City Research Online

Abstract

An investigation of the effect of urban development on streamflow was carried out using computer simulation and multiple regression analysis. In addition, a review of past work in this field is presented.

Storms occurring on the Crawters Brook catchment during the twenty-year urban development of Crawley, Sussex were analysed on a hybrid computer. A hybrid computer simulation model was developed to simulate the short-term hydrological processes of the catchment. The four parameters of the model were optimized for each of the 36 storm events using the ‘simplex' direct-search method. The sensitivity of the model to parameter changes was analysed by generating hydrographs for various sets of parameters and by plotting response functions.

Multiple regression analysis was used to link parameter values to physical and meteorological variables. It was found that the percentage of impervious area in the catchment was the most important variable in explaining the variance of three of the model parameters. The regression equations could be used to predict parameter values for hypothetical catchment conditions in order to generate hydrographs from the simulation model.

Daily flow volumes were also analysed using multiple regression and it was found that increases in the impervious area causes significant increases in mean daily flow.

A flood frequency analysis was carried out linking flow peaks to physical and meteorological data using regression analysis. The regression equations were then used to predict annual peak flows for the study period for various levels of urbanization. It was found that changing a rural catchment to an urban catchment with 40 per cent impervious area would result in the mean annual flood being increased by a factor of 2.64 and the twenty-five year flood by 2.44. The annual number of peaks above a certain threshold was also found to increase.

Publication Type:	Thesis (Doctoral)
Subjects:	T Technology > TA Engineering (General). Civil engineering (General)
Departments:	School of Science & Technology > Department of Engineering School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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