| Author | Subasinghe, S.M.C. Kaushalya |
| Note | A thesis submitted in partial fulfillment of the requirement for the
degree of Master of Engineering in
Water Engineering and Management, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The present study focuses on developing a methodology to assess the direct tangible impacts
and vulnerability of social and economic sectors in residential areas of frequently flooded
divisions in Colombo district. Flood inundation modeling in combination with stage damage
curves provides the requirements of a flood loss estimation model. The relationships are
developed for structural, content, total and indirect socio economic damages of residential
buildings with influencing parameters, which are both in quantitative and qualitative nature
based on a questionnaire survey carried out. Results showed that several parameters such as
building floor area, height of first floor, time to recover after a flood event and number of
earning persons within a family also contribute for the vulnerability other than the flood
parameters like flood height, flood duration and flow velocity. Vulnerability to floods was
assessed by computing individual vulnerability indexes, based on their socio economic
conditions, type of building, age of building etc.
The study also focuses on flood inundation modeling in the lower reach of Kelani River. The
flood inundation and river flow are modeled using NK_GIAS software with Flood Modeling
System. This has been developed for the modeling of extreme flood events and can be applied,
when the upstream discharge measurements are not present. Hydrodynamic system comprises
1D river flow and 2D overland flow. Inundations were simulated for different past flood
events and for developed scenarios. Results showed that rainfall has contributed more on
inundation within the past flood events. The importance of having very precise river cross
sections data to obtain accurate results is discussed here. According to the results, local
rainfalls have contributed more on inundation and built up area is the most influenced part
within the study area. More accurate fully hydrodynamic model should be used to obtain very
precise results. |
| Year | 2009 |
| 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) | Babel, Mukand S. ; |
| Examination Committee(s) | Sutat Weesakul ;Tawatchai Tingsanchali;Herat, Srikantha ; |
| Scholarship Donor(s) | The Netherlands; |