基于GIS的天水市秦州区樱桃园土壤重金属元素空间分布与污染评价

目的]获取土壤重金属污染状况,为促进秦州区樱桃园产业的可持续发展提供科学依据,也为其他果树用地的土壤重金属污染防治提供借鉴。方法]以天水市秦州区樱桃园主产区的6个镇(太京、玉泉、藉口、关子、牡丹、杨家寺)作为研究点,运用空间分析的方法,研究表层土壤中的重金属污染的空间分布特征,又运用尼梅罗综合污染指数法和污染负荷指数法对土壤重金属环境质量及潜在生态风险进行评价。结果]通过应用GIS得到的空间分布图可知,秦州区樱桃园土壤重金属污染程度都较轻,东北部樱桃园土壤重金属污染较西南部污染严重。结论]樱桃园土壤重金属污染程度突出元素为Pb,而Zn,Cr,Cu属轻度污染水平,Cd污染最轻,5种重金属元素之间含量差别较明显。土壤重金属污染主要集中在太京镇、玉泉镇、藉口镇,这些区域靠近城市中心,受交通、人为因素影响密切,污染严重。

Spatial Distribution and Pollution Evaluation of Heavy Metals in Cherry Orchard Soil in Qinzhou District, Tianshui City Based on GIS

Objective] The status of soil heavy metal pollution was researched to provide scientific basis for promoting the sustainable development of cherry orchard industry in Qinzhou District, and for soil heavy metal pollution prevention and control in other fruit land.Methods] Six towns of cherry orchard production area in Qinzhou District of Tianshui City(Taijing, Yuquan, Xikou, Guanzi, Mudan and Yangjiasi) were taken as the research sites. Where the spatial distribution characteristics of heavy metal pollution in surface soil was illustrated using method of spatial analysis. And the heavy metal environmental quality and its potential ecological risk were evaluated by Nemerow comprehensive pollution index and pollution load index.Results] Overall, the soil heavy metal pollution of cherry orchard in Qinzhou District was light, but the soil heavy metal pollution in the northeast region was serious than that in the southwest region of the research sites.Conclusion] The prominent heavy metal element in the cherry orchard is Pb; and Zn, Cr, Cu pollution also existed but belong to light pollution level; Cd pollution is the most light. It is obvious different among the contents of the five heavy metal elements. The heavy metal polluted towns mainly concentrated in Taijing, Yuquan and Xikou County that are adjacent to downtown, for the reason of traffic and intensive human interference, are seriously polluted.