赣南稀土尾矿堆积区水土流失规律初探

赣南是我国重要的离子型稀土矿生产基地,但在其开采的同时也对矿区周围的土壤与环境造成影响,特别是稀土尾矿的水土流失问题尤为严重。本文选择典型的尾矿水土流失区,采用野外测量等方法对矿堆的主要水土流失类型及其强烈程度进行研究,同时对典型水土流失路径进行实地监测。结果表明:尾矿水土流失区沟道平均侵蚀模数约为3.73×104 t/(km2?a),坡面细沟平均侵蚀模数为1 651.2 t/(km2?a),水土流失情况极其严重。在降雨过程中,侵蚀沟内路径为侵蚀状态,侵蚀深度不断增加,在距沟头66 m处侵蚀深度开始减小,径流流出冲沟后到距离侵蚀沟出口处大约60 m的地方侵蚀深度为0 cm,之后随着距离的增加,泥沙开始逐渐沉积,水土流失状态转为堆积。

Water and Soil Loss Research in Rare Earth Tailing Heap in Southern Jiangxi

Southern Jiangxi is an important iron-absorbed rare-earth mineral production base of China, however, strip- mining can influence the soil and environment, especially in water and soil loss. In this study, a typical tailing heap water and soil loss zone was chosen and field measurement was taken to study soil erosion type and degree, meanwhile the typical water and soil loss route was monitored. The result showed that the gully mean erosion modulus were about 3.73×104 t/(km2×a), rill mean erosion modulus were 1 651.2 t/(km2×a) and erosion modulus increased with gradient increasing. During the rainfall, a great deal of sediment was transported. The water and soil loss condition inside the erosion gully was in erosion state, and erosion depth constantly increased. The erosion depth turned to decrease at a distance of 66 m far from the gully head, and decreased further when runoff flowed outside the gully. The erosion depth was 0 cm at about 60 m distance outside the gully, then sediment deposited gradually with increasing distance. Finally, the erosion condition turned to deposit.