Study of groundwaters using the environmental tritium and hydrochemical data in the Belgrade region

Abstract

A study of tritium content and some physicochemical parameters has been performed in order to investigate interconnection between surface and atmospheric waters and underground waters in Belgrade area. Samples of the precipitation at Zeleno Brdo-Belgrade meteorological station, the Danube and the Sava river water, and underground water (Ranney wells and piezometers) have been analyzed. The³H content, the content of dissolved ions, total hardness, and electrical conductivity have been measured. The tritium data show existence of two water strata in the aquifer. The upper stratum (about 16 m thick) contains older water (mean monthly³H concentration of 17 TU) and has weak interaction with the river and the precipitation. Below this stratum lies the principal water bearing stratum, strongly connected with the river with the³H concentration similar to that of surface water (mean monthly³H concentration of 50 TU) and spreading out through the entire aquifer. The contribution of the Sava river water and the two water layers at the Ranney well are calculated starting with the hydrological aquifer model, which supposes that three water components are mixed in the pumped Ranney well water. According to calculation results using the³H concentration and physicochemical characteristics as parameters, more than 70 percent of the water pumped by the Ranney well (in 1983) comes from the Sava with a time delay of less that 15 days.

Properties of tritium distribution in precipitation, river waters, and underground water in the Belgrade region are established from the results of measurements of³H concentrations in the period 1976–1983.