Human amplified changes in precipitation-runoff patterns in large river basins of the Midwestern United StatesHydrology and Earth System Sciences (2017)
Complete transformations of land cover from prairie, wetlands, and hardwood forests to homogenous row crop
agriculture scattered with urban centers are thought to have caused profound changes in hydrology in the Upper Midwestern US since the 1800s. Continued intensification of land use and drainage practices combined with increased precipitation have caused many Midwest watersheds to exhibit higher streamflows today than in the historical past. While changes in crop type and farming practices have been well documented over the past few decades, changes in artificial surface (ditch) and subsurface (tile) drainage systems have not. This makes it difficult to quantitatively disentangle the effects of climate change and artificial drainage intensification on the observed hydrologic change, often spurring controversial interpretations with significant implications for management actions. In this study, we investigate four large (23,000-69,000 km2) Midwest river basins that span climate and land use gradients to understand how climate and agricultural drainage have influenced basin hydrology over the last 79 years. We use daily, monthly, and annual flow metrics to document streamflow changes and discuss those changes in the context of climate and land use change. While we detect similar timing of precipitation and streamflow changes in each basin, overall the magnitude and significance of precipitation changes are much less than we detect for streamflows. Of the basins containing greater than 20% area drained by tile and ditches, we observe 2 to 4 fold increases in low flows and 1.5 to 3 fold increases in high and extreme flows. Monthly precipitation has increased slightly for some months in each basin, mostly in fall and winter months (August – March), but total monthly streamflow has increased in all months for the Minnesota River Basin (MRB), every month but April for the Red River Basin (RRB), September- December and March in the Illinois River Basin (IRB), and no months in the Chippewa River basin (CRB).
Publication DateMarch, 2017
Citation InformationPatrick Belmont, Sara A. Kelly, Zeinab Takbiri and Efi Foufoula-Georgiou. "Human amplified changes in precipitation-runoff patterns in large river basins of the Midwestern United States" Hydrology and Earth System Sciences (2017)
Available at: http://works.bepress.com/patrick_belmont/96/