Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Department of Irrigation and Drainage, College of Aburaihan, University of Tehran, Tehran, Iran.
Environ Monit Assess. 2022 Oct 24;195(1):23. doi: 10.1007/s10661-022-10644-1.
The shortage of freshwater and salinization are considered two major development problems in arid and semi-arid regions. The growth of population, development of industry and agriculture, and climate change cause over-extraction of groundwater resources; consequently, the quality and quantity of groundwater decreased, especially in the arid and semi-arid areas. The present study investigates the reasons for salinization of the Kashan aquifer. In this study, 53 observation wells located in the aquifer were examined for qualitative study. A total of 80 samples were collected from selected wells over a period of 5 years (2005-2009) and analyzed for 9 chemical parameters (electrical conductivity (EC), pH, total dissolved solids (TDS), sodium (Na), potassium (K), calcium(Ca, magnesium (Mg), chlorine (Cl), and bicarbonate (HCO)). Groundwater table study shows that the direction of groundwater flow throughout the aquifer is often from the west to the east of the aquifer, except for the northeastern part of the aquifer, where a backflow from the northeast (salt lake) into the aquifer is visible. Results of ion analysis in different areas of the aquifer indicate the occurrence of upconing phenomenon in the center and south regions and the occurrence of saline water intrusion phenomenon in northeast regions. To simulate the condition of the Kashan aquifer for the next 50 years, a model of the quantity and quality of the aquifer was developed using the SEAWAT code. According to the results, the salinization of the Kashan plain aquifer should occur due to two main reasons: irregular groundwater extraction and upconing phenomenon and the intrusion of saline water from the salt lake towards the aquifer. The Kashan aquifer salinization forecast results show that the continuation of the current pumping activities for the next 50 years should increase the numbers of wells affected by salinity. Considering the critical situation of the Kashan aquifer and the existing serious threats, serious decisions and measures for the proper management of groundwater and aquifer protection are vital.
淡水短缺和盐化被认为是干旱和半干旱地区的两大发展问题。人口增长、工农业发展和气候变化导致地下水资源过度开采；因此，地下水的质量和数量都有所下降，尤其是在干旱和半干旱地区。本研究调查了卡尚含水层盐化的原因。在本研究中，对位于含水层的 53 口观测井进行了定性研究。在 5 年（2005-2009 年）的时间内，从选定的井中采集了总共 80 个样本，并对 9 个化学参数（电导率（EC）、pH 值、总溶解固体（TDS）、钠（Na）、钾（K）、钙（Ca）、镁（Mg）、氯（Cl）和碳酸氢盐（HCO））进行了分析。地下水位研究表明，整个含水层的地下水流动方向通常是从西向东，除了含水层的东北部，那里可以看到从东北（盐湖）回流到含水层的逆流。含水层不同区域的离子分析结果表明，在中心和南部地区存在上涌现象，在东北部地区存在咸水入侵现象。为了模拟卡尚含水层未来 50 年的情况，使用 SEAWAT 代码开发了一个含水层数量和质量模型。根据结果，卡尚平原含水层的盐化应归因于两个主要原因：地下水开采不规则和上涌现象以及盐湖的咸水向含水层的入侵。卡尚含水层盐化预测结果表明，在未来 50 年内继续进行当前的抽水活动，将会增加受盐度影响的井的数量。考虑到卡尚含水层的危急情况和现有的严重威胁，对于地下水的合理管理和含水层保护，必须做出严肃的决策并采取措施。
