Les falaises de Popenguine © Andre Stival - Shutterstock.com.jpg
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Désert de Lompoul © gyikka - Shutterstock.com.jpg

A relatively flat country

Facing the Atlantic Ocean in northwest Africa, Senegal looks like a head, with its hair pulled back, the Cape Verde peninsula in the shape of a nose and the Gambia in the shape of a mouth. However, under this pictorial map, a country is revealed where the reliefs are almost absent from the landscapes, or then unexpected. In this transitional zone that is the Sahel, vast expanses of undulating, sandy plains, rarely exceeding 130 meters in altitude on the Fouta-Toro side, cover a large majority of the country. One must go further southeast, into Bassari country, to see the first slopes of the Fouta-Djalon massif, which peaks across the border in Guinea Conakry at 1,500 meters. More hills and a few canyons carved out of the Niokolo Koba by the Gambia River, but nothing to get excited about: Mount Assirik, at 311 meters in a region that does not rise above 400 meters, is only the first step in the mountain range that only really rises once it crosses the border with Guinea to the south. As for the coastline, which stretches for more than 700 km along the Atlantic, it also has little relief, except for the volcanic coast of Cape Verde where the famous Mamelles hills in Dakar reach an altitude of more than 100 meters. Finally, on the Petite Côte, the famous ochre cliffs of Popenguine and Toubab Dialaw overhang magnificent fine sandy beaches, popular with surfers who come to face the waves of the Atlantic.

A limited hydrographic network

This apparently monotonous territory with a predominantly dry climate has a sparse hydrographic network, composed of rivers and lakes. The most emblematic of the country is undoubtedly the Senegal River, navigable from Saint-Louis to Kayes. It is 1,750 km long and originates in Guinea-Conakry, then traces part of its course in Mali, before finally embracing Senegal and Mauritania, which it separates by carving out a fertile strip of land in the heart of the arid Sahelian plain, before flowing into the Atlantic Ocean, near Saint-Louis. The Gambia River is the second largest river in the country in terms of size and flow. But, in reality, when it enters Senegalese territory from Guinea, it barely has time to irrigate the Bassari country before it already flows towards the Gambia to empty itself near Banjul. The Casamance River, for its part, crisscrosses the south of the country from east to west, over 320 km, before ending its course in the Atlantic Ocean, in a rather incongruous manner. More than 200 km away, the delta widens into hundreds and hundreds of arms of the sea, called bolongs, many of which are lost inland, forming marshes whose stagnant water is salinated by the rising tides. Even more striking than in Casamance, the Sine-Saloum delta, classified as a Unesco World Heritage Site since 2011, is a ria irrigated by seawater that helps feed the two eponymous fossil rivers during rising tides. Dry for much of the year, the Sine and Saloum are fed with fresh water only in the rainy season, but in insufficient quantity to avoid the movement of the tides to flow to the sea. This channel of bolongs offers to those who venture there by dugout canoe superb landscapes of mangroves, punctuated by a myriad of wild islets. In addition to its three major rivers, several lakes, lagoons and ponds complete the hydrographic network of the country, such as Lake Guiers and the ponds of the Niayes region.

Protected wetlands

Although Senegal has a rather dry and arid climate, the country is dotted with several wetlands, home to an exceptional biological diversity. The Ramsar Convention, one of the oldest agreements on the environment, aims to stop their degradation or disappearance, recognizing among other things their ecological functions. Among the 170 signatory countries, Senegal ratified this convention in 1977. Since then, eight Senegalese sites have been included in the List of Wetlands of International Importance. These include the Kalissaye Ornithological Reserve, nestled in the delta of the Casamance River, the Djoudj National Bird Park, a vast network of lakes and brackish ponds, the Somone Natural Reserve of Community Interest, consisting of a lagoon, channels, a mangrove and a sandy foreshore, and the Saloum Delta National Park, with its maze of inlets. These protected areas, which cover nearly 160,000 hectares in Senegal, are designed to preserve the most productive environments on the planet.

Lompoul, the only desert in Senegal

Almost halfway between Dakar and Saint-Louis, the fairy-tale landscapes of the Lompoul desert are revealed less than 10 km from the ocean. A bit like coming out of nowhere, it offers a foretaste of the Mauritanian deserts, although much smaller since it extends only over 30 km. Its dunes, of a fine sand of ochre color, even red at certain times of the day, sometimes reach up to 50 meters in height. Here, vegetation grows little and temperatures can rise to more than 40°C in the middle of the day and fall to less than 20°C at night. In addition to this small dune desert, there are some semi-desert areas consisting mainly of shrub savannahs in the Ferlo region of northeastern Senegal. For several decades now, the desert has been gaining more and more ground in the Sahel regions, and the Ferlo region is not spared. To combat this desertification, eleven African countries, including Senegal, have committed to planting a Great Green Wall of 7,800 km of vegetation from Dakar to Djibouti, combining desert date palms, acacias and jujube trees. The project, which began in 2008, is still a long way from its aspirations, and only about 15,000 hectares have been planted so far in Senegal.

Islands as far as the eye can see

Off the coast or lost in the meanders of the bolongs, Senegal conceals a host of islands, some of which are true refuges for birds. Nestled in the bay of Dakar, the island of Goree is certainly the most famous of the country, because of its heavy past linked to the slave trade. But it also offers beautiful landscapes, it is formed of cooled lava and dominated in the south by a granite plateau. In the middle of the roadstead that forms the southern coast of the Cape Verde peninsula, this jewel of the Atlantic is sheltered from ocean winds, for the happiness of ships that can easily dock there. Also a short distance from Dakar, its neighbors: the island of Ngor and those of the Madeleine, also of volcanic origin. On one side, the paradise of tourists who come to enjoy the beaches, protected by a rocky barrier. On the other, a virgin archipelago composed of two islands and endowed with a remarkable biodiversity. The Sine-Saloum delta is not to be outdone, offering an exceptional environment punctuated by nearly 200 islands and islets. As you go deeper into the bolongs, you will discover virgin islands covered with shells and populated by a myriad of birds, but also some inhabited islands like Mar Lodge. With its labyrinth of sea arms which advance in the lands, Casamance also conceals numerous islands, wild or inhabited. The largest of them is Carabane, located at the mouth of the Casamance River. Consisting of a sand bank and alluvial deposits, it offers a heavenly setting, with its beautiful beaches lined with palm trees. Let's also mention the islands of Egueye, Ehidje, Eloubaline and Wendaye, real little corners of paradise, among all the others.

Lake Rose, a singular phenomenon

Located 35 km northeast of Dakar and a few hundred meters from the ocean, Lake Retba, better known as Lake Rose, is part of the Niayes area, which extends from the Cape Verde peninsula to Gandiol. Once connected to the Atlantic, it has dried up with time and drought, until it is separated from the ocean by sand dunes. This lagoon of 3 km², shallow, concentrates about 380 grams of salt per liter, that is to say a hundred times more than the Dead Sea: as much to say that one floats there like a boat! But what attracts most curious travelers is the beauty of the site, which reveals an orange-pink color, on sunny and not very windy days. This hue is due to micro-algae which, in order to protect themselves from the sun and the high concentration of salt, produce a red pigment of the carotene family. This phenomenon also occurs in the lagoons of the Saloum delta, notably in Palmarin, where women dig wells into which the very salty water of the sea arm seeps. These cones then take on multiple colors, from yellow to pink or blue to green, which are due to micro-algae. From the sky, the spectacle is magnificent!

Fragile sandbars

From the Cape Verde peninsula to Saint-Louis, the coastline of the Grande Côte is protected for about 180 km by a sandy cordon called the Niayes. Between its white dunes, which can rise up to 20 meters in height, are old river beds filled with fresh water. The land is very fertile, and the market garden crops are numerous. Tomatoes, cabbages, onions, lettuce and even zucchini grow there easily to the delight of the inhabitants. Further north, between the river and the ocean, the Langue de Barbarie, a strip of white sand, stretches for about thirty kilometers from the Mauritanian border to the mouth of the Senegal River. It was a natural barrier protecting the villages of the Atlantic coast, but is now threatened with extinction. Following heavy flooding and a risk of flooding the city of Saint-Louis in 2003, the authorities acted quickly and decided to open a small breach, 7 km south of the city, to evacuate the fresh water. However, this ill-considered decision led to a real ecological disaster: the breach widened towards the south and salt water invaded the river, causing the rise in water levels, the salinization of formerly fertile land and the disappearance of villages. Today, no sustainable measures have been put in place to stop this phenomenon. Moreover, with the rise in water levels due to global warming, the Senegalese coastline is particularly exposed to erosion. This phenomenon is particularly visible on the Petite Côte where hotels are threatened by the advancing sea and in the village of Guet Ndar, in Saint-Louis where water is beginning to destroy fishermen's houses.