Groundwater level fluctuations are affected by surface properties due to complex correlations of groundwater‐surface water interaction and/or other surface processes, which are usually hard to be accurately quantified. Previous studies have assessed the relationship between groundwater level fluctuations and specific controlling factors. However, few studies have been conducted to explore the impact of the combination of multiple factors on the groundwater system. Hence, this paper tries to explore the localized and scale‐specific multivariate relationships between the groundwater level and controlling factors (such as hydrologic and meteorological factors) using bivariate wavelet coherence and multiple wavelet coherence. The groundwater level fluctuations of two wells in areas covered by different plant densities (i.e., the riparian zone of the Colorado River, USA) are analyzed. Main findings include three parts. First, barometric pressure and river stage are the best factors to interpret the groundwater level fluctuations at small scales (<1 day) and large scales (>1 day) at the well of low‐density plants stand, respectively. Second, at the well of high‐density plants stand, the best predictors to control the groundwater level fluctuations include barometric pressure (<1 day), the combination of barometric pressure and temperature (1‐7 days), temperature (7‐30 days), and the combination of barometric pressure, temperature, and river stage (>30 days). The best predictor of groundwater head fluctuations depends on the variance of the vegetation coverage and hydrological processes. Third, these results provide a suite of factors to explain the groundwater level variations, which is an important topic in water‐resource prediction and management.

中文翻译：

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多重小波相干性评估地下水系统中的局部多元关系

由于地下水与地表水相互作用和/或其他地表过程之间的复杂相关性，地下水位的波动受地表特性的影响，通常难以准确量化。先前的研究已经评估了地下水位波动与特定控制因素之间的关系。但是，很少有研究探讨多种因素组合对地下水系统的影响。因此，本文试图利用双变量小波相干和多小波相干来探讨地下水位与控制因素（例如水文和气象因素）之间的局部和特定比例的多元关系。在植物密度不同的地区，两口井的地下水位波动（即，（美国科罗拉多河的河岸带）进行了分析。主要发现包括三个部分。首先，大气压力和河流水位分别是解释低密度植物站井道小规模（<1天）和大尺度（> 1天）地下水位波动的最佳因素。其次，在高密度植物的井眼中，控制地下水位波动的最佳预测因素包括大气压（<1天），大气压和温度的组合（1-7天），温度（7-30天） ），以及大气压力，温度和河流水位（> 30天）的组合。地下水水位波动的最佳预测器取决于植被覆盖率和水文过程的变化。第三，