, the multiplication of heavy rainfall episodes is not the only explanation for the flooding in recent years of rivers like the Niger or the Nile. Luc Descroix suggests a further factor: the drought episode that impacted the region so heavily in the seventies and eighties: “For 25 to 30 years, sometimes longer, an area of 4 to 5 million km2 had a rainfall deficit of from 15 to 35%. Today we may consider that this drought episode is over, because since 1995 [1999 West of the Sahel], the annual rainfall has returned to the levels and year-to-year irregularity of the first half of the 20th century, the fifties and sixties being considered wet decades.” In his Processus et enjeux d’eau en Afrique de l’Ouest soudano-sahélienne (IRD Éditions, 2018), Luc Descroix wrote that “during that period soils became degraded, one speaks of ’soil-crusting”. Thus climate-induced drought was followed by edaphic or soil-induced drought. When the rains came again, after 1994, reaching their 1940 levels, the soils no longer had the capacity to absorb all that water. This brought about an overland flow which caused the flooding of the waterways.”

According to Luc Descroix, the increased overland flow is also tied in with the way farmers have stripped the soil. In his view, the rapid population growth in Niger since the fifties (from 3.2 million in 1960 to 15.4 million in 2015) has had a serious impact on the use of the soils. The spread of crop cultivation, the curtailing of fallow periods has produced much soil-crusting. “The fallow periods, allowing the earth to recover its original properties and especially those involving the infiltration of rainwater, are no longer respected when the population to feed is over 20 to 30 individuals per km2. Today, in some places, the figure is over 100 and the population is still growing at a brisk pace”, the IRD observed in 2016.

What with climate change and galloping demography, local decision makers would appear to have little leeway. And yet some scientists single out their responsibility … or rather their irresponsibility. Take the case of Niamey. True, the Nigerien capital, on account of its topographical location and the silting up of the Niger River observed over the past few years (and due mostly to desertification and deforestation) is especially vulnerable to flooding. But the risk has been aggravated by uncontrolled urbanisation and the lack of efficient drainage structures.

“In Niamey, the water disposal systems are inadequate and sometimes non-existent, precisely in neighbourhoods known to be most exposed to flooding,” says Hamadou Issaka, research fellow at the Niamey Institut de recherches en sciences humaines (IRSH). “Besides which, people settle in flood-prone areas and the authorities don’t lift a finger, all the while knowing the risks involved”. These bad habits were acquired during the long drought, when it was thought the river would never return to its former level.

Yet our Nigerien researcher rejects the notion of “uncontrolled urbanisation.” In his view, “the flood-prone zones are well known and have been mapped”, but the public authorities and traditional elders do nothing to prevent people settling there. In a study published in 2009, Hamadou Issaka pointed out that “in areas liable to flooding, it was easy for poor people to buy land which was not sought after by the wealthy”. He quoted a neighbourhood chief in the capital who explained the situation in these terms2: “Every seven years the neighbourhood is flooded. Houses often collapse after these floods. The reason for all that is that these people are fed up with renting houses in town. If someone comes along and even if they are forewarned that this is a flood-prone area, they will say ‘no problem’, what matters for them is finding land where they can build a shelter.”

“When people are cleared out…”

At regular intervals, people living in flood-prone areas are moved away by the public authorities. But as a former Nigerien Minister of Interior Affairs, who wishes to remain anonymous, pointed out: “when you clear people out, it makes for a lot of tension, because they don’t want to be resettled anywhere else”. “Some people are relocated but they come back despite the risk of losing everything,” Luc Descroix observes.

Various governments have, moreover, undertaken projects to deal with the problem—especially in Niger, Senegal, Burkina—often with the financial and technical backing of donors that have made it one of their priorities. “Increased efforts to prepare for emergencies and anticipate them have been made” noted recently Julie Bélanger, head of OCHA for Central and West Africa. But she also admitted that there is a lack of resources, and “possibly” a lack of real willingness on the part of governments to make the problem an absolute priority.

In Senegal, a controversy arose in the wake of the latest floods. Several homeless people called on the government to honour its promises: what about the drainage systems announced in his last electoral campaign by President Macky Sall and which are still practically non-existent? What about the rehabilitation of the flood zones? What about the 766 billion CFA francs (over 1.06 billion pounds or 1.16 billion dollars) allocated in 2012 to the Ten-Year Program of flood control?

In Niger, authorities have announced the creation of a 372 billion CFA Francs fund (over 519 billion pounds or 671 billion dollars) to relocate the homeless, provide food for them but also to build sanitation facilities and dams in Niamey and other cities across the country. “It’s a good thing, but a bit late,” says Ali ruefully, our homeless contact person from the district of Lamordé. As a teacher, he remembers the day when he and his neighbours were struggling to keep back the river water while the president was hosting in grand style the umpteenth summit of the Economic Community of West-African States (ECOWAS), with sirens screaming across the capital and red carpets rolled out in front of the posh hotels that have sprung up in recent years, and which Issoufou’s backers are so proud of. “With the money used to build those hotels or the new airport, how many culverts could have been laid, or simply used to finance cleaning up the city, how many really solid dams could have been erected?” he wonders. His question is relevant all across the Sahel.

1In August of that year, the Niger carried nearly 2,500 m3 of water per second, the largest amount ever measured since 1929. The damage was considerable, with 80 deaths.

2Hamadou Issaka and Dominique Badariotti, “[Les inondations à Niamey, enjeux autour d’un phénomène complexe(>]”, Les Cahiers d’outre-mer, n° 263, July-September 2013.