The Roles of Climate Forcing and Its Variability on Streamflow at Daily, Monthly, Annual, and Long‐Term Scales
The Roles of Climate Forcing and Its Variability on Streamflow at Daily, Monthly, Annual, and Long‐Term Scales
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DOI：
10.1029/2020wr027111
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发表时间：
2020-07
影响因子：
5.4
通讯作者：
Lili Yao;Dominic A. Libera;M. Kheimi;A. Sankarasubramanian;Dingbao Wang
中科院分区：
文献类型：
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作者：
Lili Yao;Dominic A. Libera;M. Kheimi;A. Sankarasubramanian;Dingbao Wang
降水和潜在蒸散的时间变化影响径流从日到长期尺度，但不同的气候变化对径流的日，月，年和平均年尺度的相对作用还没有系统地研究在文献中。本文提出了一个新的日水量平衡模型，为跨时间尺度的水量平衡提供了一个统一的框架。每日水平衡模型由四种气候强迫情景驱动（观测到的每日气候和观测到的每日气候，其月内，年内和年际变化被删除），并应用于78个集水区。每日径流量从水平衡模型汇总到较粗的时间尺度。通过比较模拟的径流强迫与两个连续时间尺度的气候强迫，评估了月内、年内和年际气候变率的相对作用。结果表明，在同一时间尺度上，日、月、年径流量主要受气候变率的控制。月内气候变率在月和年径流变率中的作用很小。年内气候变率在所有时间尺度上对径流量都有显著影响，而年际气候变率的相对作用对月径流量和年平均径流量也有显著影响，这一点往往被忽视。对气候变率作用的定量评估揭示了气候如何控制跨时间尺度的径流。
The temporal variability of precipitation and potential evapotranspiration affects streamflow from daily to long‐term scales, but the relative roles of different climate variabilities on streamflow at daily, monthly, annual, and mean annual scales have not been systematically investigated in the literature. This paper developed a new daily water balance model, which provides a unified framework for water balance across timescales. The daily water balance model is driven by four climate forcing scenarios (observed daily climate and observed daily climate with its intra‐monthly, intra‐annual, and inter‐annual variability removed) and applied to 78 catchments. Daily streamflow from the water balance model is aggregated to coarser timescales. The relative roles of intra‐monthly, intra‐annual, and inter‐annual climate variability are evaluated by comparing the modeled streamflow forced with the climate forcings at two consecutive timescales. It is found that daily, monthly, and annual streamflow is primarily controlled by the climate variability at the same timescale. Intra‐monthly climate variability plays a small role in monthly and annual streamflow variability. Intra‐annual climate variability has significant effects on streamflow at all the timescales, and the relative roles of inter‐annual climate variability are also significant to the monthly and mean annual streamflow, which is often disregarded. The quantitative evaluation of the roles of climate variability reveals how climate controls streamflow across timescales.