Iongel Durán Llacer | Universidad de Concepción (original) (raw)

Papers by Iongel Durán Llacer

The climatic trends observed throughout the Caribbean in the last decades show an increase in the... more The climatic trends observed throughout the Caribbean in the last decades show an increase in the frequency and intensity of the drought. In Cuba exists a close link between the significant drought events and the influence of strong anticyclonic systems, that acts against the development of any kind of rain amount. Therefore, the importance of researching how much it rains and how often and the intensity of it. This work analyzes the behavior of the amount of rainy days in total and by intervals in the central regions of Cuba, the possible relation with the occurrence of significant droughts events from 1981 to 2010. The statistical software Statgraphics 5.1 and Microsoft Office Excel 2016 were used to obtain the trend and statistical parameters of rainy days in 19 weather stations. The spatial distribution was made through the Geographic Information System ArcGIS (v 2.14). The decile method was used to analyze the highest deficit periods of rainy days and It were related to meteoro...

El presente trabajo examina la cantidad de dias con lluvia total y su distribucion por intervalos... more El presente trabajo examina la cantidad de dias con lluvia total y su distribucion por intervalos de distintas magnitudes en el occidente de Cuba, durante los periodos estacionales lluvioso (mayo-octubre) y poco lluvioso (noviembre-abril), y se establece su relacion con la ocurrencia de eventos secos en el periodo lluvioso. Para este objetivo se utilizaron series de dias con lluvia del periodo 1981-2010, coleccionadas en 20 estaciones meteorologicas del Instituto de Meteorologia, situadas en zonas costeras e interiores. Su proceso se realizo mediante los paquetes estadisticos Excel 2010, Statistica v. 7.0, aplicandose los estadigrafos de Spearman, Pettit y Kendall Man (software WinStat, v. 2.0), con miras a determinar tendencias y cambios en valores por decenios e intervalos. El metodo de los deciles se empleo para relacionar la cantidad de dias con lluvia y la ocurrencia de eventos secos. Los resultados principales incluyen una climatologia actualizada de la variable, que recoge la...

Water, 2020

Groundwater (GW) is the primary source of unfrozen freshwater on the planet and in many semi-arid... more Groundwater (GW) is the primary source of unfrozen freshwater on the planet and in many semi-arid areas, it is the only source of water available during low-water periods. In north-central Chile, there has been GW depletion as a result of semi-arid conditions and high water demand, which has unleashed major social conflicts, some due to drought and others due to agribusiness practices against the backdrop of a private water management model. The Ligua and Petorca watersheds in the Valparaíso Region were studied in order to analyze the influence of climatic and anthropogenic factors on aquifer depletion using an interdisciplinary approach that integrates hydroclimatic variables, remote sensing data techniques, and GW rights data to promote sustainable GW management. The Standardized Precipitation Index (SPI) and Normalized Difference Vegetation Index (NDVI) were calculated and the 2002–2017 land-use change was analyzed. It was shown that GW decreased significantly (in 75% of the well...

Ecological Informatics, 2020

Abstract In this study remote sensing was used as an early alert tool for chlorophyll-a changes i... more Abstract In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a continental aquatic ecosystem in central Chile. To this end, 14 LANDSAT images of Laja Lake (36° 54 'S, 71° 05' W, 1,360 meters above sea level) were taken over a 6-year period. Eleven spectral indexes were calculated. At the same time, chlorophyll-a concentrations were determined experimentally. Correlations between vegetation indices and chlorophyll-a concentrations in different monitoring zones were established. The indices that presented a good correlation were NDVI and GNDVI. A new regression model was developed that allows the primary productivity values of Laja Lake to be estimated using satellite data. Finally, chlorophyll-a maps were created.

In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a conti... more In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a continental aquatic ecosystem in central Chile. To this end, 14 LANDSAT images of Laja Lake (36 • 54 'S, 71 • 05' W, 1,360 meters above sea level) were taken over a 6-year period. Eleven spectral indexes were calculated. At the same time, chlorophyll-a concentrations were determined experimentally. Correlations between vegetation indices and chlorophyll-a concentrations in different monitoring zones were established. The indices that presented a good correlation were NDVI and GNDVI. A new regression model was developed that allows the primary productivity values of Laja Lake to be estimated using satellite data. Finally, chlorophyll-a maps were created.

The climatic trends observed in Mesoamerica and the Caribbean in the last decades, associated to ... more The climatic trends observed in Mesoamerica and the Caribbean in the last decades, associated to the increase of climatic variability and climate change show the increase of the frequency and intensity of the drought, reason why their effective knowledge is essential for the reduction the risks that are associated. In Cuba there is a close link between the development of significant drought events and the establishment of a persistent influence of strong anticyclonic systems on the area, unfavorable for the development of rains. The study of this multi-causal phenomenon is a very important endeavor, as is the deficit of days with rain in dry periods and their relation with the atmospheric conditions related to the drought. Was examined for the region, the behavior geopotential surfaces in different tropospheric levels, the magnitudes of the vertical movements represented by the Omega variable, gradations of longwave radiation (OLR), the surface of relative humidity and the presence ...

Ecological Informatics, 2020

In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a conti... more In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a continental aquatic ecosystem in central Chile. To this end, 14 LANDSAT images of Laja Lake (36 • 54 'S, 71 • 05' W, 1,360 meters above sea level) were taken over a 6-year period. Eleven spectral indexes were calculated. At the same time, chlorophyll-a concentrations were determined experimentally. Correlations between vegetation indices and chlorophyll-a concentrations in different monitoring zones were established. The indices that presented a good correlation were NDVI and GNDVI. A new regression model was developed that allows the primary productivity values of Laja Lake to be estimated using satellite data. Finally, chlorophyll-a maps were created.

Water, 2020

Groundwater (GW) is the primary source of unfrozen freshwater on the planet and in many semi-arid... more Groundwater (GW) is the primary source of unfrozen freshwater on the planet and in many semi-arid areas, it is the only source of water available during low-water periods. In north-central Chile, there has been GW depletion as a result of semi-arid conditions and high water demand, which has unleashed major social conflicts, some due to drought and others due to agribusiness practices against the backdrop of a private water management model. The Ligua and Petorca watersheds in the Valparaíso Region were studied in order to analyze the influence of climatic and anthropogenic factors on aquifer depletion using an interdisciplinary approach that integrates hydroclimatic variables, remote sensing data techniques, and GW rights data to promote sustainable GW management. The Standardized Precipitation Index (SPI) and Normalized Difference Vegetation Index (NDVI) were calculated and the 2002-2017 land-use change was analyzed. It was shown that GW decreased significantly (in 75% of the wells) and that the hydrological drought was moderate and prolonged (longest drought in the last 36 years). The avocado-growing area in Ligua increased significantly-by 2623 ha-with respect to other agricultural areas (higher GW decrease), while in Petorca, it decreased by 128 ha. In addition, GW-rainfall correlations were low and GW rights were granted continuously despite the drought. The results confirmed that aquifer depletion was mostly influenced by human factors due to overexploitation by agriculture and a lack of water management.

Resumen Las tendencias climáticas observadas en Meso América y el Caribe en las últimas décadas, ... more Resumen Las tendencias climáticas observadas en Meso América y el Caribe en las últimas décadas, asociadas al incremento de la variabilidad climática y el cambio climático muestran el aumento de la frecuencia e intensidad de la sequía, por lo que su eficaz conocimiento, resulta esencial para la reducción de los riesgos que le están asociados. En Cuba existe un estrecho vínculo entre el desarrollo de significativos eventos de sequía y el establecimiento de una persistente influencia de fuertes sistemas anticiclónicos sobre el área, desfavorables para el desarrollo de las lluvias. El estudio de este fenómeno multicausal resulta un empeño bien importante, como lo constituye el déficit de días con lluvia en períodos secos y su relación con las condiciones atmosféricas vinculadas a la sequía. Se examinó para la región, el comportamiento de las superficies geopotenciales en diferentes niveles troposféricos, las magnitudes de los movimientos verticales representados por la variable Omega, las gradaciones de la radiación de onda larga (OLR), la superficie de humedad relativa y la presencia de la vaguada de niveles medios en el mes de junio, asociados a los días con lluvia expresados en rango deciles. Los datos proceden del Laboratorio de Investigaciones del Sistema Tierra (ESRL) de la National Oceanic and Atmospheric Administration (NOAA). Los resultados confirmaron que el establecimiento de fuertes anomalías positivas en sistemas anticiclónicos dominantes, reveladas por las características de las variables climatológicas estudiadas, limitaron la convección y el contenido de humedad todo lo cual impidió que se produjera una normal presencia de los días con lluvia, resultando estrechamente relacionados con períodos significativos de sequías.

In this article the number of days with total rainfall and its distribution by intervals of diffe... more In this article the number of days with total rainfall and its distribution by intervals of different magnitudes of rain in western Cuba is examined, during rainy seasonal periods (May to October) and dry seasons (November to April) and it was established their relationship with the occurrence of dry events in the rainy season. Series of rainy days in the period from 1981 to 2010, collected in 20 meteorological stations of the Meteorological Institute, located in coastal and inland areas were used for this purpose. Their trial was performed using the statistical software Excel 2010 Statistica v. 7.0, applied statisticians Spearman and Kendall Pettit Man (WinStat software, v. 2.0) to determine changes in trends and values for decades and intervals. The method of deciles was used to relate the number of days with rain and the occurrence of dry events. The main results include an updated version of the variable weather, which reflects the spatial representation of the magnitudes and variations of the most significant indices. It was demonstrated that significant events during drought, reducing the number of days with rain, occurs similarly in all tested intervals, which disagrees with the view that significant events associated with drought deficit are essentially higher than 50 mm of rains. It is also revealed that in the intervals from 50 mm to 100 mm and above 100 mm the wet days show a statistically significant increasing trend. These results are of great interest to many activities associated with agriculture and other branches of the economy, society and the environment that are related to the behavior of rainfall, its features, natural variability and even the influence that climate change exerts on them.

In this article the number of days with total rainfall and its distribution by intervals of diffe... more In this article the number of days with total rainfall and its distribution by intervals of different magnitudes of rain in western Cuba is examined, during rainy seasonal periods (May to October) and dry seasons (November to April) and it was established their relationship with the occurrence of dry events in the rainy season. Series of rainy days in the period from 1981 to 2010, collected in 20 meteorological stations of the Meteorological Institute, located in coastal and inland areas were used for this purpose. Their trial was performed using the statistical software Excel 2010 Statistica v. 7.0, applied statisticians Spearman and Kendall Pettit Man (WinStat software, v. 2.0) to determine changes in trends and values for decades and intervals. The method of deciles was used to relate the number of days with rain and the occurrence of dry events. The main results include an updated version of the variable weather, which reflects the spatial representation of the magnitudes and variations of the most significant indices. It was demonstrated that significant events during drought, reducing the number of days with rain, occurs similarly in all tested intervals, which disagrees with the view that significant events associated with drought deficit are essentially higher than 50 mm of rains. It is also revealed that in the intervals from 50 mm to 100 mm and above 100 mm the wet days show a statistically significant increasing trend. These results are of great interest to many activities associated with agriculture and other branches of the economy, society and the environment that are related to the behavior of rainfall, its features, natural variability and even the influence that climate change exerts on them.

The climatic trends observed throughout the Caribbean in the last decades show an increase in the... more The climatic trends observed throughout the Caribbean in the last decades show an increase in the frequency and intensity of the drought. In Cuba exists a close link between the significant drought events and the influence of strong anticyclonic systems, that acts against the development of any kind of rain amount. Therefore, the importance of researching how much it rains and how often and the intensity of it. This work analyzes the behavior of the amount of rainy days in total and by intervals in the central regions of Cuba, the possible relation with the occurrence of significant droughts events from 1981 to 2010. The statistical software Statgraphics 5.1 and Microsoft Office Excel 2016 were used to obtain the trend and statistical parameters of rainy days in 19 weather stations. The spatial distribution was made through the Geographic Information System ArcGIS (v 2.14). The decile method was used to analyze the highest deficit periods of rainy days and It were related to meteoro...

El presente trabajo examina la cantidad de dias con lluvia total y su distribucion por intervalos... more El presente trabajo examina la cantidad de dias con lluvia total y su distribucion por intervalos de distintas magnitudes en el occidente de Cuba, durante los periodos estacionales lluvioso (mayo-octubre) y poco lluvioso (noviembre-abril), y se establece su relacion con la ocurrencia de eventos secos en el periodo lluvioso. Para este objetivo se utilizaron series de dias con lluvia del periodo 1981-2010, coleccionadas en 20 estaciones meteorologicas del Instituto de Meteorologia, situadas en zonas costeras e interiores. Su proceso se realizo mediante los paquetes estadisticos Excel 2010, Statistica v. 7.0, aplicandose los estadigrafos de Spearman, Pettit y Kendall Man (software WinStat, v. 2.0), con miras a determinar tendencias y cambios en valores por decenios e intervalos. El metodo de los deciles se empleo para relacionar la cantidad de dias con lluvia y la ocurrencia de eventos secos. Los resultados principales incluyen una climatologia actualizada de la variable, que recoge la...

Water, 2020

Groundwater (GW) is the primary source of unfrozen freshwater on the planet and in many semi-arid... more Groundwater (GW) is the primary source of unfrozen freshwater on the planet and in many semi-arid areas, it is the only source of water available during low-water periods. In north-central Chile, there has been GW depletion as a result of semi-arid conditions and high water demand, which has unleashed major social conflicts, some due to drought and others due to agribusiness practices against the backdrop of a private water management model. The Ligua and Petorca watersheds in the Valparaíso Region were studied in order to analyze the influence of climatic and anthropogenic factors on aquifer depletion using an interdisciplinary approach that integrates hydroclimatic variables, remote sensing data techniques, and GW rights data to promote sustainable GW management. The Standardized Precipitation Index (SPI) and Normalized Difference Vegetation Index (NDVI) were calculated and the 2002–2017 land-use change was analyzed. It was shown that GW decreased significantly (in 75% of the well...

Ecological Informatics, 2020

Abstract In this study remote sensing was used as an early alert tool for chlorophyll-a changes i... more Abstract In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a continental aquatic ecosystem in central Chile. To this end, 14 LANDSAT images of Laja Lake (36° 54 'S, 71° 05' W, 1,360 meters above sea level) were taken over a 6-year period. Eleven spectral indexes were calculated. At the same time, chlorophyll-a concentrations were determined experimentally. Correlations between vegetation indices and chlorophyll-a concentrations in different monitoring zones were established. The indices that presented a good correlation were NDVI and GNDVI. A new regression model was developed that allows the primary productivity values of Laja Lake to be estimated using satellite data. Finally, chlorophyll-a maps were created.

In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a conti... more In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a continental aquatic ecosystem in central Chile. To this end, 14 LANDSAT images of Laja Lake (36 • 54 'S, 71 • 05' W, 1,360 meters above sea level) were taken over a 6-year period. Eleven spectral indexes were calculated. At the same time, chlorophyll-a concentrations were determined experimentally. Correlations between vegetation indices and chlorophyll-a concentrations in different monitoring zones were established. The indices that presented a good correlation were NDVI and GNDVI. A new regression model was developed that allows the primary productivity values of Laja Lake to be estimated using satellite data. Finally, chlorophyll-a maps were created.

The climatic trends observed in Mesoamerica and the Caribbean in the last decades, associated to ... more The climatic trends observed in Mesoamerica and the Caribbean in the last decades, associated to the increase of climatic variability and climate change show the increase of the frequency and intensity of the drought, reason why their effective knowledge is essential for the reduction the risks that are associated. In Cuba there is a close link between the development of significant drought events and the establishment of a persistent influence of strong anticyclonic systems on the area, unfavorable for the development of rains. The study of this multi-causal phenomenon is a very important endeavor, as is the deficit of days with rain in dry periods and their relation with the atmospheric conditions related to the drought. Was examined for the region, the behavior geopotential surfaces in different tropospheric levels, the magnitudes of the vertical movements represented by the Omega variable, gradations of longwave radiation (OLR), the surface of relative humidity and the presence ...

Ecological Informatics, 2020

In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a conti... more In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a continental aquatic ecosystem in central Chile. To this end, 14 LANDSAT images of Laja Lake (36 • 54 'S, 71 • 05' W, 1,360 meters above sea level) were taken over a 6-year period. Eleven spectral indexes were calculated. At the same time, chlorophyll-a concentrations were determined experimentally. Correlations between vegetation indices and chlorophyll-a concentrations in different monitoring zones were established. The indices that presented a good correlation were NDVI and GNDVI. A new regression model was developed that allows the primary productivity values of Laja Lake to be estimated using satellite data. Finally, chlorophyll-a maps were created.

Water, 2020

Groundwater (GW) is the primary source of unfrozen freshwater on the planet and in many semi-arid... more Groundwater (GW) is the primary source of unfrozen freshwater on the planet and in many semi-arid areas, it is the only source of water available during low-water periods. In north-central Chile, there has been GW depletion as a result of semi-arid conditions and high water demand, which has unleashed major social conflicts, some due to drought and others due to agribusiness practices against the backdrop of a private water management model. The Ligua and Petorca watersheds in the Valparaíso Region were studied in order to analyze the influence of climatic and anthropogenic factors on aquifer depletion using an interdisciplinary approach that integrates hydroclimatic variables, remote sensing data techniques, and GW rights data to promote sustainable GW management. The Standardized Precipitation Index (SPI) and Normalized Difference Vegetation Index (NDVI) were calculated and the 2002-2017 land-use change was analyzed. It was shown that GW decreased significantly (in 75% of the wells) and that the hydrological drought was moderate and prolonged (longest drought in the last 36 years). The avocado-growing area in Ligua increased significantly-by 2623 ha-with respect to other agricultural areas (higher GW decrease), while in Petorca, it decreased by 128 ha. In addition, GW-rainfall correlations were low and GW rights were granted continuously despite the drought. The results confirmed that aquifer depletion was mostly influenced by human factors due to overexploitation by agriculture and a lack of water management.

Resumen Las tendencias climáticas observadas en Meso América y el Caribe en las últimas décadas, ... more Resumen Las tendencias climáticas observadas en Meso América y el Caribe en las últimas décadas, asociadas al incremento de la variabilidad climática y el cambio climático muestran el aumento de la frecuencia e intensidad de la sequía, por lo que su eficaz conocimiento, resulta esencial para la reducción de los riesgos que le están asociados. En Cuba existe un estrecho vínculo entre el desarrollo de significativos eventos de sequía y el establecimiento de una persistente influencia de fuertes sistemas anticiclónicos sobre el área, desfavorables para el desarrollo de las lluvias. El estudio de este fenómeno multicausal resulta un empeño bien importante, como lo constituye el déficit de días con lluvia en períodos secos y su relación con las condiciones atmosféricas vinculadas a la sequía. Se examinó para la región, el comportamiento de las superficies geopotenciales en diferentes niveles troposféricos, las magnitudes de los movimientos verticales representados por la variable Omega, las gradaciones de la radiación de onda larga (OLR), la superficie de humedad relativa y la presencia de la vaguada de niveles medios en el mes de junio, asociados a los días con lluvia expresados en rango deciles. Los datos proceden del Laboratorio de Investigaciones del Sistema Tierra (ESRL) de la National Oceanic and Atmospheric Administration (NOAA). Los resultados confirmaron que el establecimiento de fuertes anomalías positivas en sistemas anticiclónicos dominantes, reveladas por las características de las variables climatológicas estudiadas, limitaron la convección y el contenido de humedad todo lo cual impidió que se produjera una normal presencia de los días con lluvia, resultando estrechamente relacionados con períodos significativos de sequías.

In this article the number of days with total rainfall and its distribution by intervals of diffe... more In this article the number of days with total rainfall and its distribution by intervals of different magnitudes of rain in western Cuba is examined, during rainy seasonal periods (May to October) and dry seasons (November to April) and it was established their relationship with the occurrence of dry events in the rainy season. Series of rainy days in the period from 1981 to 2010, collected in 20 meteorological stations of the Meteorological Institute, located in coastal and inland areas were used for this purpose. Their trial was performed using the statistical software Excel 2010 Statistica v. 7.0, applied statisticians Spearman and Kendall Pettit Man (WinStat software, v. 2.0) to determine changes in trends and values for decades and intervals. The method of deciles was used to relate the number of days with rain and the occurrence of dry events. The main results include an updated version of the variable weather, which reflects the spatial representation of the magnitudes and variations of the most significant indices. It was demonstrated that significant events during drought, reducing the number of days with rain, occurs similarly in all tested intervals, which disagrees with the view that significant events associated with drought deficit are essentially higher than 50 mm of rains. It is also revealed that in the intervals from 50 mm to 100 mm and above 100 mm the wet days show a statistically significant increasing trend. These results are of great interest to many activities associated with agriculture and other branches of the economy, society and the environment that are related to the behavior of rainfall, its features, natural variability and even the influence that climate change exerts on them.

In this article the number of days with total rainfall and its distribution by intervals of diffe... more In this article the number of days with total rainfall and its distribution by intervals of different magnitudes of rain in western Cuba is examined, during rainy seasonal periods (May to October) and dry seasons (November to April) and it was established their relationship with the occurrence of dry events in the rainy season. Series of rainy days in the period from 1981 to 2010, collected in 20 meteorological stations of the Meteorological Institute, located in coastal and inland areas were used for this purpose. Their trial was performed using the statistical software Excel 2010 Statistica v. 7.0, applied statisticians Spearman and Kendall Pettit Man (WinStat software, v. 2.0) to determine changes in trends and values for decades and intervals. The method of deciles was used to relate the number of days with rain and the occurrence of dry events. The main results include an updated version of the variable weather, which reflects the spatial representation of the magnitudes and variations of the most significant indices. It was demonstrated that significant events during drought, reducing the number of days with rain, occurs similarly in all tested intervals, which disagrees with the view that significant events associated with drought deficit are essentially higher than 50 mm of rains. It is also revealed that in the intervals from 50 mm to 100 mm and above 100 mm the wet days show a statistically significant increasing trend. These results are of great interest to many activities associated with agriculture and other branches of the economy, society and the environment that are related to the behavior of rainfall, its features, natural variability and even the influence that climate change exerts on them.