Terrain shapes and bedrock
According to COUNTRYAAH, the islands volcanic bedrock has been built up over the last 30 million years. The erosion has worn down the volcanic canyons so that the country’s highest point, Piton de la Petite Rivière Noire on the main island, is only 828 m asl. The main part of the main island consists of a highland with about twenty well-preserved volcanic craters. Lava flows from these have weathered and created fertile soils.
Several rivers drain the highlands, most and farthest are the rivers on the island’s rainy east side.
According to BRIDGAT, the annual average temperature is 23-24 °C on the coasts and down to 19 °C in the highest parts of the main island. The annual rainfall on the main island is 1,000–2,000 mm on the west side and up to 4,500 mm on the east side of the high plateau. Tropical cyclones are common in June – December.
Plant-and animal life
The islands were originally covered by rainforest. Nowadays, all natural forest is gone at Rodrigues. On the main island, only fragments of lowland rainforest remain on the western slopes between Mont du Rempart and Shamarel, and highland forests are found only in the southwest in the Macchabee – Bel Ombre reserve. On the east side of the island are mangrove forests, largely harvested. About 90% of the cultivable area (45% of the total area) is covered by sugar cane plantations. Upwards of 900 species of vascular plants are known from the main island, of which about 1/3 are endemic.
Wildlife on land is relatively poor and severely threatened. A number of species are already extinct; Most famous are drone and solitaire. The only native land mammals are some bat species. There are coral reefs around the islands.
In 2011, there was a national park, the Black River Gorges on the southwest side of the main island, a biosphere reserve and away 20 nature reserves, of which Macchabee-Bel Ombre on the main island alone occupies more than half the protected area.