Influence of Rainfall Intensity and Slope on the Slope Erosion of Longling Completely Weathered Granite  
[PERSON]  
1 Faculty of Land Resources Engineering, Kunming University of Science and Technology,  
Kumming 650093, China 12 MNR Key Laboratory of Geohazard Forecast and Geoeecological Restoration in Plateau Mountainous Area,  
Kumming 650093, China 2  
Zhigang Kong  
1 Faculty of Land Resources Engineering, Kunming University of Science and Technology,  
Kumming 650093, China 12 MNR Key Laboratory of Geohazard Forecast and Geoeecological Restoration in Plateau Mountainous Area,  
Kumming 650093, China 2  
Footnote  
seepage fields under rainfall infiltration to investigate the failure mechanism and pattern of fly ash dam slopes under rainfall influence. [PERSON] et al. [13] conducted simulated rainfall experiments under various typical underlying surface conditions to study the runoff characteristics and mechanisms under different rainfall intensities and durations. In addition, researchers have also studied thin-layer water flow on slopes [14; 15; 16]. [PERSON] et al. [17] conducted artificial rainfall simulation experiments under varying slope gradients and rainfall intensities to determine the velocity law of thin-layer water flow. Various hydraulic parameters, including Reynolds number, Froude number, Manning coefficient, and hydraulic power, have been applied to slope erosion research [18; 19]. [PERSON] et al. [20] studied the soil erosion and hydraulic characteristics of the loess slope in Beijing and found that mean flow velocity is the most closely related hydraulic parameter to sediment concentration in runoff. Slope erosion, a vital aspect of soil erosion, has garnered significant attention in China. Nevertheless, the patterns of erosion differ considerably among various soil types. Presently, research on slope erosion of diverse soil types focuses mainly on the Northwest loess region [21; 22] and southern red soil region [23; 24]. In the loess region, the loose soil texture and high porosity render it vulnerable to wind and water erosion [25; 26], leading to severe slope erosion. [PERSON] et al. [27] calculated the slope, aspect, and channel network of loess slopes in different evolution stages and analyzed the relationship between variation characteristics and erosion and evolution processes of the slopes. In the southern red soil region, the red soil in the Jiangnan hilly area and Nanjing Mountains are the primary research objects [28; 29]. Red soil is characterized by high fertility, loose structure, and sensitivity to erosion [30; 31], making it susceptible to rainfall erosion. [PERSON] et al. [32] studied the impacts of rainfall intensity, slope gradient, and surface cover on the erosion process of granite red soil slopes and concluded that the impact of slope gradient on sediment yield increases with increasing rainfall intensity. However, in granite regions, erosion characteristics and mechanisms vary due to differences in granite weathering degree, resulting in limited applicability of slope management measures [33; 34; 35]. The northeast of Longling County in Yunnan Province is a distribution area of completely weathered granite and also an operating area of oil and gas pipelines. The oil and gas pipelines pass through the distribution area of completely weathered granite. To lay the pipelines, grooves need to be dug and then the completely weathered granite excavated from the grooves is backfilled. However, the backfill soil containing completely weathered granite has high sand content, low clay content, loose structure, poor physical and mechanical parameters, and low fertility. As a result, the working slope surface is exposed, leading to poor corrosion resistance. Under heavy rainfall conditions, the working slope is prone to erosion by slope runoff, resulting in slope collapse, surface water and soil loss, and other disasters. These problems result in pipeline exposure and suspension, which substantially impact the normal functioning of pipelines.