基于氢氧稳定同位素地下水补给与滞留时间研究中的应用进展

Advances in Stable Hydrogen and Oxygen Isotope Applications for Groundwater Recharge and Residence Time Studies

摘要: 地下水是全球最重要的淡水资源之一，在维系区域水安全、生态系统稳定及社会经济发展中发挥着不可替代的作用。准确识别地下水补给来源、流动路径及其滞留时间，是揭示地下水循环过程和实现水资源可持续管理的关键科学问题。氢氧稳定同位素(δ²H和δ¹⁸O)作为天然示踪剂，因其对水循环过程高度敏感、示踪尺度灵活，在地下水研究中得到了广泛应用。近年来，随着同位素分析技术和水文模型方法的不断发展，氢氧同位素在地下水补给来源识别、地表水–地下水相互作用解析以及地下水年龄与滞留时间估算等方面取得了显著进展。本文系统梳理了氢氧稳定同位素在地下水研究中的理论基础与主要应用方向，重点综述其在地下水补给与滞留时间研究中的方法体系与典型案例，总结气候变化和人类活动对地下水同位素特征的影响机制，并讨论当前研究面临的关键挑战与未来发展趋势。研究表明，氢氧同位素技术在多源补给解析和地下水时间尺度量化方面具有显著优势，但在非稳态补给条件和复杂水文地质背景下仍存在不确定性。未来，通过加强长期监测、推进多同位素联合示踪及模型耦合应用，有望进一步提升地下水系统认知水平，为区域水资源管理提供科学支撑。

Abstract: Groundwater is one of the most important freshwater resources worldwide and plays an indispensable role in regional water security, ecosystem stability, and socio-economic development. Robust identification of groundwater recharge sources, flow pathways, and residence time is fundamental to understanding groundwater cycling processes and supporting sustainable water-resources management. As natural tracers, stable hydrogen and oxygen isotopes (δ²H and δ¹⁸O) are highly sensitive to hydrological processes and can be applied across flexible spatial and temporal scales, and thus have been widely used in groundwater studies. In recent years, advances in isotope analytical techniques and hydrological modeling have substantially promoted isotope-based research on recharge-source identification, surface water-groundwater interactions, and the estimation of groundwater age and residence time. This paper systematically reviews the theoretical basis and major application domains of stable water isotopes in groundwater research, with emphasis on methodological frameworks and representative case studies related to groundwater recharge and residence time. We further summarize the mechanisms by which climate change and human activities influence groundwater isotope signatures, and discuss key challenges and future research directions. Overall, stable isotope techniques show clear advantages in resolving multi-source recharge and quantifying groundwater time scales, yet uncertainties remain under non-steady recharge conditions and complex hydrogeological settings. Future progress is expected through strengthened long-term monitoring, multi-isotope integrated tracing, and coupled modeling approaches, which will improve understanding of groundwater systems and provide scientific support for regional water-resources management.