Forecasting of Future Flooding and Risk Assessment under CMIP6 Climate Projection in Neuse River, North Carolina

Indira Pokhrel,Md Mafuzur Rahaman,Ranjeet Thakali,Ajay Kalra

doi:10.3390/forecast2030018

Indira Pokhrel, Md Mafuzur Rahaman + Show 2 more

Open Access

https://doi.org/10.3390/forecast2030018

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Abstract

Hydrological extremes associated with climate change are becoming an increasing concern all over the world. Frequent flooding, one of the extremes, needs to be analyzed while considering climate change to mitigate flood risk. This study forecast streamflow and evaluate risk of flooding in the Neuse River, North Carolina considering future climatic scenarios, and comparing them with an existing Federal Emergency Management Agency study. The cumulative distribution function transformation method was adopted for bias correction to reduce the uncertainty present in the Coupled Model Intercomparison Project Phase 6 (CMIP6) streamflow data. To calculate 100-year and 500-year flood discharges, the Generalized Extreme Value (L-Moment) was utilized on bias-corrected multimodel ensemble data with different climate projections. Out of all projections, shared socio-economic pathways (SSP5-8.5) exhibited the maximum design streamflow, which was routed through a hydraulic model, the Hydrological Engineering Center’s River Analysis System (HEC-RAS), to generate flood inundation and risk maps. The result indicates an increase in flood inundation extent compared to the existing study, depicting a higher flood hazard and risk in the future. This study highlights the importance of forecasting future flood risk and utilizing the projected climate data to obtain essential information to determine effective strategic plans for future floodplain management.

Highlights

According to the Intergovernmental Panel on Climate Change (IPCC) report, climate change has triggered extreme hydrologic events that are having adverse effect on the hydrological cycle and human livelihoods all over the world [1]
The first section discusses the bias correction results of global climate models (GCMs) obtained from Coupled Model Intercomparison Project Phase 6 (CMIP6)
The third section shows the evaluation of floodplain using classified hazard data

Summary

Introduction

According to the Intergovernmental Panel on Climate Change (IPCC) report, climate change has triggered extreme hydrologic events that are having adverse effect on the hydrological cycle and human livelihoods all over the world [1]. The rising trend in global warming maximizes the evaporation rate of surface water and soil moisture that will affect the amount of precipitation all around the globe [4] This type of alteration in the hydrologic cycle will affect the runoff and availability of both the surface and subsurface water, which eventually impacts river streamflow [5]. High flows and low flows i.e., floods and droughts, are likely to occur more frequently across the globe with increased intensity [6,7,8] These increases in both high and low flow extremes have already occurred in some parts of the world and are making societal infrastructure more sensitive to climate change [3]. Extreme events are more frequent these days and are anticipated to continue at the same frequency or even faster in the future

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