利用放射性氚估算银川平原地下水系统的更新速率

利用地下水的放射性同位素示踪剂——氚直接估算浅层地下水的平均更新速率，讨论地下水系统的更新速率变化．结果表明，贺兰山洪积扇地下水更新速率为（0．1—1．0）％／a；冲积、冲洪积平原（引黄灌区）地下水更新速率为（0．1-50）％／a；深层地下水更新速率为（0．1—6．0）％／a．说明因受地下水循环条件控制，银川平原地下水的更新能力差异较大，浅层地下水的更新能力大于深部地下水；冲积、冲洪积平原浅层地下水更新能力优于西部山前洪积扇；冲积、冲洪积平原内，南部黄河冲积扇的更新能力大于北部，北部靠近黄河的引黄灌区地下水更新能力优于扇前洼地及湖积洼地的更新能力．这对制定浅层地下水的可持续开发战略是十分有益的．

Estimating of the update speed of groundwater in Yingchuan plain by using the radioactive element-3H

In this paper we used the groundwater tracer- TU to directly estimate shallow-layer groundwater average update speed and discussed the groundwater system update speed change. What we concluded is： the update speed of groundwater is （0. 1 - 1.0） %/a in Helanshan mountain diluvium, 0. 1 - 50%/a in the alluvium and diluvium plain（yellow river filled district）, and （0. 1 -6.0）%/a in deeper layer. Combining the hydrogeology condition of groundwater and analyzing the update speed of Yinchuan plain we can conclude that： controlled by the circulation condition, the groundwater update ability discrepancy is large in Yinchuan plain. This result is very beneficial for developing the continal using strategy of shallow-layer groundwater.