<P> The expansion of the Gobi is attributed mostly to human activities, notably deforestation, overgrazing, and depletion of water resources . China has tried various plans to slow the expansion of the desert, which have met with some small degree of success, but no major effects . The most recent plan involves the planting of the Green Wall of China, a huge ring of newly planted forests; the government hopes the forests will help stabilize the soil, retain moisture, and act as a buffer against further desertification . </P> <P> The Gobi, broadly defined, can be divided into five distinct dry ecoregions, based on variations in climate and topography . </P> <Ul> <Li> Eastern Gobi desert steppe, the easternmost of the Gobi ecoregions, covering an area of 281,800 km (108,804 sq mi). It extends from the Inner Mongolian Plateau in China northward into Mongolia . It includes the Yin Mountains and many low - lying areas with salt pans and small ponds . It is bounded by the Mongolian - Manchurian grassland to the north, the Yellow River Plain to the southeast, and the Alashan Plateau semi-desert to the southeast and east . </Li> <Li> Alashan Plateau semi-desert, lies west and southwest of the Eastern Gobi desert steppe . It consists of the desert basins and low mountains lying between the Gobi Altai range on the north, the Helan Mountains to the southeast, and the Qilian Mountains and northeastern portion of the Tibetan Plateau on the southwest . </Li> <Li> Gobi Lakes Valley desert steppe, ecoregion lies north of Alashan Plateau semi-desert, between the Gobi Altai range to the south and the Khangai Mountains to the north . </Li> <Li> Dzungarian Basin semi-desert, includes the desert basin lying between the Altai mountains on the north and the Tian Shan range on the south . It includes the northern portion of China's Xinjiang province and extends into the southeastern corner of Mongolia . The Alashan Plateau semi-desert lies to the east, and the Emin Valley steppe to the west, on the China - Kazakhstan border . </Li> <Li> Tian Shan range, separates the Dzungarian Basin semi-desert from the Taklamakan Desert, which is a low, sandy desert basin surrounded by the high mountain ranges of the Tibetan Plateau to the south and the Pamirs to the west . The Taklamakan Desert ecoregion includes the Desert of Lop . </Li> </Ul> <Li> Eastern Gobi desert steppe, the easternmost of the Gobi ecoregions, covering an area of 281,800 km (108,804 sq mi). It extends from the Inner Mongolian Plateau in China northward into Mongolia . It includes the Yin Mountains and many low - lying areas with salt pans and small ponds . It is bounded by the Mongolian - Manchurian grassland to the north, the Yellow River Plain to the southeast, and the Alashan Plateau semi-desert to the southeast and east . </Li>

The sahara desert covers almost one-third of what continent