Abstract:

By utilizing the ³H and ¹⁴C dating methods, this paper calculated the distribution of groundwater age and then analyzed the groundwater renewability in the study area of Nuomuhong in Qaidam basin. The results show that: (1) in areas from the mountain to the middle part of the alluvial-proluvial fan, the groundwater age varies slightly (15-18 a), indicating that the groundwater is recharged after 1952 with a strong renewability; (2) the groundwater age, in the leading edge of the alluvial-proluvial fan, is less than 2 ka, indicating that the groundwater is a mixture of the modern groundwater with the fossil groundwater and has a poor renewability; (3) in areas from overflow zone to the center of the basin, the groundwater age gets older rapidly from 5 ka to 28 ka, indicating that the hidden fault underlaid the overflow zone has the property of water blocking, and that groundwater in this area can be considered as unrenewable resources

Key words: Qaidam basin, 3H, 14C, groundwater age