尾矿库生态退化区修复效果评价

Evaluation on Remediation Effect of Ecological Degradation Area of Tailings Pond

以歪头山铁矿尾矿库生态退化区为例,考虑多种土壤和植被指标因素,进行修复后的土壤理化性质、肥力性质、重金属污染特征以及植物生长指标检测;确定尾矿库生态修复效果的评价因子,利用灰色理论关联度分析法确定权重,进行生态修复分项指标评价;根据分项指数统计加权,得出生态修复指数,进行尾矿库修复效果综合评价。评价结果表明,随着植物栽植时间的增长,土壤pH值略有下降,电导率有所降低,土壤阳离子交换量递减;肥力指标有所增加,其中全磷、全钾增加缓慢,其余指标增加显著;重金属含量变化不明显,但沙棘对重金属的富集程度要高于紫穗槐;尾矿库生态修复综合效果随时间而提高,而紫穗槐样地的修复效果要略高于沙棘地。

Taking the ecological degradation area of tailings pond in Waitoushan Iron as an example,considering a variety of soil and vegetation indicators,the physical and chemical characteristics,fertility,heavy metals and plant growth status of soil after ecological remediation were detected.The evaluation factors of ecological remediation effect of tailings pond were determined.The weights were determined by grey theory correlation analysis to evaluate the ecological remediation sub-indicators.According to the statistical weight of the sub-indicators,the ecological remediation indexes were obtained,and the comprehensive remediation effect evaluation of tailings pond was carried out.The evaluation results showed that,with the growth of planting time,pH value of soil decreased slightly,electrical conductivity decreased and cation exchange in soil decreased.But the fertility index increased,among which the total phosphorus and potassium increased slowly,and other indexes increased significantly.The change of heavy metal content was not obvious,but the enrichment degree of heavy metal on the seabuckthorn was higher than that of robinia pseudoacacia.The comprehensive ecological remediation effect of tailings pond increased with time,and the remediation effect of robinia pseudoacacia plot was slightly higher than that of seabuckthorn plot.