大镜山水库底泥的蓄积量及营养盐空间分布特征

通过对抽水水库——大镜山水库底泥区面积及底泥厚度的调查,估算了该水库建库30年来底泥的蓄积量,并探讨了水库底泥中营养盐的空间分布特征。结果表明,该水库中蓄积的底泥体积约为48 840 m3,湿重约为54 027 t,干重约为36 137 t。底泥中淤积的无机磷、总氮和易释放磷的含量分别约为21 8866、7 015和5 867 kg。总氮、无机磷及易释放磷的水平分布,从大坝的入水口至库尾呈明显的递减趋势;水库底泥中总氮、无机磷及易释放磷含量的垂直分布,从底层向表层呈明显的递增趋势。营养盐的水平分布反映了抽水水库水动力学特点,垂直变化则反映了20世纪80年代中期到2000年初珠海及周边地区工业与城市发展对河流和水库水环境的影响。

Sediment Deposition and its Trapping Nitrogen and Phosphorus in Dajingshan Reservoir

By investigating the sediment,we estimated 30 years' sediment deposition in the Dajingshan Reservoir in Zhuhai City.Then by determining the content of nutrients in different positions including the different sediment layers,we discussed the spatial distribution of nutrients in a pumped storage reservoir.Total volume of sediment in the whole reservoir was about 48 840 m3,the total wet-weight was about 54 027 tons and the total drought-weight was about 36 137 tons.According to the contents of inorganic phosphorus and nitrogen,it was estimated that the total inorganic phosphorus(TPI),total nitrogen(TN) and releasable phosphorus(Pre) in the sediment were be about 21 886 kg,67 015 kg and 5 867 kg,respectively.The contents of TPI,TN and Pre were obviously decreased from the entry of water to the tail of reservoir,reflecting the hydrodynamic characteristic of abstracting reservoir.The contents of IP,TN and Pre in the sediment were increasing vertically from bottom to surface and the increasing trend showed the deterioration of water quality in the river and the reservoir,corresponding to the urban and economic development of the Zhuhai city from the middle of 1980s' to 2000.