人类活动对鄱阳湖水位变化的影响

Response of Stage Variation of the Poyang Lake to Human Activities

进入21世纪以来,长江干流上游水库群运行和鄱阳湖区采砂等人类活动对鄱阳湖与长江之间水沙交换过程产生了重要影响,加速了江湖关系演变。主要采用Mann-Kendall趋势检验法和其他统计分析法,分析了近50年来鄱阳湖水位变化阶段性和趋势性特征,并探讨了长江干流上游水库群调节和湖区采砂活动对鄱阳湖水位变化的影响机制。结果显示:2000~2014年鄱阳湖水位分阶段降低,2006~2014年水位降至最低,比2000年前低了1.08m。2000年之后,鄱阳湖全年、汛期和枯季平均水位都有减少趋势,特别是10月份平均水位有非常显著的减少趋势;不同季节主湖区与入江水道水位变化趋势不一致。长江干流上游水库群调节对鄱阳湖水位影响存在时空差异,水库群蓄水期加剧了鄱阳湖水位下降的幅度。人工采砂活动对鄱阳湖水位的影响在枯季尤其是冬季影响更明显。合理调度长江干流上游水库群及湖区采砂活动对维护鄱阳湖和长江关系的健康维持具有重要意义。

Since the beginning of 21st century,the operation of reservoir groups in the upper reaches of the the Yangtze River trunk stream and the artificial sand mining behavior of the Poyang Lake has an important influence on the water and sand exchange,which has accelerated the evolution of river-lake relationship.Mann-Kendall trend test and statistical analysis were used to analyze the characteristics of stage trend in Poyang Lake during recent 50 years.The influence of reservoir group regulation and sand mining activities on stage trend of Poyang Lake was also discussed.The results show that the stage of Poyang Lake decreases during 2000-2014.During 2006-2014,the stage drops to the lowest level,which is 1.08 m lower than that before 2000.Since 2000,the average stage of the Poyang Lake has a decreasing trend in the whole year,flood season and dry season;the average stage in October shows a significant reduction trend;the variation trend of the stage in the main lake area and the water channel is not consistent in different seasons.The effect of reservoir regulation of the upper reaches of the Yangtze River main stream to the stage of Poyang Lake is different in spatial and temporal.The impounding period of the reservoir group aggravates the decline of the stage of Poyang Lake.In dry season,especially in winter,it is more obvious that the sand excavating activities influence the stage of Poyang Lake.It is of great significance to control rationally reservoir groups in the upper reaches of the Yangtze River trunk stream and sand excavation activities on the Poyang Lake for maintaining the healthy relationship.