Seawalls have become a popular man-made defense against high tides and tsunamis, but a new study shows that carefully designed forested hills could provide similar protection while also protecting environmental health and beautifying our coastal cities. 

The design involves a hill covered in vegetation with surrounding buffer zones to protect infrastructure. These would look like additional mounds inland and near shore. The vegetation protects the hill from erosion and also helps clean water and purify the air. They also provide a far less disruptive habitat for local animals. 

Senior study author Jenny Suckale, an assistant professor of geophysics at Stanford University says their models prove how a single row of hills can suck the energy out of a tsunami as effectively as a sea wall. The shape of the hill can also be tailored to the structure of the coastline for optimal, personalized designs. 

To top it all off, the design is more cost-effective than expensive sea walls. They also offer more natural and accessible coastlines for locals and tourists alike. The team used Japan as a case study for their potential hill design. The country has spent $12 billion on seawall structures since the devastating 2011 tsunami, and the researchers think the new model could be perfect for them and other vulnerable coastal regions. 

Urban planning which protects communities and promotes environmental health is a win-win for everyone. Although these hills must be specially tailored to specific coastal dynamics, they could be key to creating more resilient coasts.