中巴公路(国内段)泥石流演化的非线性特征与灾害放大效应  

Nonlinear characteristics and disaster aggravation effects of debris flow evolution along the Chinese section of the China-Pakistan Highway

作　　者：刘兴荣[1] 张满银[1] 周自强[1] 宿星[1] 叶伟林[1] 文桃 张国信[1] 刘迪[1] LIU Xing-rong;ZHANG Man-yin;ZHOU Zi-qiang;SU Xing;YE Wei-lin;WEN Tao;ZHANG Guo-xin;LIU Di(Geological Hazards Prevention Institute,Gansu Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]甘肃省科学院地质自然灾害防治研究所,兰州730000

出　　处：《兰州大学学报（自然科学版）》2022年第3期364-371,共8页Journal of Lanzhou University(Natural Sciences)

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0902);甘肃省2021年度重点人才项目(2021RCXM066);甘肃省科学院科技产业化项目(CY08);甘肃省科学院应用研究与开发项目(2018JK-14)。

摘　　要：通过遥感解译和现场调查结合的手段,按照计算的沟壑密度统计,分析中巴公路沿线泥石流沟蚀作用的强度和特点,采用分形理论法分析泥石流流域形态演化的非线性特征.结果表明,中巴公路沿线52.4%的泥石流沟道发生沟蚀作用的能力较强,固体物源主要受控于沟道滑塌体和冲积扇堆积物;按照分形理论结果,研究区泥石流沟道数分别与流域面积、主沟道长度、主沟道比降、流域高差及岸坡平均坡度间的分形维数值依次为0.432、0.794、0.813、0.667和0.697,对泥石流的启动、演变或控制所起的作用由大到小依次为流域面积、流域高差、岸坡平均坡度、主沟道长度和主沟道比降;一旦流域水流较大,会促发相邻的冲积扇同时启动,泥石流能量和淹没范围会快速剧增,放大其破坏效应,即小流域、小规模泥石流也可能存在大隐患.This paper analyzed the intensity and characteristics of soil erosion in debris flow gullies along the China-Pakistan Highway by means of remote sensing interpretation and field investigation,and analyzed the nonlinear characteristics of watershed morphological evolution of debris flow gullies via the fractal theory.The results showed that more than 52.4%of the gullies along the China-Pakistan Highway belonged to the gully erosion intensity below the medium level,and the slope erosion was not strong.The solid source of the debris flow was mainly controlled by landslides and accumulation of the alluvial fan.According to the results of the fractal theory,the fractal dimension values between the number of debris flow gullies and the watershed area,main gully length,main gully gradient,watershed height difference and the average bank slope were 0.432,0.794,0.813,0.667 and 0.697 respectively.The effect on the start,evolution or control of the debris flow was as follows:watershed area,watershed height difference,average bank slope,main gully length and main gully gradient drop in a large-to-small order.Once the water flow in the watershed was large,the adjacent alluvial fan would be triggered at the same time,and the energy and submerged area of the debris flow would increase rapidly,amplifying its destructive effect.In other words,small watershed and small-scale debris flows might also pose big hidden dangers.

关 键 词：泥石流 流域形态 非线性特征 破坏效应 中巴公路 

分 类 号：X43[环境科学与工程—灾害防治]