Browsing by Author "Mosquera, Giovanny"

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    Delineation of water flow paths in a tropical andean headwater catchment with deep soils and permeable bedrock
    (2022) Páez Bimos, Carlos Sebastián; Calispa Aguilar, Marlon Fabricio; Vanacker, Veerle; Zapata Ríos, Xavier; Muñoz Martínez, Teresa del Rocío; Crespo Sánchez, Patricio Javier; Lahuatte Imbaquingo, Braulio Cesar; Mosquera, Giovanny
    Traditional hydrometric data combined with environmental tracers such as water stable isotopes contributes to improve the understanding of catchment hydrology. Nevertheless, the application of isotopic tracers in headwater catchments of the tropical Andes with deep soils and permeable parent material influenced by recent volcanism remains limited. In this study, the stable isotopic composition of precipitation, soil water, wetlands, and streamflow was studied to provide insights into the hydrology of a small tropical Andean catchment with deep and permeable volcanic soils, ash layers, and fractured bedrock resulting from Holocene volcanic activity. Although local precipitation forms under isotopic equilibrium conditions, the stable isotopic composition of precipitation is influenced by atmospheric moisture recycling processes. The spatial and temporal variability of isotopic signals and the analysis of inverse transit time proxies (ITTPs) of surface (streamflow) and subsurface (soil and wetlands) waters indicate that vertical flow paths through the deep volcanic ash soils are dominant across the catchment. The strongly damped isotopic composition of these waters points to high soil and wetlands water storage, increasing the transit time or age of stream water in the hydrological system. These findings indicate that water mobilizing through subsurface flow paths–that is, volcanic soils, ash layers, and cracks in the fractured bedrock resulting from Holocene volcanism–is the main contributor to streamflow generation. Comparison with previously published work from Andean catchments and other volcanic areas shows the diversity of hydrological conditions that can be found as a result of pedological and lithological differences shaped by volcanic activity. Therefore, site-specific strategies may be needed to improve water resources management
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    Effect of land cover and hydro-meteorological controls on soil water doc concentrations in a high-elevation tropical environment
    (2018) Pesántez Vallejo, Juan Patricio; Mosquera, Giovanny; Crespo Sánchez, Patricio Javier; Breuer, Lutz; Windhorst, David
    Páramo soils store high amounts of organic carbon. However, the effects of climate change and changes in land cover and use (LC/LU) in this high-elevation tropical ecosystem may cause a decrease in their carbon storage capacity. Therefore, better understanding of the factors influencing the Páramo soils' carbon storage and export is urgently needed. To fill this knowledge gap, we investigated the differences in dissolved organic carbon (DOC) content in the soil water of four LC/LU types (tussock grass, natural forest, pine plantations, and pasture) and the factors controlling its variability in the Quinuas Ecohydrological Observatory in south Ecuador. Weekly measurements of soil water DOC concentrations, meteorological variables, soil water content, and temperature from various depths and slope positions were monitored within the soils' organic and mineral horizons between October 2014 and January 2017. These data were used to generate regression trees and random forest statistical models to identify the factors controlling soil water DOC concentrations. From high to low concentrations, natural forest depict the highest DOC concentrations followed by pasture, tussock grass, and pine forest. For all LC/LU types, DOC concentrations increase with decreasing soil moisture. Our results also show that LC/LU is the most important predictor of soil water DOC concentrations, followed by sampling depth and soil moisture. Interestingly, atmospheric variables and antecedent evapotranspiration and precipitation conditions show only little influence on DOC concentrations during the monitoring period. Our findings provide unique information that can help improve the management of soil and water resources in the Páramo and other peat dominated ecosystems elsewhere. © 2018 John Wiley & Sons, Ltd.
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    Identificación de las principales fuentes de agua que aportan a la generación de escorrentía en zonas Andinas de páramo húmedo: mediante el uso de los isótopos estables deuterio (δ2H) y oxígeno-18 (δ18O)
    (Universidad de Cuenca, 2012-12) Mosquera, Giovanny; Lazo, Patricio; Cárdenas, Irene; Crespo Sánchez, Patricio Javier; Universidad de Cuenca; Dirección de Investigación de la Universidad de Cuenca
    The hydrologic analysis of Andean páramo catchments is currently hindered by the limited existence of studies regarding the streamflow generation processes. To improve this situation and to provide a baseline for future hydrologic studies, an isotope fractionation analysis of deuterium (2H) and oxygen-18 (18O) was conducted on water samples collected biweekly between May 2011 and March 2012, within the Zhurucay river páramo micro-catchment (7,97 km2), located in the Ecuadorian austral region, between 3200 and 3800 m a.s.l. The monitoring points encompassed rainfall and runoff stations, and soil and spring water sampling points. Results reveal that pre-event water is the main source for streamflow generation during storm conditions, where the Histosols are the main contribution to the discharge. Andosols main function is to regulate runoff and recharge Histosols during normal conditions. The latter are recharged by virtue of their low-lying position in the landscape. During less humid conditions, results suggest that the Histosols are the main sources of discharge regulation. Similarly, there is no evidence of significant groundwater contribution to discharge.