Article thumbnail

Variations of Groundwater Quality in the Multi-Layered Aquifer System near the Luanhe River, China

By Qiaona Guo, Zhifang Zhou, Guojiao Huang and Zhi Dou

Abstract

Nitrate pollution is an environmental problem in the North China Plain. This paper investigates the variation of groundwater levels and nitrate concentrations in an alluvial fan of the Luanhe river, northeast of the North China Plain. Three transects perpendicular to the riverbank were selected to investigate the exchange between river water and groundwater, and nitrate concentration with its isotopic composition (&#948;<sup>15</sup>N-NO<sub>3</sub> and &#948;<sup>18</sup>O-NO<sub>3</sub>). The results showed that the groundwater level decreased slightly during the dry season, and increased regularly during the period of river stage rise. The groundwater is recharged by the river over 10 months each year. The nitrate concentration in the groundwater and river water varied with seasons. The nitrate concentration of groundwater in wells near the river is affected by the river water, which varied in basically the same way as the river. The nitrate concentrations in the zone of groundwater level depression cone were lower than those in the wells near the river, due to the long-term pumping of groundwater. However, the nitrate concentrations of river water have little influence on those of groundwater in wells far from the river. The values of &#948;<sup>15</sup>N-NO<sub>3</sub> and the relationship between the two isotopes (&#948;<sup>15</sup>N-NO<sub>3</sub> and &#948;<sup>18</sup>O-NO<sub>3</sub>) suggested that NO<sub>3</sub>-N was mainly attributable to sewage, livestock manure and natural soil organic matter. Due to the existence of a groundwater depression cone near the river, nitrate contamination can be transported into the aquifer with the flow. The average time lag of nitrate migration from the river to the zone of groundwater level depression cone is different in different sections, which shows an increasing trend from the upstream to downstream along the river, with an average of two to six months. It is mainly related to the stratigraphic structure, the migration distance, the hydraulic conductivities of the aquifer and the riverbed sediment. Compared with the case of considering the silt layer, the time lag of nitrate migration is greater than that of the case of ignoring the silt layer. The results will provide useful information for detecting nitrate concentrations in the alluvial fan area of the Luanhe river, northeast of the NCP (North China Plain)

Topics: groundwater level, nitrate contamination, isotopes, luanhe river, Environmental effects of industries and plants, TD194-195, Renewable energy sources, TJ807-830, Environmental sciences, GE1-350
Publisher: MDPI AG
Year: 2019
DOI identifier: 10.3390/su11040994
OAI identifier: oai:doaj.org/article:dcae86779f9e4a8fbee302caf2341a77
Journal:
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • https://doaj.org/article/dcae8... (external link)
  • https://www.mdpi.com/2071-1050... (external link)
  • https://doaj.org/toc/2071-1050 (external link)

  • To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.

    Suggested articles