Application of stable isotope tracing technologies in identification of transformation among waters in Sanjiang Plain, Northeast China

In order to investigate the transformation among the precipitation, groundwater, and surface water in the Sanjiang Plain, Northeast China, precipitation and groundwater samples which were collected at the meteorological station of the Sanjiang Mire Wetland Experimental Station, Chinese Academy of Sciences and the surface water which collected from the Wolulan River were used to identify the transformation of three types of water. The isotope composition of different kinds of water sources were analyzed via stable isotope (deuterium and oxygen-18) investigation of natural water. The results show a clear seasonal difference in the stable isotopes in precipitation. During the cold half-year, the mean stable isotope in precipitation in the Sanjiang Plain reaches its minimum with the minimum temperature. The δ18O and δD values are high in the rainy season. In the Wolulan River, the evaporation is the highest in August and September. The volume of evaporation and the replenishment to the river is mostly same. The groundwater is recharged more by the direct infiltration of precipitation than by the river flow. The results of this study indicate that the water bodies in the Sanjiang Plain have close hydrologic relationships, and that the transformation among each water system frequently occurs.