基于改进水位动态法的年降水入渗补给系数推求

Calculation of Annual Precipitation Recharge Coefficient Based on Improved Dynamic Water Level Method

准确计算降水补给系数对于水资源评价等十分重要。水位动态法因其使用方便、成本低、精度高等优点被广泛用于计算降水入渗补给系数。但传统水位动态法是以次降水入渗补给过程为基础,往往忽略过程中地下水排泄、滞后等问题,导致计算结果存在偏差。针对传统水位动态法的不足,提出一种改进水位动态法,将年降水看作一次降水过程,基于水均衡原理,计算降水入渗补给系数。并以沧州市金牛镇大牛庄村为例,对比两种方法的计算结果。结果表明:虽然两种方法计算结果在同一数量级,但改进水位动态法相对于传统水位动态法减小了降水入渗补给系数间的偏差,使得结果更集中可靠。

It is important to accurately calculate precipitation recharge coefficients for water evaluation. The dynamic water level method is widely used in calculation of precipitation recharge coefficients because of its convenient operation, low cost and high precision. Due to that the traditional dynamic water level methods usually take single precipitation recharge progress as calculation bases and ignore the problem of groundwater exertion and recharge lag, however, there is some calculating deviation. According to water balance, this paper put forward an improved dynamic water level method by changing multiple precipitation processes within a year into an integrated long-term precipitation to solve the above problem. Taking the Daniuzhuang Village in Jinniu Town of Cangzhou City as a study case, the traditional and improved methods were compared. The results show that the deviation of precipitation recharge coefficient from the improved method is less than that from the traditional method.