中文摘要：

为了研究NO3-在岩溶含水系统中的存储和运移规律,对降雨条件下重庆川东平行岭谷区青木关地下河系统的水化学动态进行在线监测和高密度采样测试,结合NO3-的月动态变化,并利用主成分分析方法.结果表明,降雨期间地下河中的NO3-与全Fe、全Mn、Al^3＋是两组不同来源的元素,在含水系统中表现出不同的地球化学行为.NO3-从地表输入后随土壤水下渗存储于岩溶非饱和带的裂隙、孔隙和溶隙等含水介质中,而全Fe、全Mn、Al^3＋则是地表受雨水侵蚀的土壤随地表径流通过落水洞、竖井等通道,以集中流的形式灌入地下河造成的.进而将NO3-在岩溶含水系统中的运移过程分为输入存储、快速输出和再输入存储这3个理想的阶段.在外部条件大致相同的情况下,非饱和带的岩溶发育程度是影响降雨期间地下河中NO3-浓度变化的关键因素.降雨条件下存储于非饱和带的NO3-很容易被释放出来,破坏地下水生态环境,严重威胁着当地群众的健康安全.需要加强岩溶生态系统管理工作,改善土地利用方式,科学施肥,有效控制地下水营养成分的地表输入.

英文摘要：

In order to investigate the nitrate storage and transport in the karst aquifer system,the hydrochemical dynamics of Qingmuguan underground river system was monitored online by achieving high-resolution data during storm events and monthly data in normal weather.The principal component analysis was employed to analyze the karst water geochemistry.Results showed that nitrate in Jiangjia spring did not share the same source with soluble iron,manganese and aluminum,and exhibited different geochemical behaviors.Nitrate was derived from land surface and infiltrated together with soil water,which was mainly stored in fissure,pore and solution crack of karst unsaturated zone,whereas soluble iron,manganese and aluminum were derived from soil erosion and directly recharged the underground river through sinkholes and shafts.Nitrate transport in the karst aquifer system could be ideally divided into three phases,including input storage,fast output and re-inputting storage.Under similar external conditions,the karstification intensity of vadose zone was the key factor to determine the dynamics of nitrate concentrations in the groundwater during storm events.Nitrate stored in the karst vadose zone was easily released,which would impair the aquatic ecosystem and pose seriously threats to the local health.Thus,to strengthen the management of ecological system,changing the land-use patterns and scientifically applying fertilizer could effectively make a contribution to controlling mass nutrient input from the surface.