G219日土县段沿线由于地形等因素的显著差异形成了许多形态完整、规模宏大的泥石流堆积扇，为分析高原山区大型泥石流堆积扇对G219日土县段的影响并改善沿线泥石流灾害防治措施，通过野外调查、泥石流取样、室内分析测试及遥感解译等工作，分析了G219日土县段泥石流灾害发育特征及致灾方式，并提出了相应的防治模式。根据调查及研究结果，G219日土县段沿线泥石流堆积扇整体规模较大，超过50%泥石流堆积扇面积在1 km²以上，主沟纵坡较小，沿线泥石流性质以稀性为主；将高原公路泥石流危害形式以堆积扇角度分为淤积堵塞、堵断主河、冲刷冲蚀3类，日土段沿线泥石流主要危害形式为淤积，占总数的78%；并基于泥石流与公路通过堆积扇不同区域的扇缘、扇中、扇顶3种情形，提出具有针对性的防治模式，以改善泥石流对公路的危害状况。

Due to significant differences in terrain and other factors, numerous morphologically intact and large-scale debris flow accumulation fans have formed along the G219 highway segment in Ritu County. In order to analyze the impact of these large debris flow accumulation fans in plateau mountainous areas on the G219 Ritu County segment and improve disaster prevention measures for debris flows along the route, field investigations, debris flow sampling, indoor analytical testing, and remote sensing interpretation were conducted. Through these efforts, the developmental characteristics and disaster-inducing mechanisms of debris flows along the G219 Ritu County segment were analyzed, and corresponding prevention models were proposed. According to the survey and research results, the debris flow accumulation fans along the G219 Ritu County segment are generally large in scale, with over 50% of them covering an area of more than 1 km². The main gullies have gentle longitudinal slopes, and the debris flows prevalent along the route are predominantly dilute. From the perspective of the accumulation fans, the hazards posed by debris flows on plateau highways are classified into three types: siltation and blocking, obstruction of the main river, and scouring and erosion. The primary hazard form of debris flows along the Ritu segment is siltation, accounting for 78% of the total. Additionally, targeted control mode are proposed based on three distinct interaction zones between the highway and the debris flow accumulation fans: the fan apex, the fan middle, and the fan edge. These measures aim to improve the hazardous conditions posed by debris flows to the highway.