A New Framework for Exploring Process Controls of Flow Duration Curves
A New Framework for Exploring Process Controls of Flow Duration Curves
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DOI：
10.1029/2019wr026083
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发表时间：
2020-01
影响因子：
5.4
通讯作者：
S. Ghotbi;Dingbao Wang;Ashutosh Kumar Singh;G. Blöschl;M. Sivapalan
中科院分区：
文献类型：
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作者：
S. Ghotbi;Dingbao Wang;Ashutosh Kumar Singh;G. Blöschl;M. Sivapalan
流量持续时间曲线（FDC）实际上是水流的累积分布函数。长期以来，水文学家一直在寻求对 FDC 形状的过程控制进行更深入的了解，由于控制水流的快流和慢流成分及其相互作用的过程不同，这一直是一个挑战。在本文中，我们概述了一个探索 FDC 过程控制的新框架，其中涉及分别研究 FDC 的快流和慢流组件，并将它们统计地组合起来，明确地解释它们的依赖性。我们通过从传统基流分离获得的流动分量构建经验快流持续时间（FFDC）和慢流持续时间（SFDC）曲线来说明该框架的潜力。使用来自美国大陆 245 个 MOPEX 流域的水流时间序列数据。 FFDC 和 SFDC 组成部分的依赖性由 Gumbel copula 捕获，其强度因地区而异。在 FFDC 和 SFDC 独立的流域中，FDC 可以通过 FFDC 和 SFDC 的简单卷积来近似。所提出的概念框架为未来的建模研究开辟了道路，以分别探索水流快速和慢速成分的过程控制、它们的依赖性以及它们对 FDC 形状的相对贡献。
The flow duration curve (FDC) is effectively the cumulative distribution function of streamflow. For a long time, hydrologists have sought deeper understanding of the process controls on the shape of FDC, which has been a challenge due to contrasting processes controlling the fast flow and slow flow components of streamflow and their interactions. In this paper, we outline a new framework for exploring the process controls of the FDC, which involves studying fast and slow flow components of FDC separately and combining them statistically, explicitly accounting for their dependence. We illustrate the potential of the framework by constructing empirical fast flow duration (FFDC) and slow flow duration (SFDC) curves from the flow components obtained by traditional baseflow separation. Streamflow time series data from 245 MOPEX catchments across the continental United States are used. The dependence of FFDC and SFDC components is captured by the Gumbel copula, the strength of which varies regionally. In catchments where FFDC and SFDC are independent, FDC can be approximated by a simple convolution of FFDC and SFDC. The proposed conceptual framework opens the way for future modeling studies to explore process controls of fast and slow components of streamflow separately, their dependence, and their relative contributions to the shape of the FDC.