State Key Laboratory of Geodesy and Earth's Dynamics, Innovation Academy of Precision Measurement of Science and Technology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China.
State Key Laboratory of Geodesy and Earth's Dynamics, Innovation Academy of Precision Measurement of Science and Technology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China; Hubei Luojia Laboratory, Wuhan, China.
Sci Total Environ. 2023 Apr 10;868:161755. doi: 10.1016/j.scitotenv.2023.161755. Epub 2023 Jan 21.
The extreme change of water storage in the Yangtze River Basin (YRB) have a significant impact on identifying the characteristics of drought events in the basin. To quantify the historical hydrological drought characteristics, we put forward new framework to reconstruct the pre-2003 total water storage anomaly (TWSA) through the nonlinear autoregressive with exogenous input (NARX) model. The NARX model is developed by the Gravity Recovery and Climate Experiment (GRACE) based TWSA and the hydrometeorological data after removing the trend and seasonal signals from 2003 to 2017, then the full pre-2003 reconstructed TWSA signals were obtained by synthesizing hydrometeorological data driven NARX model results from 1979 to 2002 and GRACE-estimated seasonal cycle. We combined the reconstructed TWSA with GRACE observed TWSA to characterize the historical hydrological drought events (onset, end, duration, magnitude, intensity, and recovery) in the YRB. The results show that the drought-related extreme anomalies in total water storage can be captured successfully. From 1979 to 2017, 23 hydrological drought events were identified in the YRB with an average recovery time of 4.7 months. The longest drought lasted 28 months spanning from July 2006 to October 2008. The exceptional drought occurred in September 2011 reached to the largest deficit with a magnitude of -48.5 mm and minimum drought severity index (DSI) of -2.3. Comparing to the period of 1979-1999, the frequency, duration, and average recovery time of drought events increased significantly since 2000 in the YRB. Furthermore, we found that the duration and average recovery time of the drought events have an exponential relationship with the severity, which could help us to estimate the potential recovery time when drought events occur and predict water resources dynamic in the future.
长江流域（YRB）极端的储水变化对识别流域内干旱事件的特征有重大影响。为了量化历史水文干旱特征，我们提出了一种新的框架，通过非线性自回归外生输入（NARX）模型重建 2003 年前的总储水异常（TWSA）。该 NARX 模型是由重力恢复与气候实验（GRACE）基于 TWSA 和从 2003 年到 2017 年去除趋势和季节性信号的水文气象数据开发的，然后通过综合 1979 年到 2002 年和 GRACE 估计的季节性周期驱动的 NARX 模型结果和水文气象数据，获得了完整的 2003 年前重建的 TWSA 信号。我们将重建的 TWSA 与 GRACE 观测到的 TWSA 结合起来，描述了 YRB 历史水文干旱事件（开始、结束、持续时间、规模、强度和恢复）的特征。结果表明，总储水与干旱相关的极端异常可以成功捕捉。从 1979 年到 2017 年，YRB 共识别出 23 次水文干旱事件，平均恢复时间为 4.7 个月。持续时间最长的干旱持续了 28 个月，从 2006 年 7 月到 2008 年 10 月。2011 年 9 月发生的异常干旱达到最大亏缺，规模为-48.5mm，最小干旱严重指数（DSI）为-2.3。与 1979-1999 年相比，自 2000 年以来，YRB 干旱事件的频率、持续时间和平均恢复时间显著增加。此外，我们发现干旱事件的持续时间和平均恢复时间与严重程度呈指数关系，这有助于我们估计干旱事件发生时的潜在恢复时间，并预测未来的水资源动态。
