Articles | Volume 28, issue 7 
            
                
                    
                    
            
            
            https://doi.org/10.5194/hess-28-1605-2024
                    © Author(s) 2024. This work is distributed under 
the Creative Commons Attribution 4.0 License.
                the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/hess-28-1605-2024
                    © Author(s) 2024. This work is distributed under 
the Creative Commons Attribution 4.0 License.
                the Creative Commons Attribution 4.0 License.
HESS Opinions: The unsustainable use of groundwater conceals a “Day Zero”
Camila Alvarez-Garreton
                                            Center for Climate and Resilience Research CR2, FONDAP 1523A0002, Santiago, Chile
                                        
                                    
                                            Center for Climate and Resilience Research CR2, FONDAP 1523A0002, Santiago, Chile
                                        
                                    
                                            Department of Geophysics, Universidad de Chile, Santiago, Chile
                                        
                                    René Garreaud
                                            Center for Climate and Resilience Research CR2, FONDAP 1523A0002, Santiago, Chile
                                        
                                    
                                            Department of Geophysics, Universidad de Chile, Santiago, Chile
                                        
                                    Javier González
                                            Bluedot Consulting, Santiago, Chile
                                        
                                    Roberto Rondanelli
                                            Center for Climate and Resilience Research CR2, FONDAP 1523A0002, Santiago, Chile
                                        
                                    
                                            Department of Geophysics, Universidad de Chile, Santiago, Chile
                                        
                                    Eugenia Gayó
                                            Center for Climate and Resilience Research CR2, FONDAP 1523A0002, Santiago, Chile
                                        
                                    
                                            Department of Geography, Universidad de Chile, Santiago, Chile
                                        
                                    Mauricio Zambrano-Bigiarini
                                            Center for Climate and Resilience Research CR2, FONDAP 1523A0002, Santiago, Chile
                                        
                                    
                                            Department of Civil Engineering, Universidad de la Frontera, Temuco, Chile
                                        
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René Garreaud, Juan Pablo Boisier, Camila Alvarez-Garreton, Duncan A. Christie, Tomás Carrasco-Escaff, Iván Vergara, Roberto O. Chávez, Paulina Aldunce, Pablo Camus, Manuel Suazo-Álvarez, Mariano Masiokas, Gabriel Castro, Ariel Muñoz, Mauricio Zambrano-Bigiarini, Rodrigo Fuster, and Lintsiee Godoy
                                    Hydrol. Earth Syst. Sci., 29, 5347–5369, https://doi.org/10.5194/hess-29-5347-2025, https://doi.org/10.5194/hess-29-5347-2025, 2025
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                                                This study focuses on hyperdroughts (HDs) in central Chile, defined as years with a regional rainfall deficit exceeding 75 %. Only five HDs occurred in the last century (1924, 1968, 1998, 2019, 2021), but they caused disproportionate environmental and social impacts. In some systems, the effects were larger than expected from those considering moderate droughts and dependent on the antecedent conditions. HDs have analogs from the remote past, and they are expected to increase in the near future.
                                            
                                            
                                        Juan Pablo Boisier, Camila Alvarez-Garreton, Rodrigo Marinao, and Mauricio Galleguillos
                                    Hydrol. Earth Syst. Sci., 29, 5185–5212, https://doi.org/10.5194/hess-29-5185-2025, https://doi.org/10.5194/hess-29-5185-2025, 2025
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                                                Our study assesses water stress in Chile from the mid-20th century to the end of the 21st century using novel datasets on water availability, land use, and water demand. We compute a water stress index for all basins in the country and show that, in addition to declining precipitation, rising water demand drives a steady increase in stress. As a drier future is projected for central Chile, the water stress index provides a useful tool for guiding water governance and adaptation strategies.
                                            
                                            
                                        Anne F. Van Loon, Sarra Kchouk, Alessia Matanó, Faranak Tootoonchi, Camila Alvarez-Garreton, Khalid E. A. Hassaballah, Minchao Wu, Marthe L. K. Wens, Anastasiya Shyrokaya, Elena Ridolfi, Riccardo Biella, Viorica Nagavciuc, Marlies H. Barendrecht, Ana Bastos, Louise Cavalcante, Franciska T. de Vries, Margaret Garcia, Johanna Mård, Ileen N. Streefkerk, Claudia Teutschbein, Roshanak Tootoonchi, Ruben Weesie, Valentin Aich, Juan P. Boisier, Giuliano Di Baldassarre, Yiheng Du, Mauricio Galleguillos, René Garreaud, Monica Ionita, Sina Khatami, Johanna K. L. Koehler, Charles H. Luce, Shreedhar Maskey, Heidi D. Mendoza, Moses N. Mwangi, Ilias G. Pechlivanidis, Germano G. Ribeiro Neto, Tirthankar Roy, Robert Stefanski, Patricia Trambauer, Elizabeth A. Koebele, Giulia Vico, and Micha Werner
                                    Nat. Hazards Earth Syst. Sci., 24, 3173–3205, https://doi.org/10.5194/nhess-24-3173-2024, https://doi.org/10.5194/nhess-24-3173-2024, 2024
                                    Short summary
                                    Short summary
                                            
                                                Drought is a creeping phenomenon but is often still analysed and managed like an isolated event, without taking into account what happened before and after. Here, we review the literature and analyse five cases to discuss how droughts and their impacts develop over time. We find that the responses of hydrological, ecological, and social systems can be classified into four types and that the systems interact. We provide suggestions for further research and monitoring, modelling, and management.
                                            
                                            
                                        Nicolás Álamos, Camila Alvarez-Garreton, Ariel Muñoz, and Álvaro González-Reyes
                                    Hydrol. Earth Syst. Sci., 28, 2483–2503, https://doi.org/10.5194/hess-28-2483-2024, https://doi.org/10.5194/hess-28-2483-2024, 2024
                                    Short summary
                                    Short summary
                                            
                                                In this study, we assess the effects of climate and water use on streamflow reductions and drought intensification during the last 3 decades in central Chile.  We address this by contrasting streamflow observations with near-natural streamflow simulations. We conclude that while the lack of precipitation dominates streamflow reductions in the megadrought, water uses have not diminished during this time, causing a worsening of the hydrological drought conditions and maladaptation conditions. 
                                            
                                            
                                        Oscar M. Baez-Villanueva, Mauricio Zambrano-Bigiarini, Diego G. Miralles, Hylke E. Beck, Jonatan F. Siegmund, Camila Alvarez-Garreton, Koen Verbist, René Garreaud, Juan Pablo Boisier, and Mauricio Galleguillos
                                    Hydrol. Earth Syst. Sci., 28, 1415–1439, https://doi.org/10.5194/hess-28-1415-2024, https://doi.org/10.5194/hess-28-1415-2024, 2024
                                    Short summary
                                    Short summary
                                            
                                                Various drought indices exist, but there is no consensus on which index to use to assess streamflow droughts. This study addresses meteorological, soil moisture, and snow indices along with their temporal scales to assess streamflow drought across hydrologically diverse catchments. Using data from 100 Chilean catchments, findings suggest that there is not a single drought index that can be used for all catchments and that snow-influenced areas require drought indices with larger temporal scales.
                                            
                                            
                                        Heidi Kreibich, Kai Schröter, Giuliano Di Baldassarre, Anne F. Van Loon, Maurizio Mazzoleni, Guta Wakbulcho Abeshu, Svetlana Agafonova, Amir AghaKouchak, Hafzullah Aksoy, Camila Alvarez-Garreton, Blanca Aznar, Laila Balkhi, Marlies H. Barendrecht, Sylvain Biancamaria, Liduin Bos-Burgering, Chris Bradley, Yus Budiyono, Wouter Buytaert, Lucinda Capewell, Hayley Carlson, Yonca Cavus, Anaïs Couasnon, Gemma Coxon, Ioannis Daliakopoulos, Marleen C. de Ruiter, Claire Delus, Mathilde Erfurt, Giuseppe Esposito, Didier François, Frédéric Frappart, Jim Freer, Natalia Frolova, Animesh K. Gain, Manolis Grillakis, Jordi Oriol Grima, Diego A. Guzmán, Laurie S. Huning, Monica Ionita, Maxim Kharlamov, Dao Nguyen Khoi, Natalie Kieboom, Maria Kireeva, Aristeidis Koutroulis, Waldo Lavado-Casimiro, Hong-Yi Li, Maria Carmen LLasat, David Macdonald, Johanna Mård, Hannah Mathew-Richards, Andrew McKenzie, Alfonso Mejia, Eduardo Mario Mendiondo, Marjolein Mens, Shifteh Mobini, Guilherme Samprogna Mohor, Viorica Nagavciuc, Thanh Ngo-Duc, Huynh Thi Thao Nguyen, Pham Thi Thao Nhi, Olga Petrucci, Nguyen Hong Quan, Pere Quintana-Seguí, Saman Razavi, Elena Ridolfi, Jannik Riegel, Md Shibly Sadik, Nivedita Sairam, Elisa Savelli, Alexey Sazonov, Sanjib Sharma, Johanna Sörensen, Felipe Augusto Arguello Souza, Kerstin Stahl, Max Steinhausen, Michael Stoelzle, Wiwiana Szalińska, Qiuhong Tang, Fuqiang Tian, Tamara Tokarczyk, Carolina Tovar, Thi Van Thu Tran, Marjolein H. J. van Huijgevoort, Michelle T. H. van Vliet, Sergiy Vorogushyn, Thorsten Wagener, Yueling Wang, Doris E. Wendt, Elliot Wickham, Long Yang, Mauricio Zambrano-Bigiarini, and Philip J. Ward
                                    Earth Syst. Sci. Data, 15, 2009–2023, https://doi.org/10.5194/essd-15-2009-2023, https://doi.org/10.5194/essd-15-2009-2023, 2023
                                    Short summary
                                    Short summary
                                            
                                                As the adverse impacts of hydrological extremes increase in many regions of the world, a better understanding of the drivers of changes in risk and impacts is essential for effective flood and drought risk management. We present a dataset containing data of paired events, i.e. two floods or two droughts that occurred in the same area. The dataset enables comparative analyses and allows detailed context-specific assessments. Additionally, it supports the testing of socio-hydrological models.
                                            
                                            
                                        Camila Alvarez-Garreton, Juan Pablo Boisier, René Garreaud, Jan Seibert, and Marc Vis
                                    Hydrol. Earth Syst. Sci., 25, 429–446, https://doi.org/10.5194/hess-25-429-2021, https://doi.org/10.5194/hess-25-429-2021, 2021
                                    Short summary
                                    Short summary
                                            
                                                The megadrought experienced in Chile (2010–2020) has led to larger than expected water deficits. By analysing 106 basins with snow-/rainfall regimes, we relate such intensification with the hydrological memory of the basins, explained by snow and groundwater. Snow-dominated basins have larger memory and thus accumulate the effect of persistent precipitation deficits more strongly than pluvial basins. This notably affects central Chile, a water-limited region where most of the population lives.
                                            
                                            
                                        René Garreaud, Juan Pablo Boisier, Camila Alvarez-Garreton, Duncan A. Christie, Tomás Carrasco-Escaff, Iván Vergara, Roberto O. Chávez, Paulina Aldunce, Pablo Camus, Manuel Suazo-Álvarez, Mariano Masiokas, Gabriel Castro, Ariel Muñoz, Mauricio Zambrano-Bigiarini, Rodrigo Fuster, and Lintsiee Godoy
                                    Hydrol. Earth Syst. Sci., 29, 5347–5369, https://doi.org/10.5194/hess-29-5347-2025, https://doi.org/10.5194/hess-29-5347-2025, 2025
                                    Short summary
                                    Short summary
                                            
                                                This study focuses on hyperdroughts (HDs) in central Chile, defined as years with a regional rainfall deficit exceeding 75 %. Only five HDs occurred in the last century (1924, 1968, 1998, 2019, 2021), but they caused disproportionate environmental and social impacts. In some systems, the effects were larger than expected from those considering moderate droughts and dependent on the antecedent conditions. HDs have analogs from the remote past, and they are expected to increase in the near future.
                                            
                                            
                                        Juan Pablo Boisier, Camila Alvarez-Garreton, Rodrigo Marinao, and Mauricio Galleguillos
                                    Hydrol. Earth Syst. Sci., 29, 5185–5212, https://doi.org/10.5194/hess-29-5185-2025, https://doi.org/10.5194/hess-29-5185-2025, 2025
                                    Short summary
                                    Short summary
                                            
                                                Our study assesses water stress in Chile from the mid-20th century to the end of the 21st century using novel datasets on water availability, land use, and water demand. We compute a water stress index for all basins in the country and show that, in addition to declining precipitation, rising water demand drives a steady increase in stress. As a drier future is projected for central Chile, the water stress index provides a useful tool for guiding water governance and adaptation strategies.
                                            
                                            
                                        Daniel Nuñez-Ibarra, Mauricio Zambrano-Bigiarini, and Mauricio Galleguillos
                                        EGUsphere, https://doi.org/10.5194/egusphere-2025-2606, https://doi.org/10.5194/egusphere-2025-2606, 2025
                                    Short summary
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                                                Soil moisture plays a key role in how land and climate interact, yet it remains difficult to measure in remote or natural areas. This study compared four state-of-the-art soil moisture datasets against ground data from ten sites in Chile. Results show that some products perform better in humid areas, while others do better in dry regions. The work highlights which datasets are most reliable and suggests new ways to assess how well they track changes after rainfall events.
                                            
                                            
                                        Fabián Lema, Pablo A. Mendoza, Nicolás A. Vásquez, Naoki Mizukami, Mauricio Zambrano-Bigiarini, and Ximena Vargas
                                    Hydrol. Earth Syst. Sci., 29, 1981–2002, https://doi.org/10.5194/hess-29-1981-2025, https://doi.org/10.5194/hess-29-1981-2025, 2025
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                                                Hydrological droughts affect ecosystems and socioeconomic activities worldwide. Despite the fact that they are commonly described with the Standardized Streamflow Index (SSI), there is limited understanding of what they truly reflect in terms of water cycle processes. Here, we used state-of-the-art hydrological models in Andean basins to examine drivers of SSI fluctuations. The results highlight the importance of careful selection of indices and timescales for accurate drought characterization and monitoring.
                                            
                                            
                                        Cristóbal Soto-Escobar, Mauricio Zambrano-Bigiarini, Violeta Tolorza, and René Garreaud
                                        EGUsphere, https://doi.org/10.5194/egusphere-2025-621, https://doi.org/10.5194/egusphere-2025-621, 2025
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                                                This study aims to better understand how the spatial distribution, temporal trends and data length of hourly precipitation data influence the computation of stationary and non-stationary annual maximum precipitation intensities in a study area with diverse climate zones and topography. Our results reveal spatial differences and similarities in rainfall intensities derived from five hourly gridded precipitation datasets. Non-stationary intensities were slightly lower values than stationary ones.
                                            
                                            
                                        Anne F. Van Loon, Sarra Kchouk, Alessia Matanó, Faranak Tootoonchi, Camila Alvarez-Garreton, Khalid E. A. Hassaballah, Minchao Wu, Marthe L. K. Wens, Anastasiya Shyrokaya, Elena Ridolfi, Riccardo Biella, Viorica Nagavciuc, Marlies H. Barendrecht, Ana Bastos, Louise Cavalcante, Franciska T. de Vries, Margaret Garcia, Johanna Mård, Ileen N. Streefkerk, Claudia Teutschbein, Roshanak Tootoonchi, Ruben Weesie, Valentin Aich, Juan P. Boisier, Giuliano Di Baldassarre, Yiheng Du, Mauricio Galleguillos, René Garreaud, Monica Ionita, Sina Khatami, Johanna K. L. Koehler, Charles H. Luce, Shreedhar Maskey, Heidi D. Mendoza, Moses N. Mwangi, Ilias G. Pechlivanidis, Germano G. Ribeiro Neto, Tirthankar Roy, Robert Stefanski, Patricia Trambauer, Elizabeth A. Koebele, Giulia Vico, and Micha Werner
                                    Nat. Hazards Earth Syst. Sci., 24, 3173–3205, https://doi.org/10.5194/nhess-24-3173-2024, https://doi.org/10.5194/nhess-24-3173-2024, 2024
                                    Short summary
                                    Short summary
                                            
                                                Drought is a creeping phenomenon but is often still analysed and managed like an isolated event, without taking into account what happened before and after. Here, we review the literature and analyse five cases to discuss how droughts and their impacts develop over time. We find that the responses of hydrological, ecological, and social systems can be classified into four types and that the systems interact. We provide suggestions for further research and monitoring, modelling, and management.
                                            
                                            
                                        Ivan Vergara, Fernanda Santibañez, René Garreaud, and Germán Aguilar
                                        Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2024-27, https://doi.org/10.5194/esd-2024-27, 2024
                                    Manuscript not accepted for further review 
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                                                The denudation rate was modelled in over a thousand basins across the Earth. The results suggest that water and associated life have a positive effect across their whole range, which is regulated by topography. Because of this, bioclimatic effect is weak in flat landscapes, but it could vary denudation forty times in mountain settings. It was also observed that other things being equal, water availability steepens basins, so climate also has an indirect effect acting on geological timeframes.
                                            
                                            
                                        Rodrigo J. Seguel, Lucas Castillo, Charlie Opazo, Néstor Y. Rojas, Thiago Nogueira, María Cazorla, Mario Gavidia-Calderón, Laura Gallardo, René Garreaud, Tomás Carrasco-Escaff, and Yasin Elshorbany
                                    Atmos. Chem. Phys., 24, 8225–8242, https://doi.org/10.5194/acp-24-8225-2024, https://doi.org/10.5194/acp-24-8225-2024, 2024
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                                                Trends of surface ozone were examined across South America. Our findings indicate that ozone trends in major South American cities either increase or remain steady, with no signs of decline. The upward trends can be attributed to chemical regimes that efficiently convert nitric oxide into nitrogen dioxide. Additionally, our results suggest a climate penalty for ozone driven by meteorological conditions that favor wildfire propagation in Chile and extensive heat waves in southern Brazil.
                                            
                                            
                                        Violeta Tolorza, Christian H. Mohr, Mauricio Zambrano-Bigiarini, Benjamín Sotomayor, Dagoberto Poblete-Caballero, Sebastien Carretier, Mauricio Galleguillos, and Oscar Seguel
                                    Earth Surf. Dynam., 12, 841–861, https://doi.org/10.5194/esurf-12-841-2024, https://doi.org/10.5194/esurf-12-841-2024, 2024
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                                                We calculated disturbances and landscape-lowering rates across various timescales in a ~ 406 km2 catchment in the Chilean Coastal Range. Intensive management of exotic tree plantations involves short rotational cycles (planting and harvesting by replanting clear-cuts) lasting 9–25 years, dense forestry road networks (increasing connectivity), and a recent increase in wildfires. Concurrently, persistent drought conditions and the high water demand of fast-growing trees reduce water availability.
                                            
                                            
                                        Nicolás Álamos, Camila Alvarez-Garreton, Ariel Muñoz, and Álvaro González-Reyes
                                    Hydrol. Earth Syst. Sci., 28, 2483–2503, https://doi.org/10.5194/hess-28-2483-2024, https://doi.org/10.5194/hess-28-2483-2024, 2024
                                    Short summary
                                    Short summary
                                            
                                                In this study, we assess the effects of climate and water use on streamflow reductions and drought intensification during the last 3 decades in central Chile.  We address this by contrasting streamflow observations with near-natural streamflow simulations. We conclude that while the lack of precipitation dominates streamflow reductions in the megadrought, water uses have not diminished during this time, causing a worsening of the hydrological drought conditions and maladaptation conditions. 
                                            
                                            
                                        Oscar M. Baez-Villanueva, Mauricio Zambrano-Bigiarini, Diego G. Miralles, Hylke E. Beck, Jonatan F. Siegmund, Camila Alvarez-Garreton, Koen Verbist, René Garreaud, Juan Pablo Boisier, and Mauricio Galleguillos
                                    Hydrol. Earth Syst. Sci., 28, 1415–1439, https://doi.org/10.5194/hess-28-1415-2024, https://doi.org/10.5194/hess-28-1415-2024, 2024
                                    Short summary
                                    Short summary
                                            
                                                Various drought indices exist, but there is no consensus on which index to use to assess streamflow droughts. This study addresses meteorological, soil moisture, and snow indices along with their temporal scales to assess streamflow drought across hydrologically diverse catchments. Using data from 100 Chilean catchments, findings suggest that there is not a single drought index that can be used for all catchments and that snow-influenced areas require drought indices with larger temporal scales.
                                            
                                            
                                        Heidi Kreibich, Kai Schröter, Giuliano Di Baldassarre, Anne F. Van Loon, Maurizio Mazzoleni, Guta Wakbulcho Abeshu, Svetlana Agafonova, Amir AghaKouchak, Hafzullah Aksoy, Camila Alvarez-Garreton, Blanca Aznar, Laila Balkhi, Marlies H. Barendrecht, Sylvain Biancamaria, Liduin Bos-Burgering, Chris Bradley, Yus Budiyono, Wouter Buytaert, Lucinda Capewell, Hayley Carlson, Yonca Cavus, Anaïs Couasnon, Gemma Coxon, Ioannis Daliakopoulos, Marleen C. de Ruiter, Claire Delus, Mathilde Erfurt, Giuseppe Esposito, Didier François, Frédéric Frappart, Jim Freer, Natalia Frolova, Animesh K. Gain, Manolis Grillakis, Jordi Oriol Grima, Diego A. Guzmán, Laurie S. Huning, Monica Ionita, Maxim Kharlamov, Dao Nguyen Khoi, Natalie Kieboom, Maria Kireeva, Aristeidis Koutroulis, Waldo Lavado-Casimiro, Hong-Yi Li, Maria Carmen LLasat, David Macdonald, Johanna Mård, Hannah Mathew-Richards, Andrew McKenzie, Alfonso Mejia, Eduardo Mario Mendiondo, Marjolein Mens, Shifteh Mobini, Guilherme Samprogna Mohor, Viorica Nagavciuc, Thanh Ngo-Duc, Huynh Thi Thao Nguyen, Pham Thi Thao Nhi, Olga Petrucci, Nguyen Hong Quan, Pere Quintana-Seguí, Saman Razavi, Elena Ridolfi, Jannik Riegel, Md Shibly Sadik, Nivedita Sairam, Elisa Savelli, Alexey Sazonov, Sanjib Sharma, Johanna Sörensen, Felipe Augusto Arguello Souza, Kerstin Stahl, Max Steinhausen, Michael Stoelzle, Wiwiana Szalińska, Qiuhong Tang, Fuqiang Tian, Tamara Tokarczyk, Carolina Tovar, Thi Van Thu Tran, Marjolein H. J. van Huijgevoort, Michelle T. H. van Vliet, Sergiy Vorogushyn, Thorsten Wagener, Yueling Wang, Doris E. Wendt, Elliot Wickham, Long Yang, Mauricio Zambrano-Bigiarini, and Philip J. Ward
                                    Earth Syst. Sci. Data, 15, 2009–2023, https://doi.org/10.5194/essd-15-2009-2023, https://doi.org/10.5194/essd-15-2009-2023, 2023
                                    Short summary
                                    Short summary
                                            
                                                As the adverse impacts of hydrological extremes increase in many regions of the world, a better understanding of the drivers of changes in risk and impacts is essential for effective flood and drought risk management. We present a dataset containing data of paired events, i.e. two floods or two droughts that occurred in the same area. The dataset enables comparative analyses and allows detailed context-specific assessments. Additionally, it supports the testing of socio-hydrological models.
                                            
                                            
                                        Tomás Carrasco-Escaff, Maisa Rojas, René Darío Garreaud, Deniz Bozkurt, and Marius Schaefer
                                    The Cryosphere, 17, 1127–1149, https://doi.org/10.5194/tc-17-1127-2023, https://doi.org/10.5194/tc-17-1127-2023, 2023
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                                                In this study, we investigate the interplay between climate and the Patagonian Icefields. By modeling the glacioclimatic conditions of the southern Andes, we found that the annual variations in net surface mass change experienced by these icefields are mainly controlled by annual variations in the air pressure field observed near the Drake Passage. Little dependence on main modes of variability was found, suggesting the Drake Passage as a key region for understanding the Patagonian Icefields.
                                            
                                            
                                        Nikos Daskalakis, Laura Gallardo, Maria Kanakidou, Johann Rasmus Nüß, Camilo Menares, Roberto Rondanelli, Anne M. Thompson, and Mihalis Vrekoussis
                                    Atmos. Chem. Phys., 22, 4075–4099, https://doi.org/10.5194/acp-22-4075-2022, https://doi.org/10.5194/acp-22-4075-2022, 2022
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                                                Forest fires emit carbon monoxide (CO) that can be transported into the atmosphere far from the sources and reacts to produce ozone (O3) that affects climate, ecosystems and health. O3 is also produced in the stratosphere and can be transported downwards. Using a global numerical model, we found that forest fires can affect CO and O3 even in the South Pacific, the most pristine region of the global ocean, but transport from the stratosphere is a more important O3 source than fires in the region.
                                            
                                            
                                        Oscar M. Baez-Villanueva, Mauricio Zambrano-Bigiarini, Pablo A. Mendoza, Ian McNamara, Hylke E. Beck, Joschka Thurner, Alexandra Nauditt, Lars Ribbe, and Nguyen Xuan Thinh
                                    Hydrol. Earth Syst. Sci., 25, 5805–5837, https://doi.org/10.5194/hess-25-5805-2021, https://doi.org/10.5194/hess-25-5805-2021, 2021
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                                                Most rivers worldwide are ungauged, which hinders the sustainable management of water resources. Regionalisation methods use information from gauged rivers to estimate streamflow over ungauged ones. Through hydrological modelling, we assessed how the selection of precipitation products affects the performance of three regionalisation methods. We found that a precipitation product that provides the best results in hydrological modelling does not necessarily perform the best for regionalisation.
                                            
                                            
                                        Camila Alvarez-Garreton, Juan Pablo Boisier, René Garreaud, Jan Seibert, and Marc Vis
                                    Hydrol. Earth Syst. Sci., 25, 429–446, https://doi.org/10.5194/hess-25-429-2021, https://doi.org/10.5194/hess-25-429-2021, 2021
                                    Short summary
                                    Short summary
                                            
                                                The megadrought experienced in Chile (2010–2020) has led to larger than expected water deficits. By analysing 106 basins with snow-/rainfall regimes, we relate such intensification with the hydrological memory of the basins, explained by snow and groundwater. Snow-dominated basins have larger memory and thus accumulate the effect of persistent precipitation deficits more strongly than pluvial basins. This notably affects central Chile, a water-limited region where most of the population lives.
                                            
                                            
                                        Cited articles
                        
                        Ahmadi, M. S., Sušnik, J., Veerbeek, W., and Zevenbergen, C.: Towards a global day zero? Assessment of current and future water supply and demand in 12 rapidly developing megacities, Sustain. Cities Soc., 61, 102295, https://doi.org/10.1016/j.scs.2020.102295, 2020. 
                    
                
                        
                        Alvarez-Garreton, C., Mendoza, P. A., Boisier, J. P., Addor, N., Galleguillos, M., Zambrano-Bigiarini, M., Lara, A., Puelma, C., Cortes, G., Garreaud, R., McPhee, J., and Ayala, A.: The CAMELS-CL dataset: catchment attributes and meteorology for large sample studies – Chile dataset, Hydrol. Earth Syst. Sci., 22, 5817–5846, https://doi.org/10.5194/hess-22-5817-2018, 2018. 
                    
                
                        
                        Alvarez-Garreton, C., Boisier, J. P., Billi, M., Lefort, I., Marinao, R., and Barría, P.: Protecting environmental flows to achieve long-term water security, J. Environ. Manage., 328, 116914, https://doi.org/10.1016/j.jenvman.2022.116914, 2023a. 
                    
                
                        
                        Alvarez-Garreton, C., Boisier, J. P., Blanco, G., Billi, M., Nicolas-Artero, C., Maillet, A., Aldunce, P., Urrutia-Jalabert, R., Zambrano-Bigiarini, M., Guevara, G., Galleguillos, M., Muñoz, A., Christie D., Marinao, R., and Garreaud, R.: Seguridad Hídrica en Chile: Caracterización y Perspectivas de Futuro, Santiago, https://www.cr2.cl/seguridadhidrica/ (last access: 1 December 2023), 2023b. 
                    
                
                        
                        Alvez, A., Aitken, D., Rivera, D., Vergara, M., McIntyre, N., and Concha, F.: At the crossroads: can desalination be a suitable public policy solution to address water scarcity in Chile's mining zones?, J. Environ. Manage., 258, 110039, https://doi.org/10.1016/j.jenvman.2019.110039, 2020. 
                    
                
                        
                        Andersen, T. M., Bhattacharya, J., and Liu, P.: Resolving intergenerational conflict over the environment under the pareto criterion, J. Environ. Econ. Manage., 100, 102290, https://doi.org/10.1016/j.jeem.2019.102290, 2020. 
                    
                
                        
                        Araneda, M. C., Soledad Avendaño, M. R., and Díaz Del Río, G.: Modelo estructural de la cuenca de Santiago, Chile y su relación con la hidrogeología, Revista Geofísica, 62, 29–48, 2010. 
                    
                
                        
                        Barría, P., Barria Sandoval, I., Guzman, C., Chadwick, C., Alvarez-Garreton, C., Diaz-Vasconcellos, R., Ocampo-Melgar, A., and Fuster, R.: Water allocation under climate change: A diagnosis of the Chilean system, Elementa, 9, 1–20, https://doi.org/10.1525/elementa.2020.00131, 2021a. 
                    
                
                        
                        Barría, P., Chadwick, C., Ocampo-Melgar, A., Galleguillos, M., Garreaud, R., Díaz-Vasconcellos, R., Poblete, D., Rubio-Álvarez, E., and Poblete-Caballero, D.: Water management or megadrought: what caused the Chilean Aculeo Lake drying?, Reg. Environ. Change, 21, 19, https://doi.org/10.1007/s10113-021-01750-w, 2021b. 
                    
                
                        
                        Bierkens, M. F. P. and Wada, Y.: Non-renewable groundwater use and groundwater depletion: A review, Environ. Res. Lett., 14, 063002, https://doi.org/10.1088/1748-9326/ab1a5f, 2019. 
                    
                
                        
                        Boisier, J. P.: CR2MET: A high-resolution precipitation and temperature dataset for the period 1960–2021 in continental Chile (v2.5), Zenodo [data set], https://doi.org/10.5281/zenodo.7529682, 2023. 
                    
                
                        
                        Boisier, J. P., Rondanelli, R., Garreaud, R., and Muñoz, F.: Anthropogenic and natural contributions to the Southeast Pacific precipitation decline and recent megadrought in central Chile, Geophys. Res. Lett., 43, 413–421, https://doi.org/10.1002/2015GL067265, 2016.  
                    
                
                        
                        Boisier, J. P., Alvarez-Garretón, C., Cordero, R. R., Damiani, A., Gallardo, L., Garreaud, R. D., Lambert, F., Ramallo, C., Rojas, M., and Rondanelli, R.: Anthropogenic drying in central-southern Chile evidenced by long-term observations and climate model simulations, Elem. Sci. Anth., 6, 1–20, https://doi.org/10.1525/elementa.328, 2018. 
                    
                
                        
                        Budds, J.: Whose Scarcity? The Hydrosocial Cycle and the Changing Waterscape of La Ligua River Basin, Chile, in: Contentious geographies: Environmental knowledge, meaning, scale, Ashgate Studies in Environmental Policy and Practice, edited by: Goodman, M. K., Boykoff, M. T., and Evered, K. T., Farnham, Surrey, 59–78; eBook ISBN 9781315573953, 2008. 
                    
                
                        
                        Burls, N. J., Blamey, R. C., Cash, B. A., Swenson, E. T., Fahad, A., Bopape, M. J. M., Straus, D. M., and Reason, C. J. C.: The Cape Town “Day Zero” drought and Hadley cell expansion, NPJ Clim. Atmos. Sci., 2, 27, https://doi.org/10.1038/s41612-019-0084-6, 2019. 
                    
                
                        
                        CAMELS-CL: https://camels.cr2.cl (last access: 1 October 2023), 2023. 
                    
                
                        
                        Castilla-Rho, J. C., Rojas, R., Andersen, M. S., Holley, C., and Mariethoz, G.: Social tipping points in global groundwater management, Nat. Hum. Behav., 1, 640–649, https://doi.org/10.1038/s41562-017-0181-7, 2017. 
                    
                
                        
                        Center for Climate and Resilience Research: https://www.cr2.cl (last access: 1 October 2023), 2023. 
                    
                
                        
                        Congreso Nacional de Chile: Decreto Fuerza de Ley 1122, Fija Texto del Código de Aguas, Biblioteca del Congreso Nacional de Chile, 1–68, https://bcn.cl/2f8tw (last access: 1 October 2023), 1981. 
                    
                
                        
                        Congreso Nacional de Chile: Ley 20017, Modifica el Código de Aguas, Ministerio de Obras Públicas, 1–7, https://bcn.cl/2n3tw (last access: 1 October 2023), 2005. 
                    
                
                        
                        Congreso Nacional de Chile: Decreto con fuerza de ley 1122, Fija Texto del Código de Aguas, Ministerio de Justicia, 1–89, https://bcn.cl/2f8tw (last access: 1 October 2023), 2022. 
                    
                
                        
                        de Graaf, I. E. M., Gleeson, T., (Rens) van Beek, L. P. H., Sutanudjaja, E. H., and Bierkens, M. F. P.: Environmental flow limits to global groundwater pumping, Nature, 574, 90–94, https://doi.org/10.1038/s41586-019-1594-4, 2019. 
                    
                
                        
                        DGA: Estimación de la demanda actual, proyecciones futuras y caracterización de la calidad de los recursos hídricos en Chile, SIT 419, Realizado por: Unión temporal de proveedores Hídrica Consultores SPA y Aquaterra ingenieros LTDA, https://snia.mop.gob.cl/repositoriodga/handle/20.500.13000/6960 (last access: 1 October 2023), 2017. 
                    
                
                        
                        DGA: Plan estratégico de gestión hídrica en la cuenca del Maipo, Santiago, 1–420, https://snia.mop.gob.cl/repositoriodga/handle/20.500.13000/125473 (last access: 1 October 2023), 2021. 
                    
                
                        
                        DGA: https://snia.mop.gob.cl/BNAConsultas/reportes (last access: 1 October 2023), 2023. 
                    
                
                        
                        Döll, P. and Fiedler, K.: Global-scale modeling of groundwater recharge, Hydrol. Earth Syst. Sci., 12, 863–885, https://doi.org/10.5194/hess-12-863-2008, 2008. 
                    
                
                        
                        Duran-Llacer, I., Munizaga, J., Arumí, J. L., Ruybal, C., Aguayo, M., Sáez-Carrillo, K., Arriagada, L., and Rojas, O.: Lessons to be learned: Groundwater depletion in Chile's ligua and petorca watersheds through an interdisciplinary approach, Water, 12, 2446, https://doi.org/10.3390/w12092446, 2020. 
                    
                
                        
                        Duran-Llacer, I., Arumí, J. L., Arriagada, L., Aguayo, M., Rojas, O., González-Rodríguez, L., Rodríguez-López, L., Martínez-Retureta, R., Oyarzún, R., and Singh, S. K.: A new method to map groundwater-dependent ecosystem zones in semi-arid environments: A case study in Chile, Sci. Total Environ., 816, 151528, https://doi.org/10.1016/j.scitotenv.2021.151528, 2022. 
                    
                
                        
                        Fernández, F. J., Vásquez-Lavín, F., Ponce, R. D., Garreaud, R., Hernández, F., Link, O., Zambrano, F., and Hanemann, M.: The economics impacts of long-run droughts: Challenges, gaps, and way forward, J. Environ. Manage., 344, 118726, https://doi.org/10.1016/j.jenvman.2023.118726, 2023. 
                    
                
                        
                        Garreaud, R., Alvarez-Garreton, C., Barichivich, J., Boisier, J. P., Christie, D., Galleguillos, M., LeQuesne, C., McPhee, J., and Zambrano-Bigiarini, M.: The 2010–2015 mega drought in Central Chile: Impacts on regional hydroclimate and vegetation, Hydrol. Earth Syst. Sci., 21, 6307–6327, https://doi.org/10.5194/hess-21-6307-2017, 2017. 
                    
                
                        
                        Garreaud, R. D., Boisier, J. P., Rondanelli, R., Montecinos, A., Sepúlveda, H. H., and Veloso-Aguila, D.: The Central Chile Mega Drought (2010–2018): A climate dynamics perspective, Int. J. Climatol., 40, 421–439, https://doi.org/10.1002/joc.6219, 2019. 
                    
                
                        
                        Gayo, E. M., Latorre, C., Jordan, T. E., Nester, P. L., Estay, S. A., Ojeda, K. F., and Santoro, C. M.: Late Quaternary hydrological and ecological changes in the hyperarid core of the northern Atacama Desert (∼21° S), Earth-Sci. Rev., 113, 120–140, https://doi.org/10.1016/j.earscirev.2012.04.003, 2012. 
                    
                
                        
                        Gleeson, T., Befus, K. M., Jasechko, S., Luijendijk, E., and Cardenas, M. B.: The global volume and distribution of modern groundwater, Nat. Geosci., 9, 161–164, https://doi.org/10.1038/ngeo2590, 2016. 
                    
                
                        
                        Gleeson, T., Cuthbert, M., Ferguson, G., and Perrone, D.: Annual Review of Earth and Planetary Sciences Global Groundwater Sustainability, Resources, and Systems in the Anthropocene, Annu. Rev. Earth Planet. Sci., 48, 431–463, https://doi.org/10.1146/annurev-earth-071719-055251, 2020. 
                    
                
                        
                        Gudynas, E.: Montevideo is the world's first case of a capital without drinking water in the twenty-first century, Day zero, https://ripess.eu/en/montevideo-is-the-worlds-first-case-of-a-capital-without-drinking (last access: 1 October 2023), 2023. 
                    
                
                        
                        Hiskes, R. P.: Toward a Global Consensus on Environmental Human Rights, in: The human right to a green future: Environmental rights and intergenerational justice, Cambridge University Press, 92–116, https://doi.org/10.1017/CBO9780511575396.006, 2009. 
                    
                
                        
                        INDAP: Manual de pequeñas obras de riego en la agricultura campesina familiar, 1–231, https://bibliotecadigital.ciren.cl/handle/20.500.13082/28979 (last access: 1 October 2023), 2010. 
                    
                
                        
                        IPCC: Climate Change 2022: Impacts, Adaptation, and Vulnerability, in: Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Pörtner, H.-O. , Roberts, D. C., Tignor, M., Poloczanska, E. S., Mintenbeck, K., Alegría, A., Craig, M., Langsdorf, S., Löschke, S., Möller, V., Okem, A., and Rama, B., Cambridge University Press, 3056 pp., https://doi.org/10.1017/9781009325844, 2022. 
                    
                
                        
                        Iriarte, S., Atenas, M., Aguirre, E., and Tore, C.: Aquifer recharge and contamination determination using environmental isotopes: Santiago basin, Chile. A study case, in: Estudios de hidrologia isotopica en America Latina 2006, Organismo Internacional de Energía Atómica, 97–112, http://www-pub.iaea.org/MTCD/publications/PDF/TE_1611s_web.pdf (last access: 1 October 2023), 2009. 
                    
                
                        
                        Jódar, J., Urrutia, J., Herrera, C., Custodio, E., Martos-Rosillo, S., and Lambán, L. J.: The catastrophic effects of groundwater intensive exploitation and Megadrought on aquifers in Central Chile: Global change impact projections in water resources based on groundwater balance modeling, Sci. Total Environ., 914, 169651, https://doi.org/10.1016/j.scitotenv.2023.169651, 2023. 
                    
                
                        
                        Libertad y Desarrollo: Reforma al Código de Aguas: Principales Cambios y Desafíos, Temas públicos LyD, 1533, 1–7, https://lyd.org/wp-content/uploads/2022/03/TP-1533-REFORMA-CODIGO-DE-AGUAS.pdf (last access: 1 October 2023), 2019. 
                    
                
                        
                        Maxmen, A.: Cape Town scientists prepare for “Day Zero”: As water crisis brews, researchers plan to modify studies and prioritize public health, Nature, 554, 13–14, https://doi.org/10.1038/d41586-018-01134-x, 2018. 
                    
                
                        
                        Meza, F. J., Vicuña, S., Jelinek, M., Bustos, E., and Bonelli, S.: Assessing water demands and coverage sensitivity to climate change in the urban and rural sectors in central Chile, J. Water Clim. Change, 5, 192–203, https://doi.org/10.2166/wcc.2014.019, 2014. 
                    
                
                        
                        Moran, B. J., Boutt, D. F., and Munk, L. A.: Stable and Radioisotope Systematics Reveal Fossil Water as Fundamental Characteristic of Arid Orogenic-Scale Groundwater Systems, Water Resour. Res., 55, 11295–11315, https://doi.org/10.1029/2019WR026386, 2019. 
                    
                
                        
                        Muchnik, E., LuraschI, M., and Maldini, F.: Commercialization of water rights in Chile, Naciones Unidas. División de Desarrollo Productivo y Empresarial de la CEPAL, Santiago, 27 pp., https://hdl.handle.net/11362/4697 (last access: 1 October 2023), 1997. 
                    
                
                        
                        Muñoz, A. A., Klock-Barría, K., Alvarez-Garreton, C., Aguilera-Betti, I., González-Reyes, Á., Lastra, J. A., Chávez, R. O., Barría, P., Christie, D., Rojas-Badilla, M., and Lequesne, C.: Water crisis in petorca basin, Chile: The combined effects of a mega-drought and water management, Water, 12, 1–17, https://doi.org/10.3390/w12030648, 2020. 
                    
                
                        
                        Oki, T. and Kanae, S.: Global Hydrological Cycles and Freshwater Resources, Science, 313, 1068–1073, 2006. 
                    
                
                        
                        Pizarro, R., Garcia-Chevesich, P. A., McCray, J. E., Sharp, J. O., Valdés-Pineda, R., Sangüesa, C., Jaque-Becerra, D., Álvarez, P., Norambuena, S., Ibáñez, A., Vallejos, C., and Mendoza, R.: Climate Change and Overuse: Water Resource Challenges during Economic Growth in Coquimbo, Chile, Sustainability, 14, 3440, https://doi.org/10.3390/su14063440, 2022.  
                    
                
                        
                        Riffo, D.: Actualización del modelo DGA 2000 del acuífero Maipo-Mapocho para el análisis de la influencia del cambio climático sobre la sustentabilidad futura del sistema, Universidad de Chile, https://repositorio.uchile.cl/handle/2250/186901 (last access: 1 October 2023), 2022. 
                    
                
                        
                        Schwartz, F. W., Liu, G., and Yu, Z.: HESS Opinions: The myth of groundwater sustainability in Asia, Hydrol. Earth Syst. Sci., 24, 489–500, https://doi.org/10.5194/hess-24-489-2020, 2020. 
                    
                
                        
                        Taucare, M., Viguier, B., Figueroa, R., and Daniele, L.: The alarming state of Central Chile's groundwater resources: A paradigmatic case of a lasting overexploitation, Sci. Total Environ., 906, 167723, https://doi.org/10.1016/j.scitotenv.2023.167723, 2024. 
                    
                
                        
                        Valois, R., MacDonell, S., Núñez Cobo, J. H., and Maureira-Cortés, H.: Groundwater level trends and recharge event characterization using historical observed data in semi-arid Chile, Hydrolog. Sci. J., 65, 597–609, https://doi.org/10.1080/02626667.2020.1711912, 2020. 
                    
                
                        
                        Venegas-Quiñones, A.: New method to identify illegal uses of water by using remote sensing and neural network in Laguna de Aculeo, Chile, MS thesis, University of Arizona, https://repository.arizona.edu/handle/10150/665579 (last access: 1 October 2023), 2022. 
                    
                
                        
                        Viguier, B., Jourde, H., Yáñez, G., Lira, E. S., Leonardi, V., Moya, C. E., García-Pérez, T., Maringue, J., and Lictevout, E.: Multidisciplinary study for the assessment of the geometry, boundaries and preferential recharge zones of an overexploited aquifer in the Atacama Desert (Pampa del Tamarugal, Northern Chile), J. S. Am. Earth Sci., 86, 366–383, https://doi.org/10.1016/j.jsames.2018.05.018, 2018. 
                    
                
                        
                        Warner, J. F. and Meissner, R.: Cape Town's “Day Zero” water crisis: A manufactured media event?, Int. J. Disast. Risk Reduct., 64, 102481, https://doi.org/10.1016/j.ijdrr.2021.102481, 2021. 
                    
                
                        
                        Zhao, Y., Feng, D., Yu, L., Wang, X., Chen, Y., Bai, Y., Hernández, H. J., Galleguillos, M., Estades, C., Biging, G. S., Radke, J. D., and Gong, P.: Detailed dynamic land cover mapping of Chile: Accuracy improvement by integrating multi-temporal data, Remote Sens. Environ., 183, 170–185, 2016. 
                    
                Short summary
            This opinion paper reflects on the risks of overusing groundwater savings to supply permanent water use requirements. Using novel data recently developed for Chile, we reveal how groundwater is being overused, causing ecological and socioeconomic impacts and concealing a Day Zero
 scenario. Our argument underscores the need for reformed water allocation rules and sustainable management, shifting from a perception of groundwater as an unlimited source to a finite and vital one.
This opinion paper reflects on the risks of overusing groundwater savings to supply permanent...