| Cave-water,a signal of weather,is somehow featured in environmental information of atmospheric precipitation,and soil water.Therefore,the research about its variation and corresponding patterns should be carried out so as to indicate weather changing in short term and lay the foundation for establishing explaining system concerning cave andweather changing.By twelve-month-field study in Beishan Mountain in Jinhua from March,2016 to February,2017,during which the stable isotope such as pH,specific conductance,HCO3-?SO42-?Cl-?Na+?K+?Ca2+?Mg2+?Sr2+?Ba2and ? D??18O are observed,this paper tries to find out the connection between other chemical indexes and them,analyzing their environmental significance.Through the observation about ? D and ?180 in the area,the author has come up with the the Local Meteoric Water Line(LMWL)? D=8.97 ?18O + 15.33(R2= 0.88).With the help of HYSPLIT,the data has been analyzed for LMWL in different routs,with summer monsoon and winter monsoon showing ? D=7.57 ?18O + 4.46(R2= 0.90)while ?D =10.25 ?18O + 23.79(R2= 0.95)respectively.Since the slope and intercept of LMWL in winter monsoon is higher than that in summer monsoon,the seasonal variation of ?18O is mainly resulted from the difference in source region of summer and winter atmospheric precipitation.The ? D and ?18O in this area is ranging from-65.3 ‰ to-6.11 ‰ or from 8.89 ‰ to-2.97 ‰,with weighted average standing at-33.67 ‰ and-5.47 ‰.In addition,the ?18O in Summer monsoon is negative while it in winter monsoon is a positive number.It is because strong meteoric precipitation effect arising from monsoon that global warming does not prevail in the area.Besides,the case in dripping water is totally opposite to meteoric precipitation.The weighted average of ?18O in summer levels-6.24‰,a little higher than that in winter,-6.53‰,of which the reason requires further exploration.Moreover,there is a slight change in ?18O of yearly dripping water,which varies greatly in seasonal and meteoric precipitation.And the seasonal dripping water in variation comes the first place,with the yearly ranking at the last,which shows that seasonal dripping water more easily influenced by the environment.The isotope of cave dripping water reflects some environmental effects.the author has drawn the conclusion that there is no evident global warming in the area,for the ?18O in meteoric precipitation and temperature take the relation as ?18O=-0.13 T-2.86(R2=0.26).Meanwhile,the ?18O and meteoric precipitation comes the connection that ?18O=-0.01 X-3.75(R2?0.65),presenting negative relation.The absolute relation between them only shows in P6 collected from Erxiandong.There is less relation in yearly dripping water than that in seasonal,probably due to the stagnation.In general,the cave dripping water in Beishan Mountain shows meteoric precipitation effect and few temperature effect,with ?18O taking inheritance and variation.The primary positive ion and negative ion in the area is Ca2+ and HCO3-,SO42-respectively.The chemical category of water is Ca2+-HCO3-SO42-,showing cave water's chemical characteristic was taken control of bed rock.The concentration varies from ions,with Ca2+reaching the greatest in positive ion and SO42-in negative ion,which implies that limestone corrosion is active in the area.With regard to ?D and ?18O,there are stagnation among environmental indexes in peak value and valley value.In fact,Ca2+?B3a2+ and Sr2+ in dripping water in Pl are one month later compared with usual condition,with HCO3-two months and Na+ and Mg2+three months respectively.Compared with other variations,the author has concluded that the most sensitive indicator comes to Ca2+?Ba2+ and Sr2+.Meanwhile,the author has also found that ?18O in the meteoric precipitation and dripping water is of certain connection between SOI and monsoon,but months deviation. |
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