RESUMO
Two years of monthly observations of water stable isotopes in a temperate lowland catchment with extensive agrarian and forested landscapes in Latvia, River Salaca catchment. Observations include most significant water types within catchment: precipitation, raised bog, intermittent, groundwater and surface water at 15 observation points. The monthly data is supplemented by two intervals of one-month long sampling every second day for a subset of observation points. Water table, temperature and electrical conductivity co-observed as key variables helping to understand the isotope data. The data can be useful for in depth investigation of isotope hydrology and as background information for ecohydrological and other studies. The data is associated with the original research article "An insight into water stable isotope signatures in temperate catchment" [1].
RESUMO
A new data set of δ(2)H and δ(18)O in the groundwater from the central part of the Baltic Artesian Basin is presented. The hydrogeological section is subdivided into stagnation, slow exchange and active exchange zones. Na-Ca-Cl brine found at the deepest part - the stagnation zone - is characterized by δ(18)O values above -5 and δ(2)H values approaching -40 with respect to Vienna Standard Mean Ocean Water. The slow exchange zone where waters of mostly intermediate salinity reside is characterized by δ(18)O values around -11.7 and δ(2)H values around -85.3 . Mean δ(18)O and δ(2)H values of the fresh groundwater in the active water exchange zone are -11.1 and -79.9 , respectively. Characteristically, the groundwater in the active and slow exchange zone is isotopically more depleted compared with the precipitation values observed, and the depletion increases with depth down to the level where strongly enriched brines are encountered.