Contribution of local factors to the status of a groundwater dependent terrestrial ecosystem in the transboundary Gauja-Koiva River basin, North-Eastern Europe
Abstract A pilot study was carried out in the Matsi spring fen, southern Estonia to test a proposed methodology ( Terasmaa et al., 2020 ) for identifying potential effects of groundwater bodies on groundwater dependent terrestrial ecosystems (GDTE). A comprehensive hydrochemical and isotopic dataset was collected and analyzed using multivariate statistical methods to assess the origin of the groundwater discharging in the spring fen and to determine both the quantitative and qualitative aspects of GDTE-groundwater interdependence. The hydrochemical findings were complemented with the hydrogeological, hydrodynamical and botanical observations, and summarized into a conceptual model of the st…
Geochemical classification of groundwater using multivariate statistical analysis in Latvia
Multivariate statistical methods – principal component analysis (PCA) and hierarchical cluster analysis (HCA) – are applied to identify geochemically distinct groundwater groups in the territory of Latvia. The main processes observed to be responsible for groundwater chemical composition are carbonate and gypsum dissolution, fresh and saltwater mixing and ion exchange. On the basis of major ion concentrations, eight clusters (C1–C8) are identified. C6 is interpreted as recharge water not in equilibrium with most sediment forming minerals. Water table aquifers affected by diffuse agricultural influences are found in C3. Groundwater in C4 reflects brine or seawater admixture and gypsum dissol…
Joint Methodology for the Identification and Assessment of Groundwater Dependent Terrestrial Ecosystems in Estonia and Latvia
Dynamic interactions between ground- and surface water are widely known, but the role of groundwater in terrestrial and aquatic ecosystems is often poorly understood and documented due to the spatiotemporal complexity. Many countries have not yet completed the assessment of groundwater dependent ecosystems (GDEs). GDEs are valuable ecosystems that depend on groundwater input and can not be considered and assessed separately. Changes in the quantity and chemical composition of groundwater recharge may result in significant and permanent damage on GDE flora and fauna. Aquifers are dynamic systems which are not subject to administrative boundaries and borders, therefore should be managed in cl…