Gumti River — A River in Retreat

Web Storymap · Muradnagar, Cumilla · 2010–2026

A River
in Retreat

How unregulated brickfield soil extraction is pushing the Gumti River toward the embankment — and why the next monsoon could be catastrophic.

GUMTI RIVER CORRIDOR
RISK ASSESSMENT

LOCATION 01
MURADNAGAR UPAZILA

SATELLITE · GIS
ANALYSIS · 2026

⚠ Critical embankment failure already recorded — 2024 flood event · High monsoon-season hazard

Chapter 01 — Setting the Scene

Where the River
Meets Its Breaking Point

The Gumti River has long shaped the landscape of Cumilla — its floods, its sediment, its seasonal rhythm. But something has changed. The river is moving, and it is moving in the wrong direction.

Across Muradnagar Upazila, the Gumti is no longer adjusting naturally between its banks. It is migrating — laterally, persistently, and increasingly close to the flood-control embankment that protects tens of thousands of people, their crops, and their homes.

The driver of this shift is not natural alone. Brickfields operating near the riverbank have been extracting soil from adjacent floodplain areas for years. This repeated cutting strips away the mass and structural integrity of the bank, leaving the river margin physically weakened and increasingly unable to resist the enormous hydraulic pressure of monsoon flow.

"The river requires less force to cut laterally into a margin that has already been destabilised by soil extraction — and in Muradnagar, the margin is running out."

This study compares satellite imagery from 2010 and 2026 across two selected locations in Muradnagar, georeferenced in ArcGIS Pro, to map how far the Gumti has moved — and what that movement means for the embankment standing in its path.

FIG 01 · Study area within Muradnagar Upazila, Cumilla Zila. Locations 01 and 02 mark the primary analysis zones along the Gumti River corridor. The Gomotī Beribandh Sadak (embankment road) is visible.

16 YEARS ANALYSED Satellite imagery compared: 2010 → 2026

2 STUDY LOCATIONS Selected zones in Muradnagar showing active bank instability

2024 EMBANKMENT FAILURE Real breach event confirming escalating structural risk

Chapter 02 — The Evidence

Sixteen Years of
Vanishing Land

FIG 02 · Gumti River, Location 01 — 2010. River channel is clearly separated from the embankment by a substantial vegetated buffer. Bank line is relatively stable and contained within a broad meander arc.

FIG 03 · Gumti River, Location 01 — 2026. The river has widened and shifted dramatically toward the embankment. Outer-bank retreat is extensive; the protective buffer has collapsed in key sections.

Erosion vs. Accretion

FIG 04 · Red zones = erosion (land lost). Yellow zone = accretion (land gained). The imbalance is stark: erosion dominates almost the entire active bend length.

91,960 m² ERODED Total land lost to river advance

8,893 m² ACCRETED Inner-bend sediment gain

NET LAND LOSS RATIO EROSION : ACCRETION = 10.3 : 1

Erosion measurements (in m²) derived from georeferenced ArcGIS Pro digitization of satellite imagery, 2010 and 2026. Figures labeled in map: 39,848 m², 42,068 m², 10,044 m² erosion polygons; 8,893 m² accretion.

The Shrinking Buffer

FIG 05 · Buffer zone comparison. In 2010 (top), the separation between river edge and embankment was 64–107 m. By 2026 (bottom), this had collapsed to just 13–27 m in the most critical stretches.

2010 — BASELINE

Buffer widths: 64 m, 80 m, 107 m at measured cross-sections. Embankment well-protected by floodplain land.

2010–2026 — PROGRESSIVE LOSS

Repeated soil extraction by brickfields weakens bank structure. Outer-bank erosion accelerates. River begins steady lateral migration toward embankment.

2024 — FIRST BREACH

Monsoon/flash-flood pressure on the now-exposed embankment causes structural failure. Flood impacts local settlements and agricultural land.

2026 — CRITICAL STATE

Buffer widths: 13 m, 20 m, 27 m. River has advanced 50–80 m toward embankment in measured zones. Risk of future breach is extreme.

Chapter 03 — Causes, Consequences & the Way Forward

A Governance Failure
Wearing a Flood's Face

1

Soil Extraction as a Force Multiplier

Brickfield operations adjacent to the Gumti have been removing floodplain and bank soil for years. Each cut reduces the bank's resistance to hydraulic shear, meaning the river can erode laterally with less energy — and does.

2

A Governance Gap, Not Just a Geomorphic One

Soil extraction near riverbanks persists through weak oversight, informal arrangements, and local political structures. The river's migration is partly a map of regulatory failure. Controlling extraction is therefore a flood-risk intervention.

3

The Embankment Is No Longer Buffered

With buffers collapsed to 13–27 m in critical sections, direct lateral pressure from high-discharge flow now reaches embankment toe structures. Scouring, undercutting, and seepage can begin well before overtopping occurs.

4

2024 Was a Warning, Not an Anomaly

The embankment breach of 2024 is not an isolated extreme-weather event. It is the first observable output of a cumulative vulnerability that has been building since at least 2010. Without intervention, it will repeat.

Methodology

1

Image Acquisition: Historical satellite screenshots captured from Google Earth Pro for 2010 and 2026, along with KML reference coordinates at each location.

2

Georeferencing: KML control points imported to ArcGIS Pro and converted to shapefiles; images registered to a common spatial framework enabling accurate temporal comparison.

3

Digitization: River boundaries and embankment/buffer zones manually digitized for both years, producing spatial layers of river extent and bankline positions.

4

Change Analysis: Overlay of 2010 and 2026 boundaries to derive erosion and accretion polygons; area measurements and buffer distance assessments extracted for each location.

Muradnagar as Early Warning

This study focuses on Muradnagar, but the processes documented here — bank cutting, channel migration, erosion dominance, embankment encroachment — are likely operating at other points along the Gumti River where similar land-use pressures exist. Muradnagar is not an isolated anomaly; it is a leading indicator for the broader Cumilla corridor.

⚠ High Risk — Action Required

Unless unauthorized soil cutting is stopped and embankment-side river margins are actively protected, the Gumti River will continue advancing toward critical infrastructure. The probability of embankment damage during the next severe monsoon season is high and rising.

Risk Profile

Bank StabilityCRITICAL

Buffer AdequacyCRITICAL

Erosion RateVERY HIGH

Monsoon VulnerabilityVERY HIGH

Governance ResponseLOW

Recommendations

① Immediate: Enforce moratorium on soil extraction within 200 m of active riverbank in Muradnagar.

② Short-term: Deploy bioengineering (bamboo piling, vetiver grass) or hard revetment at critical 13–27 m buffer sections.

③ Structural: Commission full bathymetric and geotechnical survey of embankment toe condition before monsoon season.

④ Governance: Establish transparent soil-extraction licensing with satellite-based compliance monitoring district-wide.

The Gumti is not simply a river in flood — it is a river responding to human decisions. Every truckload of brickfield soil extracted from its banks is a vote for the next breach. The maps are clear. The choice that remains is whether to act before the embankment fails again, or after.

Data Sources

Google Earth Pro (2010, 2026 imagery) · ArcGIS Pro (georeferencing & digitization) · Esri, Vexcel, DigitalGlobe (basemap imagery) · Field observations, Muradnagar Upazila

Study Area

Muradnagar Upazila
Cumilla District, Bangladesh