Examining the Impact of Historic Land Use Change on Watershed Evolution, Whitewater River Watershed, Southeastern Minnesota

Abstract

The Whitewater River watershed, in southeastern Minnesota, experienced a series of devastating floods between the late 1800s to mid-1900s, plaguing those living along the river. These floods caused substantial damage, burying three small towns and ~140 homesteads. This study examines how land use and land cover (LULC) has changed from pre-settlement times (1840s) to present day (2020s). This project investigates changes in the LULC of the watershed, using survey data, historic aerial imagery, and satellite imagery. Initial results show that, as time passed, anthropogenic influences significantly impacted the watershed reducing the natural prairie cover from ~83% to ~3% by 2021, consistent with trends in the surrounding region. Agricultural lands, developed lands, and forested lands all expanded following Euro-American settlement in the mid-late 1800s. Agriculture land use increased from ~0%, pre-Euro-American settlement, to ~66% by 2021, developed lands saw a growth from ~0% to ~5%, and forested lands increased from ~18% to ~22%. While there have been efforts to control soil erosion and agriculture practices, the natural land cover remains stable, but low. Understanding how LULC has changed through time is crucial to understanding how increases in regional precipitation and discharge could work to remobilize sediment, threatening local communities.