Chen Wen-Xuan, Li Qian, Wang Zhen, Sun Zhao-Jun
College of Resources and Environment, Ningxia University, Yinchuan 750021, China.
Institute of Environmental Engineering, Ningxia University, Yinchuan 750021, China.
Huan Jing Ke Xue. 2020 Jun 8;41(6):2822-2833. doi: 10.13227/j.hjkx.201910075.
Soil is an important component of the terrestrial ecosystem and an indispensable natural resource in agricultural production. Understanding the spatial distribution characteristics and pollution levels of heavy metals in arable land soil is important to safeguard the agriculture ecosystem and human health. Based on the collected data of heavy metal concentrations in arable land soil in various administrative regions of China since 2002, first, we selected and removed the abnormal values, then obtained the spatial distribution of the provinces by the Kriging method, and discussed the spatial distribution characteristics of seven heavy metals (Cr, Cd, Pb, Zn, Cu, As, and Hg) in arable land soil. Finally, we adopted the geo-accumulation index to evaluate the pollution status of arable land soil. The results showed that the spatial distribution of heavy metals Cr, Pb, Cu, Zn, and As in arable land soil of China was obvious, while the spatial distribution of soil Cd and Hg was very similar. Furthermore, the concentration of arable land soil in south China was obviously higher than that in the north. The mean value of the results showed that heavy metals are enriched to different degrees in arable land soil of China, and the average soil heavy metal concentrations of arable land are higher in Hunan, Yunnan, Guizhou, Sichuan, Fujian, Guangxi, and Shanghai. The results of geo-accumulation index pollution evaluations showed that the pollution degree of the seven heavy metals was in the order Cd > Hg > Pb > Cu > Zn > As > Cr, among which the soil heavy metals in arable land soil had a higher enrichment degree in Fujian, Guangdong, Hainan, Zhejiang, Hunan, Shaanxi, Gansu, Henan, Chongqing, Shanxi, Tianjin, Inner Mongolia, and Anhui. In general, the geo-accumulation indexes of Cd and Hg in each administrative region are higher, whereas the average land accumulation indexes also indicate that Cd and Hg in arable land shows greater pollution specially. Results from this study provide valuable scientific basis for formulating effective arable land pollution control strategies in the future.
土壤是陆地生态系统的重要组成部分，也是农业生产中不可或缺的自然资源。了解耕地土壤中重金属的空间分布特征和污染水平对于保障农业生态系统和人类健康至关重要。基于2002年以来中国各行政区耕地土壤重金属浓度的收集数据，首先，我们筛选并剔除了异常值，然后采用克里金法得到各省的空间分布，并探讨了耕地土壤中七种重金属（铬、镉、铅、锌、铜、砷和汞）的空间分布特征。最后，我们采用地累积指数来评估耕地土壤的污染状况。结果表明，中国耕地土壤中重金属铬、铅、铜、锌和砷的空间分布明显，而土壤镉和汞的空间分布非常相似。此外，中国南方耕地土壤的浓度明显高于北方。结果平均值表明，中国耕地土壤中重金属有不同程度的富集，湖南、云南、贵州、四川、福建、广西和上海的耕地土壤重金属平均浓度较高。地累积指数污染评价结果表明，七种重金属的污染程度顺序为镉>汞>铅>铜>锌>砷>铬，其中福建、广东、海南、浙江、湖南、陕西、甘肃、河南、重庆、山西、天津、内蒙古和安徽的耕地土壤重金属富集程度较高。总体而言，各行政区镉和汞的地累积指数较高，而平均土地累积指数也表明，耕地中的镉和汞污染尤为严重。本研究结果为今后制定有效的耕地污染控制策略提供了有价值的科学依据。
