[关键词]
[摘要]
为探讨河道生态补水对受水区地下水水质的影响,收集引温济潮受水区 2007 年、2013 年和 2018 年不同含 水层的地下水水质数据,采用描述性统计分析水质参数的变化特征,利用 Piper 三线图分析生态补水后受水区不 同含水层地下水水化学相,同时利用吉布斯(Gibbs)图与离子比值图分析地下水水化学特征的控制因素,并通过改 进的综合水质指数法 (MIWQI) 对受水区进行水质评价。结果表明:不同含水层中阴阳离子分别以 HCO3?和 Ca2+为 主导;水岩相互作用和人类活动是地下水中离子变化的主要驱动因素;引温济潮生态补水后受水区地下水水质有 所改善。其中:2007 年较差水质点位占 4.4%,2013 年河道生态补水 5 年后,没有较差水质点位;对评价方法所选 水质指标进行敏感性分析,其敏感性指标较小,未超过 2.0%,表明所选指标能较好表征水质评价结果。
[Key word]
[Abstract]
With?the?acceleration?of?urbanization,?groundwater?has?been?overexploited?for?a?long?time?in?order?to support?the?development?of?Beijing,?groundwater?recharge?and?drainage?are?seriously?unbalanced,?and?groundwater level?has?been?greatly?reduced.?Dry?years?have?resulted?in?a?sharp?decrease?in?the?amount?of?surface?water?resources. The?good?infiltration?conditions?of?the?piedmont?alluvial?fan?have?made?the?river?with?a?sudden?decrease?in?flow rapidly?infiltrate?and?replenish?the?groundwater,?resulting?in?the?interruption?of?the?river?flow.?Artificial?recharge engineering?is?the?most?convenient?and?effective?means?to?solve?the?shortage?of?water?resources.?However,?once?the shallow?groundwater?quality?tends?to?deteriorate?due?to?the?infiltration?of?surface?pollution?components,?the?affected shallow?groundwater?will?continue?to?advance?to?the?deep?layer,?and?the?potential?pollution?risk?of?groundwater?will intensify. ??????Based?on?the?groundwater?data?of?“from?Wenyu?River?to?Chaobai?River”?project?in?2007,?2013?and?2018, descriptive?statistics?were?used?to?analyze?the?variation?characteristics?of?water?quality?parameters,?Piper?trigram?was used ?to ?analyze ?the ?groundwater ?hydrochemical ?phases ?of ?different ?aquifers ?in ?the ?water ?receiving ?area ?after ecological?water?replenishing,?and?Gibbs?diagram?and?ion?ratio?diagram?were?used?to?analyze?the?controlling?factors of ?groundwater ?hydrochemical ?characteristics. ?The ?water ?quality ?of ?the ?receiving ?area ?was ?evaluated ?by ?the improved?comprehensive?water?quality?Index?method?(MIWQI). ??????The?results?show?that?the?pH?values?of?different?aquifers?are?neutral?to?weakly?alkaline,?and?the?main?cations?and anions?are?Ca2+?and?HCO3?.?The?groundwater?chemical?type?changes?from?HCO3?-Ca·Mg?in?30?m?aquifer?to?HCO3?- Na·Ca·Mg?in?50?m?aquifer.?The?samples?of?different?aquifers?mainly?fall?in?the?dominant?rock?zone.The?overall quality?of?groundwater?is?good,?with?medium,?good?and?excellent?water?quality?accounting?for?more?than?90%?of?the total?number?of?samples.?Sensitivity?analysis?showed?that?HCO3??index?had?the?greatest?influence?on?the?score?of MIWQI,?and?Ca2+?index?had?the?least?impact?on?the?score?of?MIWQI,?but?their?sensitivity?values?were?not?exceeded 2%.?It?was?verified?that?MIWQI?did?not?overly?dependent?on?one?or?several?parameters,?and?all?parameters?play?a role?in?water?quality?evaluation. ??????The?index?concentration?of?50?m?aquifer?is?basically?lower?than?30?m?aquifer.?The?dissolution?of?rock?salt?and silicate,?cation?exchange?and?human?activities?are?the?driving?factors?of?the?change?of?main?ions?in?the?water?body. Water?quality?index?method?based?on?entropy?weight?(MIWQI)?method?could?describe?the?overall?water?quality reliably,?accurately?and?stably.?These?findings?can?provide?reference?for?groundwater?management?and?sustainable development?of?water?resources.
[中图分类号]
[基金项目]