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Summer rainstorm associated with a debris flow in the Amarilla gully affecting the international Agua Negra Pass (30°20′S), Argentina Texte intégral
2017
Lauro, Carolina | Moreiras, StellaM. | Junquera, Sebastian | Vergara, Ivan | Toural, Rafael | Wolf, Johannes | Tutzer, Ruben
The Central-West region of Argentina was seriously affected by a series of convective summer storms on January–February of 2013 generating many debris flows and rockfall in the Central Andes mountain regions. In particular, the unreported 8th February event caused the sad death of a 10-year-old child being completely ignored by society and local authorities. Despite this, meteorological conditions associated with this event and further episodes were rarely measured and determined mainly due to scarce meteorological stations in Andean mountain areas. In this paper, meteorological data from CMORPH algorithm and measurements of surrounding gauges were analyzed for estimating the triggering precipitation value of this event. As well, the particular debris flow channeled into the main branch of the Amarilla gully in the Agua Negra valley was geomorphologically described. The amount of precipitation associated with this debris flow was 5.5 and 13.2 mm accumulated previous to the event. This violent debris flow was generated in a talus zone in a periglacial environment located just below a covered rock glacier. However, the influence of the permafrost thawing in this process is not feasible. The altitude of the 0 °C isotherm was lower during the previous days of the event, and no monitoring on permafrost is available for this area. The volume of removed mass was estimated in 5 × 10⁴ m³, and the mean velocity was 35 km/h. Boulders of 4 m diameter were found in the source area, while the deposit is up to 75% sandy with clasts that hardly exceed 10 cm in the alluvial fan distal part. Herein the main objective is to advice about the probable catastrophic impact of similar events in the future. These findings could be useful for hazard remediation, mitigation, and prevention plans for the Agua Negra international pass under construction.
Afficher plus [+] Moins [-]Groundwater management by riverbank filtration and an infiltration channel: the case of Obrenovac, Serbia | Gestion de l’eau souterraine par filtration de berge et canal d’infiltration: le cas de Obrenovac, Serbie Manejo del agua subterránea por filtración en las márgenes del río y por un canal de infiltración: el caso de Obrenovac, Serbia Gestão de água subterrânea através de bancos filtrantes em rios e num canal de infiltração: o caso de Obrenovac, Sérvia Menadžment podzemnih voda pomoću rečne obalske filtracije i infiltracionog kanala: primer izvorišta Obrenovac, Srbija Texte intégral
2013
Polomčić, Dušan | Hajdin, Bojan | Stevanović, Zoran | Bajić, Dragoljub | Hajdin, Katarina
The Vic Bare groundwater source is used to supply water to the population and industry of Obrenovac, one of the municipalities of Belgrade (the capital of Serbia). It is a typical riverbank filtration site; exploitation is performed through 30 drilled wells and two radial wells located in the meander of the Sava River. The established hydraulic connection between the river and tapped aquifer is so great that the river regime has a dominant influence on the aquifer. As a consequence of this, water-delivery reduction occurs in the dry months (summer-autumn), when the population needs water the most. Based on the data associated with the river's gauges, precipitation, quantity of pumped water and groundwater-level fluctuation, a simulation of the groundwater regime for non-steady-state flow conditions has been undertaken through a numerical model. To overcome problems of water shortage during the dry season, the possibility of artificial recharge using an infiltration channel, made up of two connected parts, was analyzed. During the dry months, 80 % of the wells receive water partly from the infiltration channel. In this way, possibilities for extracting additional water are created. The application of this concept is discussed.
Afficher plus [+] Moins [-]Sensitivity of GRACE-derived estimates of groundwater-level changes in southern Ontario, Canada | Sensibilité des changements de niveaux d’eau souterraine estimés à l’aide des données dérivées de GRACE dans le sud de l’Ontario, Canada Sensibilidad de las estimaciones derivadas de GRACE en los cambios del nivel de agua subterránea en el sur de Ontario, Canadá GRACE导出的加拿大安大略省南部地下水位变化估算值的灵敏度 Sensibilidade das estimativas derivadas do GRACE de mudanças no nível da água subterrânea no sul de Ontário, no Canadá Texte intégral
2017
Hachborn, Ellen | Berg, Aaron | Levison, Jana | Ambadan, Jaison Thomas
Amidst changing climates, understanding the world’s water resources is of increasing importance. In Ontario, Canada, low water conditions are currently assessed using only precipitation and watershed-based stream gauges by the Conservation Authorities in Ontario and the Ministry of Natural Resources and Forestry. Regional groundwater-storage changes in Ontario are not currently measured using satellite data by research institutes. In this study, contributions from the Gravity Recovery and Climate Experiment (GRACE) data are compared to a hydrogeological database covering southern Ontario from 2003 to 2013, to determine the suitability of GRACE total water storage estimates for monitoring groundwater storage in this location. Terrestrial water storage data from GRACE were used to determine monthly groundwater storage (GWS) anomaly values. GWS values were also determined by multiplying groundwater-level elevations (from the Provincial Groundwater Monitoring Network wells) by specific yield. Comparisons of GRACE-derived GWS to well-based GWS data determined that GRACE is sufficiently sensitive to obtain a meaningful signal in southern Ontario. Results show that GWS values produced by GRACE are useful for identifying regional changes in groundwater storage in areas with limited available hydrogeological characterization data. Results also indicate that GRACE may have an ability to forecast changes in groundwater storage, which will become useful when monitoring climate shifts in the near future.
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