‘Multivariate statistical analysis of relationship between tectonic activity and drainage behavior in Qorveh-Dehgolan basin Kurdistan, Iran’

In this study, morphotectonic analysis was performed to investigate the influence of tectonic activity on drainage network in Qorve-Dehgolan basin, located in Sanandaj - Sirjan Zone (SSZ). Eight watersheds were delineated using burnt DEM and eleven morphotectonic indices including stream length gradient index (SL); drainage basin asymmetry (Af); hypsometric curve (HC); hypsometric integral (HI); roughness (R); elongation ratio (Re); mountain front sinuosity (Smf); basin shape (Bs); curvature of surface (C), basin slope (Sb) and river sinuosity index (K) were calculated. The higher altitude watersheds specifically showed various anomalies in the calculated indices. These indices when subjected to factor analysis (using Varimax rotation) resulted in extraction of “steepness factor” and “asymmetric factor” as two principal factors influencing the drainage network. The integrated analysis revealed that steepness factor, indicating ongoing tectonism, plays a significant role in the hydrology of higher altitude watersheds, whereas asymmetric factor is more dominant in lower altitude watersheds.

本研究针对位于圣安达吉-希尔詹带（Sanandaj - Sirjan Zone, SSZ）的科尔夫-德戈兰盆地（Qorve-Dehgolan basin）开展地貌构造分析，旨在探究构造活动对该盆地流域水系的影响。研究采用烧录型数字高程模型（burnt DEM）勾绘出8个独立流域，并计算得到11项地貌构造指数，具体包括：河长梯度指数（SL）、流域不对称度（Af）、高程积分曲线（HC）、高程积分值（HI）、地表粗糙度（R）、流域伸长比（Re）、山前弯曲度（Smf）、流域形状指数（Bs）、地表曲率（C）、流域坡度（Sb）及河流弯曲度指数（K）。分析结果显示，高海拔流域的各项计算指数普遍呈现异常特征。对上述指数进行因子分析（采用方差最大正交旋转）后，成功提取出影响流域水系发育的两个主因子：陡峭因子与不对称因子。综合研判表明，表征当前持续构造活动的陡峭因子对高海拔流域的水文过程具有显著调控作用，而不对称因子在低海拔流域中占据主导地位。