首页|基于PCA-APCS-MLR模型的西藏扎西岗湿地土壤重金属风险评价及来源解析

基于PCA-APCS-MLR模型的西藏扎西岗湿地土壤重金属风险评价及来源解析

Soil heavy metal risk evaluation and source analysis of Zhaxigang wetland in Tibet based on PCA-APCS-MLR Model

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  • 国家科技期刊平台
  • NETL
  • NSTL
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扎西岗湿地是典型的高原草甸沼泽湿地,也是拉萨市重要的生态功能保护区.西藏特殊的气候与地形造成湿地生态环境极其脆弱,因此对西藏湿地的研究尤为重要.为准确评估扎西岗湿地土壤中重金属的污染现状及解析污染源,采集扎西岗湿地18个表层土壤样品,分析Cr、Ni、Zn、Pb、Cd、As和Hg7种重金属元素的含量,利用地累积指数(Igeo)和污染负荷指数(PLI)法评价污染情况,基于PCA分析,结合APCS-MLR模型,解析重金属的污染来源.结果表明:(1)扎西岗湿地表层土壤中Cr和Ni含量均低于西藏土壤背景值,其余5种重金属含量都存在不同程度的累积;与《土壤环境质量农用地土壤污染风险管控标准(GB 15618-2018)》的风险筛选值相比,除Cd和As有一定程度超标外,其他5种元素的测定值均未超标.(2)地累积指数表明,除Cd和Hg外,其他5种元素污染等级均为清洁(Igeo＜0);污染负荷指数评价表明,研究区整体PLI为1.44,属于轻微生态危害,两种评价均表明,Cd和Hg为研究区主要污染元素,应引起重视并加强日常监测.(3)扎西岗湿地土壤重金属来源主要为工业-交通混合源、自然源、农业-燃煤混合源,Ni、Zn、Pb、Cd和As主要来源于工业-交通混合源,Cr主要来源为自然源,Hg的来源主要受农业和燃煤等人类活动的影响.
Zhaxigang wetland is a typical plateau meadow swamp and an important ecological function reserve in Lhasa.Wetlands in Tibet are extremely fragile due to climate and topography,which should be given full considera-tion.To accurately assess the pollution status and sources of heavy metals in the soil of Zhaxigang wetland,we ana-lyzed the contents of seven heavy metal elements(Cr,Ni,Zn,Pb,Cd,As and Hg)in 18 surface soil samples of Zhaxigang wetland.The pollution risks of heavy metals were evaluated by using the method of geo-accumulation in-dex(Igeo)and pollution loading index(PLI).Based on PCA,the APCS-MLR model was used to analyze the pol-lution sources of heavy metals.The results showed that:(1)The contents of Cr and Ni in the surface soil of Zhaxi-gang wetland were lower than the background value of Tibetan soil.The contents of the other five elements were ac-cumulated in different degrees.Except for Cd and As,the measured values of the other five elements were lower than the risk screening value in"Soil Environmental Quality Risk Control Standard for Soil Contamination of Agri-cultural Land of(GB 15618-2018)".(2)Except for Cd and Hg,the Igeovalues of other elements were less than 0,indicating a clean level.The overall PLI in the study area was 1.44,indicating light ecological hazard.Both evaluations showed that Cd and Hg were the main pollution elements in this area.More attention should be paid on those two elements,and routine monitoring should be strengthened.(3)The sources of heavy metals were mainly mixed industrial-transportation sources,natural sources,and mixed agricultural-coal combustion sources.Ni,Zn,Pb,Cd,and As were mainly from mixed industrial-transportation sources,Cr was mainly from natural sources,and the sources of Hg were mainly affected by human activities such as agriculture and coal combustion.

Zhaxigang wetlandsediment heavy metalpollution assessmentAPCS-MLR model

杨崛园、熊健、李伟、黄瑞卿、杨博、谢鹏程

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西藏大学生态环境学院,拉萨 850000

扎西岗湿地 沉积物重金属 污染评价 绝对主成分得分-多元线性回归模型

西藏自治区科技计划西藏自治区科技计划西藏自治区科技计划国家重点研发计划"固废资源化"重点专项西藏大学人才发展激励计划青年学者项目中央支持地方高校专项中央支持地方高校专项

XZ202101ZY0012GXZ202202YD0027CXZ202301ZY0020G2019YFC1904100藏财预指[2023]01[2024]01

2024

10.13292/j.1000-4890.202406.038

生态学杂志
中国生态学学会

生态学杂志

CSTPCD北大核心
影响因子：1.439
ISSN：1000-4890
年,卷(期)：2024.43(6)
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