The Research Of The Relationship Between Water Isotopes And Water Quality In The Dalinuoer Lake

This study aims at the distribution characteristic and the correlativity of water quality index and content of isotopic in ice layer and water during the freeze-up period in Dalinuoer Lake of Inner Mongolia, which make isotope tracers becoming an evaluation method for forecasting water quality. Further use of isotopic tracer circulation, by analyzing the isotopes linear relationship up in the lake area, combined with the total dissolved solids in the lake up to supply relationships were explored, using stable isotope mass balance model to estimate Dalinuoer lake evaporation, indirectly indicating the problems in the water cycle. Specifically the following conclusions:The Dalinuoer Lake water with higher content of nutrient even don’t meet the requirement of the fifth level of water quality(the national standard) during freeze-up period. The concentration of TN and TP in water are higher than that of in ice layer above the water during the freeze-up period. It is caused by the process of concentration effect on nitrogen and phosphorus when the lake water freezes up. The effect of thermodynamic isotope fractionation and the Inflow supplies of Gongger River together make that content of isotopic in ice is much larger in water during freeze-up period. The content of isotopic and nutrient appeared significantly negative correlation relationship during the freeze-up period of Dalinuoer Lake. The quantitative relationship function of the content of isotope and nutrient: TN=-0.2825D-6.0083 and TP=-0.0805D-1.2395.On the content of stable isotopes in different water bodies of the water cycle regression analysis, Deriving the atmospheric precipitation line up in the lake region of δD=6.6866δ18O-8.3124 (R2=0.7908) and evaporation trend line δD=4.5349δ18O-27.054(R2=0.9009).Further, after the site visit and survey the local hydrogeological conditions, found that ground water is the main supply source of Dalinuoer lake.With water stable isotope method to estimate atmosphere and evaporation of water vapor in the isotopic content.It is a new method for studing the water cycle in Inner Mongolia.