Person:
Célleri Alvear, Rolando Enrique

Birth Date

1975-04-07

ORCID

0000-0002-7683-3768

Scopus Author ID

15060963700

Afiliación

Universidad de Cuenca, Cuenca, Ecuador
Universidad de Cuenca, Departamento de Recursos Hídricos y Ciencias Ambientales, Cuenca, Ecuador
Universidad de Cuenca, Facultad de Ingeniería, Cuenca, Ecuador
Universidad de Cuenca, Facultad de Ciencias Agropecuarias, Cuenca, Ecuador

Organizational Units

Organizational Unit

Facultad de Ingeniería

La Facultad de Ingeniería, a inicios de los años 60, mediante resolución del Honorable Consejo Universitario, se formalizó la Facultad de Ingeniería de la Universidad de Cuenca, conformada por las escuelas de Ingeniería Civil y Topografía. Esta nueva estructura permitió una mayor especialización y fortalecimiento en áreas clave para el desarrollo regional. Cuenta con programas académicos reconocidos internacionalmente, que promueven y lideran actividades de investigación. Aplica un modelo educativo centrado en el estudiante y con procesos de mejora continua. Establece como prioridad una educación integra, la formación humanística es parte del programa de estudios que complementa a la sólida preparación científico-técnica. Las actividades culturales pertenecen a un programa permanente y activo al interior de nuestras dependencias, a la par de proyectos que desde el alumnado y bajo la supervisión de docentes cumplen con servicios de apoyo a nivel local y regional; promoviendo así una vinculación estrecha con la comunidad.

Job Title

Profesor (T)

Last Name

Célleri Alvear

First Name

Rolando Enrique

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Now showing 1 - 10 of 23

Evaluation of the Penman-Monteith (FAO 56 PM) Method for Calculating Reference Evapotranspiration Using Limited Data
(INTERNATIONAL MOUNTAIN SOCIETY, 2015-08-01) Córdova Mora, Mario Andrés; Carrillo Rojas, Galo José; Célleri Alvear, Rolando Enrique; Crespo Sánchez, Patricio Javier
(Figure Presented) Reference evapotranspiration (ETo) is often calculated using the Penman-Monteith (FAO 56 PM; Allen et al 1998) method, which requires data on temperature, relative humidity, wind speed, and solar radiation. But in high-mountain environments, such as the Andean páramo, meteorological monitoring is limited and high-quality data are scarce. Therefore, the FAO 56 PM equation can be applied only through the use of an alternative method suggested by the same authors that substitutes estimates for missing data. This study evaluated whether the FAO 56 PM method for estimating missing data can be effectively used for páramo landscapes in the high Andes of southern Ecuador. Our investigation was based on data from 2 automatic weather stations at elevations of 3780 m and 3979 m. We found that using estimated wind speed data has no major effect on calculated ETo but that if solar radiation data are estimated, ETo calculations may be erroneous by as much as 24%; if relative humidity data are estimated, the error may be as high as 14%; and if all data except temperature are estimated, errors higher than 30% may result. Our study demonstrates the importance of using high-quality meteorological data for calculating ETo in the wet páramo landscapes of southern Ecuador.
Atmosphere-surface fluxes modeling for the high Andes: the case of páramo catchments of Ecuador
(2020) Carrillo Rojas, Galo José; Schulz, Hans Martin; Orellana Alvear, Johanna Marlene; Ochoa Sánchez, Ana Elizabeth; Trachte, Katja; Célleri Alvear, Rolando Enrique; Bendix, Jorg
© 2019 Elsevier B.V. Interest in atmosphere-surface flux modeling over the mountainous regions of the globe has increased recently, with a major focus on the prediction of water, carbon and other functional indicators in natural and disturbed conditions. However, less research has been centered on exploring energy fluxes (net radiation; sensible, latent and soil heat) and actual evapotranspiration (ETa) over the Neotropical Andean biome of the páramo. The present study assesses the implementation and parameterization of a state-of-art Land-Surface Model (LSM) for simulation of these fluxes over two representative páramo catchments of southern Ecuador. We evaluated the outputs of the LSM Community Land Model (CLM ver. 4.0) with (i) ground-level flux observations from the first (and highest) Eddy Covariance (EC) tower of the Northern Andean páramos; (ii) spatial ETa estimates from the energy balance-based model METRIC (based on Landsat imagery); and (iii) derived ETa from the closure of the water balance (WB). CLM's energy predictions revealed a significant underestimation on net radiation, which impacts the sensible and soil heat fluxes (underestimation), and delivers a slight overestimation on latent heat flux. Modeled CLM ETa showed acceptable goodness-of-fit (Pearson R = 0.82) comparable to ETa from METRIC (R = 0.83). Contrarily, a poor performance of ETa WB was observed (R = 0.46). These findings provide solid evidence on the CLM's accuracy for the ETa modeling, and give insights in the selection of other ETa methods. The study contributes to a better understanding of ecosystem functioning in terms of water loss through evaporative processes, and might help in the development of future LSMs’ implementations focused on climate / land use change scenarios for the páramo.
Probabilistic forecasting of drought events using Markov chain- and Bayesian network-based models: A case study of an Andean regulated river basin
(MDPI AG, 2016-01-01) Avilés Añazco, Alex Manuel; Célleri Alvear, Rolando Enrique
The scarcity of water resources in mountain areas can distort normal water application patterns with among other effects, a negative impact on water supply and river ecosystems. Knowing the probability of droughts might help to optimize a priori the planning and management of the water resources in general and of the Andean watersheds in particular. This study compares Markov chain- (MC) and Bayesian network- (BN) based models in drought forecasting using a recently developed drought index with respect to their capability to characterize different drought severity states. The copula functions were used to solve the BNs and the ranked probability skill score (RPSS) to evaluate the performance of the models. Monthly rainfall and streamflow data of the Chulco River basin, located in Southern Ecuador, were used to assess the performance of both approaches. Global evaluation results revealed that the MC-based models predict better wet and dry periods, and BN-based models generate slightly more accurately forecasts of the most severe droughts. However, evaluation of monthly results reveals that, for each month of the hydrological year, either the MC- or BN-based model provides better forecasts. The presented approach could be of assistance to water managers to ensure that timely decision-making on drought response is undertaken.
Dynamics of precipitation anomalies in tropical South America
(2022) Célleri Alvear, Rolando Enrique; Córdova Mora, Mario Andrés; Van Delden, Aarnout
In this study, precipitation in Tropical South America in the 1931–2016 period is investigated by means of Principal Component Analysis and composite analysis of circulation fields. The associated dynamics are analyzed using the 20th century ERA-20C reanalysis. It is found that the main climatic processes related to precipitation anomalies in Tropical South America are: (1) the intensity and position of the South Atlantic Convergence Zone (SACZ); (2) El Niño Southern Oscillation (ENSO); (3) the meridional position of the Intertropical Convergence Zone (ITCZ), which is found to be related to Atlantic Sea Surface Temperature (SST) anomalies; and (4) anomalies in the strength of the South American Monsoon System, especially the South American Low-Level Jet (SALLJ). Interestingly, all of the analyzed anomalies are related to processes that operate from the Atlantic Ocean, except for ENSO. Results from the present study are in agreement with the state of the art literature about precipitation anomalies in the region. However, the added strength of the longer dataset and the larger study area improves the knowledge and gives new insights into how climate variability and the resulting dynamics are related to precipitation in Tropical South America.
Variability in evapotranspiration in the Andean páramo as influenced by fog and rainfall
(2024) Berrones Guapulema, Gina Marcela; Crespo Sánchez, Patricio Javier; Carrillo Rojas, Galo José; Célleri Alvear, Rolando Enrique
Tropical mountains such as the páramos of the Andes, which serve as ‘water towers’ for local communities and downstream cities, are important areas for early detection of climate change. Here, fog and low-intensity rainfall are very common and play a key role in ecohydrological processes. Although evapotranspiration (ET) represents an important part of the water cycle, how ET and fog processes interact and how they affect páramo vegetation and water resources availability are poorly understood. This study investigated the effects of foggy (fog only) and mixed (fog and rainfall) conditions on ET. To determine whether fog significantly reduces ET, we compared ET and meteorological data under these two conditions with those during dry days. We found that on foggy days, when fog was most prevalent in the early morning, ET declined on average by 4% and net radiation (Rn) by 9.2%. Under mixed conditions, daily ET declined by 42% and Rn by 33%. In the páramo, where mean annual precipitation and ET are 1210 and 635 mm, respectively, the estimated annual reduction in ET due to fog and rainfall combined is between 77 and 174 mm. We found that during fog and rainfall mixed conditions, solar radiation was reduced, consequently constraining the energy available for ET while sustaining high relative humidity, ultimately reducing water loss. Our findings, which suggest that the presence of fog and low-intensity rainfall restricts water losses by evaporative demand, contribute to a better understanding of the ecohydrological importance of these water inputs in the Andes.
Improving reference evapotranspiration (ETo) calculation under limited data conditions in the high Tropical Andes
(2022) Carrillo Rojas, Galo José; Córdova Mora, Mario Andrés; Vásquez Ojeda, Cristina Alejandra; Célleri Alvear, Rolando Enrique
The computation of the reference crop evapotranspiration (ETo) using the FAO56 Penman-Monteith equation (PM-ETo) requires data on maximum and minimum air temperatures (Tmax, Tmin), relative humidity (RH), solar radiation (Rs), and wind speed (u2). However, the records of meteorological variables are often incomplete or of poor quality. Frequently, in the mountain areas such as those of the Andes, environmental sensors are subject to harsh conditions, due to the diurnal/nocturnal climatic variability causing challenging conditions for meteorological monitoring, which leads to data loss. For high-elevation landscapes like the Andes, the missing variables of vapor pressure deficit and solar radiation cause a high impact on PM-ETo calculation. To assess these limitations, several methods relying on maximum and minimum temperature to estimate the missing variables have been considered in the present investigation. Based on data from three automatic weather stations in the high Tropical Andes (humid páramo, 3298 – 3955 m a.s.l.), we found that the calibration and validation of methods were essential to estimate Rs. Using the (De Jong and Stewart, 1993) (Rs-DS) method we retrieved the highest performance, a RMSE between 2.89 and 3.81 MJ m−2 day−1. Moreover, In the absence of RH observations, replacing the dew point temperature (Tdew) by Tmin was a reliable alternative, when apply the method of (Allen et al., 1998) (VPD-FAO) which showed the highest performance with RMSE between 0.08 and 0.12 kPa. These results yielded highly accurate PM-ETo estimates, with RMSE between 0.29 and 0.34 mm day−1 and RMSE between 0.12 and 0.18 mm day−1, respectively. As expected, when both variables were missing, the ETo calculation increased its error, with an RMSE between 0.32 and 0.42 mm day−1. A proper estimation of ETo in the Andean páramo contributes to improved water productivity for domestic and industrial uses, irrigated agriculture, and hydropower.
The breathing of the andean highlands: net ecosystem exchange and evapotranspiration over the páramo of southern Ecuador
(2019) Carrillo Rojas, Galo José; Silva, Brenner; Rollenbeck, Rütger; Célleri Alvear, Rolando Enrique; Bendix, Jorg
Atmospheric carbon (CO 2) exchange, evapotranspiration (ET) processes, and their interactions with climatic drivers across tropical alpine grasslands are poorly understood. This lack of understanding is particularly evident for the páramo, the highest vegetated frontier in the northern Andes, the main source of water for inter-Andean cities, and a large carbon storage area. Studies of CO 2 and ET fluxes via the standard Eddy Covariance (EC) technique have never been applied to this region, limiting the understanding of diurnal / nocturnal exchanges and budget estimations. In this paper, we report the first EC analysis conducted on the Andean páramo (3765 m a.s.l.); this analysis measured CO 2, ET, and micrometeorological variables over two years (2016–2018) to understand their interactions with climatic / biophysical controls. The páramo was found to be a source of CO 2 and exhibited a net positive exchange …
A field, laboratory, and literature review evaluation of the water retention curve of volcanic ash soils: How well do standard laboratory methods reflect field conditions?
(2021) Jan, Feyen; Marin Molina, Franklin Geovanny; Mosquera Rojas, Giovanny Mauricio; Crespo Sánchez, Patricio Javier; Windhorst, David; Lutz, Breuer; Célleri Alvear, Rolando Enrique
Accurate determination of the water retention curve (WRC) of a soil is essential for the understanding and modelling of the subsurface hydrological, ecological, and biogeochemical processes. Volcanic ash soils with andic properties (Andosols) are recognized as important providers of ecological and hydrological services in mountainous regions worldwide due to their large fraction of small size particles (clay, silt, and organic matter) that gives them an outstanding water holding capacity. Previous comparative analyses of in situ (field) and standard laboratory methods for the determination of the WRC of Andosols showed contrasting results. Based on an extensive analysis of laboratory, experimental, and field measured WRCs of Andosols in combination with data extracted from the published literature we show that standard laboratory methods using small soil sample volumes (?300 cm3) mimic the WRC of these soils only partially. The results obtained by the latter resemble only a small portion of the wet range of the Andosols' WRC (from saturation up to ?5 kPa, or pF 1.7), but overestimate substantially their water content for higher matric potentials. This discrepancy occurs irrespective of site-specific land use and cover, soil properties, and applied method. The disagreement limits our capacity to infer correctly subsurface hydrological behaviour, as illustrated through the analysis of long-term soil moisture and matric potential data from an experimental site in the tropical Andes. These findings imply that results reported in past research should be used with caution and that future research should focus on determining laboratory methods that allow obtaining a correct characterization of the WRC of Andosols. For the latter, a set of recommendations and future directions to solve the identified methodological issues is proposed.
Overcast sky condition prevails on and influences the biometeorology of the tropical Andean Páramos
(2023) Montenegro Díaz, Paola Fernanda; Célleri Alvear, Rolando Enrique; Carrillo Rojas, Galo José
Clouds play a major role in modulating the biometeorological processes. We studied the influence of cloudiness on four biometeorological variables: daily air temperature (Tair), relative humidity (RH), reference evapotranspiration (ETr), and photosynthetic active radiation (PAR), recorded at four sites of Andean Páramos in southern Ecuador during 2.5 to 5.5 years. First, we quantified both the cloud cover percentage (Cloud%) creating cloud masks over the visible bands of Landsat 7 images and the sky condition (KT) using the records of solar and extraterrestrial radiation. Second, we estimated KT from Cloud%. Finally, we quantified Tair, RH, ETr, and PAR under clear, cloudy, and overcast KT and their dependence on KT. The average Cloud% ranged between 65%–76%, and KT corroborated the prevailing overcast sky (between 55% and 72.5% of the days) over the páramos. The proposed model performed well in the sites of calibration (R2 = 0.80; MBE = 0.00; RMSE = 0.05) and validation (R2 = 0.74; MBE = -0.07; RMSE = 0.11). The overcast sky diminished Tair (≤ 10oC), ETr (≤ 1.6 mm day-1), and PAR (4 MJ m-2 day-1) and increased RH (≥ 88%), while the variables showed the opposite behavior during the uncommon clear sky (≤ 5.5% of the days). Thus, mostly the dynamic of RH (R2 ≥ 0.62), ETr (R ≥ 0.85), and PAR (R2 ≥ 0.77) depended on KT. Hence, the prevailing overcast sky influenced the biometeorology of the páramos.
Interactions between leaf area index, canopy density and effective precipitation of a polylepis reticulata forest located in a paramo ecosystem
(2021) Suqui Velásquez, Amanda Magali; Carrillo Rojas, Galo José; Crespo Sánchez, Patricio Javier; Célleri Alvear, Rolando Enrique
The measurement of vegetation cover is fundamental to quantify the precipitation percentage intercepted by it. The most widely techniques used to measure the cover in situ are the leaf area index (LAI) and the canopy density (CD). However, no attention has been paid to the differences recorded in the use of the two techniques or how these variables influence the hydrological balance on the throughfall (TF). For this reason, the objective of the study is to evaluate the relationship between vegetation cover measurements conducted by the LAI and CD methods and to identify how they relate with the TF, important for hydrological applications. The study was developed in a Polylepis reticulata forest of 15633 m2 , located at the Zhurucay Ecohydrological Observatory, south of Ecuador, in an altitudinal range of 3765 to 3809 m.a.s.l. The LAI was measured with the CI-110 Plant Canopy Imager equipment and CD with a spherical densiometer, covering a wide range of canopy cover values. The study site was instrumented with 9 tipping-bucket rain gauges to measure TF. The results indicate that LAI and CD averages are 2.43 m2 m−2 y 88% respectively; whose relationship is significant (R2 = 0.913; p< 0.05). Mean annual TF is 773.2 mm, which tends to decrease with the increase of the LAI and CD; although, their relationship is not statistically significant (p-value> 0.05). This study shows the importance of characterizing the vegetation cover to understand the interaction with TF