Calibration and validation of EPA SWMM for stormwater runoff modelling in Nyabugogo catchment, Rwanda

  • Paterne Niyonkuru Civil Engineering (Environmental and ASAL)

Abstract

Rapid urbanization is known to have several negative impacts towards hydrological cycle. Urban growth contributes to the increase of impervious area which increases stormwater runoff peak flows and volumes. Nyabugogo catchment has been repeatedly subjected to a growing number of flooding events which resulted in negative effects on water supply system, damage of properties, disruption to business and traffic, discomfort to community, loss of human lives, loss of biodiversity, destruction of environment and deterioration of health conditions owing to water bone diseases. Characterization of stormwater runoff is essential in implementing stormwater management and flood mitigation strategies. Hydrological and hydraulic models are used to perform the study and analysis of stormwater quantity and floods in a catchment. In this study, the United States Environmental Protection Agency’s Storm Water Management Model (EPA SWMM 5.1) was calibrated and validated for stormwater runoff quantity modelling in Nyabugogo catchment. The Geographic Information Systems (ArcGIS) tool was used for catchment delineation; dividing the catchment into sub-catchments and parameterizing the required elements for the model. The collected data from three meteorological stations for period of 1996 to 2017 and three hydrological stations for a period of 1996 to 2017 were used to calibrate and validate EPA SWMM. The performance of EPA SWMM for Nyabugogo catchment was assessed using the coefficient of determination r2, Nash-Sutcliffe efficiency NSE, and index of agreement d. The calibration resulted in r2 of 0.72, NSE of 0.6 and d of 0.77 and validation resulted in r2 of 0.84, NSE of 0.72 and d of 0.8. The calibration and validation results indicated a good fit between simulated and measured data. Overall, the model is acceptable for runoff quantity modelling in Nyabugogo catchment.
Published
Jan 29, 2019
How to Cite
NIYONKURU, Paterne. Calibration and validation of EPA SWMM for stormwater runoff modelling in Nyabugogo catchment, Rwanda. JOURNAL OF SUSTAINABLE RESEARCH IN ENGINEERING, [S.l.], v. 4, n. 4, p. 152-159, jan. 2019. ISSN 2409-1243. Available at: <http://sri.jkuat.ac.ke/ojs/index.php/sri/article/view/715>. Date accessed: 23 feb. 2019.