A preliminary assessment of water partitioning and ecohydrological coupling in northern headwaters using stable isotopes and conceptual runoff models

Tetzlaff, Doerthe; Buttle, J. M.; Carey, Sean K.; Huijgevoort, M.H.J. van; Laudon, Hjalmar; McNamara, J. P.; Mitchell, Carl P. J.; Spence, C.; Gabor, R. S.; Soulsby, Chris

doi:10.1002/hyp.10515

Cited by 67 publications

(55 citation statements)

References 104 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The uncertainty of the snowmelt end‐member was highest in 2011, potentially due to a long‐duration snowmelt season compounding the inherent spatio‐temporal variability of infiltrating snowmelt. For example, snowmelt at the beginning of the season may be more enriched than later in the snowmelt season, due to evaporation of light water isotopes in the snow accumulation period and a longer transit time (Tetzlaff et al, ). Notwithstanding, Euclidean distances and tracer reconstructions in the context of our uncertainty and young water fraction analyses suggest that the tracer‐based results were not obviously subject to deleterious effects from hydrodynamic mixing and/or molecular diffusion at this spatial scale (e.g., Jones, Sudicky, Brookfield, & Park, ; Park, Sudicky, Brookfield, & Jones, ).…”

Section: Discussionmentioning

confidence: 99%

Surface and subsurface water contributions to streamflow from a mesoscale watershed in complex mountain terrain

Zhang

Knowles

Barnes

et al. 2018

Hydrological Processes

View full text Add to dashboard Cite

An understanding of surface and subsurface water contributions to streamflow is essential for accurate predictions of water supply from mountain watersheds that often serve as water towers for downstream communities. As such, this study used the end‐member mixing analysis technique to investigate source water contributions and hydrologic flow paths of the 264 km2 Boulder Creek Watershed, which drains the Colorado Front Range, USA. Four conservative hydrochemical tracers were used to describe this watershed as a 3 end‐member system, and tracer concentration reconstruction suggested that the application of end‐member mixing analysis was robust. On average from 2009 to 2011, snowmelt and rainwater from the subalpine zone and groundwater sampled from the upper montane zone contributed 54%, 22%, and 24% of the annual streamflow, respectively. These values demonstrate increased rainwater and decreased snow water contributions to streamflow relative to area‐weighted mean values derived from previous work at the headwater scale. Young water (2.3 ± 0.8 months) fractions of streamflow decreased from 18–22% in the alpine catchment to 8–10% in the lower elevation catchments and the watershed outlet with implications for subsurface storage and hydrological connectivity. These results contribute to a process‐based understanding of the seasonal source water composition of a mesoscale watershed that can be used to extrapolate headwater streamflow generation predictions to larger spatial scales.

show abstract

Section: Discussionmentioning

confidence: 99%

Surface and subsurface water contributions to streamflow from a mesoscale watershed in complex mountain terrain

Zhang

Knowles

Barnes

et al. 2018

Hydrological Processes

View full text Add to dashboard Cite

show abstract

“…Average annual precipitation is 1020 mm yr -1 at Dorset and 622 mm yr -1 at Krycklan. A detailed comparison of the hydro-meteorological conditions at the three catchments was presented by 15 Tetzlaff et al (2015). Soils of the four sites were characterized as freely draining podzols of generally coarse texture ranging between loamy or silty sands to sand with an overlying organic layer of about 10-20 cm thickness.…”

Section: Study Sitesmentioning

confidence: 99%

Water ages in the critical zone of long-term experimental sites in northern latitudes

Sprenger¹,

Tetzlaff²,

Buttle³

et al. 2018

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. As northern environments undergo intense respond due to a warming climate and altered land use practices, there is an urgent need for improved understanding of the impact of atmospheric forcing and vegetation on water storage and flux dynamics in the critical zone. We therefore assess the age dynamics of water stored in the upper 50 15 cm of soil, and in evaporation, transpiration or recharge fluxes at four soil-vegetation units of podzolic soils in the northern latitudes with either heather or tree vegetation (Bruntland Burn in Scotland, Dorset in Canada, and Krycklan in Sweden). We derived the age dynamics with the physically based SWIS (Soil Water Isotope Simulator) model, which has been successfully used to simulate the hydrometric and isotopic dynamics in the upper 50 cm of soils at the study sites. The modelled subsurface was divided into interacting fast and slow flow domains. We tracked each day's 20 infiltrated water through the critical zone and derived forward median travel times (which show how long the water takes to leave the soil via evaporation, transpiration or recharge), and median water ages (to estimate the median age of water in soil storage or the evaporation, transpiration and recharge fluxes). Resulting median travel times were time-variant, mainly governed by major recharge events during snow melt in Dorset and Krycklan or during the wetter winter conditions in Bruntland Burn. Transpiration travel times were driven by the vegetation growth period with 25 longest travel times (200 days) for waters infiltrated in early dormancy and shortest travel times during the vegetation period. However, long tails of the travel time distributions in evaporation and transpiration revealed that these fluxes comprised waters older than 100 days. At each study site, water ages of soil storage, evaporation, transpiration and recharge were all inversely related to the storage volume of the critical zone: water ages generally decreased exponentially with increasing soil water storage. During wet periods, young soil waters were more likely to be 30 evapotranspired and recharged than during drier periods. While the water in the slow flow domain showed long-term seasonal dynamics and generally old water ages, the water ages of the fast flow domain were generally younger and much flashier. Our results provide new insights into the mixing and transport processes of soil water in the upper layer of the critical zone, which is relevant for hydrological modelling at the plot to catchment scales as the common assumption of a well-mixed system in the subsurface neither holds for the evaporation, transpiration nor recharge. 35Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2018-144 Manuscript under review for journal Hydrol. Earth Syst. Sci. Discussion started: 27 March 2018 c Author(s) 2018. CC BY 4.0 License. 2 IntroductionWater ages are useful metrics to assess hydrological processes as they reveal interactions between storage and fluxes of water in a hydrological system (Hrachowitz et al.,...

show abstract

“…With the model presented here, we improve the conceptualisation of these internal catchment processes by using a more spatially distributed approach. We have also changed the interception of precipitation in the model compared with previous model work to more accurately characterise the influence of vegetation on water partitioning (Tetzlaff et al, ). At the same time, the aim was to keep the model relatively simple in order to derive a generic tool that can be applied across northern sites (Tetzlaff et al, ).…”

Section: Introductionmentioning

confidence: 99%

“…We have also changed the interception of precipitation in the model compared with previous model work to more accurately characterise the influence of vegetation on water partitioning (Tetzlaff et al, ). At the same time, the aim was to keep the model relatively simple in order to derive a generic tool that can be applied across northern sites (Tetzlaff et al, ). The main research aims of this study are therefore to: (1) develop a spatially explicit representation of water and tracer fluxes at the catchment scale using a conceptual spatially distributed, tracer‐aided runoff model, (2) understand how landscape structure affects the routing and mixing of water, (3) characterise how these interactions affect the dynamics of water ages in different components of the system and how this affects the non‐stationarity in stream water ages.…”

Section: Introductionmentioning

confidence: 99%

Using high resolution tracer data to constrain water storage, flux and age estimates in a spatially distributed rainfall‐runoff model

Huijgevoort

Tetzlaff

Sutanudjaja

et al. 2016

Hydrological Processes

View full text Add to dashboard Cite

Abstract:Models simulating stream flow and conservative tracers can provide a representation of flow paths, storage distributions and mixing processes that is advantageous for many predictive purposes. Compared with models that only simulate stream flow, tracer data can be used to investigate the internal consistency of model behaviour and to gain insight into model performance. Here, we examine the strengths and weaknesses of a data-driven, spatially distributed tracer-aided rainfall-runoff model. The model structure allowed us to assess the influence of landscape characteristics on the routing and mixing of water and tracers. The model was applied to a site in the Scottish Highlands with a unique tracer data set;~4 years of daily isotope ratios in stream water and precipitation were available, as well as 2 years of weekly soil and ground water isotopes. The model structure was based on an empirically based, lumped tracer-aided model previously developed for the catchment. The best model runs were selected from Monte Carlo simulations based on dual calibration criteria using objective functions for both stream isotopes and discharge at the outlet. Model performance for these criteria was reasonable (Nash-Sutcliffe efficiencies for discharge and isotope ratios were~0.4-0.6). The model could generally reproduce the variable isotope signals in the soils of the steeper hill slopes where storage was low, and damped isotope responses in valley bottom cells with high storage. The model also allowed us to estimate the age distributions of internal stores, water fluxes and stream flow. Average stream water age was~1.6 years, integrating older groundwater in the valley bottom and dynamic younger soil waters. By tracking water ages and simulating isotopes, the model captured the changes in connectivity driven by distributed storage dynamics. This has substantially improved the representation of spatio-temporal process dynamics and gives a more robust framework for projecting environmental change impacts.

show abstract

A preliminary assessment of water partitioning and ecohydrological coupling in northern headwaters using stable isotopes and conceptual runoff models

Cited by 67 publications

References 104 publications

Surface and subsurface water contributions to streamflow from a mesoscale watershed in complex mountain terrain

Surface and subsurface water contributions to streamflow from a mesoscale watershed in complex mountain terrain

Water ages in the critical zone of long-term experimental sites in northern latitudes

Using high resolution tracer data to constrain water storage, flux and age estimates in a spatially distributed rainfall‐runoff model

Contact Info

Product

Resources

About