Dry season plant water sourcing in contrasting tropical ecosystems of Costa Rica

Ecohydrology, Journal Year: 2023, Volume and Issue: 16(5)

Published: March 7, 2023

Abstract Tracer‐aided studies to understand plant water uptake sources and dynamics in tropical ecosystems are limited. Here, we report the analysis of dry season source patterns five unique Costa Rica across altitudinal (<150–3,400 m asl) latitudinal (Caribbean Pacific slopes) gradients: evergreen seasonal rainforests, cloud forest, Páramo forest. Soil samples were collected during 2021. Plant soil extractions conducted using centrifugation. Stem extracted volume stem total content calculated via gravimetric analysis. Water contributions estimated a Bayesian mixing model. Isotope ratios stems exhibited strong meteoric origin. Enrichment trends only detected cactus within forest ecosystem. profiles revealed nearly uniform isotopic profiles; however, depletion trend was observed ecosystem below 25 cm. More enriched compositions reported for volumes above ~20% ( adj. r 2 = 0.34, p < 0.01). The most prominent rainforest (74.0%), (86.4%) (66.0%) corresponded well‐mixed water. In ecosystem, recent rainfall produced by trade wind incursions resulted significant (61.9%), whereas mean annual precipitation (38.6%) baseflow (33.1%) dominant sources. latter highlights prevalence distinct between cold front (near‐surface storage) more moisture season, revealing ecohydrological processing previously unknown this region.

Language: Английский

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Tracer‐aided ecohydrological modelling across climate, land cover, and topographical gradients in the Tropics

Hydrological Processes, Journal Year: 2023, Volume and Issue: 37(5)

Published: April 19, 2023

Abstract Quantitative estimations of ecohydrological water partitioning into evaporation and transpiration remains mostly based on plot‐scale investigations that use well‐instrumented, small‐scale experimental catchments in temperate regions. Here, we attempted to upscale adapt the conceptual tracer‐aided ecohydrology model STARRtropics simulate partitioning, tracer, storage dynamics over daily time steps a 1‐km grid larger‐scale (2565 km 2 ) sparsely instrumented tropical catchment Costa Rica. The was driven by bias‐corrected regional climate outputs simultaneously calibrated against discharge observations from 30 years at four gauging stations 1‐year, monthly streamwater isotope record 46 streams. overall performance for best simulations ranged KGE values 0.4 0.6 correlation coefficients streamflow isotopes 0.3 0.45. More importantly, independent model‐derived estimates, point‐scale residence measured groundwater showed reasonable simulated spatial temporal patterns pointing towards an realism scale reduced headwaters. system dominated low‐seasonality high precipitation inputs marked topographical gradient. Climatic drivers overrode smaller, landcover‐dependent fluxes giving seemingly homogeneous rainfall‐runoff dominance likely related input bias rainfall isotopes, oversimplistic Potential Evapotranspiration (PET) estimates averaged Leaf Area Index (LAI). Topographic influences resulted more dynamic tracer headwaters further downstream aggregated scales. Modelled greater capacity nearly order magnitude compared lowlands, which also favoured slightly longer times (>250 days) superficially well‐connected contributing shorter (<150 lowlands. Our findings confirm modelling, even data‐scarce Tropics, can help gain first, but crucial approximation spatio‐temporal how is partitioned, stored transported beyond only few .

Language: Английский

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The Observed Isotopic Errors in Extreme Precipitation Leads to Overestimation of Long‐Term Soil‐Streamflow Hydrological Connectivity

Hydrological Processes, Journal Year: 2025, Volume and Issue: 39(4)

Published: April 1, 2025

ABSTRACT The tracer‐aided modelling has gained widespread attention in recent years as a crucial approach for investigating watershed hydrological functions. However, errors model inputs, such precipitation, evapotranspiration (ET) and isotopes can lead to uncertainty physically meaningful parameters, which, turn, affects the accurate depiction of In this study, we focused on Hemuqiao watershed, typical humid mountainous region southeast China, equipped with intensive isotopic monitoring. Two Reservoirs StorAge Selection (TRSAS) was adopted explore impact input data understanding connectivity preferential flow. results show that observation precipitation ET do not significantly reduce performance (with optimal NSE value decreasing by up 0.05). they increase simulation primarily due associated large events. contrast, observed particularly during extreme events, meanwhile significant differences some parameters compared no error data. Although proportion young water fraction streamflow does noticeable difference, proportions lateral subsurface flow tend be overestimated (i.e., approximately 0.14 0.08, respectively, average over long term). This an overestimation between soil streamflow. These findings suggest models, improving accuracy is more critical accurately processes than enhancing spatial observations ET.

Language: Английский

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Assessing land use effects on ecohydrological partitioning in the critical zone through isotope‐aided modelling

Earth Surface Processes and Landforms, Journal Year: 2023, Volume and Issue: 48(15), P. 3199 - 3219

Published: Sept. 11, 2023

Abstract Stable water isotopes are naturally occurring conservative tracers that can ‘fingerprint’ sources and track ecohydrological fluxes across the critical zone (CZ). Parsimonious, tracer‐aided models allow effective quantification of partitioning rainfall into different fluxes. We incorporated stable a one‐dimensional, model (EcoIsoPlot) to follow pathway precipitation through CZ at lowland catchment—the long‐term experimental Demnitzer Millcreek Catchment (DMC), Germany—with contrasting vegetation covers (forest, agroforestry, grassland arable). Precipitation (amount δ 2 H), potential evapotranspiration (PET), leaf area index (LAI), air temperature relative humidity were used as input data for modelling growing season 2021. The year had relatively average overall wetness, but dry, cold spring with snowfall, an exceptionally large summer storm event (~60 mm precipitation). Multi‐criteria calibration was conducted using depth‐specific soil moisture H measurements targets. novel incorporation constrained process representation estimated balance reasonable simulations uncertainty bounds partitioning. Throughout profile, dynamics isotope variations captured reasonably well. Green (evapotranspiration) highest forest site blue (groundwater recharge) grassland. Comparing (ET) measured groundwater table fluctuations added further confidence result. Overall, these may suggest slight underestimation ET overestimation recharge, though results similar previous findings. Our study demonstrated enhance simple, transferrable approaches in help improve consistency. Such low‐parameterised have major evidence‐based applications aid management stakeholder communication.

Language: Английский

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Nitrate Legacy in a Tropical and Complex Fractured Volcanic Aquifer System

Journal of Geophysical Research Biogeosciences, Journal Year: 2023, Volume and Issue: 128(8)

Published: July 18, 2023

Abstract Nitrate legacy is affecting groundwater sources across the tropics. This study describes isotopic and ionic spatial trends a tropical, fractured, volcanic multi‐aquifer system in central Costa Rica relation to land use change over four decades. Springs wells (from 800 2,400 m asl) were sampled for NO 3 − Cl concentrations, δ 18 O water , 15 N NO3 . A Bayesian isotope mixing model was used estimate potential source contributions nitrate groundwater. Land evaluated using satellite imagery from 1979 2019. The lower concentrations (<1 mg/L N) reported headwater springs near protected forested areas, while greater (up ∼63 mg/L) (mid‐ low‐elevation sites unconfined unit) springs. High‐elevation characterized by low moderate /Cl ratios, indicating influence of soil nitrogen (SN) inputs. Wells exhibited ratios above 100 μmol/L. calculations suggest mixture sewage (domestic septic tanks), SN (forested recharge areas), chemical fertilizers (coffee plantations), as direct result abrupt last 40 years. Our results confirm incipient trend increasing highlight urgent need multi‐municipal plan transition domestic tanks regional treatment sustainable agricultural practices prevent future quality degradation effectively.

Language: Английский

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Effects of passive-storage conceptualization on modeling hydrological function and isotope dynamics in the flow system of a cockpit karst landscape

Hydrology and earth system sciences, Journal Year: 2022, Volume and Issue: 26(21), P. 5515 - 5534

Published: Nov. 7, 2022

Abstract. Conceptualizing passive storage in coupled flow–isotope models can improve the simulation of mixing and attenuation effects on tracer transport many natural systems, such as catchments or rivers. However, effectiveness incorporating different conceptualizations complex karst flow systems remains poorly understood. In this study, we developed a model that conceptualizes both “fast-flow” “slow-flow” processes heterogeneous aquifers well hydrological connections between steep hillslopes low-lying depression units cockpit landscapes. The tested contrasting configurations fast- slow-flow was optimized using multi-objective optimization algorithm based detailed observational data discharge isotope dynamics Chenqi Catchment southwestern China. Results show one to three passive-storage zones distributed hillslope fast-/slow-flow reservoirs and/or provided optimal structures study catchment. This effectively accuracy for outlet signatures. Additionally, tracer-aided reflects dominant paths units, yielding reasonable source area apportionment components (e.g., more than ∼ 80 % fast total discharge) solute unit systems. Our provides novel, flexible tool realistic catchment easily be transferred other catchments.

Language: Английский

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Tracing Urban Drinking Water Sources: Global State of the Art and Insights From an IAEA‐Coordinated Research Project

Hydrological Processes, Journal Year: 2024, Volume and Issue: 38(10)

Published: Oct. 1, 2024

ABSTRACT Climate change, inter‐annual precipitation variability, recurrent droughts and flash flooding, coupled with increasing water needs, are shaping the co‐evolution of socioeconomic cultural assemblages, laws regulations, equitable drinking access allocation worldwide. Recognising need for mitigation strategies availability in urban areas, Isotope Hydrology Section International Atomic Energy Agency (IAEA) coordinated a state‐of‐the‐art global assessment to evaluate sources distribution supply centres, an initiative entitled ‘Use Techniques Evaluation Water Sources Domestic Supply Urban Areas (2018–2023)’. Here, we report on (a) current research trends studying systems during last two decades (b) development, testing integration new methodologies, aiming better assessment, mapping management resources used settings. Selected examples isotope applications (Canada, USA, Costa Rica, Ecuador, Morocco, Botswana, Romania, Slovenia, India Nepal) provide context insights recommendations reported highlight versatility isotopes underpin seasonal temporal variations across various environmental climate scenarios. The study revealed that areas depend large spectrum recharge mountain ranges, extensive local groundwater extraction transfer from nearby or distant river basins. latter is reflected spatial snapshot variability. High‐resolution monitoring (hourly sub‐hourly) sampling diurnal wet tropics (Costa Rica) (up 1.5‰ δ 18 O) more uniform centres fed by (0.08‰ (Ljubljana, Slovenia). Similarly, while d ‐excess was fairly close mean value (+10‰) all (10‰–15‰), reservoir‐based show lower values ~ −20‰) (Arlington, TX, USA Gaborone, Botswana), as result strong evapoconcentration processes. O time series depth‐integrated highlighted influence catchment damping ratio ultimate intake composition. By introducing new, traceable tools span source end‐user linked engineered socio‐economic structure system, governmental, regional community‐based operators practitioners could enhance treatment (including accurate surface blending estimations) improve conservation plans light warming.

Language: Английский

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Incorporating experimentally derived streamflow contributions into model parameterization to improve discharge prediction

Hydrology and earth system sciences, Journal Year: 2023, Volume and Issue: 27(6), P. 1325 - 1341

Published: March 28, 2023

Abstract. Environmental tracers have been used to separate streamflow components for many years. They allow us quantify the contribution of water originating from different sources, such as direct runoff precipitation, subsurface storm flow, or groundwater total at variable flow conditions. Although previous studies explored value incorporating experimentally derived fractions event and pre-event into hydrological models, a thorough analysis hydrograph-separation-derived information on multiple varying conditions model parameter estimation has not yet performed. This study explores achieve more realistic simulations catchment discharge. We use modified version process-oriented HBV that simulates discharge through interplay hillslope, riparian-zone discharge, small forested which is located in mountainous north South Korea, subject monsoon season between June August. Applying Monte-Carlo-based scheme Kling–Gupta efficiency (KGE) compare observations across two seasons (2013 2014), we show able provide accurate (KGE ≥ 0.8) but fails robust predictions estimates components. Using simple framework compares simulated observed contributions riparian zone, during sub-periods, precision can be increased, while remaining with simulations. further additional increases identifiability all parameters results predictions. Our shows how tracer-derived improve simulation scale without adding complexity model. The complementary temporally resolved modeling provides promising direction prediction by representing internal dynamics realistically.

Language: Английский

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Preface special issue: “Processes and patterns in tropical hydrology”

Hydrological Processes, Journal Year: 2023, Volume and Issue: 37(7)

Published: July 1, 2023

This is the preface to an SI.

Language: Английский

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Key controls on water transit times along a tropical precipitation gradient

Journal of Hydrology, Journal Year: 2024, Volume and Issue: 645, P. 132134 - 132134

Published: Oct. 10, 2024

Language: Английский

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