Effect of growing watershed imperviousness on hydrograph parameters and peak discharge

Abstract

Abstract:An increasing impervious area is quickly extending over the Wu-Tu watershed due to the endless demands of the people. Generally, impervious paving is a major result of urbanization and more recently has had the potential to produce more enormous flood disasters than those of the past. In this study, 40 available rainfall-runoff events were chosen to calibrate the applicable parameters of the models and to determine the relationships between the impervious surfaces and the calibrated parameters. Model inputs came from the outcomes of the block kriging method and the non-linear programming method. In the optimal process, the shuffled complex evolution method and three criteria were applied to compare the observed and simulated hydrographs. The tendencies of the variations of the parameters with their corresponding imperviousness were established through regression analysis. Ten cases were used to examine the established equations of the parameters and impervious covers. Finally, the design flood routines of various return periods were furnished through use of approaches containing a design storm, block kriging, the SCS model, and a rainfall-runoff model with established functional relationships. These simulated flood hydrographs were used to compare and understand the past, present, and future hydrological conditions of the watershed studied. In the research results, the time to peak of flood hydrographs for various storms was diminished approximately from 11 h to 6 h in different decrements, whereas peak flow increased respectively from 127 m 3 s 1 to 629 m 3 s 1 for different storm intensities. In addition, this study provides a design diagram for the peak flow ratio to help engineers and designers to construct hydraulic structures efficiently and prevent possible damage to human life and property.

The role of storm scale, position and movement in controlling urban flood response

“…(e.g. Rose and Peters, 2001;Cheng and Wang, 2002;Du et al, 2012;Huang et al, 2008). However, several studies have found mixed effects of urban-ization on peak flows and response times, associated with a combination of imperviousness and flood mitigation measures, especially for basins where urbanization has predominantly taken place after implementation of stormwater control legislation (e.g.…”

Effects of urbanization variables on model parameters for watershed divisions

“…Thus, the hydrographical characteristics of a developed watershed vary in conjunction with the degree of urbanization (Kliment and Matoušková 2009). Previous studies have shown that the affected factors include rainwater loss (Gremillion et al 2000, Cheng et al 2008b, watershed function (Krug 1996, Kang et al 1998, Aronica and Cannarozzo 2000, Cheng and Wang 2002, surface runoff (Boyd et al 1994, Junil et al 1999, Rodriguez et al 2003, runoff volume (Arnell 1982), peak discharge (Huang et al 2008a(Huang et al , 2008b, time to peak (Huang et al 2012) and baseflow (Simmons and Reynolds 1982). However, the hydrological effects of urbanization may be particularly severe in watershed divisions that are vulnerable to the breaking of links in the hydrological cycle.…”

Statistical analysis of hydrological response in urbanising catchments based on adaptive sampling using inter-amount times

“…(e.g. Rose and Peters, 2001;Cheng and Wang, 2002;Du et al, 2012;Huang et al, 2008). On the other hand, several studies have found mixed effects of urbanisation on flow peaks asso-ciated with a combination of imperviousness and flood mitigation measures, especially for basins in the USA where urbanisation has predominantly taken place after implementation of stormwater legislation to lower peak discharges (e.g.…”