17 - Development of a water transfer equation for a groundwater/surface water interface and use of it to forecast floods in the Yanghe Reservoir Basin

Summary

ABSTRACT An equation is developed to describe water transfer on and across a groundwater/surface water interface. The interface is divided into two categories, simple and complex, and conceptualised as having a wedge-shaped profile with depths ranging from zero to a maximum value. The maximum depth is defined as water capacity of the interface. The equation is used to forecast floods of the Yanghe Reservoir Basin in the Hebei Province of China. Because of the scarcity of data describing the basin as well as its irregular shape, simulation using common conceptual models, e.g., the Xin'anjiang Model, is difficult. The equation is derived using principles of fluid dynamics and exhibits a good capability to forecast floods in this case. This approach avoids some confounding concepts, such as hydrograph separation and runoff-formation identification, which, although important, are difficult to incorporate into conceptual models. The relationship between the equation and the conceptual watershed model is explored.

INTRODUCTION

Hydrologists, biologists, and water resources managers have become increasingly interested in groundwater/surface water interfaces as an appreciation of their importance to the integrity of natural systems is revealed, and in response to a renewed appreciation of environmental problems associated with man's manipulation and interference of this interface. Because of the importance of this interactive zone to many of man's needs, it is vital to our common good to develop sustainable, conjunctive management of this resource. Mass transfer is one of the principal functions of ground-water/surface water interfaces (Unesco MAB and IHP Programs, 1992).