摘要
在西南地区有众多大小不等的岩溶盆地,相比于岩溶石山地区,盆地是水、土资源丰富和人类聚集、经济发展较快的地区。岩溶盆地的水资源自成系统,水循环从降雨开始,经过表层岩溶带、河网、包气带、饱水带的调蓄,然后进入到地下河管道,最终通过地下河排泄。在农田面源污染和村镇生活排污的作用下,水循环的各个环节受到不同程度的影响,具体表现在:(1)受人类活动影响的表层岩溶泉K+、Na+、Ca2+、Mg2+、Cl-、SO42-、HCO3-和NO3-八种离子的浓度有所升高,并且表层岩溶泉之间K+、Na+和Cl-浓度的离散程度增大;(2)易受影响的或脆弱性高的浅层地下水(包含表层岩溶泉)、地表水和地下河中的K+、Na+和Cl-离子浓度较高且接近,与脆弱性低的饱水带岩溶泉的差别较大,浅层地下水和河流的SO42-浓度较高且接近,而与饱水带岩溶泉和地下河的差别较大;(3)易受污染的浅层地下水的NO3-浓度最高。因此可以认为农田和生活排污首先影响到的是浅层地下水和地表水,然后伴随水循环向深部地下河转移,而饱水带岩溶泉脆弱性低,水化学变化不明显。研究还发现村镇生活排污对表层岩溶泉水质的影响比农田面源污染更显著。
A karst basin was one of the geological cells where water, soil resources are rich and anthropologic activities have heavy impact on the environment. Water circulation in the karst basin often has a single outlet, and it begins with precipitation, then is regulated by epikarst zone, river network, aeration zone and saturated zone, finally reaches to the karst conduit. Water quality is affected by non-point sources from agriculture and settlement. Forty samples were taken from epikarst springs, saturated zone springs, sinkholess and outlet of the karst conduit. The result indicated that ： （1） The concentrations of K^＋ , Na^＋ , Ca^2＋ , Mg^2＋ , Cl^-, SO4^2- , HCO3^- and NO3^- in epikarst springs increased a little, and dispersion of K＋ , Na＋ and Cl^- concentrations increased, too. （2）K^＋ , Na^＋ and Cl^- in shallow groundwater （represented by epikarst springs）, surface water （represented by sinkholes） and karst conduit were very similar, but much distinguished from saturated zone springs. （3） SO4^2- in shallow groundwater and surface water was similar, but different from saturated springs and karst conduits. （4） NO3^- in epikarst springs was highest than others. It could be concluded that： （1）agricultural non-point source pollution and domestic waste firstly polluted shallow groundwater and surface water, and then polluted karst conduit water. While saturated springs had stronger capability of self-protection, representing no obvious change in water quality. （2） impact of domestic waste on epikarst springs was more serious than agricultural non-point source pollution.
出处
《地球与环境》
CAS
CSCD
北大核心
2008年第1期56-63,共8页
Earth and Environment
基金
中国地质调查局项目(1212010340104
1212010634806)
关键词
喀斯特
落水洞
水质
非点源污染
karst
sinkhole
water quality
non-point source pollution
