三峡水库水动力分区及总磷标准研究

采用EFDC模型计算2010~2018年三峡水库流域水龄.结果表明，三峡水库水龄由上游库尾至下游库首愈来愈大，尤其坝前水龄高达100余天，湖泊属性增强，坝前支流受库区影响大，大坝调度对水龄影响较大，高水位运行期水龄将增长至2~4倍.基于水龄空间分布将三峡水库及其17条主要支流划分为河流型、河湖过渡型和湖泊型.水龄影响因素定量分析表明，水龄与水位呈正相关，与流量呈负相关，泄水期变化速率较蓄水期明显，单位流量与水位内水龄变化幅度高达6~7d，变化区间介于30~100d之间.最后，提出基于水龄权重法的河湖过渡区总磷评价标准，该标准可揭示库区水体总磷的时空变化特征.

Study on hydrodynamic partition and total phosphorus standard in the Three Gorges Reservoir

The EFDC model was used to calculate water age in the Three Gorges Reservoir from 2010 to 2018. Result shows water age increased from the end to the head of the dam, especially in Baqian where water age over 100 days. With the lake attributes increased, tributaries nearby the dam were greatly affected. Dam operation has great influence on the water age, it will increase to 2~4 times during the high water level period. Based on the spatial distribution of water age, the Three Gorges Reservoir and its 17tributaries were divided into riverine, intermediate and lacustrine zones. Quantitative analysis of factors affecting water age showed that water age is positively correlated with water level, negatively correlated with discharge, and the change rate of drainage period is more obvious than that of impoundment period. Water age varies up to 6 to 7 days within unit flow and water level, and the variation range is between 30 and 100 days. Finally, the evaluation standard of total phosphorus in intermediate zone based on the weight method of water age was put forward, which revealed the temporal and spatial variation characteristics of total phosphorus, and provide scientific basis for the management and early warning of phosphorus pollution in the Three Gorges Reservoir.