3. The transformation of landscapes 9. Huacachina Oasis, in Peru's coastal desert. This lagoon was formed by the emergence of groundwater and is believed to have medicinal properties. A health resort was built around it in the 1960s and attracts thousands of tourists a year. What are the contributing factors? Settlements and human activities modify natural landscapes. The larger the population , the greater the modification , due to the need for resources ( farmland , water, land for building and infrastructures, etc.). In addition , modern technology and new energies increase our ability to modify the environment to make more intensive use of resources. For this reason , there is not much modification in sparsely populated regions. This applies to areas with extreme climates, such as high mountain areas at temperate latitudes, polar regions and deserts. (9) The degradation of hot landscapes In the Earth's intertropical convergence zone, hot climates predominate. Three types of landscapes develop there: Rainforests, associated with an equatorial climate. Savannahs, where a tropical climate predominates. Deserts, in the driest regions. Despite being ver y sparsely populated , some rainforest and savannah landscapes are modified greatly. Rainforests are sparsely populated due to heat, high humidity, dense vegetation and infertile soils. Despite this, deforestation has destroyed a third of tropical rainforests, especially in the Amazon. (10) A similar surface area is severely degraded . The main reason for deforestation is to make land available for the cultivation of commercial produce such as cof fee or soya . Another cause is fires due to heat waves and droughts. Rainforest Savannahs are extensive plains covered with tall grasses and a few isolated trees and shrubs. (11) This landscape is a transition zone between rainforests and semi-arid landscapes. Savannahs are greatly endangered by climate change. The practice (now banned) of burning vegetation to clear land for cultivation has degraded the soil , increasing the risk of desertification. Savannahs 10. 40 % of the Amazon could become savannah. 11. African savannah
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