红壤区稀土矿开发导致河流泥沙淤积量的估算--以江西省信丰县崇墩沟小流域为例

不合理的人为活动是侵蚀产沙的主要原因之一。在江西省信丰县崇墩沟小流域内由于稀土矿产的无序开发,导致河流泥沙严重淤积。通过实测河流淤积泥沙断面,计算出在7 500 m长的河道共淤积泥沙30 193 t,考虑到输移比,整个流域内土壤流失量可达3 500 t/km2,平均侵蚀模数也高达1 150 t/(km2.a)以上,属于中等强度的土壤侵蚀。调查结果发现,河流中淤积的泥沙主要来源于稀土矿开发的尾矿流失;土壤流失量高到99 730 t/km2,年平均侵蚀模数为34 000 t/(km2.a)以上,属于极强度的水土流失。治理水土流失,须加强对稀土矿开发的管理,防止形成新的水土流失;将已废弃的稀土尾矿作为治理的重中之重,可有效地降低流域内土壤侵蚀的强度。

Estimation of Sediment Silting in River Channeldue to Developing Rare Earth Mine in Red Earth Region

the unreasonable human activity is one of the key factors for soil erosion and sedimentyield. Irrational developing ofrare earth m ine ongdonggou watershed,Xinfeng County,induced to serious sediment silting in the river channel,and thetotal silting sediment was 30193 tiven the 7500m river channel estimated by measuring the siltiveng sectiveon. Based on the sediment delivery ratio,soil loss in thewhole tershed was 3500t/km²,and soilerosive radius was more than 1150 t/(km² Erosion degree in the watershed was of middle erosion density. Soilloss from the tailings ofrare earth mine was the most serious sources for sedimentiven river,and the loss was 99 730t/km² with annual erosion amount greater than 34000t/(km³a) as the severest loss type. Among all the soil and water loss controlling easurements,managementofrare earth mine development should be intensified and con-trolling abandoned mine tailings should be as a key aspect.