Research on the hydrologic cycle characteristics using stable isotopes of oxygen and hydrogen in the Jinxiuchuan Basin

Stable isotopes of oxygen (δ18O) and hydrogen (δD) in water were used as important indicators to research the hydrologic cycle or processes. To study the hydrologic cycle characteristics of the Jinxiuchuan basin, the isotope labelling and the industrial salt tracing method were used in this research. Sixty-seven samples of different water bodies were collected at different sampling sites from July 2011 to July 2012. The stable hydrogen and oxygen isotopes in water samples were measured by using Liquid Water Isotope Analyzer (LWIA-24d) to study the conversion relationship among precipitation, river water, soil water, and groundwater of the Jinxiuchuan basin in Jinan. The results show that δD and δ18O varied from 35.6 ‰ to 128.3 ‰ and from 5.3 ‰ to 17.5‰, respectively. A meteoric water line of δD = 7.16δ18O + 4.35‰, which was in accordance with the global meteoric water line and the meteoric water line of China, was established in the Jinxiuchuan basin. The deuterium excess values vary with time and space, ranging from 5.1 to 22.3‰, and increase gradually from the southeast to the northwest. In addition, the exchange of different water bodies was determined preliminarily, the rates of precipitation transforming into river water, soil water, and groundwater are 43.76%, 21.91% and 6.84%, and the remaining is 27.49% returned to the atmosphere. The results indicated the hydrologic cycle characteristics in the Jinxiuchuan basin. It may provide the references for precipitation isotopes research in semi-humid regions.