Wang L.,Water Resources University |
Wang L.,BGI Engineering Consultants LTD. |
Hu F.,Water Resources University |
Yin L.,Xian Geology Investigation Institute |
And 2 more authors.
Environmental Earth Sciences | Year: 2013
The Yinchuan plain is located in the arid climate zone of NW China. The western margin of the plain is the Helan mountain connecting a series of normal slip faults. The eastern margin of the plain connects with the Yellow River and adjacents with the Ordos platform. The south of the plain is bordered by the EN fault of the Niushou mountain. The bottom of the plain is the Carboniferous, Permian, or Ordovician rocks. Based on the analysis of groundwater hydrochemical and isotopic indicators, this study aims to identify the groundwater recharge and discharge in the Yinchuan plain, China. The hydrochemical types of the groundwater are HCO3-SO4 in the west, HCO3-Cl in the middle, and Cl-SO4 in the east. The hydrochemical types are HCO3-SO4 in the south, HCO3-Cl and SO4-HCO3 in the middle. The hydrochemical types are complex in the north, mainly SO4-HCO3 and Cl-SO4. Deuterium, 18O, and tritium values of groundwater indicate that groundwater recharge sources include precipitation, bedrock fissure water, and irrigation return water. Groundwater discharges include evaporation, abstraction, and discharge to surface water. According to the EW isotopic profile, the groundwater flow system (GFS) in the Yinchuan plain can be divided into local flow systems (LFS) and regional flow systems (RFS). Groundwater has lower TDS and higher tritium in the southern Yellow River alluvial plain and groundwater age ranges from 6 to 25 years. The range of groundwater renewal rates is from 11 to 15 % a-1. The depth of the water cycle is small, and groundwater circulates fast and has high renewal rates. Groundwater has higher TDS and lower tritium in the northern Yellow River alluvial plain. The range of groundwater age is from 45 to 57 years, and renewal rate is from 6 to 0.1 % a-1. The depth of the water cycle is larger. Groundwater circulates slowly and has low renewal rates. © 2012 Springer-Verlag Berlin Heidelberg.
Li Y.,Water Resources University |
Hu F.S.,Water Resources University |
Xue Z.Q.,Ningxia Institute of Geo engineering and Reconnaissance |
Yu Y.Q.,Ningxia Institute of Geo engineering and Reconnaissance |
Wu P.,Ningxia Institute of Geo engineering and Reconnaissance
Arabian Journal of Geosciences | Year: 2015
The salt chemical industrial base of Guyuan is located in the south of Ningxia, northwestern China. Guyuan had been not only an important but also a challenging area for the state’s poverty alleviation and development work for a long time. In addition, the overexploitation of groundwater for agriculture activities in recent decades had led to the decline of the water table and the degradation of the water quality. In this study, environmental isotope data for different water sources are presented and discussed to identify the hydrochemical character of the aquifer systems and to investigate the geochemical processes controlling groundwater mineralization. Piper trilinear diagrams indicate that shallow groundwater in the western mountainous area is characterized by three water types (i.e., SO4–HCO3, HCO3–SO4, and SO4) while deep groundwater is characterized by two water types (i.e., SO4 and SO4–Cl). Furthermore, hydrochemical tracers show that the groundwater in the Qingshuihe plain is of the (1) HCO3–SO4 and HCO3 types in the southern piedmont recharge zone, (2) SO4 type in the southwestern recharge zone, (3) SO4–HCO3 and HCO3–SO4 types in the midwestern recharge zone, (4) SO4–HCO3 and SO4–Cl–HCO3 types in the northwestern recharge zone, and (5) SO4–HCO3, HCO3–SO4, and SO4 types in the runoff and discharge zone. Dissolution of soluble salts is the principal contributor to the water geochemistry in the western mountainous area within the study region. However, water geochemistry in the Qingshuihe plain is primarily controlled by mixing processes and by the recharge of highly mineralized surface water and groundwater in the southwestern and northwestern piedmont areas. In the conventional δD and δ18O diagram, the distribution of data points indicates that the groundwater is of meteoric origin and has been affected by evaporation before or during underground transit. The deep groundwater in the western mountainous area is recharged under conditions that are different from currently prevailing conditions. © 2014, Saudi Society for Geosciences.