Abstract

A comprehensive integrated framework was designed to categorize individual streams and watersheds based on their temporal variation, and to determine the key drivers controlling watershed hydrology in the Qorveh-Dehgolan Basin. Four stream networks were extracted from multi-temporal Pan-Sharpened Landsat 7 and Landsat 8 imageries. Nineteen geomorphometric indices are measured and classified into the linear aspect, aerial aspect, and relief aspect. The results revealed a significant decline in stream networks from 2000 to 2017, reducing basin order. The factor analysis identified three principal factors including ‘factor of basin magnitude’ (affecting low-altitude watersheds), ‘factor of steepness’ (influencing high-altitude watersheds), and ‘factor of texture’. The focal mechanism highlighted the complex fault mechanisms in the study area. Finally, RadViz clustering showed that for the lower order streams in the high-altitudes watersheds, stream width showed higher temporal variability in comparison to other parameters. In contrast, flow accumulation showed high variance in higher-order streams.

摘要

设计了一个综合的综合框架，根据河流和流域的时间变化对其进行分类，并确定控制Qorveh-Dehgolan流域水域水文学的关键驱动因素。从多时间Pan-Sharpened Landsat 7和Landsat 8影像中提取了四个河流网络。测量了19个地貌指标并将其分类为线性方面，空中方面和起伏方面。结果显示，从2000年到2017年，河流网络显着减少，减少了流域秩序。因子分析确定了三个主要因子，包括“流域规模因子”（影响低海拔流域），“陡度因子”（影响高海拔流域）和“质地因子”。震源机制突出了研究区复杂的断层机制。最后，RadViz聚类表明，对于高海拔流域的低阶流，与其他参数相比，流宽显示出较高的时间变化性。相反，流量累积在高阶流中显示出高的方差。