| چکیده انگلیسی مقاله |
More frequent extreme rainfall events associated with global climate change causes greater challenges for soil conservation. Severe erosion occurs on unpaved roads since these structures create important water flow paths during heavy storms. However, research on this topic is still lacking and erosion severity associated with unpaved roads is overlooked. This research aimed to investigate the intensity and influencing factors of unpaved road erosion under varied land use and management conditions (sloping agriculture, terrace, forest & grass) in the watersheds contributing water to the roads after the greatest rainfall event ever recorded in the mountain area of northern China caused by Typhon Lekima. The research was conducted in an agricultural-forest-dominated watershed based on field investigation and UAV-based image analysis. A road erosion level classification standard was given according to the occurrence of rills, ephemeral gullies, and gullies. Significant erosion happens on 67.5% of the unpaved roads; 42.8% of them suffered moderate to severe erosion which had ephemeral gullies or gullies developed. The average erosion amount from these roads was 2283.83 ton.ha-1 and was significantly influenced by the watershed land use type and management. The dominant factor of unpaved road erosion in terraced areas was vegetation coverage on roads, and in sloping agriculture areas was slope gradient. Slope gradient and drainage area were both critical factors in forest & grass dominated areas. Terraces, forest & grass in drainage areas significantly reduced unpaved road erosion by 84.75%, 45.97%, respectively, compared to sloping agriculture. More integrated measures should be used to prevent unpaved road erosion. The results of this research could be applied to road protection against erosion in heavy storms. |
