【摘要】 地下水年龄是评价地下水的资源属性重要参数之一,但是随着氚在大气中的含量恢复到核爆前水平,地下水中氚年龄估算变得困难。而利用多期次的样品数据可以弥补这一不足。文中利用具有多期次地下水氚的样品点,确定了不同水文地质单元地下水全混合模型的弥散参数(PD)。根据该参数计算只有一次取样数据的地下水氚年龄。不同天然水体氚分布特征表明:黄河水与地下水水力联系密切,单一潜水区与多层结构区的积极循环带极限深度分别是120m和80m。根据氚含量计算的潜水年龄是5~> 60a,年龄老的区域分布在平原中部和细粒带,形成多个局域流动系统,向平原边缘年龄趋于年轻。更多还原

【Abstract】 Excessive groundwater exploitation and agricultural irrigation have resulted in a significant changes of shallow groundwater system in Yinchuan Plain,and it’s believed that groundwater will be intensively used continuously in the future so. it’ s essential to reveal the flow patter of the groundwater for reasonable management.Based on the analyses of the Tritium characteristics of different water bodies and ages of groundwater,the3 H concentrations of samples from groundwater and Yellow River in one stage are similarly,suggested that Yellow River and groundwater had closely hydraulic connection. The Tritium in groundwater varies from < 0. 5 to 36. 1 TU with mean value of-11. 96 ± 11. 63 TU in the single aquifer,whose recharges were influenced by bedrock fissure water and precipitation,as well as the water blocking effect of fine grained belt,informing mixed characteristics of modern and secondary water. The variation of Tritium content in multi-layer diving is large with < 0.5 ～ 56. 9 TU and the mean value is 17. 84 + 14. 53 TU. There are several high or low value zones. The positive cycle limit depth of single aquifer area and multi-layered aquifers area are 120 m and 80 m,respectively,above the depth water cycle alternating rapidly. According to the dating results of3 H,of the Tritium,the groundwater age is 5 ～ > 60 a. The regional distribution of old age in the Central plain and the fine belt,forming a plurality of local flow system,and the edge of the plains age tends to be younger. This phenomenon may attribute to groundwater flowing sluggishly and recovering slowly in the Central plain and the fine belt.更多还原