Evaluation of Streamflow Partitioning Methods

Evaluating the relative amounts of stored or moving water via the different components of the hydrological cycle is highly depended on prudent management and planning. Proper characterization of hydrological cycle components is even more critical since both water quality and water quantity are considered in the water management scheme. One of the most challenging parts of this process is the separation and quantification of baseflow from the streamflow hydrograph. Streamflow partitioning has long been a topic of interest in the science of hydrology. Baseflow recession curve itself contains valuable information about ground water flow and it is widely used in hydrological models such as HEC-1 and other water resource applications. During the last few decades, an important number of case studies have been made with the aim of identifying the streamflow partitioning and physical factors, which control it. As a result of the limitation of available data, most of them were developed and tested on specific physiographic regions. The large number of existing techniques and high level of subjectivity in separating baseflow from streamflow indicates that the problem is not fully understood. The purpose of this paper is to review and evaluate the previously developed streamflow partitioning methods and highlight their advantages and disadvantages. This is important for appropriate use and to avoid any misuse. Successful application of hydrological models depends on their calibration and validation; therefore, the main part of this study focuses on the principles governing streamflow separation and its elements.