Chapter 1 Hydrogeochemical Processes in the Groundwater System 1.1 Groundwater resource 1.2 Groundwater cycling 1.3 Evapotranspiration 1.4 Dissolution and precipitation 1.5 Oxidization and reduction 1.6 Adsorption and desorption References Chapter 2 Theory and Principle of Isotopes 2.1 Definition 2.2 Isotope fractionation processes 2.3 Radioisotopes References Chapter 3 Isotopic Analytical Methods 3.1 Introduction 3.2 Standards 3.3 Analytical methods References Chapter 4 Hydrogen and Oxygen Isotopes 4.1 Analytical techniques 4.2 Fractionation processes 4.3 Variations of Hydrogen and Oxygen isotopes in groundwater 4.4 Application References Chapter 5 Carbon Isotope 5.1 Carbon species in groundwater 5.2 Analytical techniques for the 13 CDIC and 13 CDOC 5.3 Fractionation processes 5.4 Variations of Carbon isotopes in groundwater 5.5 Application References Chapter 6 Nitrogen Isotope 6.1 Nitrogen species in groundwater 6.2 Analytical techniques for the 15N-NO3- and 18O-NO3- 6.3 Fractionation processes 6.4 Variations of Nitrogen isotopes in groundwater 6.5 Application References Chapter 7 Sulfur Isotope 7.1 Sulfur species in groundwater 7.2 Analytical techniques 7.3 Fractionation processes 7.4 Variations of sulfur isotopes in groundwater 7.5 Application References Chapter 8 Chlorine and Bromine Isotope 8. 1 Chlorine and bromine species in groundwater 8.2 Analytical techniques for the chlorine and bromine isotope 8.3 Fractionation processes 8.4 Variations of chlorine and bromine isotopes in groundwater 8.5 Application References Chapter 9 Calcium and Strontium Isotope 9.1 Analytical techniques for the Calcium and Strontium Isotope 9.2 Fractionation processes 9.3 Variations of Calcium and Strontium isotopes in the environment 9.4 Application References Chapter 10 Iron Isotope 10.1 Iron species in groundwater 10.2 Analytical techniques for the Iron isotope 10.3 Fractionation processes 10.4 Variations of Iron isotopes 10.5 Application References Chapter 11 Compound-Specific Isotope 11.1 Definitions 11.2 Analytical techniques-Gas chromatography coupled to isotope-ratio mass spectrometry 11.3 Fractionation processes 11.4 Application References Chapter 12 Groundwater Dating 12.1 3H 12.2 3H/3He 12.3 85Kr 12.4 32Si 12.5 39Ar 12.6 14C 12.7 81Kr 12.8 36Cl 12.9 4He 12.10 129I 12.11 Application References