National Geographic puts hydrographer on the map

By Allison Flynn Bernhard Lehner is a hydrographer whose work is about to go global. Fusing the fields of hydrology and cartography, he has created a one-of-a-kind map of the world’s rivers that is included as a pull-out in the April 2010 “Fresh Water” Issue of National Geographic, the iconic magazine that’s read in 32 [...]