Variation Characteristics of Cave Water Hydrogeochemistry in Naduo Cave of Guizhou and Its Implications for Environment Research

During the period from December 2012 to December 2014,three dripping water sites( S1,S2,S3) and one pool water site( SC) have been selected for a long-term monitoring of geochemical indexes in Naduo Cave,Guanling county of Guizhou Province,China. Based on the local meteorological data,this paper analyzed the seasonal change of hydro-geochemical indicators and their feedbacks to climate events. The results indicated that the hydro-geochemical type of cave water was HCO_3~--Ca~(2+). Dripping water and pool water were in deposition all the year,except in the month with the maximum precipitation. There were some discrepancies of main ions' concentration among three dripping water sites due to the difference of the migration pathways and migration time. Affected by mixed water and high CO_2 concentration of cave air,the ion concentration of pool water was higher than dripping water,and there was considerable fluctuation. The geochemistry indexes of water in Naduo Cave showed extraordinary seasonal variation rules and could perfectly respond to the external climate environment. The concentration of ions was sensitive to the response of the annual precipitation change caused by extreme climate events. During the rainy season,the concentrations of Ca~(2+),Mg~(2+)and SO_4~(2-) in 2013 were relatively higher and more stable than those in 2014. The response time and susceptivity of each monitoring site were inconsistent.