Impact of urbanization on hydrochemical evolution of groundwater and on unsaturated-zone gas composition in the coastal city of Tel Aviv, Israel

摘要: Abstract The coastal city of Tel Aviv was founded at the beginning 20th century. number its inhabitants and water consumption increased rapidly. This study analyses a 15-year record (1934–1948) pre-industrial development groundwater chemistry in urban area. Archive data on concentrations major ions, dissolved gases (CO 2 O ), organic matter, pH were available for each half-year during period 1934–1948. factors causing changes flowing three sandy sub-aquifers have been seawater encroachment due to overpumping, infiltration effluents from pit-latrine collectors. Influence these decreases with depth. Landward-penetrating passed through clayey sediments, interbedded among sands calcareous sandstones, spread into Kurkar Group aquifer. has led exchange sodium (dominant seawater) calcium adsorbed clay particles, enriching calcium. Intensity cation inland Infiltration introduced large amounts ammonium unsaturated zone. Its rapid oxidation sediments caused massive nitrate production, accompanied by pore-water acidification. process induces dissolution vadose carbonate, resulting enrichment recharge Anthropogenically induced calcite zone factor increase Ca 2+ concentration groundwater, accounting about 80% this increase. In interface zone, an additional 20% supplied exchange. Owing denitrification aquifer, -rich waters supersaturated could be formed, especially capillary fringe uppermost sub-aquifer, which induce precipitation ultimately lead cementation aquifers. Urban drastic gas content groundwater. Carbon dioxide intensively generated nitrification–denitrification processes, hydration urea, lesser degree probably anoxic biodegradation organics. Between 1934 1948, CO sediment air rose 3.2% 7.6%. oxygen matter lowered unusually low values 3.9–12.9%. Nitrification thus serve as pump, sucking atmospheric rate 0.3–0.5 g m −2 day −1 . extreme preserved production under conditions diminishing areas open atmosphere, uncovered buildings roads.