Groundwater mixing and mineralization processes in a mountain–oasis–desert basin, northwest China: hydrogeochemistry and environmental tracer indicators

Journal Article · Wed Feb 14 23:00:00 EST 2018 · Hydrogeology Journal

DOI:https://doi.org/10.1007/S10040-017-1659-0· OSTI ID:22780890

Ma, Bin ^[1]; Jin, Menggui; Liang, Xing; Li, Jing ^[2]

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1. China University of Geosciences, State Key Laboratory of Biogeology and Environmental Geology (China)
2. China University of Geosciences, School of Environmental Studies (China)

Hydrogeochemistry and environmental tracers ({sup 2}H, {sup 18}O, {sup 87}Sr/{sup 86}Sr) in precipitation, river and reservoir water, and groundwater have been used to determine groundwater recharge sources, and to identify mixing characteristics and mineralization processes in the Manas River Basin (MRB), which is a typical mountain–oasis–desert ecosystem in arid northwest China. The oasis component is artificial (irrigation). Groundwater with enriched stable isotope content originates from local precipitation and surface-water leakage in the piedmont alluvial–oasis plain. Groundwater with more depleted isotopes in the north oasis plain and desert is recharged by lateral flow from the adjacent mountains, for which recharge is associated with high altitude and/or paleo-water infiltrating during a period of much colder climate. Little evaporation and isotope exchange between groundwater and rock and soil minerals occurred in the mountain, piedmont and oasis plain. Groundwater δ{sup 2}H and δ{sup 18}O values show more homogeneous values along the groundwater flow direction and with well depths, indicating inter-aquifer mixing processes. A regional contrast of groundwater allows the {sup 87}Sr/{sup 86}Sr ratios and δ{sup 18}O values to be useful in a combination with Cl, Na, Mg, Ca and Sr concentrations to distinguish the groundwater mixing characteristics. Two main processes are identified: groundwater lateral-flow mixing and river leakage in the piedmont alluvial–oasis plain, and vertical mixing in the north oasis plain and the desert. The {sup 87}Sr/{sup 86}Sr ratios and selected ion ratios reveal that carbonate dissolution and mixing with silicate from the southern mountain area are primarily controlling the strontium isotope hydrogeochemistry.

• OSTI ID: 22780890
• Journal Information: Hydrogeology Journal, Journal Name: Hydrogeology Journal Journal Issue: 1 Vol. 26; ISSN 1431-2174
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ALTITUDE
AQUIFERS
CARBONATES
CHINA
CLIMATES
DESERTS
DEUTERIUM
DISSOLUTION
ECOSYSTEMS
EVAPORATION
GROUND WATER
GROUNDWATER RECHARGE
IRRIGATION
ISOTOPIC EXCHANGE
LEAKS
MINERALIZATION
MINERALS
MOUNTAINS
OXYGEN 18
PRECIPITATION
RIVERS
ROCKS
SILICATES
SOILS
STRONTIUM 86
STRONTIUM 87
SURFACE WATERS
WATER RESERVOIRS