The geographic variation of salt precipitated over Western Australia

Abstract

The amounts of Na+, Mg2 +, K+, Ca2 +, C1-, SO42-, HCO3- and dust precipitated in rainfall and as dry fallout into continuously open collection funnels are reported for 59 centres throughout Western Australia. Ionic accessions for 1973 were in the following ranges; Na+, 2-98 kg ha-1; Mg2+, 0.3-15 kg ha-1; Ca2+, 0.8-35 kg ha-1; K+, 0.3-14 kg ha-1; SO42-, 2-57 kg ha-1; C1-, 2-180 kg ha-1; HCO3-, 1-105 kg ha-1. Chloride deposition at the coast is approximately an order of magnitude greater in the south-west of the state than in the north. In each region the amount of chloride precipitated exhibited the usual decrease with distance inland. There were regional differences in rainwater salt composition. Excess of ions over the amounts attributed to oceanic aerosols are explained by the locations of sampling centres relative to other source areas. Perth, the largest city, had the highest excess sulphur and above average values were obtained at the larger mining and country centres. Industry and domestic fires are the probable sources of this sulphur. Excesses of all ions from terrestrial sources were indicated at many inland centres, and were greatest in the zone of salt lakes and occluded drainage in the south-west.

The origin of gypsum in Vertisols in New Caledonia determined by isotopic characteristics of sulphur

“…For a rainfall of 400 to 800 mm per year, and with sulphate concentrations in the rain varying from 1 to 2 mg I-', the amount of sulphate input by rainfall ranges from 0.4 to 1.6 kg m-* 1000 yr-' (4 to 16 kg ha-' yr-I). These values are similar to the mean value of 1.5 kg ha-' yr-' of sulphate input by rainfall registered in southwest Australia (Hingston and Gailitis, 1976). The importance of the rainfall input of sulphates in the southwest Pacific is confirmed by the following recent measures: 1.9 kg m-* 1000 yr-' for the Tonga Islands (Manu et al 1990) and 0.15 to 4.5 kg m-' 1000 yr-' for New Zealand (Ledgard and Upsdell, 1991).…”

“…As this oceanic influence decreases, the relative importance of continental sulphate increases consequently. This relation is found in many South Pacific locations (Hingston and Gailitis, 1976;Blackburn and McLeod, 1983;Ledgard and Upsdell, 1991). All the New Caledonian gypsum soils are found within 20 km of the coast.…”

Roles of forest bioproductivity, transpiration and fire in a nine-year record of cave dripwater chemistry from southwest Australia

“…Modelled dust flux from inland Australia is small or insignificant, dust in this coastal area being mainly sourced from the surrounding calcareous dunes (Hingston and Gailitis, 1976). However, the prevailing mid-latitude westerly winds ensure a high marine aerosol flux e.g.…”

“…However, the prevailing mid-latitude westerly winds ensure a high marine aerosol flux e.g. annual chloride precipitation is >100 kg/ha along the SW Australian coastline (Hingston and Gailitis, 1976). …”

Farm-scale nitrogen, phosphorus, potassium and sulfur balances and use efficiencies on Australian dairy farms

“…N, 2.8%; P, 0.72%; K, 0.2%; and S, 0.8%) according to ARC (1994). Atmospheric deposition estimates were based on published figures which accounted for proximity to the coast or emissions from industry (Hutton and Leslie 1958;Hingston and Gailitis 1976;Probert 1976;Blackburn and McLeod 1983).…”