According to the general pattern of ground water lowering, this paper suggested a volume calculation method in the natural river courses in the freezing period.
根据地下水退水的一般规律，提出了针对天然河道封冻期流量推求方法的建议。
2
By using the method of event study, this paper studies on the reactions of the trading volume and returns around the period of the rename announcement of the stock.