Distribution of soil heavy metals and ecological risk assessment of agricultural land in Nianchu River basin, Tibet
-
摘要:
以西藏年楚河流域江孜县、白朗县农用地土壤为研究对象，对Hg、As、Pb、Cd、Cr、Cu、Mn、Zn和Ni 9种重金属进行调查；采用单因子指数法、内梅罗综合污染指数法等方法，结合空间插值法评价年楚河流域农用地土壤重金属污染状况，同时运用相关性和主成分分析探究土壤重金属来源。结果表明：1)农用地土壤中Hg、Cu、Mn和Ni浓度与西藏土壤环境背景值相比，均表现为不同程度的累积，与GB 15618—2018《土壤环境质量 农用地土壤污染风险管控标准（试行）》比较，As元素超标率最大；从江孜县到白朗县，农用地土壤重金属综合生态风险指数逐步增大；2)研究区的区域污染负荷指数为1.45，属低污染等级，重度污染集中在白朗县；3)主成分分析表明，9种重金属的来源可分为自然与人为源复合因子、矿山开采因子、农业因子、土壤母质因子和大气传输因子。
Abstract:Taking the cultivated soil in Bailang County and Jiangzi County of Nianchu River basin in Tibet as the research objects, the contents of 9 kinds of heavy metals, Hg, As, Pb, Cd, Cr, Cu, Mn, Zn and Ni, were investigated and analyzed. The single factor index method, Nemerow comprehensive pollution index method and other methods, combined with the spatial interpolation method were used to evaluate the heavy metal pollution of agricultural land in Nianchu River basin. Meanwhile, correlation analysis and principal component analysis were used to explore the sources of soil heavy metals. The results showed that: 1) The content of Hg, Cu, Mn and Ni in the soil of agricultural land showed different degrees of accumulation, compared with the background values of the soil environment in Tibet. Compared with Soil Environmental Quality: Risk Control Standard for Soil Contamination of Agricultural Land (GB 15618-2018), As had the highest rate exceeding the standard. From Jiangzi County to Bailang County, the comprehensive ecological risk index of soil heavy metals in agricultural land gradually increased. 2) The regional pollution load index of the study area was 1.45, which was a low pollution level. Severe pollution was concentrated in Bailang County. 3) Principal component analysis showed that the sources of 9 kinds of heavy metals could be divided into natural and anthropogenic complex factors, mining factors, agricultural factors, soil parent material factors and atmospheric transmission factors.
-
Key words:
- Nianchu River basin /
- agricultural land /
- heavy metals /
- pollution assessment /
- source analysis
-
图 1 年楚河流域行政区划及采样点分布
Figure 1. Administrative divisions and distribution of sampling points in Nianchu River basin
图 2 采样点农用地土壤PN空间分布
Figure 2. PN spatial distribution of soil in agricultural land at each sampling point
图 3 各采样点农用地土壤中9种重金属Igeo统计
Figure 3. Igeo distribution of 9 heavy metals in soils of agricultural land at sampling sites
图 4 各采样点农用地土壤中9种重金属Er统计
Figure 4. Er distribution of 9 heavy metals in soils of agricultural land at sampling sites
图 5 各采样点农用地土壤中Hg、Cd和Ni的Er空间分布
Figure 5. Er spatial distribution of Hg, Cd and Ni in soils of agricultural land at sampling points
图 6 研究区农用地土壤RI空间分布
Figure 6. RI spatial distribution in soils of agricultural land in the study area
图 7 农用地土壤9种重金属主成分载荷
Figure 7. Principal component loading of nine heavy metals in soils of agricultural land
表 1 单因子指数法与内梅罗指数法评价标准
Table 1. Evaluation criteria of single-factor index method and Nemerow index method
Pi PN 数值 污染等级 数值 污染等级 <1 清洁 <0.7 清洁 1~2 轻度 0.7~1 警戒 2~3 中度 1~2 轻度 ≥3 重度 2~3 中度 ≥3 重度 
下载: 导出CSV
表 2 潜在生态风险指数法评价标准
Table 2. Evaluation standard of potential ecological risk index method
Er RI 风险等级 <40 <150 低风险 40~80 150~300 中等风险 80~160 300~600 重度风险 160~320 ≥600 较重度风险 ≥320 严重风险
下载: 导出CSV
表 3 农用地采样点土壤中重金属浓度统计结果
Table 3. Statistical results of heavy metal concentrations in the soil of sampling sites in agricultural land
重金属 浓度/(mg/kg) 变异系数 西藏土壤环境背景值[18]/(mg/kg) 超标采样点数量占比/% 最大值 最小值 平均值 Hg 0.16 0.03 0.06 0.54 0.026 100 As 34.10 8.09 20.96 0.38 18.70 68.8 Pb 30.90 14.50 22.84 0.23 28.90 12.5 Cd 0.18 0.08 0.12 0.20 0.08 100 Cr 516.00 69.20 161.63 0.86 77.40 87.5 Cu 52.10 29.50 39.18 0.16 21.90 93.8 Mn 1 287.88 666.67 903.88 0.19 626.00 93.8 Zn 148.00 67.70 93.22 0.20 73.70 87.5 Ni 583.33 38.89 117.69 1.43 32.10 93.8
下载: 导出CSV
表 4 农用地土壤各采样点Igeo和PLI统计结果
Table 4. Statistical results of Igeo and PLI at each sampling point of agricultural land soil
样点编号 Igeo PLI Hg As Pb Cd Cr Cu Mn Zn Ni 1 0.65 −1.61 −1.58 −0.58 −0.10 −0.04 −0.05 −0.13 −0.17 1.14 2 0.11 −1.79 −1.46 0.12 0.69 0.32 −0.05 0.42 0.39 1.36 3 1.20 −0.23 −0.49 0.32 −0.06 0.67 −0.17 −0.09 −0.05 1.63 4 0.14 −0.14 −0.73 0.12 −0.40 0.28 −0.49 −0.39 −0.31 1.29 5 0.56 −0.84 −0.82 0.12 −0.20 0.62 −0.17 −0.13 0.00 1.40 6 0.79 0.09 −0.61 0.58 −0.10 0.34 −0.17 −0.16 −0.07 1.58 7 0.05 0.20 −0.88 0.00 −0.34 0.12 −0.40 −0.39 −0.25 1.30 8 −0.28 0.03 −0.79 0.00 −0.45 0.23 −0.05 −0.35 −0.20 1.30 9 −0.35 −0.47 −0.53 0.32 −0.75 0.27 0.37 −0.14 −0.28 1.33 10 0.47 0.28 −0.63 0.12 −0.46 0.10 0.46 −0.21 −0.14 1.50 11 0.27 −1.50 −1.39 −0.26 0.92 0.29 −0.05 −0.52 1.62 1.43 12 0.59 −0.55 −1.05 0.12 −0.36 0.03 −0.35 −0.36 −0.07 1.29 13 2.05 −0.16 −0.89 0.00 −0.38 0.10 −0.17 −0.07 0.41 1.60 14 −0.17 −0.53 −1.08 −0.13 0.39 0.42 −0.17 −0.55 0.95 1.40 15 0.80 −0.56 −1.17 −0.55 2.07 −0.16 0.18 −0.71 3.60 1.96 16 0.28 −0.85 −1.25 0.00 2.15 0.24 0.07 −0.53 3.37 1.96
下载: 导出CSV
表 5 研究区农用地土壤中重金属元素之间相关系数
Table 5. Correlation coefficients of heavy metal elements in the soil of agricultural land in the study area
重金属 Hg As Pb Cd Cr Cu Mn Zn Ni Hg 1 As 0.125 1 Pb 0.103 0.750** 1 Cd 0.022 0.453 0.745** 1 Cr −0.61 −0.357 −0.480 −0.414 1 Cu −0.67 −0.057 0.406 0.519* −0.242 1 Mn −0.142 0.018 0.125 −0.057 0.235 −0.229 1 Zn 0.174 −0.226 0.020 0.364 −0.380 0.268 0.034 1 Ni −0.002 −0.243 −0.384 −0.437 0.976** −0.326 0.276 −0.480 1 注：*表示在0.05水平上显著相关；**表示在0.01水平上显著相关。
下载: 导出CSV
-
[1] 环境保护部, 国土资源部. 全国土壤污染状况调查公报[EB/OL].（2014-04-17） [2021-07-20] 北京: 环境保护部. http: //www.gov.cn/ xinwen/2014-04/17/content_2661765.htm． [2] 梁耀杰.我国土壤重金属污染现状及其防治措施探讨[J]. 资源节约与环保,2020(1):98. doi: 10.3969/j.issn.1673-2251.2020.01.083 [3] LIÉNARD A, COLINET G. Assessment of vertical contamination of Cd, Pb and Zn in soils around a former ore smelter in Wallonia, Belgium[J]. Environmental Earth Sciences,2016,75(19):1-15. [4] HUANG L M, DENG C B, HUANG N, et al. Multivariate statistical approach to identify heavy metal sources in agricultural soil around an abandoned Pb-Zn mine in Guangxi Zhuang Autonomous Region, China[J]. Environmental Earth Sciences,2013,68(5):1331-1348. doi: 10.1007/s12665-012-1831-8 [5] 旦增, 周鹏, 汪晶, 等.拉萨市生活垃圾卫生填埋场土壤重金属调查和分析评价[J]. 环境工程,2019,37(11):194-199. doi: 10.13205/j.hjgc.201911032DAN Z, ZHOU P, WANG J, et al. Investigation and research about soil heavy metals in the vicinity of the domestic waste sanitary landfill site-Lhasa[J]. Environmental Engineering,2019,37(11):194-199. doi: 10.13205/j.hjgc.201911032 [6] 杨安, 邢文聪, 王小霞, 等.西藏中部河流、湖泊表层沉积物及其周边土壤重金属来源解析及风险评价[J]. 中国环境科学,2020,40(10):4557-4567. doi: 10.3969/j.issn.1000-6923.2020.10.043YANG A, XING W C, WANG X X, et al. Source and risk assessment of heavy metals in surface sediments of rivers, lakes and their surrounding soils in central Tibet[J]. China Environmental Science,2020,40(10):4557-4567. doi: 10.3969/j.issn.1000-6923.2020.10.043 [7] 刘青海, 邱城, 张飞龙, 等.拉萨蔬菜生产基地土壤重金属状况初探[J]. 西藏农业科技,2021,43(1):11-15. doi: 10.3969/j.issn.1005-2925.2021.01.004LIU Q H, QIU C, ZHANG F L, et al. Preliminary study on soil heavy metals in vegetable production base of Lhasa[J]. Tibet Journal of Agricultural Sciences,2021,43(1):11-15. doi: 10.3969/j.issn.1005-2925.2021.01.004 [8] 李丹, 田沛佩, 罗红英, 等.西藏“一江两河”耕地生态安全时空格局与障碍诊断[J]. 农业机械学报,2020,51(10):213-222. doi: 10.6041/j.issn.1000-1298.2020.10.024LI D, TIAN P P, LUO H Y, et al. Spatio-temporal characteristics and obstacle diagnosis of cultivated land ecological security in "one river and two tributaries" region in Tibet[J]. Transactions of the Chinese Society for Agricultural Machinery,2020,51(10):213-222. doi: 10.6041/j.issn.1000-1298.2020.10.024 [9] 王伟鹏, 卢宏玮, 冯三三.西藏一江两河流域中部地区土壤重金属生态风险评价[J]. 农业资源与环境学报,2020,37(6):970-980. doi: 10.13254/j.jare.2019.0421WANG W P, LU H W, FENG S S. Ecological risk assessment of soil heavy metals in the middle of the "One River and Two Tributaries" basin in Tibet[J]. Journal of Agricultural Resources and Environment,2020,37(6):970-980. doi: 10.13254/j.jare.2019.0421 [10] 顿珠加措.年楚河流域径流变化及其对气候变化的响应[J]. 人民黄河,2015,37(4):33-37. doi: 10.3969/j.issn.1000-1379.2015.04.008DUN Z. Runoff variation of the Nianchu river in Yarlung Tsangpo River Basin and its response to climate change[J]. Yellow River,2015,37(4):33-37. doi: 10.3969/j.issn.1000-1379.2015.04.008 [11] 旦增, 孟德安, 周文武, 等.西藏班戈县垃圾填埋场环境影响综合分析与评价[J]. 环境工程技术学报,2021,11(1):202-208. doi: 10.12153/j.issn.1674-991X.20200062Dan Z, Meng D A, ZHOU W W, et al. Comprehensive analysis and evaluation of environmental impact of sanitary landfill in Baingoin County, Tibet[J]. Journal of Environmental Engineering Technology,2021,11(1):202-208. doi: 10.12153/j.issn.1674-991X.20200062 [12] 王涛, 司万童, 欧阳琰, 等.陕西某钼矿区土壤重金属污染特征及评价[J]. 环境工程技术学报,2019,9(4):440-446. doi: 10.12153/j.issn.1674-991X.2019.01.080WANG T, SI W T, OUYANG Y, et al. Characteristic and evaluation of soil heavy metals pollution in the molybdenum mine area in Shaanxi[J]. Journal of Environmental Engineering Technology,2019,9(4):440-446. doi: 10.12153/j.issn.1674-991X.2019.01.080 [13] 范志平, 王琼, 孙学凯, 等.辽河流域湿地水质污染特征及净化效果实证评估[J]. 环境工程技术学报,2020,10(6):1050-1056. doi: 10.12153/j.issn.1674-991X.20200032FAN Z P, WANG Q, SUN X K, et al. Water pollution characteristics in wetlands and empirical evaluation of purification effect in Liaohe River Basin[J]. Journal of Environmental Engineering Technology,2020,10(6):1050-1056. doi: 10.12153/j.issn.1674-991X.20200032 [14] 王硕, 魏文侠, 李佳斌, 等.某钢铁厂土壤中多环芳烃污染评价与风险评估[J]. 环境工程技术学报,2019,9(4):447-452. doi: 10.12153/j.issn.1674-991X.2019.01.220WANG S, WEI W X, LI J B, et al. Evaluation and risk assessment of polycyclic aromatic hydrocarbons in soil of a steel plant[J]. Journal of Environmental Engineering Technology,2019,9(4):447-452. doi: 10.12153/j.issn.1674-991X.2019.01.220 [15] MÜLLER G. Index of geoaccumulation in sediments of the Rhine River[J]. Geology Journal,1969,2:108-118. [16] TOMLINSON D L, WILSON J G, HARRIS C R, et al. Problems in the assessment of heavy-metal levels in estuaries and the Formation of a pollution index[J]. Helgolä nder Meeresuntersuchungen,1980,33(1):566-575. [17] 鞠铁男, 吴啸, 师华定, 等.海沟河小流域耕地土壤重金属污染与生态风险评价[J]. 环境工程技术学报,2018,8(5):556-562.JU T N, WU X, SHI H D, et al. Heavy metal pollution and ecological risk assessment of arable land soil in Haigou small watershed[J]. Journal of Environmental Engineering Technology,2018,8(5):556-562. [18] 成延鏊, 田均良. 西藏土壤元素背景值及其分布特征[M]. 北京: 科学出版社, 1993. [19] 许燕颖, 刘友存, 张军, 等.赣江上游典型流域水体三氮及重金属空间分布特征与风险评价[J]. 地球与环境,2020,48(5):574-583. doi: 10.14050/j.cnki.1672-9250.2020.48.070XU Y Y, LIU Y C, ZHANG J, et al. Spatial distribution and risk assessment of nitrogen and heavy metals in typical watershed of the upper reaches of Ganjiang River[J]. Earth and Environment,2020,48(5):574-583. doi: 10.14050/j.cnki.1672-9250.2020.48.070 [20] 王莉霞, 柴小琴, 金豆豆, 等.天水市蔬菜大棚土壤重金属污染特征及生态风险评价[J]. 水土保持通报,2021,41(3):110-117. doi: 10.13961/j.cnki.stbctb.2021.03.016WANG L X, CHAI X Q, JIN D D, et al. Heavy metal pollution characteristics and assessment of ecological risk for vegetable greenhouse soils in Tianshui City[J]. Bulletin of Soil and Water Conservation,2021,41(3):110-117. doi: 10.13961/j.cnki.stbctb.2021.03.016 [21] 郑度, 姚檀栋.青藏高原隆升及其环境效应[J]. 地球科学进展,2006,21(5):451-458. doi: 10.3321/j.issn:1001-8166.2006.05.002ZHENG D, YAO T D. Uplifting of Tibetan Plateau with its environmental effects[J]. Advances in Earth Science,2006,21(5):451-458. doi: 10.3321/j.issn:1001-8166.2006.05.002 [22] NANOS N, RODRÍGUEZ MARTÍN J A. Multiscale analysis of heavy metal contents in soils: spatial variability in the Duero River Basin (Spain)[J]. Geoderma,2012,189/190:554-562. doi: 10.1016/j.geoderma.2012.06.006 [23] 刘瑞平, 徐友宁, 张江华, 等.青藏高原典型金属矿山河流重金属污染对比[J]. 地质通报,2018,37(12):2154-2168. doi: 10.12097/j.issn.1671-2552.2018.12.005LIU R P, XU Y N, ZHANG J H, et al. A comparative study of the content of heavy metals in typical metallic mine rivers of the Tibetan Plateau[J]. Geological Bulletin of China,2018,37(12):2154-2168. doi: 10.12097/j.issn.1671-2552.2018.12.005 [24] 谢国雄, 应金耀, 章明奎.大气沉降与施肥方式对梨园重金属平衡的影响[J]. 中国农学通报,2019,35(16):88-94. doi: 10.11924/j.issn.1000-6850.casb18020074XIE G X, YING J Y, ZHANG M K. Mass balance of heavy metals in typical pear orchard ecological system affected by fertilization and atmospheric deposition[J]. Chinese Agricultural Science Bulletin,2019,35(16):88-94. doi: 10.11924/j.issn.1000-6850.casb18020074 [25] ŠAJN R, HALAMIĆ J, PEH Z, et al. Assessment of the natural and anthropogenic sources of chemical elements in alluvial soils from the Drava River using multivariate statistical methods[J]. Journal of Geochemical Exploration,2011,110(3):278-289. doi: 10.1016/j.gexplo.2011.06.009 [26] YANG H D, BATTARBEE R W, TURNER S D, et al. Historical reconstruction of mercury pollution across the Tibetan Plateau using lake sediments[J]. Environmental Science & Technology,2010,44(8):2918-2924. ⊕ -
下载:
点击查看大图
计量
- 文章访问数: 365
- HTML全文浏览量: 219
- PDF下载量: 35
- 被引次数: 0
