On November 14-25, the International Atomic Energy Agency (IAEA) held a training course on isotope hydrology for the Asian-Pacific region in Xi'an, China. This training course is a part of IAEA's water resource activity in the Asian-Pacific region, which was sponsored by IAEA, hosted by our institute and co-organized by Xi'an Geological Survey Center, China Geological Survey. Twenty-five foreign students from 15 countries in the Asian-Pacific region and 5 Chinese students participated in the training. Five experts from China, America, Japan and the head office of IAEA gave lectures. The main topic of this training course was Underground Water Evaluation by Using Isotope and Related techniques. 

The opening ceremony of the training course was chaired by Prof. PANG Zhonghe, a Chinese Coordinator for IAEA's water resource project and a research fellow from IGG. PANG extended a warm welcome to the participants and introduced the general information of this training course entitled 'IAEA/RCA Regional Training Course on the Underground Water Evaluation by Using Isotope and Related techniques (RAS7030)'. Mr. I. Matiatos, a technical officer from the IAEA, Ms. ZHANG Lin, a project officer from China Atomic Energy Authority (CAEA) and Mr. HOU Guangcai, from Xi'an Geological Survey Center, China Geological Survey, made speeches and expressed welcome to the students from various Asian-Pacific counties. They all attached great importance to the application of isotopes and related techniques in underground water surveys and investigations. 

The research on underground water recharge and circulation is vital for the sustainable exploitation and protection of underground water. Environmental isotopes are indispensible in determining the origin, supply and movement of underground water, as well as mixing and dating. In this two-week training course, the experts explained in detail the stable isotope and underground circulation, underground water dating, underground pollutant tracing, the use of common software and methods for field sampling. The course also organized two field sampling trips. Pang Zhonghe gave five lectures in total, including "Principle and Application of Isotope Indicator in Hydrologic Process, Principle and Example of C-14 Dating in Old Underground Water" , "Quantification Model of Deuterium Excess and the Applications" , "A Case Study of the Application of Stable Isotopes in Hydrology in China" and "A Case Study of Underground Water Dating using C-14 in China" . These lectures reflected some of our institute's achievements in investigating the underground water isotope tracing and age in northwest China over the past decade. Prof. HOU Guangcai and Prof. YIN Lihe, two research fellows from Xi'an Geological Survey Center, China Geological Survey, gave a report entitled Application of Isotope Evaluation Technique in Evaluation of Underground Water Supply and Circulation - A Case Study in Erdos Basin. HUANG Tianming, an associate research fellow from IGG, also participated in the demonstration of field sampling.  

The students also visited the Field Test Site for Hydrogeology in Chang'an University and karst hot spring, Qiachuan County, Shaanxi, China.