五元联系度评价福州市主要蔬菜地土壤环境质量研究

Soil environmental quality evaluation for vegetable-growing land in Fuzhou on five-element connection coefficient

为明确福州市主要蔬菜地土壤环境质量现状,用集对分析法的五元联系度模型对其进行综合评价分析。结果表明,福州市滨海岛屿区蔬菜地土壤环境质量级别为1级,城郊区和近郊区蔬菜地为Ⅱ级,台地丘陵区、中低山区、平原区的蔬菜地为Ⅰ级,但有向Ⅱ级转化的趋势。结合其当前的土壤环境质量现状,建议今后福州市的蔬菜基地的建设布局应限制在城郊区、近郊区的发展,尽量向山区、台地丘陵等区域转移,并严格控制山区、台地丘陵区等区域的重金属污染影响,以防止其由I级向Ⅱ级转化。

Based on the five-element connection coefficient of the set pair analysis, this paper is focused on the evaluation of the soil environmental quality for vegetable-growing farms in Fuzhou by choosing five heavy metal indexes, namely, Pb, As, Cd, Cr, and Hg. Classified by region and soil-distribution, the vegetable farms can be evaluated in six types, to be exact, the farm lands in suburban area, urban area, plain area, hill-side area, mountainous area and island area. The soil samples we adopted for our research were collected and classified by Fujian Geological Testing Research Center. Among them, Pb and Cr were analyzed by X-ray fluorescence spectrometry; Cd was analyzed by atomic absorption spectrometry, whereas As and Hg were analyzed by atomic fluorescence spectrometry. Referring to the soil environmental quality standard（GB 15618—1995） and some related literatures, we have divided the soil quality into five grades, namely, clean（grade Ⅰ）, nearly clean（grade Ⅱ）, slightly polluted（grade Ⅲ）, moderately polluted（grade Ⅳ） and heavily polluted（grade Ⅴ）. The eventual conclusion we have arrived at is that the vegetables soil environment in different districts of Fuzhou are on the whole suitable for vegetable-growing. For the time being, the environment of the city does not affect human health and vegetable growing. The soil quality of vegetable lands on the islands belong to grade Ⅰ, followed by the suburban and urban lands belonging to grade Ⅱ. Although hill-side area, plain area and mountainous area belonging to grade Ⅰ, there exists danger to be downcast into grade Ⅱ or Ⅲ. In accordance with the soil environment quality situation at present, our research suggests that it is better for the vegetable lands of Fuzhou to be confined in the suburban and urban area of the city, trying to save the mountainous and hill-side areas from being polluted by the heavy metals. And it is for this need that measures are to be taken to control heavy metal pollution of soil in these areas to degrade the soil quality from grade Ⅰ into grade Ⅱ or Ⅲ.