8/12/2019 Abstract IESL Kulathunga SPSP Corrected by Ransara
1/2
Abstract
IESL
Development of flood damage estimation functions based on
flood simulation scenarios and a GIS platform- A case study at Thawalama, Galle
Kulathunga S.P.S.P.a, Rajapaksha R.M.K.C .b, Ransara N.D.P.c, Silva G.H.A.C.d
a Undergraduate Student, Department of Civil and Environmental Engineering, Faculty ofEngineering.
b Undergraduate Student, Department of Civil and Environmental Engineering, Faculty ofEngineering.
cHydraulic Modeller, Sri Lanka Land Reclamation & Development [email protected]
dSenior Lecturer, Department of Civil and Environmental Engineering, Faculty of [email protected]
Flood damage estimation and provide compensation for victims are utmost important post
flood procedures. Generally the flood damage is estimated through conducting post-flood
field surveys. This consumes more time and the collected information may not be reliable and
fair as often questioned by many flood-victims. Eventhough Sri Lanka is experiencing
frequent flood catastrophies, very limited reseach has been done in relation to flood damage
estimation. Hence the flood damage compensation is mostly made through adhoc methods. A
GIS-based flood damage estimation model is proposedas a solution to these ever expandingproblems which has been widely used in many flood affected regions across the globe. Such a
system would generate swift damage estimation and well organized outputs. Main objective
of this study is to prepare GIS and Hydrological/Hydrodynamic based flood damage
estimation model for Thawalama area that often confronts with flash floods due to overspill
of the Gin River. Developed methodology would be a good resource for the relevant
authorities to estimate actual flood damage for future flood scenarios. Catastrophic floodwhich in May 2003 has been recognized as the most desperate event during the last century
and which has been considered for the development of the flood-damage estimation model.
Preparation of flood-damage estimation demands, many parameters such as property
distribution, inundated area and depth, flow velocity, stage-damage functions etc. In thisstudy, an attempt has been made to estimate some of these parameters. Available 2003 flood
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]8/12/2019 Abstract IESL Kulathunga SPSP Corrected by Ransara
2/2
extent which was generated using Hydrological Engineering Centre (HEC), a public domain
hydrological/hydrodynamic model has been used and the flood depths were extracted by
overlaying the topographic layer with the flood extent. Subsequently, an onsite questionnaire
survey was conducted to gather damage related information. Flood-compensation data those
are issued from Thawalama Divisional Secretariat office were compared with the flood
damage parameters. Finally depth-damage functions for the flood affected Thawalama area
were developed. Validated model can generate reliable flood damage estimation includingpercentage property damage at particular house location for particular inundation height.
Keywords:Flood damage estimation, GIS, HEC, Thawalama, depth-damage functions
Top Related