On the Isotopic Altitude Effect of Precipitation in the Northern Adriatic (Croatia)

The upper (northern) Adriatic is very rich in precipitation. This input into the water system and its stable isotope composition is a basic factor, knowledge of which is required for proper use and management of water resources. The geomorphology of the region (e.g., mountains of 1400 m next to the sea) can cause specific local conditions. The isotopic composition of precipitation has been measured in various locations at different altitudes. For δ18O this 'altitude effect' is found to lie around -0.2 per mille /100 m; its exact value depends on the specific location and the season. The δ2H values and the d-excess vary correspondingly. (author)