霍山山前断裂带冲沟纵剖面数学拟合函数的构造响应特征

Mathematical Functions Fitting to the Longitudinal Profiles of the Gullies across the Huoshan Piedmont Fault and Their Response to the Tectonic Movement

处于不同构造环境以及不同发育阶段的冲沟会呈现出不同的数学函数形态特征,常见的有线性函数、指数函数、对数函数以及乘幂函数等。它们反映了冲沟演化对发育时间、区域气候特征、河床基岩性质和构造运动等因素的响应。基于DEM数据提取了横跨霍山山前断裂带的64条冲沟,分析了冲沟纵剖面的拟合函数及其所反映的冲沟对断裂活动的响应特征。结果显示,横跨霍山山前断裂带的冲沟均表现为幼年期的线性函数形态或轻微下凹的指数函数形态,这反映了上新世以来霍山山前断裂带持续而强烈的正断层作用,尤其是全新世以来时间间隔较短的多次强烈活动。

Longitudinal profiles of the gullies in different tectonic settings and different evolutionary sta-ges show different morphological forms which can be fitted ordinarily by such mathematical functions as linear function,exponential function,logarithmic function and power function.These forms reflect the re-sponse of the gullies to the factors such as the time,the climate,the bedrock of the riverbed and the tec-tonic movement.Based on DEM data,64 gullies across the Huoshan piedmont fault are extracted and their profiles are fitted by four types of mathematical functions above.The best-fitting mathematical func-tion for each gully is selected and the responding characteristics of the gullies to the tectonic movement of the fault are analyzed.The result shows that the gullies are in their infancy which is exhibited by their linear forms or the exponential forms with very small concavity.This is due to the response of the gullies to the constant normal-fault movement of the Huoshan piedmont fault since Pliocene, especially the strong activities with short interval in Holocene.