中文摘要：

为更好地理解矿区土壤退化机理,该文利用137Cs技术研究了焦作矿区具有15a沉陷历史的采煤沉陷坡土壤侵蚀特征及其对土壤养分的影响。沉陷坡137Cs含量从坡顶到下坡逐渐降低,及至坡脚急剧增大且表现出最高的值。基于137Cs本底（1 645 Bq/m2）,沉陷坡坡顶至下坡表现为土壤侵蚀,而坡脚为土壤沉积。沉陷坡土壤侵蚀高达3.75 kg/（m2·a）,属于中度侵蚀。沉陷坡土壤黏粒含量沿下坡方向增加,表明水蚀的分选性搬运。与对照区相比,沉陷坡侵蚀区土壤总有机碳（total organic carbon,TOC）、水溶性有机碳（water-soluble organic carbon,WSOC）、全氮、碱解氮、全磷、有效磷含量均出现了显著降低（P〈0.05）;沉积区除WSOC显著降低（P〈0.05）外,其他养分含量变化不明显（P〉0.05）。在沉陷坡的侵蚀区,TOC与WSOC含量沿下坡方向逐渐减小,表现出与137Cs一致的分布格局;其他养分含量的坡面变化与137Cs分布不一致。相较于对照区,WSOC/TOC与碳氮比、碳磷比在沉陷坡侵蚀强烈的坡位分别出现了显著增大与降低（P〈0.05）。研究结果表明：1）焦作矿区自采煤沉陷坡形成以来发生了较严重的水蚀;2）侵蚀引起的土壤再分配影响沉陷坡土壤碳、氮、磷动态,其中,土壤再分配对土壤碳动态的影响最强;3）在土壤侵蚀作用下,采煤沉陷坡侵蚀强烈的坡位土壤有效态碳、氮、磷养分潜在的侵蚀风险大。采煤沉陷坡土壤侵蚀及其对土壤养分的不利影响应引起矿粮复合区土地整治的关注。

英文摘要：

The variation in soil nutrients related to soil erosion is crucial to the understanding of land degradation in mining areas. In this study, a representative subsidence slope induced by coal mining in Jiaozuo mine area, China was selected as the research site. The slope is a three-degree slope, has a horizontal length of 100 m, and has experienced a subsidence period of 15 years. Soil erosion and its impacts on total organic carbon（TOC）, water soluble organic carbon（WSOC）, total nitrogen（TN） and phosphorus（TP）, and available nitrogen（AN） and phosphorus（AP） were determined by using the 137 Cs technique. The 137 Cs reference inventory, i.e. the total 137 Cs concentration held in natural soil profiles free of erosion and human disturbance, was（1645±34） Bq/m2 in the study area. Across the subsidence slope, it was found that 137 Cs inventory gradually decreased from the summit to the lower slope positions and then sharply increased at the toe slope positions where the highest values occurred. The summit, upper, middle and lower positions of the subsidence slope were erosional, which was indicated by the lower 137 Cs inventories in these positions than the 137 Cs reference level. The most erosional positions were found in the middle slope and lower slope. On the other hand, the elevated 137 Cs inventories in the toe slope positions revealed the occurrence of the deposition. It was evaluated that the subsidence slope suffers from a moderate erosion with erosion rate estimated at 3.75 kg/（m2·a） according to the Ministry of Water Resources criteria for soil erosion（SL190-2007）. Soil clay content increased downslope on the subsidence slope, suggesting the selective transport after the water erosion. The contents of soil nutrients including TOC, TN, TP, AN, and AP were lower at the erosional sites than the depositional sites of the subsidence slope. Compared with the control field, i.e. a non-subsidence cropland near the subsidence slope, the erosional sites of the subsidence slope showe