Effect of meteorological and building parameters on peak discharge for urban drainage design | |
| Author | Wisut Termsintaveesuk |
| Call Number | AIT Thesis no.WM-20-21 |
| Subject(s) | Urban runoff Drainage |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Nowadays, an increase of urbanization negativity affects peak discharge for urban drainage design after sudden rain because land use and other human activities also influence the hydraulic characteristics of floods. Moreover, meteorological and building parameters also affect magnitude of rainfall sway by wind speed and vertical catchment area of building is not the same as that of horizontal. Both variables have not yet taken into urban drainage design. This study focuses on the hydraulic characteristics calculated from the interaction between wind-driven rainfalls and cascade of buildings using meteorological and building data. The numerical model is developed based on laminar flow condition. Nusselt equation is used in a modified kinematic wave model to compute the hydraulic characteristics of thin film along cascade of buildings. In highly developed areas, high-rise and tall buildings are constructed in a small catchment. As vertical area (Av) is greater than the drainage horizontal area (Ah), a ratio of Av and Ah affects peak discharge change. It seems that increasing vertical area influences peak discharge and it does not included in conventional design method which uses only the change of physical conditions for runoff coefficient (C). Furthermore, ratio of the WDR intensity through the imaginary vertical surface or wind-driven rainfall intensity (Rwdr) and the intensity of rainfall falling through a horizontal plane or horizontal rainfall intensity (Rh) also affect the peak discharge due to effect of wind speed and direction. The effects of meteorological and building data have been tested using numerical model. Conventional design of urban drainage has used empirical formula, rational method for surface discharge computation. It is subjective to determine appropriate C value. The result shows that the C value is linearly varied with peak discharge when rational method is modified to use in vertical plan, runoff coefficient increase 1.2 to 2.1 times due to effect of wind direction. Comparing peak discharge computed from present model and conventional method when building parameters are constant, it shows that percentage of absolute error errors between present model and rational method of peak discharge are similarly increased linearly when Rh increased, but the percentage of absolute errors are differently increased linearly when wind speed increased. Moreover, the percentage of absolute errors are differently decreased when wind direction increased. Time of concentration (tc) has been derived at the first time using result from the present model, and it shows relationship with height of building (H) and Rh. The higher Rh provides less tc on vertical plane. The present study successfully shows that interaction of meteorological and building parameters, estimated discharge both peak discharge and total discharge. The new design concept on urban drainage design using present numerical model should be promoted and revised in order to implement with development in highly urbanized area. |
| Year | 2020 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Sutat Weesakul; |
| Examination Committee(s) | Babel, Mukand S.;Sarawut Ninsawat;Somchai Chonwattana; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2020 |