钱塘江杭州段沿岸土壤中铁锰的分布特征

Characteristics of Iron and Manganese in Soil Along Section of Qiantang River in Hangzhou

对钱塘江杭州段沿岸土壤11个采样点中的铁锰及相关指标进行了系统研究。结果表明,土壤中Fe,Mn的平均质量分数分别为1.97%(425 mg/kg),变异系数分别为13%,37%。土壤pH值范围在4.64～7.56,处于酸性-弱碱性,变化幅度较大。矿质元素Al的平均质量分数5.68%,变异系数11%。K,Na,Mg的平均质量分数分别为1.76%,1.21%,0.76%;3个指标的变异系数均不超过25%。Ca的质量分数范围为0.55%～1.85%,变异系数较大,为33%。土样矿质元素聚类分析结果表明,钱塘江沿岸土样分为3类:第1类Fe,Mn,Al最低,Ca,Na,Mg较高,主要位于萧山;第2类Fe,Mn,Al次之,Ca,Mg最低,主要位于桐庐以及富阳东郊;第3类Fe,Mn,Al相对较高,主要位于富阳。相关性分析结果表明,Fe与Mn,Al呈极显著相关,Mn与Al呈显著相关,Ca与Na,Mg呈极显著相关,矿质元素与粉砂粒(2～20μm)的相关性较好,而与粘粒不具相关性。

This paper investigated the characteristics of iron, manganese and other indexes from the eleven main surface soil samples. Results showed that the average content of iron （Fe） is 1.97% and manganese （Mn） is 425 mg/kg, and the coefficient of variation of iron is 13% and manganese is 37%. The area of pH is 4.46 - 7.56, which is acidity or alkaleseence. The average content and coefficient of variation of aluminium （Al） is 5.65% and 11%. The average content of kalium （K）, natrium （Na） and magnesium （Mg） is 1.76%, 1.21% and 0.76%, respectively, and the coefficient of variation of these three elements are all less than 25%. The area of the content of autunite （Ca） is 0.55% - 1.85%, and the coefficient of variation is 33%, which is bigger than others. There are three kinds of soil sample by systematic clustering. First kind is the average content of iron, manganese and aluminium is lowest, and aumnite, natrium and magnesium is higher, which is distributed in Xiaoshan. Second kind is the average content of iron, manganese and aluminium is higher than the first kind, and autunite and magnesium is lowest of all, which is distributed in Tonglu and eastern of Fuyang. Third kind is the average content of iron, manganese and aluminium is higher, which is distributed in Fuyang. Results by element correlation analysis showed that it is markedly significant correlation between iron and manganese, between iron and aluminium, between autunite and natrium, and between autunite and magnesium. And it is significant correlation between manganese and aluminium. It is better associated between mineral element and silty sand, and it is non-associative between mineral element and cosmid.