【作者】 刘琼峰； 李明德； 段建南； 吴海勇； 文星；

【Author】 LIU Qiong-feng 1,2 , LI Ming-de 1* , DUAN Jian-nan 2 , WU Hai-yong 1 , WEN Xing 1,3 (1.Soil and Fertilizer Institute of Hunan Province, Changsha 410125, China;2. College of Resource and Environment, Hunan Agricultural University, Changsha 410128, China;3. Longping Branch of Graduate School,Central South University,Changsha 410125,China)

【机构】 湖南省土壤肥料研究所； 湖南农业大学资源环境学院； 中南大学研究生院隆平分院；

【摘要】 采集长沙城郊18个乡镇513个农田土壤样点,运用模糊综合评价法和层次分析法从农田土壤重金属Pb、Cd的含量、土壤理化特性(pH值、有机质、碱解氮、有效磷)、土壤区位特征(土壤采样点离城镇的距离、离建设用地的距离、离河流的距离、离农村居民点的距离)三个方面选取评价指标,建立农田土壤重金属Pb、Cd的生态风险评价模型。根据生态风险指数值(ERI)将生态风险等级划分为四级(Ⅰ级ERI>0.70、Ⅱ级0.6<ERI≤0.70、Ⅲ级0.4<ERI≤0.60、Ⅳ级ERI≤0.40),22.9%的土壤样点生态风险指数为Ⅲ级和Ⅳ级水平,具有较高的生态风险,主要分布在河流、城镇、建设用地和农村居民点的聚集区。根据各乡镇生态风险等级的差异,划分农田土壤重金属Pb、Cd的高、中、低生态风险区。农田土壤重金属的生态风险评价与分级、分区是建立农田土壤重金属生态风险防控体系的必要手段,可为农田土壤的科学合理利用提供参考。更多还原

【Abstract】 The purpose of this study was to assess the ecological risk of heavy metals Pb and Cd in agricultural soil of changsha suburb cropland.A total of 513 surface soil samples were collected, and the concentrations of Pb and Cd were analyzed. Evaluation indexs were picked up from three aspects such as the the concentrations of Pb and Cd, soil physicochemical properties, and soil location characteristic. The indexs of soil physicochemical properties were soil pH, organic matter, alkali-hydro nitrogen and rapidly-available phosphorus, while the indexs of soil location characteristic were the distance from cropland to town, the distance from cropland to industrial construction land, the distance form cropland to river, and the distance from cropland to settlement. The ecological risk grade were divided to four ranks according to the values of ecological risk index(class one were ERI>0.70, class two were 0.6<ERI≤0.70, class three were 0.4<ERI≤0.60, class four were ERI≤0.40).There were 22.9% sampling points at class three or class four levels. Most of points with high ecological risk were distributed at accumulation area of river, town, industrial construction land and settlement. The ecological risk regions of farmland soil heavy metals Pb and Cd were divided to three ranks such as high, middle, and low. Ecological risk assessment,classification and regionalization of heavy metals in agricultural soil have important significance for farmland ecological risk prevention and controlling system construction and soil utilization scientifically.更多还原