Seasonal isotope hydrology of a coffee agroforestry watershed in Costa Rica
Improved information of seasonal variations in watershed hydrology in the tropics can strengthen models and understanding of hydrology of these areas. Seasonality in the tropics produces rainy seasons versus dry seasons, leading to different hydrologic and water quality processes throughout the year. We questioned whether stable isotopes in water can be used to trace the seasonality in this region, despite experiencing a “drier” season, such as in a Tropical Humid location. This study examines the fluctuations of stable isotope compositions (δ O and δD) in water balance components in a small (<1 km ) coffee agroforestry watershed located in central Costa Rica on the Caribbean side. Samples were collected in precipitation, groundwater, and stream water for more than two years, across seasons and at an hourly frequency during storm events to better characterize spatial and temporal variations of the isotopic composition and of the respective contribution of surface and deeper groundwater to streamflow in the watershed. Isotope composition in precipitation ranged from -18.5 to -0.3‰ (∂18O) and -136.4 to 13.7‰ (∂D), and data indicate that atmospheric moisture cycling plays an important role in this region. A distinct seasonality was observed in monthly-averaged data between enriched dry season events as compared with the rainy season events. Streamflow data indicate that a deep groundwater system contributes significantly to baseflow, although a shallow, spring-driven system also contributes to stream water within the watershed. During storm events, precipitation contributes to stormflow in the short-term, confirming the role of superficial runoff. These results indicate that isotopes are helpful to partition the water balance even in a Tropical Humid situation where the rainfall seasonality is weak.
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dig-cirad-fr-5787942020-05-14T08:02:05Z http://agritrop.cirad.fr/578794/ http://agritrop.cirad.fr/578794/ Seasonal isotope hydrology of a coffee agroforestry watershed in Costa Rica. Boll Jan, Welsh Kristen, Roupsard Olivier. 2014. . San Francisco : AGU, 1 p. AGU Fall Meeting, San Francisco, États-Unis, 15 Décembre 2014/19 Décembre 2014. Researchers Seasonal isotope hydrology of a coffee agroforestry watershed in Costa Rica Boll, Jan Welsh, Kristen Roupsard, Olivier eng 2014 AGU F08 - Systèmes et modes de culture P40 - Météorologie et climatologie Improved information of seasonal variations in watershed hydrology in the tropics can strengthen models and understanding of hydrology of these areas. Seasonality in the tropics produces rainy seasons versus dry seasons, leading to different hydrologic and water quality processes throughout the year. We questioned whether stable isotopes in water can be used to trace the seasonality in this region, despite experiencing a “drier” season, such as in a Tropical Humid location. This study examines the fluctuations of stable isotope compositions (δ O and δD) in water balance components in a small (<1 km ) coffee agroforestry watershed located in central Costa Rica on the Caribbean side. Samples were collected in precipitation, groundwater, and stream water for more than two years, across seasons and at an hourly frequency during storm events to better characterize spatial and temporal variations of the isotopic composition and of the respective contribution of surface and deeper groundwater to streamflow in the watershed. Isotope composition in precipitation ranged from -18.5 to -0.3‰ (∂18O) and -136.4 to 13.7‰ (∂D), and data indicate that atmospheric moisture cycling plays an important role in this region. A distinct seasonality was observed in monthly-averaged data between enriched dry season events as compared with the rainy season events. Streamflow data indicate that a deep groundwater system contributes significantly to baseflow, although a shallow, spring-driven system also contributes to stream water within the watershed. During storm events, precipitation contributes to stormflow in the short-term, confirming the role of superficial runoff. These results indicate that isotopes are helpful to partition the water balance even in a Tropical Humid situation where the rainfall seasonality is weak. conference_item info:eu-repo/semantics/conferenceObject Conference info:eu-repo/semantics/publishedVersion http://agritrop.cirad.fr/578794/1/Boll%20AGU_isotopes_poster_2014.pdf text cc_0 info:eu-repo/semantics/openAccess https://creativecommons.org/publicdomain/zero/1.0/ |
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F08 - Systèmes et modes de culture P40 - Météorologie et climatologie F08 - Systèmes et modes de culture P40 - Météorologie et climatologie Boll, Jan Welsh, Kristen Roupsard, Olivier Seasonal isotope hydrology of a coffee agroforestry watershed in Costa Rica |
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Improved information of seasonal variations in watershed hydrology in the tropics can strengthen models and understanding of hydrology of these areas. Seasonality in the tropics produces rainy seasons versus dry seasons, leading to different hydrologic and water quality processes throughout the year. We questioned whether stable isotopes in water can be used to trace the seasonality in this region, despite experiencing a “drier” season, such as in a Tropical Humid location. This study examines the fluctuations of stable isotope compositions (δ O and δD) in water balance components in a small (<1 km ) coffee agroforestry watershed located in central Costa Rica on the Caribbean side. Samples were collected in precipitation, groundwater, and stream water for more than two years, across seasons and at an hourly frequency during storm events to better characterize spatial and temporal variations of the isotopic composition and of the respective contribution of surface and deeper groundwater to streamflow in the watershed. Isotope composition in precipitation ranged from -18.5 to -0.3‰ (∂18O) and -136.4 to 13.7‰ (∂D), and data indicate that atmospheric moisture cycling plays an important role in this region. A distinct seasonality was observed in monthly-averaged data between enriched dry season events as compared with the rainy season events. Streamflow data indicate that a deep groundwater system contributes significantly to baseflow, although a shallow, spring-driven system also contributes to stream water within the watershed. During storm events, precipitation contributes to stormflow in the short-term, confirming the role of superficial runoff. These results indicate that isotopes are helpful to partition the water balance even in a Tropical Humid situation where the rainfall seasonality is weak. |
format |
conference_item |
topic_facet |
F08 - Systèmes et modes de culture P40 - Météorologie et climatologie |
author |
Boll, Jan Welsh, Kristen Roupsard, Olivier |
author_facet |
Boll, Jan Welsh, Kristen Roupsard, Olivier |
author_sort |
Boll, Jan |
title |
Seasonal isotope hydrology of a coffee agroforestry watershed in Costa Rica |
title_short |
Seasonal isotope hydrology of a coffee agroforestry watershed in Costa Rica |
title_full |
Seasonal isotope hydrology of a coffee agroforestry watershed in Costa Rica |
title_fullStr |
Seasonal isotope hydrology of a coffee agroforestry watershed in Costa Rica |
title_full_unstemmed |
Seasonal isotope hydrology of a coffee agroforestry watershed in Costa Rica |
title_sort |
seasonal isotope hydrology of a coffee agroforestry watershed in costa rica |
publisher |
AGU |
url |
http://agritrop.cirad.fr/578794/ http://agritrop.cirad.fr/578794/1/Boll%20AGU_isotopes_poster_2014.pdf |
work_keys_str_mv |
AT bolljan seasonalisotopehydrologyofacoffeeagroforestrywatershedincostarica AT welshkristen seasonalisotopehydrologyofacoffeeagroforestrywatershedincostarica AT roupsardolivier seasonalisotopehydrologyofacoffeeagroforestrywatershedincostarica |
_version_ |
1758024783004434432 |