Study on the isotopic compositionof rainwater in Long Khanh city,Southeast of the Mekong Delta region

The 2H/1H and 18O/16O isotope ratios in rainwater bring a lot of information about the fractionation water molecules hydrosphere. relationship between an area characterised by local meteoric line, which is known as reliable reference value for studies related to identification recharge source groundwater climate change investigations. This study aims establish line Long Khanh city (LK LMWL) period 2020-2021, considered basis research on origin subsequent Southeast Mekong Delta region Dong Nai river basin. Results show that δ2H ranges from -73.64 0.36 (‰ VSMOW) with average -49.74‰ (n=19) figure δ18O -10.91 -1.59 mean -7.68‰ (n=19). Due amount specific meteorological conditions region, are enriched dry season but deplete rainy season. LK LMWL follows model δ2H=(7.89±0.38)xδ18O + (10.28±2.93) (R2=0.96, n=19), shows isotopic composition more than δ2H. deuterium excess (d-excess) found be 10.28±2.93‰, comparable those global scale 10‰.