Impact of Flooding on Oman’s Infrastructure and Management Strategies

The arid wadi systems in Oman are often hit by flash floods that are created during ephemeral convective storms. Wadi Dhayqah in Oman has one of the largest dams in the Arabian Peninsula. The given study proposes an integrated approach to analyse flood-management systems and holistically integrates the GIS-catchment-based analysis, Hydrological modelling, and the hybrid grey-green infrastructure design. A validated HEC-HMS model indicates that Wadi Dhayqah dam cannot manage a storm with greater than 50 years return period that requires an efficient dam operation and to consider other mitigations measures in addition to the dam. Combining Wadi Dhayqah Dam with Nature-Based Solutions (namely, afforestation of 20 % of the catchment and permeable pavements in urban areas) provides an extra set of peak-flow reductions at the range of 1.5 to 26 % in various returns periods. The recommendations are further incremental field data-driven iterative improvement, the extension of the scope of NBS implementation, and the ongoing monitoring which would facilitate the development of flood resilience in arid catches.