In recent years, groundwater level in Arak plain aquifer, Iran, declines due to overabstraction and sustainable management of the aquifer is changed to a vital issue. Spatiotemporal variation groundwater quality associated with identifying hydrogeochemical characteristics is the goal of this research. In the current study, graphical methods results are compared to two distinct clustering methods, hierarchical cluster analysis (HCA), and fuzzy C-mean (FCM) to analyze the hydrogeochemical dataset. Groundwater quality of Arak aquifer is monitored over an 11-year period in two-year intervals ranging from 2004 to 2014 (i.e., 2004, 2006, 2008, 2010, 2012, and 2014) by sampling from 52 abstraction wells for each year. Graphical methods identified dominant hydrogeochemical processes in the study area. The resulting clusters were categorized into freshwater (HC1, FC1), brackish-saline water (HC2, FC2), and saline water (HC3, FC3). The analysis resulted in three clusters including recharge, transition or mixing, and discharge zones, designated as FC1 and HC1, FC2 and HC2, and FC3 and HC3; respectively. The comparison of groundwater facies in 2004 and 2014 showed that the mixing zone (classes FC2 and FC3 and classes HC2 and HC3) has expanded with time. Observation well monitoring in the area showed that groundwater quality decrease due to groundwater level declines, especially in the residential zone. In addition, the role of geological formations in groundwater quality was evident in the distribution of clusters. Comprehensive regulation and integrated groundwater management is essential to prevent further degradation of groundwater quality in the region.

中文翻译：

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基于层次聚类分析和模糊C均值方法的伊朗阿拉克平原地下水水文地球化学分析

近年来，由于过度开采，伊朗阿拉克平原含水层的地下水位下降，含水层的可持续管理已成为一个至关重要的问题。与确定水文地球化学特征相关的地下水时空变化是本研究的目标。在当前的研究中，将图形方法的结果与两种不同的聚类方法（层次聚类分析（HCA）和模糊C）进行了比较-均值（FCM）分析水文地球化学数据集。通过从每年的52口抽水井中取样，对Arak含水层的地下水质量在11年期间内（从2004年至2014年，即2004年，2006年，2008年，2010年，2012年和2014年），每两年进行一次监测。图形方法确定了研究区域的主要水文地球化学过程。将所得的簇分类为淡水（HC1，FC1），咸淡盐水（HC2，FC2）和盐水（HC3，FC3）。分析得出三个集群，包括补给区，过渡区或混合区和放电区，分别称为FC1和HC1，FC2和HC2以及FC3和HC3。分别。2004年和2014年的地下水相比较表明，混合带（FC2和FC3类以及HC2和HC3类）随时间而扩大。该地区的观察井监测表明，由于地下水位下降，地下水质量下降，特别是在居民区。此外，在团簇的分布中，地质构造对地下水质量的作用也很明显。全面监管和地下水综合管理对于防止该地区地下水质量进一步恶化至关重要。