TITLE:
Spatio-Temporal Variability of Shallow Groundwater Quality in a Hilly Red-Soil Agricultural Catchment in Subtropical Central China
AUTHORS:
Qiao Luo, Yong Li, Yuyuan Li, Xinliang Liu, Runlin Xiao, Jinshui Wu
KEYWORDS:
Drinking Water, Nitrogen, Phosphorus, 3D Spatio-Temporal Geostatistics
JOURNAL NAME:
International Journal of Geosciences,
Vol.6 No.1,
January
14,
2015
ABSTRACT: Groundwater quality varies
not only in space but also in time. In order to analyze the spatiotemporal
variety of ground water quality, the concentration of ammonium nitrogen (NH4N),
nitrate nitrogen (NO3N), total nitrogen (TN) and total phosphorus
(TP) in very shallow groundwater were investigated in a red-soil catchment in
subtropical central China, based on a three-dimensional kriging method. The
spatio-temporal analysis demonstrated that NH4N, NO3N and
TP presented strong spatio-temporal autocorrelation (with a nugget-to-sill
ratio of 4N, NO3N, TN and TP to the whole catchment was 20.05%,
1.46%, 5.07%, 5.98%, respectively. The 3D delineation of continuously dynamic
variation of contaminated area indicated that the catchment’s very shallow
groundwater had a moderate contamination by NH4N, slight by TN and
TP, and almost non by NO3N. Although the contaminated area was very
small, only occurring in small dispersed patches, a close attention should be
paid to the shallow groundwater quality because local farmers obtain their
domestic drinking water directly from this shallow groundwater without any
treatment prior to consuming and the potential health hazard is considerable.
The findings from this study highlight the importance of surveillance of the
contaminated area over time for decision making to protect public health and
maintain sustainable development of the catchment.