Temporal variation of chemical and isotopic signals in major discharges of an alpine karst aquifer in Turkey: implications with respect to response of karst aquifers to recharge
Temporal variation of chemical and isotopic signals in major discharges of an alpine karst aquifer in Turkey: implications with respect to response of karst aquifers to recharge
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DOI：
10.1007/s10040-007-0217-6
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发表时间：
2008-03
影响因子：
2.8
通讯作者：
N. Ozyurt;C. Bayarı
中科院分区：
文献类型：
--
作者：
N. Ozyurt;C. Bayarı
妥善管理岩溶含水层需要更好地了解这些系统中的流动和运输机制。由于补给和排泄之间的非线性和非平稳关系，岩溶含水层中的水流本质上非常复杂。在土耳其中南部的Aladaglar山脉，已经获得了一个大型（1 000平方公里）多山（海拔3 500米以上）岩溶含水层与深层非饱和带（海拔2 000米以上）之间这种关系的资料。在12个月期间，定期观察含水层的所有主要排泄物的电导率、氚和氧-18变化，含水层几乎排干了所有补给。观测结果表明，该系统的回灌反应强烈地依赖于渗透和排水速度之间的竞争。这些速度受降水时间、渗透时间、强度和补给连续性等变量的控制，决定了含水层中不同类型流动机制的主导程度。旁路，充分混合和活塞流机制被用来解释含水层的响应的时空变化的补给。看来，含水层切换这些流动机制取决于当时的补给模式和渗透和排水速度之间的竞争。
Proper management of karst aquifers requires a better understanding of flow and transport mechanisms in these systems. Flow in karst aquifers is inherently very complex due to the non-linear and non-stationary relationship between recharge and discharge. Information on this relationship has been acquired for a large (1,000 km2), mountainous (>3,500 m asl) karst aquifer with a deep unsaturated zone (>2,000 m) in the Aladaglar mountain range of south-central Turkey. All major discharges from the aquifer, which drain almost all the recharge, have been observed periodically for specific electrical conductivity, tritium and oxygen-18 variations during a period of 12 months. Observations reveal that the system’s response to recharge depends strongly on the competition between the infiltration and drainage velocities. These velocities, which are controlled by variables such as the time of precipitation, time of infiltration, intensity, and continuity of recharge, determine the degree of dominance of different types of flow mechanisms in the aquifer. Bypass, well-mixed and piston flow mechanisms are used to explain the response of the aquifer to the spatio-temporal variations in recharge. It appears that the aquifer switches among these flow mechanisms depending on the prevailing recharge mode and the competition between infiltration and drainage velocities.