Shift from nival to pluvial recharge of an aquifer-fed lake increases water temperature
Shift from nival to pluvial recharge of an aquifer-fed lake increases water temperature
复制标题
含水层补给的湖泊从积雪向雨水补给的转变导致水温升高
作者：
G. Flaim;A. Nishri;F. Camin;S. Corradini;U. Obertegger
全球变暖正在影响全球的生态系统，山区尤其脆弱。在中等海拔地区，冬季降水的变化将对湖泊功能产生直接影响。托维尔湖（海拔1178米）是意大利布伦塔白云岩（Brenta Dolomites）的一个深（39米）含水层湖泊，2017年水温异常高。主成分分析表明，2000年至2016年的月度数据，包括欧洲最热的2003年和当地最热的2015年，并没有显示出相对较高的水温。2017年6月至9月的体积加权平均水温比长期温度高1.3-2.1°C（2000-2016年平均值：6.6-8.8°C）。2016年12月和2017年2月和3月气温升高，导致冬季降水从降雪转为降雨。因此，春季融雪事件的缺失导致整个湖变暖，水柱的稳定性增加，这可以从体积加权平均水温和施密特稳定性中得到证明。稳定同位素被用作湖水来源的示踪剂。相对于长期平均值（2009-2016年：- 11.9‰），2017年湖水年平均δ18O更富（- 10.9‰），支持2017年的暴雨成因而非暴雨成因。托维尔湖的暂时变暖是山区水文未来变化的早期迹象，我们主张增加对湖泊集水区的关注，考虑到它们对许多生态系统服务的影响。
ABSTRACT Global warming is affecting ecosystems worldwide, with mountainous regions particularly vulnerable. At mid-altitudes, changes in winter precipitation will have immediate effects on lake functioning. Lake Tovel (1178 m a.s.l.), a deep (39 m) aquifer-fed lake in the Brenta Dolomites (Italy), showed unusually high water temperatures in 2017. As evidenced by a principal component analysis, monthly data from 2000 to 2016, including the hot European year 2003 and the locally warmest year 2015, did not show comparably high water temperatures. Volume-weighted mean water temperature from June to September 2017 was 1.3–2.1 °C higher than long-term temperatures (mean 2000–2016: 6.6–8.8 °C). Warmer air temperatures in December 2016 and February and March 2017 led to a shift in winter precipitation from snow to mostly rain. The consequent lack of a spring snowmelt event resulted in whole-lake warming and increased stability of the water column, as evidenced by volume-weighted mean water temperature and Schmidt stability. Stable isotopes were used as tracers for the origin of lake water. The yearly mean δ18O of lake water in 2017 was more enriched (−10.9‰) with respect to the long-term mean (2009–2016: −11.9‰), supporting a pluvial instead of a nival origin in 2017. The temporary warming of Lake Tovel is an early sign of future changes in mountain hydrology, and we advocate for increasing attention to lake catchments considering their impact on many ecosystem services.
影响因子：
5.2
作者：
O'Reilly, Catherine M.;Sharma, Sapna;Zhang, Guoqing
通讯作者：
Zhang, Guoqing
影响因子：
6.4
作者：
Ala-aho, P.;Soulsby, C.;Tetzlaff, D.
通讯作者：
Tetzlaff, D.