Author(s)

Katherine Clancy

College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, WI, USA.

The aim of this study was to determine if runoff estimates from the curve number model were affected by seasons for different land covers. Eighteen watersheds with varying land covers were delineated using three methods. The delineation methods differ in how internal drainage is evaluated. Runoff estimates from storms for spring, summer, and fall were compared to observed runoff from USGS gaging station data. Errors (difference between estimate runoff and observed runoff) were found to be highest for fall by 3% for all the two delineation methods which do not consider internal drainage. Watersheds were categorized by their dominant land cover (agriculture, forest, or urban). Seasonal differences were found to be significant for certain land covers. The greatest differences between observed and estimated data were found in agriculture and urban especially spring versus fall for all delineations. Forest land cover was found to have no seasonal difference for all three delineation methods. The research suggests that this work contributes to the growing body of research suggesting that vegetative seasonal differences have a greater impact on runoff than is accounted for in the runoff model.

Runoff, Curve Number, Vegetation, Seasonal

Clancy, K. (2021) Evaluating the Effect of Land Cover, Seasonality and Delineation Method on Runoff at the Watershed Scale. Journal of Water Resource and Protection, 13, 750-765. doi: 10.4236/jwarp.2021.139039.