CNR-IRSA activities related to INHABIT

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Hyporreic system

The hyporheic zone, i.e. the transition zone between ground water and surface water, is an important ecotone characterized by intense biochemical activities that can affect nutrient dynamics in lotic ecosystems and their self purifying capacity. The study of the biological and geochemical properties of the hyporheic zone, thence represents an opportunity to reduce the impact of groundwater on related river ecosystems, and vice versa.
Experimental activities for the study of hyporheic areas have been carried out in Mediterranean rivers in Cyprus and Sardinia as part of projects dedicated to the application of the European Water Framework Directive. A two-year study was also conducted on the Curone (Italy, Lecco), a small lowland stream characterized by unimpaired chemical and hydromorphological features.
In different discharge conditions, water samples were collected in hyporheic piezometers placed in different microhabitat differentiated by flow type, substrate type and position within the riverbed. The same river stretches have been characterized for both biological (macroinvertebrates) and hydromorphological aspects (application of CARAVAGGIO method). Differences in concentration of NO3, NH4, TP, DOC and dissolved O2, observed in different microhabitats, were put in relation to abiotic factors, such as particle size and flow velocity, and the characteristics of morphology, vegetation and land use on the banks.
The chemical characterization of samples, monthly collected in Curone, showed significant differences in the concentrations of O2, NO3 and NH4 between the pool and riffle areas, only considering the hyporheic compartment.

         

1) Mini-piezometers placed in the Curone burn, Montevecchia Regional Park (Italy, Lecco)

2) Mini-piezometers placed in the Diarizos river (Cyprus)