福建省山仔水库沉积物磷对水体磷浓度贡献的估算

Calculation of the contribution of the sediment phosphorus to the phosphorus concentration of the water body of Shanzi deep reservoir in Fujian Province

从沉积物磷的化学形态特征、沉积物-水界面的环境条件和水库的水文参数等角度探讨了山仔水库沉积物磷对上覆水体的磷浓度贡献,并从沉积物间隙水与水体垂向溶解性磷的浓度梯度估算对水体磷浓度的贡献大小.结果表明:山仔水库沉积物具有大的释放磷的潜力,沉积物间隙水和水体之间存在着明显的溶解性磷的浓度梯度,沉积物的溶解性磷释放通量在0.0420-0.167μg/(cm2·d))之间,沉积物磷对水体营养贡献大小在0.7%-6%之间,其中秋冬季节沉积物磷对水体的贡献大于春夏季节,当外源减少时,沉积物磷负荷在一定时间内将成为水库营养状态的重要贡献因子.

The contribution of the sediment phosphorus to the phosphorus concentration of the water body was studied through measuring the chemical forms of the sediment phosphorus and the environmental conditions at the sediment-water interface and the hydrological parameters of reservoir, and then we calculated the contribution from the concentration gradient of the total soluble phosphorus between the surface sediment and the water body. The result showed that the sediment of shanzi reservoir had a great release potential of the phosphorus and there was an apparent concentration gradient of the total soluble phosphorus between the surface sediment and the water body which releasing flux was from 0.0420μg/（cm^2·d） to 0.167μg/（cm^2.d）. The contribution of sediment phosphorus to the phosphorus concentration of the water body was from 0.7% to 6%. The contribution in Autumn and in Winter were bigger than in Spring and in Summer. The sediment phosphorus load would be an important factor of the trophic status of the reservoir if the outside sources had been reduced.