工程地质学报2026，Vol.34Issue(3)：988-996,9.DOI:10.13544/j.cnki.jeg.2023-0477
川西南不同岩性区火烧迹地灰烬泥沙层分布规律
DISTRIBUTION CHARACTERISTICS OF ASH-SEDIMENT IN BURNED AR-EAS WITH DIFFERENT LITHOLOGY IN SOUTHWESTERN SICHUAN,CHINA
摘要
Abstract
Ash-sediment—a complex mixture of wildfire ash and surface mineral soil that has lost its structure due to high-temperature combustion—is highly susceptible to erosion by runoff.Its abundance strongly influences hillslope erosion processes and the sediment supply for post-fire debris flows.This study examined burned areas with different lithologies in southwestern Sichuan,including sedimentary rocks(Xichang wildfire of March 30,2020),igneous rocks(Mianning wildfire of April 20,2020),and metamorphic rocks(Jiulong wildfire of February 16,2022).The spatial distribution of ash-sediment in each burned area was investigated,and the relationships among ash-sediment,litter,and soil erodibility were analyzed.The results indicate that ash-sediment thickness and mass load are positively correlated with fire severity.Bulk density of ash-sediment showed no significant difference between low-and moderate-severity areas but increased significantly in high-severity zones.Furthermore,due to differences in litter and soil properties,ash-sediment thickness,bulk density,and load varied notably among the burned areas,with the highest values in the Jiulong area,followed by Mianning and Xichang.Ash-sediment thickness and load were significantly positively correlated with litter thickness and soil erodibility factors.Higher soil erodibility factors corresponded to soils more prone to structural loss and loosening under high temperatures.These findings provide a scientific basis for understanding variations in sediment supply for post-fire debris flows across different lithological settings and support disaster prevention and mitigation efforts in burned areas.关键词
火后泥石流/火烧迹地/地层岩性/灰烬泥沙层Key words
Post-fire debris flow/Burned area/Lithology/Ash-sediment分类
天文与地球科学引用本文复制引用
曹希超,胡卸文,杨瀛,周永豪,何坤,周瑞宸,金涛,胡亚运..川西南不同岩性区火烧迹地灰烬泥沙层分布规律[J].工程地质学报,2026,34(3):988-996,9.基金项目
国家自然科学基金项目(资助号:42377170).This research is supported by the National Natural Science Foundation of China(Grant No.42377170). （资助号:42377170）
