Toumi Naji, Hussein Belal H M, Rafrafi Sarra, El Kassas Neama
Biology Department, Faculty of Science and Arts Al Ula, Taibah University, Al Madinah Al Munawarh, Kingdom of Saudi Arabia.
Environ Monit Assess. 2015 Mar;187(3):84. doi: 10.1007/s10661-014-4241-4. Epub 2015 Feb 6.
Groundwater quality monitoring is one of the most important aspects in groundwater studies in arid environments particularly in developing countries, like Saudi Arabia, due to the fast population growth and the expansion of irrigated agriculture and industrial uses. Groundwater samples have been collected from eight locations in Al-Ula in Saudi Arabia during June 2012 and January 2013 in order to investigate the hydrochemical characteristics and the groundwater quality and to understand the sources of dissolved ions. Physicochemical parameters of groundwater such as electrical conductivity, pH, total dissolved solid, and major cations and anions were determined. Chloride was found to be the dominant anion followed by HCO(-) 3 and SO4 (2-). Groundwater of the study area is characterized by the dominance of alkaline earths (Ca(2+) + Mg(2+)) over alkali metals (Na(+) + K(+)). The analytical results show that the groundwater is generally moderately hard and slightly alkaline in nature. The binary relationships of the major ions reveal that water quality of the Al-Ula region is mainly controlled by rock weathering, evaporation, and ion exchange reactions. Piper diagram was constructed to identify hydrochemical facies, and it was found that majority of the samples belong to Ca-Cl and mixed Ca-Mg-Cl facies. Chemical indices like chloro-alkali indices, sodium adsorption ratio, percentage of sodium, residual sodium carbonate, and permeability index were calculated. Also, the results show that the chemical composition of groundwater sources of Al-Ula is strongly influenced by lithology of country rocks rather than anthropogenic activities.
在干旱环境中的地下水研究里，尤其是在像沙特阿拉伯这样的发展中国家，由于人口快速增长以及灌溉农业和工业用途的扩张，地下水水质监测是最重要的方面之一。2012年6月至2013年1月期间，从沙特阿拉伯乌拉的八个地点采集了地下水样本，以调查其水化学特征和地下水质量，并了解溶解离子的来源。测定了地下水的物理化学参数，如电导率、pH值、总溶解固体以及主要阳离子和阴离子。发现氯离子是主要阴离子，其次是HCO₃⁻和SO₄²⁻。研究区域的地下水以碱土（Ca²⁺ + Mg²⁺）比碱金属（Na⁺ + K⁺）占主导为特征。分析结果表明，地下水总体上性质为中等硬度且略呈碱性。主要离子的二元关系表明，乌拉地区的水质主要受岩石风化、蒸发和离子交换反应控制。绘制了派珀图以识别水化学相，发现大多数样本属于Ca-Cl和混合Ca-Mg-Cl相。计算了氯碱指数、钠吸附比、钠百分比、残余碳酸钠和渗透指数等化学指标。此外，结果表明，乌拉地下水源的化学成分受围岩岩性的强烈影响，而非人为活动。
