多波长水位起伏条件下盆地地下水流系统的水动力学特征

Hydraulics of groundwater flow systems in drainage basins with multi-wavelength undulating water table

Tóth采用线性函数和正弦函数的叠加刻画潜水面起伏,发现盆地中可以发育局部、中间和区域三个不同级次的地下水流系统。由于实际水位起伏更复杂,潜水面起伏需要用更多波长的函数叠加来刻画。以三波长为例,研究多波长水位起伏条件下盆地地下水流系统的空间分布规律,发现两层不同深度内部驻点的存在,驻点数目与水位起伏频率有关,水位起伏波长对内部驻点深度及对应水流系统的穿透深度有控制作用。

Tóth（ 1963） used the superposition of a linear and a sine function to characterize the undulation of water table and found that the undulation of water table could lead to development of local,intermediate,and regional flow systems in a drainage basin. Considering the complexity of the actual water table in a drainage basin,more functions with different wavelengths should be combined to characterize the undulation of water table. In this study,the superposition of three different cosine functions are utilized to describe the undulating water table. Under the condition of three-wavelength water table undulations,the distribution of internal stagnation points is analyzed. It is found out that there are two layers of stagnation points with different depths.The relationship between the number of stagnation points and the undulation frequency is also discussed. The depth of internal stagnation point and the penetration depth of the flow system are found to be controlled by the wavelength of the corresponding scale of water table undulation.