In our new paper in Nature Communications (link here) we ask where do people live in relation to water? Human societies evolved alongside rivers, but how has this relationship changed over time? We conducted a dynamic analysis in the conterminous US to assess the coevolution of humans and water resources from 1790 to 2010. We found that humans moved closer to major rivers in pre-industrial periods, but since industrialization humans have moved farther from major rivers, with preferential attraction to areas overlying major aquifers. We explain regional heterogeneity in these general patterns based on varied climate and settlement histories. The dynamic human distance to water reflects changes in the societal reliance on adjacency to major rivers, and also implies temporally changing anthropogenic impacts on water resources.
Our main hypotheses are illustrated below
a Hypothesized relationship between normalized population density (NPD) and distance to major rivers (DMR), and their temporal trends associated with the development of settlements from frontier, to towns, and to cities, in pre-industrial societies. The dynamics of the importance of b major rivers and c groundwater for human settlement locations after industrialization
And below are the results that show support for these hypotheses
The dynamic human population distance to water. The relationship between normalized population density (NPD) and distance to major rivers (DMR) in the conterminous US from a1790 to 1870 and b 1870 to 2010. c The changing desirability of living close to major rivers, reflected in the slope of NPD vs. DMR. d Mean population density overlying each aquifer type from 1790 to 2010. Recharge rates, mm per year, are shown offset. We use the red-to-blue gradient to indicate the trend for the decades to 1870 in a and the gradient from blue to red for decades from 1870 in b. The data points for a, b are based on DMR classes while those for c and d are based on census year
Finally, There was a very nice article (here) written about this work on growingamerica.com by Sam Grenrock. And a nice blurb (here) about this work from the UF Water Institute.