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Event-based rainfall-runoff modeling for a data-scarce semi-urban catchment using PC-SWMM: A case study for Vizianagaram town, Andhra Pradesh, India.
  • L K S V PRASAD SALLANGI,
  • Venkatesh Kasi,
  • Maheswaran Rathinasamy
L K S V PRASAD SALLANGI
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY, JAWAHARLAL Nehru Technological University, kakinada

Corresponding Author:[email protected]

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Venkatesh Kasi
Indian Institute of Technology, Bhubaneswar
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Maheswaran Rathinasamy
Indian Institute of Technology, Hyderabad.
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Abstract

The rainfall-runoff model is essential to derive a relationship between Rainfall and Runoff, in which the hydrological response of the catchment can be derived. A real case study is chosen to simulate the rainfall-runoff modeling, in which small urban catchments are selected and are located in the center part of Vizianagaram Town. The present case study aims to develop an event-based rainfall-runoff model for upstream and downstream catchments of peddacheruvu catchment (PC). In this study, Cartosat-10mDEM, Hourly rainfall data are taken from (weather station), i.e., 1st July to 30th September, the Maximum and Minimum Infiltration rates, Evaporation data, soil data, Groundwater parameters, and dry weather flow patterns are used as in input for model simulation to know the wet weather flow and dry weather flow quantity contributing from the catchment. The model simulation is carried out by using the stormwater management model i.e., PC-SWMM version 5.7.1868. The model simulation is performed at two outlet points in the catchment. The upstream and downstream catchments are selected for computing the total runoff hydrographs. The model calibration is done for nine selected streamflow events from 1st July to 31st August 2019, and the remaining three streamflow events are chosen from 1st to 30th September 2019 are set for model validation. The model performance was checked by computing nine goodness of fit measures. The results of this study suggest that simulated runoff values have satisfactory results with the observed streamflow. In recent years, understanding the hydrological modeling and process has become more important in water resource management, especially in analyzing extreme hydrological events like floods or droughts. The availability of metrological and hydrological data is often scarce in a semi-urban catchment. Some of the significant issues are associated with obtaining reliable long-term hydrological data in the semi-urban region. This study investigates the performance of event-based modeling for data-scarce semi-urban catchments using PC-SWMM in computing the total runoff hydrograph. A real case study, i.e., Peddacheruvu (PC) Upstream and Downstream catchment, were selected, and model performance was examined using 12 streamflow events from 1 July 2019 to 31 September 2019. The model performances are evaluated using five goodness of fit measures like root mean square error (RMSE), Nash Sutcliffe efficiency (NSE), coefficient of determination (R2), RSR, and Kling Gupta efficiency (KGE). The model performance is acceptable throughout model calibration (1 July to 31 August 2019) as the NSE and R2 varies between 0.75 to 0.77 and 0.76 to 0.78, respectively. Similarly, the model validation performances (1 September to 31 September 2019) revealed best fitted with the observed hydrograph for NSE and R2 were 0.62 to 0.64 and 0.62 to 0.85. KGE for model calibration and validation model varies between 0.65 to 0.75 and 0.62 to 0.75.