ABSTRACT
Ravines are common features within the Minnesota River Basin (MRB) and are the natural product of a landscape adjusting to disequilibrium caused by a regional baselevel fall 11,500 years before present. Overall sediment contribution by ravines to the Minnesota River (MNR) must be understood to mitigate sediment loading to the MNR and focus remediation strategies. This study defines the morphometry of MRB ravines and their relationship with characteristics of the upland contributing area (UCA) upslope of the ravine. Boundaries for 70 study ravines in the MRB and their associated UCA were digitized. Primary and secondary attributes such as area, slope, relief, and stream power index (SPI) values were estimated for each ravine and their associated UCA. Ravine area, volume, and relief were strongly correlated with ravine slope, length, and SPI. Ravine width-to-depth ratios were negatively correlated with the UCA mean slope. Ravine area was strongly correlated with UCA, suggesting that increasing volumes of water discharged from the UCA result in larger ravines that potentially deliver more sediment to the MRB than smaller ravines. Ravines with larger UCA could be targeted for conservation practices such as cover crops or perennial grass plantings to reduce discharge of water and sediment loading to the ravine.
