State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, Chengdu 610065, China.
Sci Total Environ. 2020 Apr 15;713:136274. doi: 10.1016/j.scitotenv.2019.136274. Epub 2019 Dec 26.
The Yarlung Zangbo River Basin is a regulator of water vapor changes in China and even Asia. To avoid the shortcomings of traditional water resource monitoring methods, this study used Gravity Recovery and Climate Experiment (GRACE) data to monitor the terrestrial water storage anomaly (TWSA) in this river from 2002 to 2015 with the help of the polynomial-least squares approach (P-LSA) and the empirical orthogonal function (EOF). The obtained TWSA was compared with hydrometeorological data from several sources to discuss the applicability, uniqueness and response relationship. The results showed that (1) the combination of P-LSA and EOF had strong applicability to explore the TWSA in the study area, with R = 0.75 and 0.80, respectively, and could indirectly reflect dry and wet conditions in southwestern China. (2) The TWSA revealed significant cyclical and seasonal fluctuations of approximately 12 months and increased from upstream to downstream and from north to south, which was discussed for the first time in the research area. (3) The EOF method can effectively identify the TWSA principal component and structure (EOF1 contribution = 91.08%) by removing noise and redundancy, which is beneficial for revealing the laws essential for TWSA changes. (4) The TWSA in the studied watershed was unique (i.e., the clearest periodic changes with the best fitting effect (R = 0.90); peak, low and peak-low difference values that were 1.82, 1.19 and 1.52 times larger than those of the 8 other rivers; and the largest downward trend of 4.13 mm·a). (5) Rainfall was the decisive factor influencing the TWSA, with correlation coefficients (R) >0.60. This study enhances our overall understanding of the TWSA in this plateau watershed and provides a scientific basis for optimal water resource management.
雅鲁藏布江流域是中国乃至亚洲水汽变化的调节器。为避免传统水资源监测方法的局限性，本研究采用重力恢复与气候实验（GRACE）数据，借助多项式最小二乘法（P-LSA）和经验正交函数（EOF），从 2002 年至 2015 年对该流域的陆地水储量异常（TWSA）进行监测。所得 TWSA 与来自多个来源的水文气象数据进行了比较，以探讨其适用性、独特性和响应关系。结果表明：（1）P-LSA 和 EOF 的组合对探索研究区 TWSA 具有较强的适用性，相关系数分别为 0.75 和 0.80，且可间接反映中国西南地区的干湿状况；（2）TWSA 存在约 12 个月的显著周期性和季节性波动，且从上游到下游、从北到南逐渐增加，这在研究区域内尚属首次发现；（3）EOF 方法可有效识别 TWSA 主分量和结构（EOF1 贡献度为 91.08%），从而去除噪声和冗余，有利于揭示 TWSA 变化的基本规律；（4）研究流域内的 TWSA 具有独特性（即周期变化最明显、拟合效果最佳（R=0.90）；峰值、低值和峰低值分别是其他 8 条河流的 1.82、1.19 和 1.52 倍；且呈 4.13mm·a 的最大下降趋势）；（5）降雨是影响 TWSA 的决定性因素，相关系数（R）>0.60。本研究增强了我们对高原流域 TWSA 的整体认识，为优化水资源管理提供了科学依据。
