Effects of Climate and Anthropogenic Drivers on Surface Water Area in
the Southeastern United States
Abstract
Surface water is the most readily accessible water resource and provides
an array of ecosystem services, but is stressed by changes in climate,
land cover, and population size. Understanding drivers of surface water
dynamics in space and time is key to better managing our water
resources. However, few studies estimating changes in surface water
account for climate and anthropogenic drivers both independently and
together. We used 19 years (2000-2018) of the newly developed Dynamic
Surface Water Extent Landsat Science Product in concert with time series
of precipitation, temperature, land cover, and population size to
statistically model maximum seasonal percent surface water area as a
function of climate and anthropogenic drivers in the Southeastern U.S.
We fitted three statistical models (linear mixed effects, random
forests, and mixed effects random forests) and three groups of
explanatory variables (climate, anthropogenic, and their combination) to
assess the accuracy of estimating percent surface water area at the
watershed scale with different drivers. We found that anthropogenic
drivers accounted for approximately 37% more of the variance in the
percent surface water area than the climate variables. The combination
of variables in the mixed effects random forest model produced the
smallest mean percent errors (mean -0.17%) and the highest explained
variance (R2 0.99). Our results indicate that
anthropogenic drivers have greater influence when estimating percent
surface water area than climate drivers, suggesting that water
management practices and land use policies can be highly effective tools
in controlling surface water variations in the Southeastern U.S.