Abstract: According to the related planning, CLUE-S model was applied to simulate and analyze the future characters of land use changes under three future scenarios (i.e., trend scenario, economic development scenario, and ecological protection scenario) in the Luanhe River Basin. Accordingly, hydrological processes, such as surface runoff, groundwater flow, and sediment yield under the three scenarios, were explored by the SWAT model. At the same time, we revealed the differences of hydrological characters and identified the critical areas of sediment yield under the three scenarios in the Luanhe River Basin. The results showed that the hotspots of construction land expansion could be located in the vicinity of Chengde City in the midstream of the Luanhe River Basin under the three scenarios in 2030. Different characters of hydrological processes in the different scenarios were observed. The annual average surface runoff (11.34 mm·a^-1) was the smallest under the ecological protection scenario, equaling to 47.51% and 46.02% of that under the trend scenario and ecological protection scenario, respectively. The annual average groundwater flow (7.94 mm·a^-1) was the smallest under the economic development scenario, equaling to 51.90% and 23.26% of that under the trend scenario and ecological protection scenario, respectively. The annual average sediment yield was the smallest under ecological protection scenario, being 0.35×10⁵ kg·km^-2·a^-1. Compared with the trend scenario and economic development scenario, annual average sediment yield was obviously reduced by 60% under the ecological protection scenario. The ecological protection scenario was most suitable for soil and water conservation. Under the trend scenario, soil erosion was the strongest, while the economic development scenario had the worst water conservation. Therefore, the current land use planning can be implemented in the Luanhe River Basin, but the partitioning management should be implemented based on spatial distribution of soil erosion. Additionally, critical source areas of sediment yield should be carefully monitored and managed.

Key words: cold-waterlogged paddy field, soil property, soil quality assessment, assessment factor, minimum data set, multivarate statistics.