Storage and runoff are the two fundamental surface hydrological variables of a catchment. Research studies have been focused on the storage-runoff (S-R) hysteretic relationship of a catchment and its explanation very recently, thanks to satellite gravimetry. However, a complete analysis of a hydrological process starting from recharge to runoff has not been investigated. The S-R hysteretic relationship of Yangtze River Source Region (YRSR) situated in the northeast Tibetan Plateau is also unexplored. This study aims to investigate the Recharge-Storage-Runoff relationship of this catchment using gravimetrically-derived terrestrial water storage (TWS), satellite-derived and gauged precipitation, land surface modeled and gauged evapotranspiration, and runoff data measured during 2003–2012. We found that the Pearson correlation coefficient (PCC) of S-R relationship is 0.7070, in addition to the fact that the peak of runoff every year comes earlier than that of the storage. This finding enables us to further calculate equivalent runoff based on water balance equation using the above data, while comparing to measured runoff time series. The comparison of Global Land Data Assimilation System (GLDAS)-derived (gauge-derived) equivalent runoff against measured runoff reveals a PCC of 0.8992 (0.9402), respectively, indicating both storage and runoff are largely controlled by the recharge derived from precipitation and evapotranspiration. This implies the storage is not coupled with runoff prominently due to steep topography in YRSR unable to hold the water in the form of storage. Exceptional anomalous water storage time series in 2006 has also been investigated. We speculate that the low rainfall might partly be related to an El Nino Southern Oscillation event. The low rainfall and abrupt groundwater transfer are likely to be the causes of the anomaly in 2006.

中文翻译：

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气候变化条件下长江源区补给-蓄-径过程特征

蓄水和径流是流域的两个基本地表水文变量。由于卫星重力测量，最近的研究一直集中在集水区的蓄水-径流 (SR) 滞后关系及其解释上。然而，尚未对从补给到径流的水文过程进行完整的分析。位于青藏高原东北部的长江源区 (YRSR) 的 SR 滞后关系也未得到探索。本研究旨在利用重力衍生的陆地蓄水量 (TWS)、卫星衍生和测量的降水、陆地表面模拟和测量的蒸散量以及 2003-2012 年期间测量的径流数据来研究该流域的补给-存储-径流关系。我们发现SR关系的Pearson相关系数（PCC）为0.7070，此外每年径流高峰比蓄水高峰来得更早。这一发现使我们能够使用上述数据根据水平衡方程进一步计算等效径流，同时与实测径流时间序列进行比较。全球土地数据同化系统 (GLDAS) 导出的（仪表导出的）等效径流与实测径流的比较显示 PCC 分别为 0.8992 (0.9402)，表明储存和径流在很大程度上受降水和蒸散产生的补给控制. 这意味着由于 YRSR 的陡峭地形无法以存储的形式保持水，因此存储不会与径流显着耦合。还研究了 2006 年异常异常蓄水时间序列。我们推测低降雨量可能部分与厄尔尼诺南方涛动事件有关。低降雨量和突然的地下水转移很可能是 2006 年异常的原因。