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地下水作为我国重要的战略资源,与居民生活和经济建设休戚相关[1]。居民的饮水安全和健康问题与区域地下水的水环境直接相关[2]。近年来由于经济社会快速发展、人类活动对环境的影响不断加剧,水环境也遭受到一定的污染,大量生产生活污水的排放,对地下水的质量构成了严重的威胁[3-4]。因此,为了可以更加合理的配置地下水,推进生态环境的保护与建设,区域地下水质的评价和水环境的调查就显得尤为重要。
西安作为一带一路的重要节点城市,坐落于关中平原,南与秦岭相依、北与渭河相傍,自古就有“八水润长安”的美誉[5],既是中华民族重要的发祥地,又是中华文明的摇篮。西安市主城区是西安市人口分布最多,经济发展水平最高的区域,地下水作为西安主城区主要供水水源之一[6],近年来由于社会经济的迅速发展和城市大量排放废水与各类垃圾,使得该区水资源供需矛盾日益突出。目前有大量学者对西安地区的地下水环境进行了合理研究,如吴晓娟[7]绘制了西安市地下水脆弱性分区图,并对地下水的6种污染物进行了建模分析;张琼华[8]选取了西安长安区22个浅层地下水,运用修正的F值评价,认为研究区浅层地下水水质较好;周彦龙[9]研究了西安地下水潜水系统对城市化进程的响应;黄新[10]分别从时间和空间上研究了渗滤液的扩散情况;董艳慧等[11]对西安地下水质进行了评价,获得了年际水质变化情况。然而,对于西安主城区地下水水化学环境空间特点及污染物来源方面的分析明显不足。
本文选取2018年和2019年53个潜水和33个承压水的水样水质数据,运用数理统计分析[12]、水化学方法[13]、改进的模糊综合评价法[14]、综合评价法[1]和因子分析法[15]对地下水的水化学特征和水质进行了分析研究,并对可能造成污染的原因进行了解析,以达到对西安主城区地下水资源的合理配置与可持续利用的目的。
西安主城区地下水化学特征及水质评价
Groundwater chemical characteristics and water quality evaluation in the main urban area of Xi’an
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摘要: 城市地下水环境对城市的可持续发展具有重要意义。本文运用数理统计分析、改进的模糊综合评价、综合评价法、水化学和因子分析法对研究区地下水水化学特征及水质进行分析评价。结果表明,研究区地下水中钠离子、钙离子、硫酸根和碳酸氢根相对含量较高,承压水水化学组分比潜水稳定。潜水的水化学类型主要是HCO3-Ca·Mg和SO4·Cl-Ca·Mg·Na,承压水的水化学类型主要是HCO3-Na和HCO3-Ca·Mg。两种评价方法均显示,研究区潜水以Ⅱ类和Ⅲ类水居多,模糊综合评价法显示研究区承压水大部分为Ⅰ类水,而综合评价法显示研究区多为Ⅱ类、Ⅲ类水。水岩作用是水化学组分的主要控制因素。相较于承压水而言,潜水水质存在不同程度的污染,潜水污染的原因主要包括原生地质背景污染和人为污染两大类。该研究为研究区地下水资源的合理开发利用和生态环境保护与建设提供了理论依据。Abstract: The groundwater environment is of great significance to the sustainable development of the urban. Mathematical statistics, improved fuzzy comprehensive evaluation, comprehensive evaluation, hydrochemistry method and factor analysis were used to evaluate the hydrochemical characteristics and water quality of groundwater. The results showed: 1) The relative contents of Na+, Ca2+,
${\rm{SO}}_4^{2 - } $ and${\rm{HCO}}_3^ - $ in groundwater were relatively high, and the hydrochemical composition of confined water was more stable than phreatic water. 2) The hydrochemical types of phreatic water were mainly HCO3-Ca·Mg type and SO4·Cl-Ca·Mg·Na type. The hydrochemical types of confined water were mainly HCO3- Na type and HCO3-Ca·Mg type. 3) The results of improved fuzzy comprehensive evaluation and comprehensive evaluation both showed that most of the phreatic water in the study area was Grade II and III. The fuzzy comprehensive evaluation method showed that most of the confined water in the study area was Grade I, while the comprehensive evaluation method showed that the study area was mostly Grade Ⅱ and Ⅲ. Water-rock interaction was the main controlling factor of the hydrochemical composition. 4) Compared with confined water, there were different levels of pollution in phreatic water quality. The causes of phreatic water pollution mainly included the primary geological background pollution and artificial pollution. This research is not only conducive to the rational development and utilization of groundwater, but also provides a theoretical basis for ecological environment protection and construction. -
表 1 潜水和承压水主要化学组分统计特征(除pH外,单位为mg·L−1)
Table 1. Statistical characteristics of main chemical components of phreatic water and confined water (except pH, unit: mg·L−1)
指标Indicators 潜水 Phreatic water 承压水 Confined water 最大值Max 最小值Min 平均值Average 标准差
SD变异系数/% CV 最大值Max 最小值Min 平均值Average 标准差
SD变异系数/% CV pH 8.42 6.99 7.62 0.29 3.78 8.6 7.49 8.09 0.26 3.23 K+ 80.1 0.65 6.76 14.07 207.92 3.36 0.37 1.27 0.66 52.07 Na+ 365 1.07 102.48 63.42 61.89 157 15.6 66.98 39.06 58.32 Ca2+ 481 12 103.12 72.55 70.36 140 8.02 46.64 30.66 65.74 Mg2+ 136 2.43 53.64 30.45 56.77 63.2 1.22 16.35 13.03 79.67 Cl- 709 7.09 89.22 100.94 113.14 81.5 3.54 29.18 22.7 77.8 ${\rm{SO}}_4^{2 - } $ 1633 14.4 176.39 234.31 132.83 490 4.8 57.04 83.95 147.17 ${\rm{HCO}}_3^ - $ 708 55 449.66 140.86 31.33 470 146 275.3 87.74 31.87 ${\rm{NO}}_3^ - $ 185 2.97 62.01 44.3 71.44 114 2.72 24.77 28.9 116.7 ${\rm{NO}}_2^ - $ 5.161 0.007 0.25 0.83 326.79 0.451 0.004 0.05 0.11 204.6 TDS 2628 100 808.53 403.66 49.93 1112 196 384.24 172.77 44.96 TH 1651 45 478.21 247.59 51.77 611 25 183.97 118.25 64.28 表 2 KMO和Bartlett检验结果
Table 2. Results of KMO and Bartlett’s test
取样足够度的Kaiser-Meyer-Olki检验值
Sample the Kaiser-Meyer-Olkin test value of
sufficient degreeBartlett的球形度检验
Bartlett’s test for sphericity检验值x2
The x2 test value自由度df
Degrees of freedom df显著水平sig
Significant level sig0.581 689.877 78 0.000 表 3 潜水水质旋转因子荷载矩阵及其主因子贡献率
Table 3. The water quality rotation factor load matrix and its main factor contribution rates of phreatic water
指标
Indicators因子Factor F1 F2 F3 F4 TH 0.908 −0.231 0.291 0.088 TDS 0.868 0.017 0.419 0.176 ${\rm{SO}}_4^{2 - } $ 0.967 −0.001 0.013 −0.094 Cl− 0.422 −0.027 0.879 0.003 Fe 0.513 0.012 −0.086 −0.641 Mn 0.88 −0.083 −0.052 −0.312 ${\rm{NH}}_4^ + $ −0.023 −0.04 0.946 −0.076 F− −0.048 0.963 0.035 0.076 Cr6+ −0.03 0.206 −0.081 0.263 As 0.03 0.962 −0.016 0.008 -N${\rm{NO}}_3^ - $ 0.082 −0.008 −0.044 0.896 -N${\rm{NO}}_2^ - $ −0.111 −0.073 0.088 −0.057 pH −0.465 0.55 −0.344 0.078 特征值 4.661 2.1 1.713 1.284 贡献率/% 30.513 17.436 15.962 11.15 累计贡献率/% 30.513 47.949 63.911 75.061 -
[1] 胡云虎, 张付海, 钮志远, 等. 皖北地区集中式深层地下水饮用水源地水化学特征及水质评价 [J]. 中国科学技术大学学报, 2014, 44(11): 913-920, 925. doi: 10.3969/j.issn.0253-2778.2014.11.005 HU Y H, ZHANG F H, NIU Z Y, et al. Hydro-chemical characteristics of groundwater in centralized drinking water sources and its quality assessment in northern Anhui Province [J]. Journal of University of Science and Technology of China, 2014, 44(11): 913-920, 925(in Chinese). doi: 10.3969/j.issn.0253-2778.2014.11.005
[2] 魏屹峤. 我国地下水污染现状与防治对策研究 [J]. 绿色环保建材, 2019(1): 52, 55. WEI Y Q. Study on the present situation and countermeasures of groundwater pollution in China [J]. Green Environmental Protection Building Materials, 2019(1): 52, 55(in Chinese).
[3] 林永生, 裴建国, 杜毓超, 等. 广西姚村地下河水化学特征及其时空变化 [J]. 长江科学院院报, 2016, 33(12): 6-9, 16. doi: 10.11988/ckyyb.20151049 LIN Y S, PEI J G, DU Y C, et al. Temporal and spatial distribution of the hydrochemical characteristics of Yaocun underground river in Guangxi Province [J]. Journal of Yangtze River Scientific Research Institute, 2016, 33(12): 6-9, 16(in Chinese). doi: 10.11988/ckyyb.20151049
[4] 于树宾, 马振民, 张慧申. 南水北调中线焦作典型区浅层地下水污染特征 [J]. 济南大学学报(自然科学版), 2012, 26(1): 91-95. YU S B, MA Z M, ZHANG H S. Pollutant characteristics of shallow groundwater in Jiaozuo site of the middle south-to-north water diversion project [J]. Journal of University of Jinan (Science and Technology), 2012, 26(1): 91-95(in Chinese).
[5] 杨法暄, 郑乐, 钱会, 等. 基于DPSIR模型的城市水资源脆弱性评价: 以西安市为例 [J]. 水资源与水工程学报, 2020, 31(1): 77-84. YANG F X, ZHENG L, QIAN H, et al. Vulnerability assessment of urban water resources based on DPSIR model: A case study of Xi'an City [J]. Journal of Water Resources and Water Engineering, 2020, 31(1): 77-84(in Chinese).
[6] 李慧. 城市化影响下西安市地下水流场演变及其机制[D]. 西安: 长安大学, 2018. LI H. The evolution of groundwater flow field and its mechanism in xi’an city with the influence of urbanization[D]. Xi'an: Changan University, 2018(in Chinese).
[7] 吴晓娟. 西安市地下水污染脆弱性与时空动态分析[D]. 西安: 陕西师范大学, 2007. WU X J. Analysis of vulnerability of groundwater pollution and space-time change in xi’an city from 1985 to 2003[D]. Xi'an: Shaanxi Normal University, 2007(in Chinese).
[8] 张琼华. 西安南郊长安地区浅层地下水水质分析及健康评价[D]. 西安: 陕西师范大学, 2006. ZHANG Q H. Quality analysis and evaluation on shallow groundwater in Chang’an area of xi’an[D]. Xi'an: Shaanxi Normal University, 2006(in Chinese).
[9] 周彦龙. 西安市地下潜水系统对城市化进程的响应[D]. 西安: 长安大学, 2018. ZHOU Y L. Xi’an underground phreatic water system response to urbanization[D]. Xi'an: Changan University, 2018(in Chinese).
[10] 黄新. 西安市地下水污染风险研究[D]. 西安: 西安科技大学, 2010. HUANG X. Risk analysis of groundwater pollution in Xi’an City[D]. Xi'an: Xi'an University of Science and Technology, 2010(in Chinese).
[11] 董艳慧, 周维博, 赖坤容, 等. 基于概率神经网络的西安地区地下水水质评价 [J]. 自然资源学报, 2009, 24(4): 737-742. doi: 10.3321/j.issn:1000-3037.2009.04.020 DONG Y H, ZHOU W B, LAI K R, et al. The application of probabilistic neural network model in evaluating the groundwater quality of Xi'an area [J]. Journal of Natural Resources, 2009, 24(4): 737-742(in Chinese). doi: 10.3321/j.issn:1000-3037.2009.04.020
[12] 李奇. 云南勐兴铅锌矿矿区水质分析数理统计探讨 [J]. 价值工程, 2017, 36(25): 144-147. LI Q. Discussion on the mathematical statistics of water quality analysis of Yunnan mengxing lead zinc mine [J]. Value Engineering, 2017, 36(25): 144-147(in Chinese).
[13] 熊贵耀. 基于水化学和地球物理方法的莱州湾南岸咸水入侵研究[D]. 北京: 中国地质大学(北京), 2020. XIONG G Y. Study on seawater intrusion on the south bank of Laizhou bay based on hydrochemical and geophysical methods[D]. Beijing: China University of Geosciences, 2020(in Chinese).
[14] 杨静. 改进的模糊综合评价法在水质评价中的应用[D]. 重庆: 重庆大学, 2014. YANG J. Application of the improved fuzzy comprehensive evaluation method in water quality evaluation[D]. Chongqing: Chongqing University, 2014(in Chinese).
[15] 左锐, 韦宝玺, 王金生, 等. 基于多元统计分析的地下水水源地污染源识别 [J]. 水文地质工程地质, 2012, 39(6): 17-21. ZUO R, WEI B X, WANG J S, et al. Identification of groundwater pollution sources based on multivariate statistical approach [J]. Hydrogeology & Engineering Geology, 2012, 39(6): 17-21(in Chinese).
[16] 牟乃夏, 刘文宝, 王海银, 等. 《ArcGIS10地理信息系统教程: 从初学到精通》出版 [J]. 测绘通报, 2012(12): 43. MOU N X, LIU W B, WANG H Y, et al. ArcGIS10 Geographic Information System Course - From Beginner to Master [J]. Bulletin of Surveying and Mapping, 2012(12): 43(in Chinese).
[17] 地下水质量标准: GB/T 14848—2017[S]. [18] 时雯雯, 周金龙, 曾妍妍, 等. 新疆乌昌石城市群地下水多重水质评价[J]. 干旱区资源与环境, 2021, 35(2): 109-116. SHI W W, ZHOU J L, ZENG Y Y, et al. Multiple groundwater quality evaluation of Urumqi-Changji-Shihezi city agglomeration in Xinjiang[J]. Journal of Arid Land Resources and Environment, 2021, 35(2): 109-116(in Chinese).
[19] 蒋辉. 河南省博爱县平原区地下水环境质量数字化综合评价 [J]. 水文地质工程地质, 2004, 31(3): 46-50. doi: 10.3969/j.issn.1000-3665.2004.03.010 JIANG H. Integrated digitization evaluation of environmental quality of groundwater in the Bo'ai County plain area in Henan Province [J]. Hydrogeology and Engineering Geology, 2004, 31(3): 46-50(in Chinese). doi: 10.3969/j.issn.1000-3665.2004.03.010
[20] 王月, 安达, 席北斗, 等. 某基岩裂隙水型危险废物填埋场地下水污染特征分析 [J]. 环境化学, 2016, 35(6): 1196-1202. doi: 10.7524/j.issn.0254-6108.2016.06.2015111602 WANG Y, AN D, XI B D, et al. Groundwater pollution characteristics of the hazardous waste landfill built upon bedrock fissure water [J]. Environmental Chemistry, 2016, 35(6): 1196-1202(in Chinese). doi: 10.7524/j.issn.0254-6108.2016.06.2015111602
[21] 杨咪, 屈文岗, 钱会. 基于熵权的贝叶斯模型及其在水质评价中的应用 [J]. 灌溉排水学报, 2018, 37(1): 85-90. YANG M, QU W G, QIAN H. Bayesian model based on entropy weight and its application in water quality assessment [J]. Journal of Irrigation and Drainage, 2018, 37(1): 85-90(in Chinese).
[22] 柳凤霞, 史紫薇, 钱会, 等. 银川地区地下水水化学特征演化规律及水质评价 [J]. 环境化学, 2019, 38(9): 2055-2066. doi: 10.7524/j.issn.0254-6108.2019043003 LIU F X, SHI Z W, QIAN H, et al. Evolution of groundwater hydrochemical characteristics and water quality evaluation in Yinchuan area [J]. Environmental Chemistry, 2019, 38(9): 2055-2066(in Chinese). doi: 10.7524/j.issn.0254-6108.2019043003
[23] 柳金甫, 于义良. 应用数理统计[M]. 北京: 清华大学出版社, 2008: 254-286. LIU J F, YU Y L. Apply mathematical statistics [M]. Beijing: Tsinghua University Press, 2008: 254-286(in Chinese).
[24] QIAN C, WU X, MU W P, et al. Hydrogeochemical characterization and suitability assessment of groundwater in an agro-pastoral area, Ordos Basin, NW China [J]. Environmental Earth Sciences, 2016, 75(20): 1-16. [25] GIBBS R J. Mechanisms controlling world water chemistry [J]. Science, 1970, 170(3962): 1088-1090. doi: 10.1126/science.170.3962.1088 [26] 孟利, 左锐, 王金生, 等. 基于PCA-APCS-MLR的地下水污染源定量解析研究 [J]. 中国环境科学, 2017, 37(10): 3773-3786. doi: 10.3969/j.issn.1000-6923.2017.10.020 MENG L, ZUO R, WANG J S, et al. Quantitative source apportionment of groundwater pollution based on PCA-APCS-MLR [J]. China Environmental Science, 2017, 37(10): 3773-3786(in Chinese). doi: 10.3969/j.issn.1000-6923.2017.10.020
[27] 杨素珍. 内蒙古河套平原原生高砷地下水的分布与形成机理研究[D]. 北京: 中国地质大学(北京), 2008. YANG S Z. Formation of high as groundwater and water-rock interaction in shallow aquifers from the Hetao basin, Inner Mongolia[D]. Beijing: China University of Geosciences, 2008(in Chinese).