Much of the resistance to Drumpf’s edicts comes not from the media, or Democrats, or the millions of people who voted against him, it comes from science. You know, actual facts, not ‘alternative’ (i.e. made up) facts.

Many of the science sites I visit daily, in the US and overseas, are girding for the coming four years of assaults on the truth.

The usually apolitical Smithsonian Magazine interviewed a geophysicist and a hydrologist about Drumpf’s pipe dream border wall and they spell out quite clearly why, if it did happen, it would take years and years to finish. (And wouldn’t keep out  people any more effectively than China’s Great Wall did)

Today’s fence consists of roughly 650 miles of disparate segments, made out of a combination of steel posts and rails, metal sheeting, chain link, concrete vehicle barriers and wire mesh. To replace that fence with what has been described as a 20- to 50-foot concrete structure that will traverse 1,000 of the some 2,000 miles of the U.S.’s border with Mexico will be no easy feat. Besides dealing with a proposed Mexican lawsuit and navigating the private ownership of much of Texas’ lands, there is another concern few have addressed in detail: geology.

Compared to building a marble palace or high-steepled church, erecting a wall may seem relatively straightforward. It isn’t. (Just ask the Chinese, whose Great Wall took 2,000 years to build and failed to keep out invaders.) Though most wall designs are fairly simple, builders must adapt to a wide range of terrains, explains Gary Clendenin, a senior hydrogeologist at ICF International. The southern U.S. border alone contains desert, wetlands, grasslands, rivers, mountains and forests—all of which create vastly different problems for builders.

“You’re going to encounter hundreds, if not thousands, of different types of soils along [such a lengthy] linear pathway,” says Gary Clendenin, a senior hydrogeologist at ICF International. (In fact, there are over 1,300 kinds of soil in Texas alone.) And many of those soils aren’t going to be the right type to build on top of. At that point, would-be wall-builders have two options: Spend more time and money excavating the existing soils and replacing them with better dirt—or avoid the region altogether.

In the case of the border wall, they would have to traverse the entire length of the proposed path, working in segments to evaluate the region, collect data, develop plans. (This necessity makes the process of erecting walls—especially ones spanning thousands of miles—more challenging than building, say, a 95-story skyscraper.)

Source: What Geology Has to Say About Building a 1,000-Mile Border Wall | Science | Smithsonian