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结合三峡水库“蓄清排浊”、反季节调度模式,通过对消落区首次自然干湿交替土壤中磷的赋存形式、含量变化的分析,揭示了新生消落区土壤中磷的分布特征和释放规律。结果表明:水库夏季低水位运行时上覆水总磷含量远高于冬季枯水期高水位时上覆水总磷含量,且由于汛期径流量大,上下游上覆水总磷含量波动明显。自然干湿交替状态下土壤中不同形态磷分布规律一致,活性磷、有机磷含量变化程度剧烈,成为新生消落区上覆水内源磷负荷的主要来源,且库区首次蓄水至175m后新生消落区土壤有机磷是土壤内源磷贡献的主要承担者。覆水初期干湿交替土壤各形态磷含量没有显著差异。覆水后消落区土壤总磷释放程度与本底土壤的总磷、有机磷、活性磷呈现出显著线性相关关系。新生消落区土壤作为潜在磷源,在成库初期对库区水质影响不大。
Combined with the “Three Gorges Reservoir” “clear storage turbid”, the off-season scheduling model, through the first natural alternate wetting and drying of soil alternate forms of phosphorus in the form and content analysis revealed the phosphorus in the emerging area of phosphorus Distribution characteristics and release patterns. The results show that the total phosphorus content of overlying water in the summer low water level operation is much higher than that in winter when the water level is high, and the total phosphorus content of overlying and overlying water fluctuates obviously due to the large runoff in flood season. The distribution of different forms of phosphorus in the soil under alternating dry-wet conditions was consistent, and the content of active phosphorus and organic phosphorus changed drastically, which became the main source of endogenous phosphorus loading in the overlying waters in the new- Soil organic phosphorus in the drop zone is the main contributor to the contribution of endogenous phosphorus in the soil. There was no significant difference in the content of phosphorus in all forms of alternate wet-dry soil at the initial stage of water-covering. The release of total phosphorus from the soil in the fall-off area after water-covering showed a significant linear correlation with the total phosphorus, organic phosphorus and active phosphorus in the soil. As a potential source of phosphorus, the soil in the emerging area was not significantly affected by the initial storage.