Amplified Extreme Floods and Shifting Flood Mechanisms in the Delaware River Basin in Future Climates
[1];
[2];
[1];
[1];
[4];
- Earth Systems Science Division Energy and Environment Directorate, Pacific Northwest National Laboratory Richland WA USA
- Earth Systems Science Division Energy and Environment Directorate, Pacific Northwest National Laboratory Richland WA USA, Department of Civil and Environmental Engineering University of Washington Seattle WA USA
- Department of Civil and Environmental Engineering University of Washington Seattle WA USA, Coastal Sciences Division Energy and Environment Directorate, Pacific Northwest National Laboratory Seattle WA USA
- Coastal Sciences Division Energy and Environment Directorate, Pacific Northwest National Laboratory Seattle WA USA
Abstract Historical records in the Delaware River Basin reveal complex and spatially diverse flood generating mechanisms influenced by the region's mountains‐to‐plains gradients. This study focuses on predicting future flood hazards and understanding the underlying drivers of changes across the region. Using a process‐based hydrological model, we analyzed the hydrometeorological condition of each historical and future flood event. For each event, at the subbasin scale, we identified the dominant flood generating mechanism, including snowmelt, rain‐on‐snow, short‐duration rain, and long‐duration rain. The rain‐induced floods are further categorized based on the soil's Antecedent Moisture Condition (AMC) before the event, whether dry, normal, or wet. Our historical analysis suggests that rain‐on‐snow is the primary flood mechanism of the Upper Basin. Although most frequent, the magnitude of rain‐on‐snow floods is often less severe than short rain floods. In contrast, historical floods in the Lower Basin are primarily caused by short rain under normal AMC. Given the uncertainties in climate projections, we used an ensemble of future climate scenarios for flood projections. Despite variations in regional climate projections, coherent perspectives emerge: the region will shift toward a warmer, wetter climate, with a projected intensification of extreme floods. The Upper Basin is projected to experience a marked decrease in rain‐on‐snow floods, but a substantial increase in short rain floods with wet AMC. The largest increase in flood magnitude will be driven by short rains with wet AMC in the Upper Basin and by short rains with normal AMC in the Lower Basin.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 2325453
- Alternate ID(s):
- OSTI ID: 2325454
- Journal Information:
- Earth's Future, Journal Name: Earth's Future Vol. 12 Journal Issue: 3; ISSN 2328-4277
- Publisher:
- American Geophysical Union (AGU)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Scaling of Floods With Geomorphologic Characteristics and Precipitation Variability Across the Conterminous United States
Potential Impacts of Climate Change on Streamflow and Flooding in Snow Dominated Forest Basins