水体交换与传输的时间维特征

从水体交换时间维的特征出发对相关概念进行了总结,分析了宏观概念、微观概念的意义,比较了不同概念的异同。重点给出了更替周期及更新时间的计算方法,并分析了两者的关系。还参照前人研究,分析了水体入口、出口位置不同时水体更替周期、平均传输时间、平均寿命、平均滞留时间的关系。最后以20世纪90年代黄河中下游河段为例对其更替周期及逐月变化规律进行了计算分析,并证实径流量与更替周期存在负相关关系。

Temporal characteristics of exchange and transit of water bodies

Exchange and transit of water and material in natural reservoirs and between the reservoirs and their environments occur all the time.The characteristics of different reservoirs vary.In the paper,some concepts to describe the temporal characteristics of these reservoirs are analyzed.The similarities and dissmilarities of different concepts are compared.The calculations of replacement period and re newal time are introduced especially and their relationship is ana-lyzed by formula(6)and figure1.On the basis of predecessors' studies,the relationships among replacement period,average transit time,average age and average residence time are analyzed when the locations of inlet and outlet of water bodies are different.As an application,the re-placement periods for middle and lower reaches of the Yellow River are computed.The change trends of the monthly replacement periods are analyzed.The results show that during less runoff period,the values for replace ment period are larger than values during more runoff period.The relationship between replacement period and flow are researched also.Negative correlation be-tween them is found.