US EPA

7260804 

Journal Article 

Development of a model for predicting the changes in flow duration curves due to altered land use conditions 

Best, AE; Zhang, L; Mcmahon, TA; Western, AW; , 

2003 

UNIV WESTERN AUSTRALIA 

NEDLANDS 

861-866 

WOS:000189470800145 

Broad scale vegetation changes within a catchment are likely to lead to changes in water yield and flow regime. The Flow Duration Curve (FDC) represents the relationship between the magnitude and frequency of stream flow and provides a useful means for estimating changes in flow regime under altered land use conditions. The FDC for a catchment is dependent on the climate, soil, vegetation and other catchment characteristics. The ability to predict the change in FDC for a catchment undergoing land use change would provide a useful tool for water allocation and water quality management. This paper aims to develop a simple model for describing a catchment's FDC under current land use and assesses which of the model parameters change under altered land use conditions. Three potential models with different levels of complexity are considered. The three models have two common parameters, the proportion of zero flow days and the median discharge of the non-zero flow days. The models differ in the type of curve that is fitted to the normalised FDC when plotted in log-normal space. Data from forty seven paired catchment studies covering a wide range of climatic, vegetation and soil conditions were used to evaluate the ability of the models to describe the FDC. The results indicate that under altered land use conditions the major changes occur in the parameters common to all three models, while the most complex model provides the most accurate description of the FDC. 

1-74052-098-X 

International Congress on Modelling and Simulation 

Townsville, AUSTRALIA