One of the threats for the mankind can be prevented

One of threats for mankind can be prevented David Judbarovski, systems engineering, principle inventor Background. Mapping the global threat of land subsidence 1. Gerardo Herrera-García, 2. Pablo Ezquerro, 3. Roberto Tomás, 4. Marta Béjar-Pizarro, 5. Juan López-Vinielles, 6. Mauro Rossi, 7. Rosa M. Mateos, 8. Dora Carreón-Freyre, 9. Livin in 10. Pietro Teatini, 11. Enrique Cabral-Cano, 12. Gilles Erkens, 13. Devin Galloway, 14. Wei-Chia Hung, 15. Najeebullah Kakar, 16. Michelle Sneed, 17. Luigi Tosi, 18. Hanmei Wang, 19. Shujun Ye 1. Email: g.herrera@igme.es Science 01 Jan 2021: Vol. 371, Issue 6524, pp. 34-36 DOI: 10.1126/science.abb8549 The said researchers predict after many years global investigations and scientific modeling, that to 2040 yr. 19% the world population now living in 23% of largest cities on 12 million km2 are under threat of land subsidence can ruin them, because underground water and minerals resources exploiting. Just immediately it was reacted by me in https://judbarovski.blogspot.com/2021/01 , posted on 09.01.2021 with a possible decision of the said problem, now here updated and upgraded. After geophysical investigation inside and nearby of as actual holes as abandoned ones and wells to them, in a danger we can pump pressed air into the holes to compensate load fully or partly on them from upper sides. For the following, the said air pressure can be controlled by very cheap sensor and small and cheap diaphragm compressor. Frequently large aquifers can be pumped by waste water of householders after preliminary purification, because purification of consume water from such aquifers would be much more simple and cheap than desalination of sea water.