TITLE:
Characteristics of Stable Isotopes in an Inland Lake and Their Implications for Water Management in Northwestern China
AUTHORS:
Honghua Zhou, Weihong Li, Yun Wang, Zhaoxia Ye
KEYWORDS:
Isotope Composition, Spatial and Temporal Variation, Hydrograph Separation, Bosten Lake, Arid Area
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.8 No.6,
May
27,
2016
ABSTRACT: Bosten
Lake is the largest inland freshwater lake in China, functioning as a critical
control and allocation facility for agricultural, industrial, ecological and
social development in southern Xinjiang in northwestern China. The distribution
of stable isotopes, spatial and temporal variations of δ18O, and
hydrograph separation of Bosten Lake and its principal recharge rivers—the
Kaidu River and the Huangshuigou River—were analyzed using isotope composition.
Hydrograph separation indicated that Bosten lake water comprised four
components as follows: river runoff, groundwater, agricultural and industrial drainage,
and local precipitation. Their contributions were 31%, 35%, 25%, and 9%,
respectively. Irrigation drainage and industrial wastewater, enriched high TDS,
were the main factors affecting the water quality of Bosten Lake. The δ18O
of lake water, which was significantly reduced compared with river water,
remained below the local meteoric water line (LMWL), indicating strong
evaporation in the lake, especially during summer. The spatial and temporal
distribution of δ18O exhibited slow water circulation in the lake.
Both the Kaidu River and the Huangshuigou River depend on alpine precipitation
and glacier snow, especially the Kaidu River, where ice-snow-melt water
accounts for 43% of the river runoff. These rivers are sensitive to climate
change. The Bosten Lake inflows would be reduced by the decrease in river
runoff and groundwater under future climate change. To improve water quality
and reduce evaporative loss, the amount of wastewater should be strictly
restricted by local government, and water diversions from Bosten Lake should be
concentrated between May and September.