Research on the infiltration characteristics of surface water is fundamental for understanding the entire hydrological process. Therefore, studying the water infiltration process of sandstone slopes overlaid with loess and predicting soil moisture content are of great importance for investigating hydrological processes and controlling soil erosion in the hilly and gully areas of the Loess Plateau in China. This study mainly focuses on the simulation of the vertical water infiltration characteristics and water movement patterns of four kinds of sandstone (feldspathic and argillaceous sandstone) structures covered with thin layers of loess. In the one-dimensional vertical infiltration experiment and Hydrus-1D model simulation, the interlayer transition planes of loess–feldspathic and loess–feldspathic–argillaceous sandstones were found to present two conditions: fine soil covering coarse soil and coarse soil covering fine soil. Therefore, water infiltration reduced permeability. The existence of a transition layer between loess and feldspathic sandstone decreased the water infiltration rate and infiltration amount and decelerated the speed of the wetting front, thereby further affecting the ability of water infiltration. By using the Hydrus-1D model, 15 sets of soil hydraulic parameters, including θx (0.028–0.05795 cm³/cm³), θs (0.2306–0.4786 cm³/cm³), α (0.01899–0.06071 cm⁻¹), n (1.438–6.408), and Ks (1.96·10⁻⁴–0.0576 cm/s) were inverted and optimized for each 20 cm soil layer (total of 60 cm). The Van Genuchten model constructed using these parameters demonstrated high accuracy in the simulation of water content in the vertical infiltration process of sandstone covered by loess with the coefficient of determination R² > 0.849 and relative error RE < 5.311.

Land cover change influences the provision of regional ecosystem services, posing a threat to regional ecological security and sustainable development. The Kuye River Basin, a vital tributary of the Yellow River Basin, has experienced significant land cover changes due to intense human activity. Building on analysing the spatiotemporal evolution of land use cover and ecosystem service values from 1990 to 2022, this study predicted the land cover structure and ecosystem service value with two future scenarios, the NDC and the EPC, to provide insights into guiding sustainable policy interventions. We found the predominant land cover types were greensward and forest land, accounting for 67.22% of the total area. Forest land, greensward, and farmland have increased, while desert, water area, and other land types have decreased from 1990 to 2022. Forest land, greensward, farmland, and water areas are the main contributors to ecosystem service value in the Kuye River Basin. However, water area services have significantly decreased from 1990 to 2022. Under the NDC scenario, land development primarily relies on greensward and farmland, reducing forest and water areas and weakening the ecosystem’s regulatory and supporting functions. In contrast, the EPC scenario enhances ecosystem services by protecting critical ecological regions. Ecological protection measures significantly increase the ecosystem service values of the Kuye River Basin, and well-planned land use can effectively balance economic development with ecological preservation. This study provides scientific evidence to inform policies integrating ecological protection and economic growth, contributing to the sustainable development of the Kuye River Basin.

The Kuye River is the second largest tributary of the middle Yellow River. (1) Background: The Kuye River Basin, a typical erosion area of the Loess Plateau region, faces significant environmental challenges and intense human activities. Balancing environmental sustainability and economic development in this region is urgent. (2) Methods: This study analyses the phenomena, evolutionary processes, driving mechanisms, and future development trends. We assess ecological risks and drivers of land use change using data from 2000, 2005, 2010, 2015, and 2022. (3) Results: Farmland, grassland, and construction land are the main land use types, accounting for 85.63% of the total area. Construction land increased by 7.95 times over 22 years, mainly due to the conversion of woodland, grassland, and farmland. The landscape pattern increased in patches from 4713 in 2000 to 6522 in 2022. Patch density decreased from 0.0945 to 0.0771 between 2000 and 2015, then rose to 0.0788 in 2022. Post-2015, increased human intervention and urban development led to significant landscape fragmentation and higher ecological risk, expected to persist until 2030. Geographical detector analysis identified distance from roads, distance from cities, night light, and precipitation as key factors influencing landscape ecological risk. The interaction of anthropogenic disturbance with other factors showed a non-linear increase in risk, with combined factors having a greater impact than individual ones. (4) Conclusions: The Kuye River Basin’s landscape ecological risk is influenced by both natural conditions and human activities. To achieve sustainability, it is essential to protect critical areas, regulate development, and improve the adaptive management of ecological risks through innovative policies, integrated regulations, and technological solutions for ecosystem restoration. These findings provide empirical evidence to support decision-making and underscore the need for comprehensive strategies to mitigate ecological risks and promote sustainable development in the Kuye River Basin.