Liu Xintong, Zhao Hongrui
Institute of Transportation Engineering and Geomatics, Department of Civil Engineering, Tsinghua University, Beijing 100084, China.
3S Center, Tsinghua University, Beijing 100084, China.
Entropy (Basel). 2022 Aug 7;24(8):1088. doi: 10.3390/e24081088.
Runoff complexity is an important indicator reflecting the sustainability of a watershed ecosystem. In order to explore the multiscale characteristics of runoff complexity and analyze its variation and influencing factors in the Yanhe watershed in China during the period 1991-2020, we established a new analysis method for watershed runoff complexity based on the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) method for the decomposition of multiscale characteristics and the refined composite multiscale entropy () method for the quantification of the system complexity. The results show that runoff and its components all present multiscale complexity characteristics that are different from random signals, and the intermediate frequency modes contribute the most to runoff complexity. The runoff complexity of the Yanhe watershed has decreased gradually since 1991, and 2010 was a turning point of runoff complexity, when it changed from a decline to an increase, indicating that the ecological sustainability of this basin has improved since 2010, which was mainly related to the ecological restoration measures of the Grain for Green Project. This study expands the research perspective for analyzing the variation characteristics of runoff at the multiscale, and provides a reference for the study of watershed ecological sustainability and ecological management.
径流复杂性是反映流域生态系统可持续性的重要指标。为了探究径流复杂性的多尺度特征，并分析1991—2020年中国延河流域径流复杂性的变化及其影响因素，我们基于具有自适应噪声的完备总体经验模态分解（CEEMDAN）方法分解多尺度特征、改进的复合多尺度熵（ ）方法量化系统复杂性，建立了一种新的流域径流复杂性分析方法。结果表明，径流及其各分量均呈现出不同于随机信号的多尺度复杂特征，且中频模态对径流复杂性的贡献最大。延河流域的径流复杂性自1991年以来逐渐降低，2010年是径流复杂性的转折点，由下降转为上升，表明该流域的生态可持续性自2010年以来有所改善，这主要与退耕还林工程的生态恢复措施有关。本研究拓展了多尺度分析径流变化特征的研究视角，为流域生态可持续性及生态管理研究提供了参考。
