| 土壤重金属累积对土地利用与景观格局的响应 |
| 摘要点击 2341 全文点击 805 投稿时间：2018-09-06 修订日期：2018-11-15 |
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| 中文关键词 土壤重金属 土地利用 景观格局 污染程度 冗余分析 |
| 英文关键词 soil heavy metals land use landscape pattern pollution degree redundancy analysis |
| 作者 | 单位 | E-mail | | 舒心 | 浙江大学公共管理学院, 土地科学与不动产研究所, 杭州 310058 | Leewin26@163.com | | 李艳 | 浙江大学公共管理学院, 土地科学与不动产研究所, 杭州 310058 | liyan522@zju.edu.cn | | 李锋 | 杭州电子科技大学材料与环境学院, 环境工程系, 杭州 310018 | | | 冯靖仪 | 浙江大学公共管理学院, 土地科学与不动产研究所, 杭州 310058 | | | 沈嘉瑜 | 浙江大学公共管理学院, 土地科学与不动产研究所, 杭州 310058 | | | 史舟 | 浙江大学环境与资源学院, 农业遥感与信息技术应用研究所, 杭州 310058 | |
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| 中文摘要 |
| 土地利用/覆被既能反映重金属污染物的主要来源，亦能通过改变土壤物理、化学和生物性质从而控制重金属在土壤中的迁移性和活性，造成土壤中重金属的累积直至污染.基于2003年和2013年宁波市区土壤重金属采样点数据和土地利用数据，采用面向对象的决策树分类方法进行土地利用/覆被分类，采用单项污染指数、内梅罗综合污染指数评价土壤重金属污染状况，采用景观格局指数探索重金属不同累积程度下的土地利用变化和景观格局演变，采用冗余和偏冗余分析识别对研究区土壤重金属累积影响最为显著的景观格局因子及不同因子之间的交互作用.结果表明：①2003~2013年研究区8种土壤重金属元素均出现了不同程度的累积，其中以Hg、Ni和Cr的累积程度最高；研究区大多数区域已受到了土壤重金属的污染且重度污染区的污染程度仍在加剧.②较高的重金属累积程度并不完全出现在土地利用类型一直为建设用地的区域，或由其他类型转为建设用地的区域，有相当一部分发生在利用类型一直为耕地或者是由其他类型转为耕地的区域.③重金属污染地区都有着破碎、复杂和聚集的景观格局特征，其中耕地、住宅用地和工业用地的这种特征与土壤重金属累积的相关性最大；④建设用地的斑块聚集程度越高，大多数重金属元素的累积程度会显著增加；景观的多样性程度和农用地的形状复杂程度越高，Cu、Hg、Pb和Cd的累积程度会显著增加；距离采矿用地越近，Cd含量增加的效应越明显. |
| 英文摘要 |
| Land use cover change (LUCC) is one of the most important human activities that drive the evolution of the environment. It has great effect on the accumulation, distribution, and migration of heavy metals in the environment. Vegetation can absorb heavy metals directly, and it can also change the physical, chemical, and biological properties of soil and then control the mobility and activity of heavy metals in soil, which will eventually cause pollution of heavy metals in soil. In addition, the migration of heavy metals in soil is also affected by changes of landscape element composition and landscape pattern at sample points, plots, watersheds, and regional scales. Based on the soil sampling data and land use data of Ningbo city in 2003 and 2013, the decision tree classification method based on classification and regression tree algorithm was used to classify the land use and cover type. Single-factor pollution index and Nemero composite pollution index were used to evaluate the soil heavy metal pollution status. The landscape pattern indexes were used to explore the change of landscape patterns under different degrees of heavy metal accumulation. Finally, redundancy analysis and partial redundancy analysis were used to identify those landscape pattern factors that had the most significant impacts on the soil heavy metal accumulation in the study area. The results showed that:①The eight soil heavy metal elements including As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn presented different degree of accumulation from 2003 to 2013 in the study area, of which Hg, Ni, and Cr had the highest degree of accumulation. Most of the study area has been polluted by heavy metals, and the pollution degree in the heavily polluted areas is still increasing. ②Higher accumulation degrees of heavy metals was not distributed entirely in areas where land use types have always been construction land, or in areas where other types of land use had been converted to construction land. A considerable proportion of heavy metals accumulated in areas where land use types have always been cultivated land or converted from other types to cultivated land. ③Heavy metal polluted areas have fragmented, complex, and aggregated landscape pattern, and the correlation between this kind of landscape pattern characteristics and soil heavy metal accumulation in arable land, residential land, and industrial land was the highest. ④The higher the aggregation degree of construction land patch, the higher the accumulation degree of most heavy metals. The accumulation degree of Cu, Hg, Pb, and Cd increased significantly with the increase of landscape diversity and shape complexity of agricultural land. The closer the distance to the mining site, the more obvious the effect on the increase of Cd content. |
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