This paper is the result of urban geological survey engineering.

Objective Kangbao area is located northwest of Beijing, within the agro−pastoral ecotone of the Bashang Plateau in Hebei Province, adjacent to the Hunshandake Sandy Land. Land desertification is relatively prominent in this region, which to a certain extent restricts the construction and protection of the ecological barrier of the national capital. Therefore, conducting research on land desertification in this area is of great significance for safeguarding the ecological security of the national capital.

Methods This study analyzed the degree and changes of land desertification in Kangbao County through a combination of remote sensing interpretation and field surveys, and identified the main driving factors and material sources of land desertification.

Results In 2021, approximately 95% of the land area in Kangbao area experienced varying degrees of desertification, with severe and extremely severe desertification accounting for 1.34% and 6.23% respectively. These severely desertified areas are mainly distributed in the northern, eastern, and southwestern parts of Kangbao area. Compared with 2016, the overall degree of land desertification showed a mitigating trend: the area of severe desertification decreased by 326.31 km², and the area of extremely severe desertification reduced by 35.79 km². In comparison with 1984, the degree of land desertification has been significantly improved: the area of severe desertification decreased by 759.61 km², and the area of extremely severe desertification declined by 158.46 km². Land desertification in Kangbao area is jointly driven by climate, geological environment, and human activities. Human activities such as afforestation and grass planting, as well as changes in land use patterns, are the main reasons for the mitigation of land desertification in recent years. The surface sediments are mainly derived from the weathering, or water erosion and transportation, of Permian granitic intrusions.

Conclusions Land desertification is a major factor affecting the ecological security of Kangbao area. The overall trend of land desertification is continuously improving. Natural conditions provide the geological and environmental background for desertification, while human activities (such as reclamation and grazing, groundwater exploitation, afforestation and grass planting, and changes in land use types) are the main driving factors for the changes in land desertification in recent years.