Bista et al. (2025) Local-scale flood hazard projections in historically vulnerable communities

Identification

• Journal: Modeling Earth Systems and Environment
• Year: 2025
• Date: 2025-10-18
• Authors: Sunil Bista, Saurav Bhattarai, Sanjib Sharma, Rocky Talchabhadel
• DOI: 10.1007/s40808-025-02599-2

Research Groups

• Jackson State University, Jackson, MS, United States
• Howard University, Washington D.C., United States

Short Summary

This study developed an integrated hydrologic-hydrodynamic modeling framework to project local-scale fluvial flood hazards in Jackson, Mississippi, finding a significant increase in flood risks under future climate change scenarios, disproportionately impacting vulnerable communities and critical infrastructure.

Objective

• To assess localized 100-year fluvial flood hazard projections in the City of Jackson, Mississippi, under future climate change scenarios (Shared Socioeconomic Pathways SSP245 and SSP585) using an integrated hydrologic-hydrodynamic modeling framework.

Study Configuration

• Spatial Scale: City of Jackson, Mississippi, United States, within the Pearl River Basin.
• Temporal Scale: Historical period for model calibration and validation (e.g., 2020 flood event) and future projections extending to the late 21st century under SSP245 and SSP585 climate scenarios.

Methodology and Data

• Models used:
  • Hydrologic model: Soil & Water Assessment Tool (SWAT)
  • Hydrodynamic model: HEC-RAS (physically-based, semi-distributed)
• Data sources:
  • Climate projections: Multiple climate models from Coupled Model Intercomparison Project Phase 6 (CMIP6) via NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6) for SSP245 and SSP585.
  • Topographic data: U.S. Geological Survey (USGS) Digital Elevation Models (DEMs).
  • Observed data: USGS gage station data (discharge, gage height).
  • Land cover data: National Land Cover Database (NLCD) 2021.
  • Soil data: SSURGO/STATGO2.
  • Socioeconomic data: U.S. Socio Vulnerability Index Grids, U.S. Census Bureau, and projected population data.
  • Infrastructure data: National Structure Inventory (NSI), Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM).
  • Satellite imagery: Sentinel-2 (for comparison).

Main Results

• Future scenarios project a significant increase in flood hazards, with the number of residents living in flood-prone areas in Jackson, Mississippi, projected to nearly double from approximately 24,700 currently by the late 21st century.
• Downtown Jackson is anticipated to experience disproportionately greater flood impacts.
• Single-story, single-family residential buildings without basements are identified as among the most exposed structures.
• A wastewater treatment lagoon located in a high flood hazard area is projected to experience flood depths exceeding 3 meters, posing a severe contamination risk to the downstream potable water treatment facility.
• Levee-1 is projected to be completely overtopped under both SSP245 and SSP585 scenarios.

Contributions

• Provides valuable, local-scale flood hazard projections for a historically vulnerable community, integrating climate change impacts with socioeconomic factors.
• Offers critical insights for policymakers and planners to prioritize investments in flood resilience, enhance critical infrastructure protection, and develop equitable floodplain management strategies.
• Introduces a scalable and adaptable integrated hydrologic-hydrodynamic modeling approach for application in other flood-prone urban communities.

Funding

• Hydrological Impacts Computing, Outreach, and Resiliency Partnership (HICORPS) Project.
• Collaboration between the U.S. Army Engineer Research and Development Center (ERDC), WOOLPERT-Taylor Engineering, and Jackson State University.

Citation

@article{Bista2025Localscale,
  author = {Bista, Sunil and Bhattarai, Saurav and Sharma, Sanjib and Talchabhadel, Rocky},
  title = {Local-scale flood hazard projections in historically vulnerable communities},
  journal = {Modeling Earth Systems and Environment},
  year = {2025},
  doi = {10.1007/s40808-025-02599-2},
  url = {https://doi.org/10.1007/s40808-025-02599-2}
}