SPATIAL DISTRIBUTION OF SALT IONS IN SURFACE SOILS IN THE SOUTH COAST OF LAIZHOU BAY

This study is devoted to provision of a reference for the rational use of land in coastal saline soil areas. A total of 111 surficial samples were collected and measured for the K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl⁻, SO₄²⁻, HCO₃⁻, in addition to total salt content. Multivariate statistics and geostatistics were applied to seek for the spatial distribution pattern of surface soil salt segregants on the southern bank of Laizhou Bay. The results show that the salinity of surface sediments in the southern coast of Laizhou Bay is quite low. Non-salt soil accounts for 51.7% of the total area with 34.3% mildly and moderately polluted. Heavily salinized soil area occupies a total of 148 km² which is mainly distributed in north-eastern coastal areas, accounting for 14% of the study area. Spatially, the distribution of salinization intensity decreases from coast to inland. Na⁺ and Cl⁻, SO₄²⁻ and Ca²⁺, Mg²⁺ and Cl⁻ dominate, seconded by SO₄²⁻, K⁺, Mg²⁺ and HCO₃. Cl⁻ shows positive correlation with Na⁺ and Ca²⁺. The salt content in soil has moderate and strong spatial variability. High-value regions are found in the areas often invaded by sea water.