Methodology for Agricultural Flood Damage Assessment

This chapter describes a method for assessing flood damage to the agricultural sector, specifically focusing on flood damage to rice crops. The chapter also includes the case studies of flood damage assessment conducted in the Asian river basins, the Pampanga River basin of the Philippines, and the Lower Indus River basin of Pakistan. The assessment was performed by defining flood damage to rice crops as a function of flood depth, duration, and growth stage of rice plants and using depth-duration-damage function curves for each growth stage of rice plants. In the case studies, flood characteristics such as flood depth, duration, and distribution were computed using a rainfall-runoff-inundation (RRI) model. Flood damage to rice crops was assessed for the 2011 flood and 100-year flood events in the case of the Pampanga River basin and for the 2010 flood in the case of Lower Indus River basin. The calculated values of agricultural damage were compared with reported data for validation of methodology, and it was found that the calculated damage reasonably agreed with reported data. The rice-crop damage assessment method described in this chapter can also be applied in other areas for flood risk assessment.