Alejandra Stehr | MTI University (original) (raw)
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Papers by Alejandra Stehr
Hydrological Sciences Journal
The 2022-2023 Chilean summer showed increased temperatures and similar burned area, compared to t... more The 2022-2023 Chilean summer showed increased temperatures and similar burned area, compared to the 2016-2017 season, where more than 500,000 hectares were compromised, mainly in the rural areas. After a brief review, it is revealed that the effects of forest fires on soil and hydrological properties are barely debated in Chile. Here, we showed a climatological analysis where temperature records in the 2016-2017 season were unusual, as well as another unexpected increase in the summer of 2022-2023, resulting in high-severity fires known as ‘mega-fires’ or “storm-fires”. Mega-fires affect forest plantations and native forests mainly from 33º S (Maule Region) to 39º S (Los Ríos Region) and they are expected to become frequent due to climate change, moving from the north to the south. We present an overview of the influence of wildfires on soil components in the most affected areas (inland, Coastal, and Andes ranges), their hydrological impacts, and potential erosion risk due to high w...
The Draft Framework Law on Climate Change establishes the necessary procedures to elaborate Chile... more The Draft Framework Law on Climate Change establishes the necessary procedures to elaborate Chile's Long Term Climate Strategy (LTCS). Article 5 states that the LTCS must include a prior report by the Scientific Advisory Committee on Climate Change. In this context, the Committee prepares this report to be submitted to the Chilean Ministry of Environment to be used as an input in the elaboration of the LTCS. The Committee members took over one or more chapters for review and comment, according to their experience and expertise.<br>
This study presents the main results of the project “Economic Evaluation of Climatic Change Impac... more This study presents the main results of the project “Economic Evaluation of Climatic Change Impacts on Water Resources at River Basin Scale”. We evaluate the economic consequences of climate change at river basin scale using a hydroeconomic model, which includes two water demand sectors: residential and agricultural. The main quantitative results are complemented with a qualitative social and vulnerability analysis. According to our results, climate change will have minor overall impacts on the basin economy with large distributional consequences. Moreover, subsistence agricultural communities, seem to be the most vulnerable groups to climate change.
Water
Flash floods, produced by heavy seasonal rainfall and characterized by high speeds and destructiv... more Flash floods, produced by heavy seasonal rainfall and characterized by high speeds and destructive power, are among the most devastating natural phenomena and are capable of causing great destruction in very little time. In the absence of hydrological data, morphometric characterization can provide important information on preventive measures against flash floods. A priority categorization of hydrographic units in the Cañete River basin was carried out using morphometric analysis together with a weighted sum analysis (WSA) based on a statistical correlation matrix. The delineation of the drainage network was performed based on Digital Elevation Model (DEM) data from the Shuttle Radar Topography Mission (SRTM). The Cañete River basin was subdivided into 11 sub-basins, and 15 morphometric parameters were selected. The priority category (very high, high, and moderate) of each sub-basin was assigned according to the value of the composite factor obtained through WSA. The results of this...
Water
As precipitation is a fundamental component of the global hydrological cycle that governs water r... more As precipitation is a fundamental component of the global hydrological cycle that governs water resource distribution, the understanding of its temporal and spatial behavior is of great interest, and exact estimates of it are crucial in multiple lines of research. Meteorological data provide input for hydroclimatic models and predictions, which generally lack complete series. Many studies have addressed techniques to fill gaps in precipitation series at annual and monthly scales, but few have provided results at a daily scale due to the complexity of orographic characteristics and in some cases the non-linearity of precipitation. The objective of this study was to assess different methods of filling gaps in daily precipitation data using regression model (RM) and machine learning (ML) techniques. RM included linear regression (LRM) and multiple regression (MRM) algorithms, while ML included multiple regression algorithms (ML-MRM), K-nearest neighbors (ML-KNN), gradient boosting tree...
Aqua-LAC, 2019
Se analizan los modelos de gestión del agua y la utilidad de la mediación ambiental en los casos ... more Se analizan los modelos de gestión del agua y la utilidad de la mediación ambiental en los casos de conflictividad sobre los recursos hídricos de España y Brasil y su aplicabilidad a Chile. Se parte de la experiencia de España, que establece las cuencas hidrográficas como las bases territoriales de la administración. En España, se crean en 1926 por Real Decreto las Confederaciones Sindicales Hidrográficas, instituciones adscritas al Ministerio de Fomento para “el aprovechamiento intensivo, máximo de los recursos hidráulicos de las cuencas de nuestros grandes ríos”, que establece las cuencas hidrográficas como las bases territoriales de la administración. La trasposición de la Directiva Marco del Agua conservó la Demarcación Hidrográfica como base territorial de gestión, incorporando la participación social activa e integra de los implicados como principio crucial para la gestión sostenible. Brasil y Chile están entre los 14 países del mundo con más disponibilidad de agua. Sin embarg...
Journal of Paleolimnology, 2013
SSRN Electronic Journal, 2016
Hydrological Sciences Journal
The 2022-2023 Chilean summer showed increased temperatures and similar burned area, compared to t... more The 2022-2023 Chilean summer showed increased temperatures and similar burned area, compared to the 2016-2017 season, where more than 500,000 hectares were compromised, mainly in the rural areas. After a brief review, it is revealed that the effects of forest fires on soil and hydrological properties are barely debated in Chile. Here, we showed a climatological analysis where temperature records in the 2016-2017 season were unusual, as well as another unexpected increase in the summer of 2022-2023, resulting in high-severity fires known as ‘mega-fires’ or “storm-fires”. Mega-fires affect forest plantations and native forests mainly from 33º S (Maule Region) to 39º S (Los Ríos Region) and they are expected to become frequent due to climate change, moving from the north to the south. We present an overview of the influence of wildfires on soil components in the most affected areas (inland, Coastal, and Andes ranges), their hydrological impacts, and potential erosion risk due to high w...
The Draft Framework Law on Climate Change establishes the necessary procedures to elaborate Chile... more The Draft Framework Law on Climate Change establishes the necessary procedures to elaborate Chile's Long Term Climate Strategy (LTCS). Article 5 states that the LTCS must include a prior report by the Scientific Advisory Committee on Climate Change. In this context, the Committee prepares this report to be submitted to the Chilean Ministry of Environment to be used as an input in the elaboration of the LTCS. The Committee members took over one or more chapters for review and comment, according to their experience and expertise.<br>
This study presents the main results of the project “Economic Evaluation of Climatic Change Impac... more This study presents the main results of the project “Economic Evaluation of Climatic Change Impacts on Water Resources at River Basin Scale”. We evaluate the economic consequences of climate change at river basin scale using a hydroeconomic model, which includes two water demand sectors: residential and agricultural. The main quantitative results are complemented with a qualitative social and vulnerability analysis. According to our results, climate change will have minor overall impacts on the basin economy with large distributional consequences. Moreover, subsistence agricultural communities, seem to be the most vulnerable groups to climate change.
Water
Flash floods, produced by heavy seasonal rainfall and characterized by high speeds and destructiv... more Flash floods, produced by heavy seasonal rainfall and characterized by high speeds and destructive power, are among the most devastating natural phenomena and are capable of causing great destruction in very little time. In the absence of hydrological data, morphometric characterization can provide important information on preventive measures against flash floods. A priority categorization of hydrographic units in the Cañete River basin was carried out using morphometric analysis together with a weighted sum analysis (WSA) based on a statistical correlation matrix. The delineation of the drainage network was performed based on Digital Elevation Model (DEM) data from the Shuttle Radar Topography Mission (SRTM). The Cañete River basin was subdivided into 11 sub-basins, and 15 morphometric parameters were selected. The priority category (very high, high, and moderate) of each sub-basin was assigned according to the value of the composite factor obtained through WSA. The results of this...
Water
As precipitation is a fundamental component of the global hydrological cycle that governs water r... more As precipitation is a fundamental component of the global hydrological cycle that governs water resource distribution, the understanding of its temporal and spatial behavior is of great interest, and exact estimates of it are crucial in multiple lines of research. Meteorological data provide input for hydroclimatic models and predictions, which generally lack complete series. Many studies have addressed techniques to fill gaps in precipitation series at annual and monthly scales, but few have provided results at a daily scale due to the complexity of orographic characteristics and in some cases the non-linearity of precipitation. The objective of this study was to assess different methods of filling gaps in daily precipitation data using regression model (RM) and machine learning (ML) techniques. RM included linear regression (LRM) and multiple regression (MRM) algorithms, while ML included multiple regression algorithms (ML-MRM), K-nearest neighbors (ML-KNN), gradient boosting tree...
Aqua-LAC, 2019
Se analizan los modelos de gestión del agua y la utilidad de la mediación ambiental en los casos ... more Se analizan los modelos de gestión del agua y la utilidad de la mediación ambiental en los casos de conflictividad sobre los recursos hídricos de España y Brasil y su aplicabilidad a Chile. Se parte de la experiencia de España, que establece las cuencas hidrográficas como las bases territoriales de la administración. En España, se crean en 1926 por Real Decreto las Confederaciones Sindicales Hidrográficas, instituciones adscritas al Ministerio de Fomento para “el aprovechamiento intensivo, máximo de los recursos hidráulicos de las cuencas de nuestros grandes ríos”, que establece las cuencas hidrográficas como las bases territoriales de la administración. La trasposición de la Directiva Marco del Agua conservó la Demarcación Hidrográfica como base territorial de gestión, incorporando la participación social activa e integra de los implicados como principio crucial para la gestión sostenible. Brasil y Chile están entre los 14 países del mundo con más disponibilidad de agua. Sin embarg...
Journal of Paleolimnology, 2013
SSRN Electronic Journal, 2016