Online rumors recently spread across social media claiming the Three Gorges Dam had sustained severe deformation and was at imminent risk of collapse, accompanied by photos showing an apparently warped, distorted dam structure. Chinese authorities and leading engineering experts have stepped forward to debunk these false allegations.
Expert: Minimal, Normal Structural Shifts Are Invisible to the Naked Eye
Eighty-seven-year-old academician Chen Houqun has participated in quality inspections for the Three Gorges Project since 1994 as head of the project’s expert quality inspection panel under the Chinese Academy of Engineering.
According to official monitoring data compiled through April 2019:
- Vertical foundation settlement ranges from 1.45 mm to 26.69 mm and has stabilized with no notable spikes after reservoir impoundment.
- Horizontal foundation displacement along the upstream-downstream axis varies between -0.24 mm and 4.63 mm, with most post-impoundment shifts below 1 mm.
- Horizontal crest displacement spans -1.82 mm to 28.70 mm.
All measured readings fall fully within the dam’s engineered safety thresholds.
Chen Houqun, CAE Academician:
All man-made structures experience minor deformation under physical load unless constructed from perfectly rigid material. The Three Gorges Dam’s slight positional changes follow standard physical rules: higher water levels push the structure marginally downstream, while falling water allows partial rebound within its elastic design range. Seasonal temperature swings also trigger regular cyclic shifts: cold winter temperatures cause concrete contraction and downstream movement, and summer heat expansion pulls the structure slightly upstream. All such movement is predictable.
Comprehensive safety monitoring was built into the dam’s original design as one of eight core specialized engineering components. Starting in 1994 alongside main construction, engineers installed a total of 12,087 monitoring sensors, including 2,681 dedicated deformation-tracking gauges with a 99.8% functional rate. All recorded displacement values are microscopic and only detectable via precision industrial instruments, impossible to spot with human vision. The inspection team conducts on-site assessments no fewer than twice annually, thoroughly auditing all monitoring datasets. Any abnormal micro-changes trigger immediate root-cause investigations; visible large-scale warping is structurally impossible and would never go undetected.
Satellite Imagery from China Aerospace Confirms Dam Remains Straight and Undamaged
Shortly after the distorted images went viral, China Aerospace Science and Technology Corporation released side-by-side comparisons pairing the questionable distorted online photo with fresh high-resolution satellite shots captured by China’s Gaofen-6 satellite. The official satellite footage clearly shows a uniformly straight dam with zero structural bending.
Wang Haibo, Senior Engineer at China Resources Satellite Application Center:
This valid imagery was captured on June 4, 2019. Gaofen-6 delivers 2-meter spatial resolution and covers a 90-kilometer-wide swath in a single full-frame shot without image splicing, eliminating stitching errors. No structural irregularities appear on the dam in this raw satellite data. Cross-checks against China’s national public geographic information platform’s satellite maps also confirm an intact, straight dam structure.
Experts traced the distorted viral photo source to unprocessed Google Maps satellite previews. Per Wang Haibo, raw satellite imagery commonly suffers geometric distortion caused by spacecraft flight attitude, orbital speed, the Earth’s curvature, uneven terrain and building topography. Such lens and projection warping is a normal raw-image flaw fixed through post-processing calibration to produce geographically accurate final maps.
0 Comments