Abstract: In order to find out the shallow groundwater quality and contamination situation of Huludao City, the groundwater samples were analyzed with the fuzzy comprehensive evaluation and hierarchy ladder methods. Based on the evaluation results, some main indicators affecting the water quality and pollution status were chosen. The hydrogeochemical simulation method was then adopted to analyze the genetic mechanism of various indicators. The results showed that, from the inland mountain foothills to coastal alluvial plain, the shallow groundwater chemical type changed from HCO₃ to HCO₃·SO₄ and HCO₃·Cl gradually. Groundwater quality levels of Ⅰ-Ⅲ, Ⅳ and Ⅴ accounted for 44%, 4% and 52% of the total, respectively. Moderately, heavy and severely heavy polluted water samples accounted for 48%, 36% and 16% of the total, respectively. It was concluded that Na⁺, K⁺, Ca²⁺, Mg²⁺, HCO₃^-, SO₄^2-, Cl^-, Br, NH₄⁺, NO₃^- and Pb were impact indicators of the groundwater quality and contamination status. The genetic mechanism mainly included cation exchange adsorption, transpiration, evaporation, and redox reaction. Regional agricultural production, mining activities and seawater intrusion were the major factors leading to the quality deterioration and contamination severity of the shallow groundwater.

Key words: CERES-Rice crop model., cold-terra rice, CO₂ and temperature, OTC