Abstract:

In order to reveal the characteristics of stable hydrogen and oxygen isotopes in precipitation of Tengchong region,based on the 339 precipitation samples in Tengchong region from Jan.2009 to Dec.2011, the compositions and influencing facters of hydrogen and oxygen isotope in precipitation were analyzed. The results indicated that the rainfall of δ18O ranged from -2678‰ to 405‰,and the rainfall of δD ranges from -20095‰ to 3689‰ in Tengchong,these date were comparable to the world range and the Chinese range.Under the synoptic timescales,the results showed that there was negative correlation of δ18O  in precipitation with the precipitation amount and temperature,thus,it indicatated that the variations of δ18O in precipitation had significant precipitation amount effects and antitemperature effects. However,during the monsoon,if the adjacent two days both had rainfall in Tengchong region, the vatiations of δ18O in precipitation would not necessarily adhere to the precipitation amount effects.In addition,based on the reanalysis date of the total column water vapour from the European Centre for MediumRange Weather Forecasts,it was found that the variations between the δ18O and the TCWV existed significant inverse phase. The reason was that they affected by the same circulation condition and vapour condition.The meteoric water line was fitted as δD=818δ18O+1172 in Tengchong,which the slope and intercept were bigger than the Globe Meteoric Water Line and Chinese Meteoric Water Line. It revealed that the climatic characteristics was humid and rainy in Tengchong region.At the same time,with the precipitation amount decreased,the slope and intercept values varied from 848 to 797 and 1628 to 935,respectively.d in precipitation had distinct seasonality.In the rainy season of Tengchong, in the vapour of generating precipitation with high humidity,low stable isotopic ratios was result from the rainout of vapour on the transport way,and small d in precipitation was primarily from low latitude oceans. However,in the dry season,in the vapour of generating precipitation with low humidity,great stable isotopic ratios and high d in precipitation were primarily from the westerly transportation and the replenishment of reevapourated vapour in inland.The study would provide sufficient evidence to understand the water cycle characteristics,the water vapour sources and the changes of the environment evolution and it would also promote the society,the economy and the environment sustainable coordinated development