氢氧稳定同位素对东平湖枯水期水环境的指示作用

为掌握东平湖枯水期水环境质量, 采集氢氧稳定同位素样品分析了氢氧同位素分布、氘盈余( d 值) 和富营养 化状况, 揭示了枯水期蒸发作用和人为因素对湖泊水质的影响, 结果表明: ( 1) 单因子评价法反映出东平湖枯水期富 营养化现象严重, 水体中 COD、TN 和 T P 含量平均值分别为 161 92 mg/ L、01 80 mg/ L 和 01 31 mg / L, 接近重富营养 化; ( 2) 枯水期DD 和D18O 呈现出从湖区的东南向西北逐渐增加的规律, 而氘盈余值则表现出与DD 和 D18O 比值相 反的空间分布。湖水的氘盈余在- 41 77 j ~ - 121 48 j 之间, d 值严重偏负, 说明水体的蒸发作用较强烈; ( 3) 枯 水期湖水的 D18O、DD 与 COD、pH 、EC、呈显著相关性, 反映出蒸发分馏对 COD 等含量的影响; 而水中 T N、T P 含量 与DD 和D18O 比值无显著相关性, 其含量的大小一定程度是受人为因素影响的。 To learn about the quality of water environment o f Do ng ping Lake in dr y perio d, w e collected hydro gen and ox yg en stable isoto pes samples and analyzed the distributio n of hydro gen and o x yg en isoto pes, deuterium surplus, and eutro phicatio n co nditions in Dongping Lake. We revealed the effect of evapor ation and human factors on w ater quality during dr y period. T he results showed that: ( 1) The sing le2facto r ev aluatio n showed serious eut rophicatio n in Do ng ping Lake during dry period. T he averag e concentr atio ns of COD, TN and TP in Dong ping Lake w ere 161 92 mg / L, 01 80 mg/ L and 01 31 mg / L, respectiv ely . They wer e close to heavy eutr ophicatio n in the dry period. ( 2) The spatial distribut ions of DD and D18O showed a g radual increasing trend from t he southeast to the northw est o f t he lake area, w hile the d value showed an o pposite distribution tr end to that o f DD and D18O. T he d value o f lake wat er is negative between - 41 77 j and - 121 48 j , indicat ing that the eva po ratio n of water is st rong . ( 3) In the dry period,D18O and DD of lake w ater showed a sig nificant correlat ion w ith the COD, pH and EC, w hich re2 flect ed the effect o f evapor ation fr actionatio n o n the content of COD. Howev er, TN and TP had no significant co rr elatio n with DD and D18O iso topic values because the co ntent of T N and TP w as affected by human facto rs. 国家自然科学基金( 40901276) ; 聊城大学基金项目 ( 318011407)