Study On Dynamic Variation And Influencing Factors Of Karst Groundwater Quality

Karst water resources is very rich in southwest of China karst region, Subteranean is the major location for karst water's movement and deposition. It plays an important role in the living and development of local people. Therefore, in order to make use of groundwater and prevent groundwater pollution, we must study dynamic variation of karst groundwater.Mt.Jinfo is a National Nature Reserve and a well-known tourism witnessed in Chongqing. Shuifang spring is located in the heart of Mt.Jinfo peak. And also it is a typical karst area of the southwest china. At present, Shuifang spring groundwater is the only supply water for the local people and the tourists. The groundwater quality is directly related to residents and tourists' health. In this study area, we study dynamic characteristics and impact factors of karst Groundwater quality, which are contribute to a deeper understanding for the forming, distributing and variation rules of groundwater, also can offer scientific basis for reasonable exploitation and protection of groundwater resource.In this paper, we establish automated monitoring station to monitor the groundwater runoff and physical characteristics. We take samples continuous from March 2008 to February 2009. In particular we take it day by day at the tourist times. The paper analyzed the physicochemical characteristics and Sr isotopes, also analyzed its influencing factors. Through the study we get the following points:1. The water quality and quantity of Shuifang spring has seasonal dynamical variation. Most of the time, the water quality is good, but in some season with the influence of tourism activities, the water quality can become worse.2. Ca²⁺ and Mg²⁺ are the dominant cations of the total cations and HCO₃^- and SO₄²⁺ are the dominant antions. The principal elements' characteristics of groundwater analysis showed that the eight major ions have seasonal dynamical variation. We found that both natural factors and human activity factors has effect concentration of K⁺,Na⁺,Cl^-,NO₃^-,SO₄^2-.3. According to tourism season analysis of water samples, we found that groundwater quality have a better response to change of the tourism factors. The tourist season changed groundwater quality significantly, showed that the normal physicochemical characteristics level before the peak of tourism; a sudden increase during the peak of tourism; and the drop at the end of the tourism period. Compare with the normal times, we can see tourism activity had polluted karst groundwater quality obviously.4. Researches on strontium and strontium isotope of the groundwater have revealed the relation between ⁸⁷Sr/⁸⁶Sr ratios and the different water bodies. In conclusion, Sr²⁺ concentration and the ⁸⁷Sr/⁸⁶Sr isotope have three sources, the water-rock interaction, atmosphere input and human pollute. Natural and anthropogenic factors have affected groundwater quality.