To investigate the source identification of soil elements and risk assessment of trace elements under different land-use types, 32 pairs of topsoil samples (0–20 cm) were collected from two subcatchments in the Liudaogou watershed. The areas of the two subcatchments were 0.343 and 0.045 km², respectively, and the two subcatchments were divided into four land-use types, including bare land, forestland (FL), grassland (GL) and check-dam land (CDL). The results showed that the coefficients of variations of all soil elements indicated moderate spatial variation. The mean concentrations of Cu, K, Mn, Na and Zn under different land-use types exceeded the soil background values. The results of correlation analysis and principal component analysis illustrated that high homology existed between Cu and Mn in subcatchment 1, and the main source was from coal mines and smelters. Consistent sources of Zn and K in subcatchment 1 were mainly fertilizers and sewage sludge. Cu, K, Mg, Mn, Na and Zn in subcatchment 2 had similar sources, mainly mining and smelting plants, fertilizers and sewage. In addition, Ca had high homology with Fe in two subcatchments, mainly from natural weathering. The enrichment factor values indicated that there was a certain degree of trace element pollution. The values of the pollution index and Nemerow integrated pollution index revealed that moderate pollution was mainly concentrated in FL, GL and CDL. The trace element pollution of GL and CDL may induce contamination of the food chain and threaten human health safety.

为了调查不同土地利用类型下土壤元素的来源识别和微量元素的风险评估，从六道沟流域的两个子汇水区收集了32对表土样品（0-20厘米）。两个子汇水面积分别为0.343和0.045 km ²，并将两个子汇水区分为四种土地利用类型，包括裸地，林地（FL），草地（GL）和防洪坝（CDL）。结果表明，所有土壤元素的变化系数表明空间变化适中。不同土地利用类型下的铜，钾，锰，钠和锌的平均浓度超过了土壤本底值。相关分析和主成分分析的结果表明，子汇水区1中的铜和锰之间存在高度同源性，主要来源是煤矿和冶炼厂。子汇水面积1中锌和钾的一致来源主要是化肥和污水污泥。子汇水面积2中的铜，钾，镁，锰，钠和锌的来源相似，主要是采矿和冶炼厂，化肥和污水。此外，Ca在两个子汇水区与Fe具有高度同源性，主要是自然风化。富集因子值表明存在一定程度的痕量元素污染。污染指数和Nemerow综合污染指数的值表明，中等污染主要集中在FL，GL和CDL。GL和CDL中的微量元素污染可能导致食物链污染并威胁人类健康。