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- Interpretation of an injection test in a large diameter well in south Portugal and contribution to the understanding of the local hydrogeologyPublication . Costa, Luís R. D.; Monteiro, José Paulo; Oliveira, Manuel M.; Ferreira, João Paulo Lobo; Leitão, Teresa E.; Carvalho, Tiago; Carvalho, José Martins de; Agostinho, RuiThis paper refers to the interpretation of an injection test in a traditional large diameter well in Querença-Silves aquifer, south Portugal, under the scope of the project FP7-ENV-2013-WATER-INNO-DEMO MARSOL. Hydraulic parameter estimates were found within a high level of uncertainty regarding aquifer and well configuration. Given the injection test results together with the knowledge acquired on the field and from previous well logs and pumping tests on this aquifer section, it seems plausible to assume that the water injected in the well is locally flowing to an opposite direction to the regional aquifer flow. This forcing could possibly be caused by the existence of a local confinement or aquitard separating the injection well from the regional aquifer, or simply due to local scale heterogeneities and fracturation patterns.
- Assessing the use of harvested greenhouse runoff for managed aquifer recharge to improve groundwater status in South PortugalPublication . Costa, Luis; P. Monteiro, J.; Hugman, Rui TwohigConcentration of nitrates in groundwater at the Nitrate Vulnerable zone of Faro, south Portugal, reaches values as high as 300 mg/l; therefore, according to the EU Water Framework Directive, mitigation measures need to be implemented. A Managed Aquifer Recharge scheme is proposed to accelerate the dilution and natural discharge of nitrates from the system. Source water availability is estimated from rainfall intercepted at existing greenhouses. Within the highest nitrate concentration area, estimated water availability for injection in existing wells is 1.50 hm(3)/year, a significant volume which represents approximately 15% of the aquifer direct recharge. It is proposed this is recharged to the aquifer through existing large-diameter traditional wells that are no longer used for abstraction. Injection test results suggest that the likely infiltration capacity of such wells is more than sufficient to allow collection of 95% of daily rainfall events. The effect of injecting this volume in the aquifer was estimated with the support of a 3D numerical groundwater flow and transport model. Results show considerable improvement in nitrate concentrations in the study area, in certain locations decreasing up to 70 mg/l by 2027. The model results predict a decrease in the number of nitrate threshold exceedances in observation points, from 33 to 30 by 2027 and 14 to 9 by 2040. It is likely that this measure may have a positive effect on other issues identified in the area, mostly related with quantity problems and seawater intrusion. Notwithstanding, issues including landowner support, clogging, conditions of greenhouses and wells, water quality, and climate change impacts will require further consideration to develop a successful and beneficial MAR scheme.
- In-channel managed aquifer recharge: a review of current development worldwide and future potential in EuropePublication . Standen, Kathleen; Costa, Luis; Monteiro, José PauloManaged aquifer recharge (MAR) schemes often employ in-channel modifications to capture flow from ephemeral streams, and increase recharge to the underlying aquifer. This review collates data from 79 recharge dams across the world and presents a reanalysis of their properties and success factors, with the intent of assessing the potential of applying these techniques in Europe. This review also presents a narrative review of sand storage dams, and other in-channel modifications, such as natural flood management measures, which contribute to the retardation of the flow of flood water and enhance recharge. The review concludes that in-channelMARsolutions can increase water availability and improve groundwater quality to solve problems a ecting aquifers in hydraulic connection with temporary streams in Europe, based on experiences in other parts of the world. Therefore, to meet the requirements of the Water Framework Directive (WFD), in-channel MAR can be considered as a measure to mitigate groundwater problems including saline intrusion, remediating groundwater deficits, or solving aquifer water quality issues.