The chemical composition and sources of the bulk deposition on Lake Kinneret (The Sea of Galilee), Israel

Abstract

The chemical composition of the bulk deposition into Lake Kinneret, Israel was determined for the three hydrological years from 1992 to 1995. The fluxes of the elements and ions in the bulk deposition around the lake are fairly uniform although some local effects due to anthropogenic activity are observed; temporal effects are more pronounced. Na and Cl fluxes are greatly affected by rainfall that has passed over the Mediterranean Sea whilst Ca fluxes increase during dust storm episodes. The amount of each of the determined constituents entering the lake was calculated. The major chemical constituent entering the lake (except Ca) is SO4 whose main source is long-range transport from Europe. Enrichment factor analysis shows that the insoluble portion of the bulk deposition has the same characteristics as regional (and Saharan) dust storms, whilst the soluble portion is strongly affected by the marine environment. Significant additions to the previously known input of nitrogen and phosphorous enter the lake due to bulk deposition: 10% for nitrogen and 40% for phosphorous. The Pb content of the lake sediments correlates with Pb usage in petrol. Full experimental results are given in the electronic appendices.