A Tale of Two Deltas: New Study Reveals How River Deltas Grow

"Some deltas grow uniformly, while others concentrate growth along main channels—a finding that could reshape how we predict coastal land-building."

A new study led by University of Illinois Urbana-Champaign professor Hongbo Ma reveals two distinct patterns of sediment deposition in river deltas: uniform and composite.

The research examined satellite images of 29 deltas worldwide, including the Wax Lake Delta in Louisiana and the Po River Delta in Italy.

Key Findings

Uniform growth: Some deltas expand steadily, following a natural principle known as Hack's law.

Composite growth: Other deltas grow quickly at first, then slow down—concentrating their expansion along a few main channels.

These distinct patterns offer scientists a powerful new tool for predicting how coastal regions will build land over time.

Publication & Support

The findings were published in the journal Science. Co-authors include researchers from:

• University of Texas Rio Grande Valley
• University of California, Irvine
• Universidad de Zaragoza, Spain
• University of Texas at Austin

The research was supported by the National Science Foundation, NASA, and the Agencia Española de Investigación.