Chloride and stable isotope Ç8o and D) contents of precipitations in a mountainous area (Guadalquivir headwaters, Jaén province)

Precipitation water has been sampled from October 2002 to March 2003 in a number of stations located in a mountainous area (Guadalquivir headwaters, Jaen province, 5. Spain: from 400 m to 2000 m of altitude) in order to quantify chloride, deuterium and oxygen 1 8 contents. The obtained values range approximately between 0,2 and 2,4 mg/L (Cl), -1 00 %o and-15%o (D) and-14 %0 and-3 %q C’O). The respective averages are 1 mg/L, -6,8 %o and -42,8 %o. The obtained values are in good agreement with global estimates (for the isotopes), and with previous measurements in adjacent or nearby areas (for the three species). Thé great variability shown by the data of the three species is mainly caused by: a) the effect of temperature, both'seasonally or altitudinally induced (the gradients for the isotopes are typical values), and b) the different procedence of the vapour masses which produce the precipitations over the area, as is also shown by the dispersion in the deuterium excess value