Thermal effect of climate change on groundwater-fed ecosystems
Thermal effect of climate change on groundwater-fed ecosystems
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DOI：
10.1002/2016wr020007
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发表时间：
2017-04-01
影响因子：
5.4
通讯作者：
Dunham, Jason B.
中科院分区：
文献类型：
--
作者：
Burns, Erick R.;Zhu, Yonghui;Dunham, Jason B.
地下水温度变化将滞后于气候变化引起的地表温度变化。热传输方程的稳态解用于确定控制泉水和其他地下水排放对气候变化的长期热响应的关键过程，特别是（1）地下水补给率和温度以及（2）地表温度的变化通过包气带传输。开发瞬时解决方案来估计新的热信号到达生态系统所需的时间。该解决方案适用于美国加州的火山梅迪辛湖高地，以及与地下水依赖生态系统相关的泉水复合体。在这个系统中，上游盆地地下水温度的强烈影响，只有补给条件。然而，随着包气带从高地逐渐变薄，年平均地表温度的变化也会影响地下水温度。对温度变化的瞬态响应取决于传导时间尺度和充电传递热量的速率。高海拔地区地下水的大多数热响应将在补给温度发生变化的20年内发生，但低海拔地区的大型泉水响应较慢，大约一半的传导响应发生在最初的20年内，大约一半的对流响应发生在大约60年内。（并已得到证实），可以预测气候变化对支持重要生境的泉水和渗漏处地下水温度的影响。
Groundwater temperature changes will lag surface temperature changes from a changing climate. Steady state solutions of the heat-transport equations are used to identify key processes that control the long-term thermal response of springs and other groundwater discharge to climate change, in particular changes in (1) groundwater recharge rate and temperature and (2) land-surface temperature transmitted through the vadose zone. Transient solutions are developed to estimate the time required for new thermal signals to arrive at ecosystems. The solution is applied to the volcanic Medicine Lake highlands, California, USA, and associated springs complexes that host groundwater-dependent ecosystems. In this system, upper basin groundwater temperatures are strongly affected only by recharge conditions. However, as the vadose zone thins away from the highlands, changes in the average annual land-surface temperature also influence groundwater temperatures. Transient response to temperature change depends on both the conductive time scale and the rate at which recharge delivers heat. Most of the thermal response of groundwater at high elevations will occur within 20 years of a shift in recharge temperatures, but the large lower elevation springs will respond more slowly, with about half of the conductive response occurring within the first 20 years and about half of the advective response to higher recharge temperatures occurring in approximately 60 years.Plain Language Summary Tools are developed (and demonstrated) that allow prediction of the effect of climate change on groundwater temperature at springs and seeps that support critical habitat.