RESUMEN
The organic pollutants disposed at the Sardas landfill in Sabiñánigo (Huesca, northeastern Spain) by the INQUINOSA lindane factory have reached the Gállego alluvial aquifer and could affect the Sabiñánigo reservoir. The daily oscillations of the reservoir water level produce a tidal effect on the piezometric heads of the aquifer. These oscillations are transmitted in a damped way with a time lag, thus attesting that the silting sediments of the reservoir and the natural silts of the Gállego alluvial are interposed between the reservoir water and the layer of sands and gravels. A 2D finite element groundwater flow and total dissolved hexachlorocyclohexane (HCH) transport model through the Gállego alluvial aquifer is presented here. The flow model was constructed to: (1) Quantify the tidal effect, produced by the daily fluctuations of the reservoir water level on the aquifer; (2) Estimate the hydrodynamic parameters of the layer of sands and gravels; and 3) Estimate the vertical hydraulic conductivity of the silting sediments and silts; and (4) Quantify aquifer/reservoir interactions. The flow model reproduces the dynamics of the tidal effect and attests that groundwater velocity and flow direction changes daily in response to the oscillations of the reservoir level. Model results reproduce the measured well hydrographs and the Darcy velocity derived from tracer tests and confirm the validity of the conceptual model. The transport model of total dissolved HCH simulates the time evolution of the contaminant plume. The computed concentrations of total dissolved HCH and the contaminant mass outflux are very sensitive to changes in the source terms and the distribution coefficient, Kd of HCH. The best fit to the measured HCH plumes in September 2010 and December 2020 is obtained with a Kd ranging from 1 to 3 L/kg. The computed flux of dissolved HCH leaving the Sardas site in 2020 towards the Sabiñánigo reservoir ranges from 0.6 kg/year for Kd = 3 L/kg to 3.1 kg/year for Kd = 1 L/kg. The findings of this study will be most useful for planning and designing remedial and containment actions at the Sardas site and other similar lindane-affected sites.
Asunto(s)
Agua Subterránea , Hexaclorociclohexano , Movimientos del Agua , Contaminantes Químicos del Agua , Agua Subterránea/análisis , España , Contaminantes Químicos del Agua/análisis , Hexaclorociclohexano/análisis , Modelos Teóricos , Monitoreo del Ambiente , Instalaciones de Eliminación de ResiduosRESUMEN
The expansion of cities towards flood zones, and the increasingly frequent episodes of torrential rains arising from global warming, mean that the population is becoming more exposed to floods. Due to this, a correct assessment of flood events is of great help in the development of preventive actions, planning and resource management, or interventions. For this reason, in this work we aim to establish guidelines to assess the hazard, exposure, and vulnerability of the population and its properties to flood events, using Hec-Ras for the simulation of the flood and ArcGis and GeoHecRas to treat geographic information and prepare the cartography. The study was focused on the Tormes River in Salamanca (Spain). We studied three return periods with different probabilities of occurrence and intensity, corresponding to 5, 100, and 500 years. The flow corresponding to each episode was calculated, along with the extension, speed, and depth that would be achieved in each case. Then, the probability of occurrence was delimited, as well as the magnitude, allowing us to obtain different hazard maps. In addition, the areas of greatest hazard to people and property were established for each event. Regarding the exposure, the areas and land use, infrastructure, and buildings that would be flooded in each case were identified, quantifying the extension or length of the affected properties at the different levels of hazard in each case. Additionally, the vulnerability of the different buildings and exposed infrastructure was studied. Finally, the flood risk was estimated by combining these three components.
Asunto(s)
Inundaciones/estadística & datos numéricos , Ríos , Ciudades , Modelos Estadísticos , Probabilidad , Medición de Riesgo , EspañaRESUMEN
The safety of autologous bone marrow mononuclear cells (ABMNC) intraspinal infusion in amyotrophic lateral sclerosis (ALS) patients was evaluated considering breathing and sleep patterns. Patients between 20 and 65 years old were eligible if they had definite ALS, spinal onset, a disease duration between 6 and 36 months, FVC>50%, and a below 90% oxygen saturation (T90) <2% of sleep time. The transplant was performed 6 months after enrollment. ABMNC were infused at thoracic 3-4 level. Eleven patients were included. The REM sleep decreased slightly one year after the cell transplant but not significantly. There were no differences in apnea-hipopnea index, mean oxygen saturation and nadir desaturation evolution. An increase of T90 was observed 180 and 360 days after injection (2.95±1.51% and 4.30±4.10% respectively), although it was not statistically significant. The central drive determined by occlusion pressure (P01) and inspiratory flow showed non-significant differences after one year. Intramedullary injection of ABMNC did not worsen the cortico medullar diaphragmatic pathways.