Physico-chemical status of groundwater near Varuna river in Varanasi city, India
Physico-chemical status of groundwater near Varuna river in Varanasi city, India
复制标题
印度瓦拉纳西市瓦鲁纳河附近地下水理化状况
DOI：
--
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Achal Singh
中科院分区：
文献类型：
--
作者：
J. Chaurasia;P. Rai;Achal Singh
瓦鲁纳河是恒河的一条小支流，在北纬25°27‘到东经82°18’，北纬25°45‘到东经82°3’之间，从阿拉哈巴德的富尔普尔特西尔向东向东南延伸，在北纬25°19‘和东经83°44’处与恒河汇合，正好位于瓦拉纳西的下游。位于恒河平原中部的瓦拉纳西地区的瓦鲁纳河下游流域是一个高产的农业区，也是印度发展最快的城市地区之一。农业和城市化活动对研究区地下水水质有较大影响。研究区下伏为第四系冲积物，由粘土、粉砂、砂砾等不同等级组成。水文地球化学研究是通过在全区范围内的挖井和钻孔中随机采集12个地下水样品，以了解溶解离子的来源，评估促进农业生产和人类健康标准的化学质量。研究发现，地下水的过度开采对地下水的质量和数量都造成了不利的影响。除1个地下水样品(12号样品)外，大部分地下水样品都适合灌溉。虽然瓦鲁纳河下游地下水的总体质量适合灌溉，但有41%的样品硝酸盐含量超过允许限值(>；45 mg/L)，不利于人类消费。在瓦鲁纳河河道沿线的农田上，氮肥作为作物营养物质的使用，是地下水中硝酸盐污染的主要原因，因为淋洗所用的灌溉水。研究区最北部、南部和西南部地区硝酸盐浓度高的另一个潜在来源是污水和排水设施差、非常旧的化粪池的人类排泄物泄漏，以及卫生垃圾填埋场。
The Varuna is a minor tributary of the Ganges and extended between 25°27’ N to 82°18’E and 25°45’ N to 82°3’ E flows east to southeast from some of 100 km from Phulpur tehsil of Allahabad and joins the Ganges at 25°19’ N 83°2’ E and 25° 32’ N 83° 44’ E just downstream of Varanasi. The lower Varuna river basin in Varanasi district situated in the central Ganga plain is a highly productive agricultural area and also one of the fast growing urban areas in India. The agricultural and urbanization activities have a lot of impact on the ground water quality of the study area. The study area is underlain by Quaternary alluvial sediments consisting of clay, silt, sand and gravel of various grades. The hydrogeochemical study was undertaken by randomly collecting 12 groundwater samples from dug wells and bore wells covering the entire area in order to understand the sources of dissolve ions and to assess the chemical quality of the promoting agricultural production and standard of human health. It is found that over exploitation of groundwater has detrimentally affected groundwater in terms of quality and quantity. Most groundwater samples are suitable for irrigation except one sample (sample no. 12). Although the general quality of groundwater of the lower Varuna river basin is suitable for irrigation purpose, forty one percent of the samples are found having nitrate content more than permissible limit (>45mg/L) which is not good for human consumption. Application of N- fertilizers on agricultural land as crop nutrients along the Varuna river course is responsible for nitrate pollution in the groundwater due to leaching applied irrigation water. The other potential source of high nitrate concentration in extreme northern, southern and southwestern parts of study area are poor sewerage and drainage facilities, leakage of human excreta from very old septic tanks, and sanitary landfills.