Abstract:

The Yellow River catchment is high in the west and low in the east， spanning four geomorphic units， namely Tibetan Plateau， Inner Mongolia Plateau， Loess Plateau and Huang-Huai-Hai Plain from west to east， with a total area of 79.6×10⁴ km². The Yellow River catchment is an important ecological barrier and economic belt in China. Today， ecological protection and high-quality development in the Yellow River catchment has become a national strategy of China. Aeolian desertification is the main form of land degradation in arid， semi-arid and partly humid areas of northern China， and it has a great impact on the Yellow River catchment， especially in the middle and upper reaches of the catchment. To obtain the spatial distribution characteristics of aeolian desertified land in the Yellow River catchment， the Landsat remote sensing image was taken as the data source to monitor the aeolian desertified land distribution in the Yellow River catchment in 2010 based on geographic information system （GIS） technology. The monitoring result shows that the area of aeolian desertification land in the Yellow River catchment is 128 667 km²， accounting for 16.2% of the total area. The area of aeolian desertification land in the upper reaches of the Yellow River was the largest， followed by the middle reaches of the Yellow River， the source region of the Yellow River， and the lower reaches of the Yellow River， and the area is 89 341 km²， 21 426 km²， 17 894 km²， and 7 km²， respectively， accounting for 69.4%， 16.7%， 13.9%， and 0.01% of the total area of aeolian desertification land in the whole catchment. The result also shows that most of the aeolian desertification land in the Yellow River catchment is distributed in Inner Mongolia， with an area of 91 398 km²， accounting for 71.0% of the total area of aeolian desertification land in the catchment， and it was followed by Qinghai， Shaanxi and Ningxia， accounting for 13.5%， 8.3% and 6.5%， respectively. It is concluded that the spatial pattern of aeolian desertification land in the Yellow River catchment is mainly controlled by precipitation， because 92.6% （119 114 km²） of desertification land in the region is distributed in arid and semi-arid regions. Since the 1970s， the aeolian desertification in the Yellow River catchment has experienced a process of rapid development-slow development-obvious reversal， and the significant change trend of aeolian desertification is mainly caused by human activities. Nevertheless， the positive effect of the continuous decline in wind speed over the past few decades on aeolian desertification reversal should be emphasized.

Key words: aeolian desertification, distribution pattern, Yellow River, Yellow River catchment