Department of Geomatics, National Cheng Kung University, No. 1, University Road, Tainan City 701, Taiwan.
Environ Monit Assess. 2012 Oct;184(10):5971-82. doi: 10.1007/s10661-011-2394-y. Epub 2011 Oct 21.
This study applied a method of the rotated empirical orthogonal functions to directly decompose the space-time groundwater level variations and determine the potential recharge zones by investigating the correlation between the identified groundwater signals and the observed local rainfall records. The approach is used to analyze the spatiotemporal process of piezometric heads estimated by Bayesian maximum entropy method from monthly observations of 45 wells in 1999-2007 located in the Pingtung Plain of Taiwan. From the results, the primary potential recharge area is located at the proximal fan areas where the recharge process accounts for 88% of the spatiotemporal variations of piezometric heads in the study area. The decomposition of groundwater levels associated with rainfall can provide information on the recharge process since rainfall is an important contributor to groundwater recharge in semi-arid regions. Correlation analysis shows that the identified recharge closely associates with the temporal variation of the local precipitation with a delay of 1-2 months in the study area.
本研究应用旋转经验正交函数方法，通过研究识别的地下水信号与观测到的当地降雨量记录之间的相关性，直接分解时空地下水位变化，并确定潜在的补给区。该方法用于分析台湾屏东平原 1999-2007 年期间每月观测的 45 口井的贝叶斯最大熵法估计的测压头的时空过程。结果表明，主要的潜在补给区位于近扇区，补给过程占研究区测压头时空变化的 88%。与降雨相关的地下水位分解可以提供补给过程的信息，因为降雨是半干旱地区地下水补给的重要因素。相关分析表明，识别的补给与当地降水的时间变化密切相关，在研究区域中存在 1-2 个月的延迟。
