A new analysis of America’s 28 largest population centers found that all but three are sinking overall, and in many cases significantly. Several of the most affected areas are in Texas, particularly around Fort Worth and Houston. But the problem is nationwide, affecting cities as scattered as Seattle, Detroit and Charlotte, N.C. The sinking of land, also called subsidence, can worsen the effects of sea-level rise, intensify flooding and strain the very foundations of urban infrastructure.