Flood damage assessment in the Pampanga river basin of the Philippines

Abstract

In this study, a flood damage assessment method was proposed for the assessment of flood risk in data-poor river basins by using a physical-based numerical model, satellite-based information and socio-economic factors. The Pampanga river basin of the Philippines was selected for the case study. For the flood damage assessment, hazard characteristics, such as flood depth and duration, were computed using the rainfall runoff inundation model. Agriculture and households, which are major exposures in flood-prone areas, were taken into account for the flood damage assessment. The potential damage to agriculture was estimated by using the damage functions of agriculture and flood characteristics. The damage functions of agriculture for each growing stage were defined as the function of flood depth and duration. Field investigations and questionnaire surveys were conducted at the selected barangays (villages) in the Pampanga river basin to develop a methodology for household damage estimation. The damage estimation approach for damage to household buildings including assets, was developed based on the flood and household characteristics. The potential damage to house building and assets was estimated. The estimated damage of agriculture and households was compared with the reported values.

Flood risk‐benefit assessment to support management of flood‐prone lands

“…In Candaba, residences concentrated in the western part of the municipality sustain frequent moderate inundation. In some flood‐prone villages, many people live in two‐story residences or elevated houses with silts to reduce potential damages during regular floods (Juarez‐Lucas et al, ; Shrestha et al, ). Damage analyses of the 2011 floods, for instance, report mean damages of US $1,245 to residential buildings and households assets in Candaba (Shrestha et al, ).…”

“…In some flood‐prone villages, many people live in two‐story residences or elevated houses with silts to reduce potential damages during regular floods (Juarez‐Lucas et al, ; Shrestha et al, ). Damage analyses of the 2011 floods, for instance, report mean damages of US $1,245 to residential buildings and households assets in Candaba (Shrestha et al, ). Similarly, by assessing only benefits from wild fish capture and rice agriculture we address only a portion of benefits derived from the use of flood‐prone land.…”

“…To derive benefit curves related to rice yields at different levels of inundation, we estimate attainable crop production as the complementary percentage of yields lost due to floods as reported by Shrestha, Okazumi, Miyamoto, and Sawano (). The relation of rice yields at varying depths and durations of inundation (Figure b) indicates attainable crop production from total potential harvest at the mature growth stage.…”

RCP8.5-Based Future Flood Hazard Analysis for the Lower Mekong River Basin

“…The RRI model setup and its equations are explained in Sayama [26,54]. The various applications of the RRI model in hydrological studies can be found in several studies [26,41,54,58,59]. The model equations are derived based on the following mass balance Equation (1) and momentum Equations (2) and (3) for gradually varied unsteady flow:…”

Development of model for the estimation of direct flood damage including the movable property

“…The damage was the sum of the cost of sediment removal (cleaning) and the loss of crops, which changed according to the growth phase. Depth-damage curves for crops can be found in different studies (CEIWR-HEC, 1985;Hansen, 1987;Shrestha et al, 2015). Owing to modelling on a mesoscale, our approach was simpler: we set a threshold value of water depth that causes total crop damage.…”