The crowd from the sky in San Francisco for @standupforscience.bsky.social

also compared to the land subsidence due to low groundwater table, the liquefaction of structures can be well mitigated and even prevented if the stucture engineerers are well of the risk.

Particularly when the restored region is prone to earthquake-induced liquefaction, which is basically all silty-sandy alluvial deposited landform with the earthquake possibility. 😂😂😂

6 and the last. While we should not underestimate the benefits of groundwater restoration (to ecology and ground subsidence mitigation), its unanticipated risk should raise more awareness for local residents, structure designers, and risk evaluators.

5. Considering the similar urbanization process worldwide, i.e the pattern of the sync extraction-construction and a later restoration, this case provides a fair warning to (re)evaluate the earthquake risk of the region with recovering groundwater tables.

4. In this study, we used Beijing as a demonstration where the South-to-North Water Diversion Project （the world's largest）significantly recovered the previously low groundwater table. Its earthquake-induced liquefaction extent and severity has drastically increased

3. As groundwater restoration projects kick in, the shallower, rising groundwater table facilitates a granular phenomenon called soil liquefaction whereby shaking ground builds up excessive pore pressure in the saturated soil, which loosens grain contacts and their strength.

2. During urbanization, groundwater extraction is usually the first choice for the urban water supply, and its process syncs with the construction of most urbanizing structures on a lowering groundwater table

With the separation of two layers and water detrainment mechanism, the lower layer can propagate 100's to 1000's of km without overthickening (dissipation of stratified structure), whereas previous model can only simulate 10's of km flow propagation.

This destrainment mechanism is embedded at the interface between two layers: a gravity-driven, faster, lower layer that contains most of the sediment and a slower upper layer that almost has not sediment.

We identify a water destrainment mechanism in which sediment settling fights back against the turbulent mixing, maintaining a slowly thickening layer, sometimes a subsiding layer.

Previous models suffer from the overthickening of the turbidity current layer and thus fail to confine the flow in the channel for 100's of km, except adding a overspill mechanism.