气候变化领域集成服务门户(CCPortal): New water fractions and transit time distributions at Plynlimon; Wales; estimated from stable water isotopes in precipitation and streamflow

CCPortal

DOI	10.5194/hess-23-4367-2019
	New water fractions and transit time distributions at Plynlimon; Wales; estimated from stable water isotopes in precipitation and streamflow
	Knapp J.L.A.; Neal C.; Schlumpf A.; Neal M.; Kirchner J.W.
发表日期	2019
ISSN	1027-5606
起始页码	4367
结束页码	4388
卷号	23 期号:10
英文摘要	Long-term, high-frequency time series of passive tracers in precipitation and streamflow are essential for quantifying catchment transport and storage processes, but few such data sets are publicly available. Here we describe, present, and make available to the public two extensive data sets of stable water isotopes in streamflow and precipitation at the Plynlimon experimental catchments in central Wales. Stable isotope data are available at 7-hourly intervals for 17 months, and at weekly intervals for 4.25 years. Precipitation isotope values were highly variable in both data sets, and the high temporal resolution of the 7-hourly streamwater samples revealed rich isotopic dynamics that were not captured by the weekly sampling. We used ensemble hydrograph separation to calculate new water fractions and transit time distributions from both data sets. Transit time distributions estimated by ensemble hydrograph separation were broadly consistent with those estimated by spectral fitting methods, suggesting that they can reliably quantify the contributions of recent precipitation to streamflow. We found that on average, roughly 3 % of streamwater was made up of precipitation that fell within the previous 7 h, and 13 %-15 % of streamwater was made up of precipitation that fell within the previous week. The contributions of recent precipitation to streamflow were highest during large events, as illustrated by comparing new water fractions for different discharges and precipitation rates. This dependence of new water fractions on water fluxes was also reflected in their seasonal variations, with lower new water fractions and more damped catchment transit time distributions in spring and summer compared to fall and winter. We also compared new water fractions obtained from stable water isotopes against those obtained from concentrations of chloride, a solute frequently used as a passive tracer of catchment transport processes. After filtering the chloride data for dry deposition effects, we found broadly similar new water fractions using chloride and stable water isotopes, indicating that these different tracers may yield similar inferences about catchment storage and transport, if potentially confounding factors are eliminated. These stable isotope time series comprise some of the longest and most detailed publicly available catchment isotope data sets. They complement extensive solute data sets that are already publicly available for Plynlimon, enabling a wide range of future analyses of catchment behavior. © Author(s) 2019.
语种	英语
scopus关键词	Catchments; Chlorine compounds; Digital storage; Isotopes; Runoff; Stream flow; Time series; Experimental catchments; High frequency time series; High temporal resolution; Hydrograph separation; Precipitation rates; Stable isotope data; Stable water isotopes; Transit-time distributions; Precipitation (chemical); catchment; dry deposition; hydrogen isotope; precipitation (climatology); seasonal variation; stable isotope; streamflow; streamwater; Ceredigion; Plynlimon; United Kingdom; Wales
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159582
作者单位	Knapp, J.L.A., Department of Environmental Systems Science, ETH Zurich, Zurich 8092, Switzerland; Neal, C., Centre for Ecology and Hydrology, Wallingford, OX10 8BB, United Kingdom; Schlumpf, A., Swiss Federal Research Institute WSL, Birmensdorf 8903, Switzerland; Neal, M., Centre for Ecology and Hydrology, Wallingford, OX10 8BB, United Kingdom; Kirchner, J.W., Department of Environmental Systems Science, ETH Zurich, Zurich 8092, Switzerland, Swiss Federal Research Institute WSL, Birmensdorf 8903, Switzerland, Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, United States
推荐引用方式 GB/T 7714	Knapp J.L.A.,Neal C.,Schlumpf A.,et al. New water fractions and transit time distributions at Plynlimon; Wales; estimated from stable water isotopes in precipitation and streamflow[J],2019,23(10).
APA	Knapp J.L.A.,Neal C.,Schlumpf A.,Neal M.,&Kirchner J.W..(2019).New water fractions and transit time distributions at Plynlimon; Wales; estimated from stable water isotopes in precipitation and streamflow.Hydrology and Earth System Sciences,23(10).
MLA	Knapp J.L.A.,et al."New water fractions and transit time distributions at Plynlimon; Wales; estimated from stable water isotopes in precipitation and streamflow".Hydrology and Earth System Sciences 23.10(2019).