Browsing by Author "Stehr, Alejandra"

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    Desalinización: oportunidades y desafíos para abordar la inseguridad hídrica en chile
    (Ministerio de Ciencia, Tecnología, Conocimiento e Innovación, 2022) Vicuña, Sebastián; Daniele, Linda; Farías, Laura; González, Humberto; Marquet, Pablo A.; Palma Behnke, Rodrigo; Stehr, Alejandra; Urquiza, Anahí; Wagemann, Elizabeth; Arenas Herrera, María J.; Bórquez, Rodrigo; Cornejo Ponce, Lorena; Delgado, Verónica; Etcheberry, Gabriel; Fragkou, María Christina; Fuster, Rodrigo; Gelcich, Stefan; Melo, Óscar; Monsalve, Tamara; Olivares, Marcelo; Ramajo, Laura; Ramírez Pascualli, Carlos; Rojas, Carolina; Rojas, Christian; Vilca Salinas, Patricia; Winckler, Patricio; Winckler, Patricio; Lambert, Fabrice
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    Drought and Wildfire Trends in Native Forests of South-Central Chile in the 21st Century
    (2024) Duarte, Efrain; Rubilar, Rafael; Matus, Francisco; Garrido-Ruiz, Claudia; Merino, Carolina; Smith-Ramirez, Cecilia; Aburto, Felipe; Rojas, Claudia; Stehr, Alejandra; Dorner, Jose; Najera, Francisco; Barrientos, Guillermo; Jofre, Ignacio
    Over the last decades, Chile has experienced a long-term drought with significant consequences for water availability, forest productivity, and soil degradation, ultimately dramatically increasing the surface of burned area. Here, we quantify the Palmer Drought Severity Index (PDSI) to ascertain the extent of "moisture deficiency" across the central-southern region of Chile from 2000 to 2023 to assess the drought's relationship with the frequency of wildfires focusing on the impact of native forests. Our methodology quantifies the PDSI from the burned area data using MODIS MCD64A1 satellite imagery, validated by in situ wildfire occurrence records. The findings indicate that 85.2% of fires occurred under moderate to severe drought conditions. We identified 407,561 ha showing varying degrees of degradation due to wildfires, highlighting the critical areas for targeted conservation efforts. A significant increase in both the frequency of wildfires and the extent of the affected area in native forests was observed with the intensification of drought conditions in the 21st century within mesic to humid Mediterranean climatic zones where drought explains up to 41% of the variability in the burned area (r(2) = 0.41; p < 0.05). This study highlights the relationship between drought conditions and wildfire frequency, showing the paramount need to adopt comprehensive wildfire mitigation management in native forests.
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    The status quo effect in the sociohydrology of floods
    (2024) Leal, Catalina Mendoza; Coloma, Rocio; Ponce, Diego; Alarcon, Benjamin; Guerra, Maricarmen; Stehr, Alejandra; Carrasco, Juan Antonio; Alcayaga, Hernan; Rojas, Octavio; Link, Felipe; Link, Oscar
    Two behavioural types in sociohydrology of floods have been described in more detail than others: the levee effect and the learning effect. However, additional types of behaviour operate and need further research. Taking the case of frequent flash floods occurring in an ephemeral stream, a tributary of the Vilama River, located in San Pedro de Atacama, Chile, at the interphase between the Atacama desert and the Andean Altiplano, we explore the existence of further behavioural types in the sociohydrology of floods at four neighbourhoods along the tributary. Fieldwork to reconstruct a recent flood event, hydrological analysis and semistructured interviews with key informants to characterize people's responses to floods were conducted. Results show evidence that the so-called status quo effect is present at the riparian community scale, i.e. when communities do not learn and adapt to prevent damage even when exposed to frequent floods. Possible causes of the status quo effect are discussed.
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    Water Use and Climate Stressors in a Multiuser River Basin Setting: Who Benefits from Adaptation?
    (2021) Ponce Oliva, Roberto D.; Arias Montevechio, Esteban; Fernandez Jorquera, Francisco; Vasquez-Lavin, Felipe; Stehr, Alejandra
    Adapting to new climate conditions will require an intricate mix of knowledge, planning, coordination, and foresight. There is increasing sectoral evidence on the implementation of successful adaptation actions. However, the success of these actions when we consider the interdependencies among sectors remains debatable. This paper aims to assess who benefits from implementing adaptation options in a multiuser river basin to both climate-induced and demographic stress on water use. Our analysis relies on a hydro-economic model that considers two sets of water users: agriculture and urban households. We innovate in our modelling approach by analyzing and explicitly integrating the household-level economic behavior through its water demand. We assess the cross-user consequences of autonomous and planned adaptation actions. We provide insights into the different trade-offs at the basin level, demonstrating the compatibilities and divergences between agriculture and household-level water demand. We found different consequences of implementing either autonomous or planned adaptation measures. For instance, a decentralized scheme would drive negative implications for the entire basin, although the less water-intensive sector will be better off. On the other hand, different policy interventions would drive positive consequences for the entire basin, with the most water-intensive sector benefiting the most. These results highlight the distributional consequences across users of different adaptation measures.