1,720,999 research outputs found
Il contributo della geologia allo studio degli acquiferi in ambito montano: casi di studio relativi all'Appennino piacentino e parmense.
Estimation of recharge in mountain hard-rock aquifers based on discrete spring discharge monitoring during base-flow recession
Estimation of aquifer recharge is key to effective groundwater management and protection. In mountain hard-rock aquifers, the average annual discharge of a spring generally reflects the vertical aquifer recharge over the spring catchment. However, the determination of average annual spring discharge requires expensive and challenging field monitoring. A power-law correlation was previously reported in the literature that would allow quantification of the average annual spring discharge starting from only a few discharge measurements in the low-flow season, in a dry summer climate. The correlation is based upon the Maillet model and was previously derived by a 10-year monitoring program of discharge from springs and streams in hard-rock aquifers composed of siliciclastic and calcareous turbidites that did not have well defined hydrogeologic boundaries. In this research, the same correlation was applied to two ophiolitic (peridotitic) hard-rock aquifers in the Northern Apennines (Northern Italy) with well-defined hydrogeologic boundaries and base-outflow springs. The correlation provided a reliable estimate of the average annual spring discharge thus confirming its effectiveness regardless of bedrock lithology. In the two aquifers studied, the measurable annual outputs (i.e. sum of average annual spring discharges) could be assumed equal to the annual inputs (i.e. vertical recharge) based on the clear-cut aquifer boundaries and a quick groundwater circulation inferable from spring water parameters. Thus, in such setting, the aforementioned correlation also provided an estimate of the annual aquifer recharge allowing the assessment of coefficients of infiltration (i.e. ratio between aquifer recharge and total precipitation) ranging between 10 and 20%
Studio pilota per la caratterizzazione geologica delle sorgenti nella zona del M. Nero (alta Val Ceno e alta Val Nure - Province di Parma e Piacenza)
Rivista dell'Ordine dei Geologi dell'Emilia-Romagn
Combining biological and hydrogeological approaches: The grass Molinia arundinacea as a possible bioindicator of temporary perched aquifers in ophiolitic systems
Is there an ideal protocol for sampling macroinvertebrates in springs?
Sampling in springs has several technical problems due to their reduced dimensions and habitat heterogeneity. A standardized quantitative method for sampling crenic macroinvertebrates has never been proposed. The aim of this study was to compare different sampling methods and consider their environmental impacts. First, we present a review of sampling methods found in the literature and discuss their advantages and disadvantages with respect to selective collection of the target community and habitat disturbance. Altogether, 10 different methods have been reported, the use of nets being the most common protocol. Second, we report the results of macroinvertebrate samplings performed in three springs, each surveyed twice, using three different methods (multi-habitat proportional hand net, baited traps, and vegetation washing), in order to compare their effectiveness in collecting macroinvertebrates. Overall, 32 macroinvertebrate taxa, mostly identified at family level, were collected in the sampled springs. Significant differences in abundances were found using different methods, while results for community structure were comparable between the hand net sampling and the combined use of the other two methods, notwithstanding slight differences in the composition of Coleoptera and Diptera assemblages. The hand net, with a multi-habitat proportional approach, yielded more thorough results, making it suitable for biodiversity inventories but having some potentially negative effects on spring habitats. Traps and vegetation washing are also reliable methods with negligible impacts on spring ecosystems that can be conveniently used in ecological studies
Monitoring and modelling groundwater flow systems in hard rock aquifers: Experiences from northern Apennines (Italy). International Conference on grounwater in fractured rocks, Prague 21-24 may
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