TR(BR)-123 : Modelling of spring flow in different geohydrological conditions

Abstract

Most of the existing hydrological models are based on the assumption that the spring discharge is linearly proportional to the dynamic storage in the spring flow domain. The validity of such assumption is yet to be verified. In an earlier study, an attempt has been made to verify this for a spring flow domain which is infinite in one side. But it is found that the relationship between spring discharge during the recession period and the dynamic storage of the spring is not linear even for a linear aquifer system.

In the present study the relationship between a spring flow and the dynamic storage will be verified for linearity for a flow domain of finite areal extent. The solution for an unsteady flow from a well in a confined aquifer of finite areal extent is available. The same solution has been used to find out the relationship between spring flow and dynamic storage. The relationship between the dynamic storage and the spring flow become linear for the finite flow domain.

For a single spring flow domain the method of image has been used and for multiple images, the non dimensional spring flow has been plotted with non dimensional time in log log paper and the plot has been compared with the plot given by Glover. It matches with the values of non dimensional discharge and non dimensional time (3000)given by him for any position of the spring between the recharge zones. But for large values of non dimensional time more than 3000) the respective plot varies from each other for different position of the spring in the flow domain especially when the distance between the recharge zones is large.