Daily and Monthly Lumped Parameter Hydrologic Models for Analysis of Small Watersheds in Sri Lanka

Chamal Perera1, R Rajapakse1

  • 1University of Moratuwa, Sri Lanka

Details

09:15 - 09:30 | Thu 31 May | CCLR3 | T.1.1-2

Session: Civil and Environmental Engineering III

Abstract

Water resource management has become vital with the increase of demand for water and modelling of ungauged basins under the conditions of data scarcity has always been a challenge. The two-parameter (2-P) and four-parameter (4-P) models have been used in this study to simulate the response of two river basins Maha Oya and Kelaniya river in Sri Lanka in an attempt to investigate the potential of these lumped parameter models. Both daily and monthly rainfall and streamflow data sets have been used with these models to evaluate the model performance. Two key performance indices, Pearson Correlation Coefficient (PC) and Mean Relative Error (MRE) have been used as objective functions to compare goodness of fit of the observed and simulated streamflow. The two models were calibrated for 2011-2014 period and validated for 2008-2010 period. Based on the comparison of the results, it was found that the 4-P model provides a greater accuracy for the evaluation of the streamflow of the two selected river basins with a PC > 0.75 in both basins with both daily and monthly data. Even the 2-P model provided results with PC > 0.70 when used with monthly data which is within the acceptable range.