By Steff Gaulter
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Flooding has gripped the Mediterranean. France, Switzerland and Italy have all seen deadly flooding, and the torrential rain has also been affecting North Africa. Morocco, Algeria and Tunisia have been doused by heavy rain over the last few weeks with Morocco seeing the worst of the flooding. At least 36 people were killed in Morocco on November 23 alone, and the rain has continued to cause major problems ever since.
It is not uncommon for flooding to affect Morocco at this time of year. The country is extremely arid after very little rain has fallen in the summer months. This means the ground is baked hard by the sun, and when the rain does fall at the start of the rainy season in October and November, it cannot simply soak into the soil. Instead the water forms a layer on top of the ground, and flows downhill to collect in huge pools. Despite the regularity of the flooding, even by Moroccan standards, the devastation seen at the end of November this year has been exceptional.
The amount of rain that is expected in Morocco depends on how far north you are. Typically along the coast the rain is heavier in the north. Usually Casablanca receives 417mm (16.4 inches) of rain in a year, which is far more than Doha, which only expects 75mm (3 inches) and similar to the Spanish capital Madrid, which receives an average of 436mm (17.2 inches).
Further inland there are mountains, which disrupt this weather pattern, but if you travel further south along the coast, the climate becomes progressively drier. Agadir in the southern half of the country receives just 263mm (10.4 inches) of rain, and the amount of water drops off even further to the south of Agadir, eventually allowing the Sahara Desert to extend to the coast.
Given this general pattern of the Moroccan climate, it may be a surprise to learn that the worst of the recent flooding hit the city of Guelmim. This is over 150km (93 miles) to the south of Agadir and is in a region which normally escapes the heaviest of the rain. However, this is where the 36 people lost their lives as floodwater surged down the Tamsourt River.
Like many rivers in Morocco, the Tamsourt river bed is dry for the majority of the year. This is partly due to the long dry summer months, but some claim that it is also due to the dwindling amount of rainwater which has fallen in recent years, causing a number of rivers to dry up. This means these river beds now act like the wadis do in the Gulf region— they remain dry for the majority of the year, but as soon as rain falls, they fill quickly, turning into raging torrents of water.
The sandy soil in southern Morocco and Qatar are fairly similar; however, Morocco differs from Qatar in that it is mountainous. This can make wadis, and the dried up Moroccan river beds, highly dangerous. It might be sunny on the coast, but pouring with rain across the mountains. This means that despite no rain falling along some parts of the river bed, the river can still become a raging torrent in a matter of seconds, catching people completely unaware.
November 23, rain was widespread and fell across the region. However, the Tamsourt riverbed was transformed into a fast-flowing torrent of water in seconds. In the city of Guelmim the landscape was transformed and the majority of those killed were trapped in their vehicles as they were swept away by the flood water. However, it wasn’t only the river beds that were flooded, approximately a hundred homes constructed of mud and brick were either partially or completely destroyed and a hundred roads, including several national highways, became impassable.
Ironically Guelmim’s nickname is ‘the Gateway to the Desert’, but as rain poured the city didn’t resemble a desert at all. Unfortunately Guelmim doesn’t have particularly reliable weather data, but the heavy rain was widespread. Approximately 170km (105 miles) to the north is the major tourist destination of Agadir, which reported a staggering 248mm (9.8 inches) of rain in the month of November, far exceeding the average of 48mm (1.9 inches) and only just short of the amount of rain that’s expected in the entire year.
It may surprise you to hear that London’s average annual rainfall is only 558mm, (22 inches) according to the World Meteorological Organisation. Given that many people think London is a grey and wet place, for the ‘Gateway to the Desert’ to receive nearly half London’s annual rain in a month is clearly quite exceptional. What’s more, 150mm (almost 6 inches) of that fell in just one day; clearly flooding was inevitable.
More rain is expected across the region during the winter months. The rainy season is expected to continue until April, traditionally with December being the wettest month in Agadir. However, given the amount of rain that has been seen in November, it would be very surprising if December were the wettest month this year. There is always the risk of more thunderstorms bringing more flooding during the remainder of the rainy season, but the Moroccans will be hoping that the worst is now behind them.
