Abstract

Agricultural expansion and urbanization, coupled with climatechange represent major threats to the sustainability of river ecosystems andinfrastructure. In this study, we evaluated how subbasins with differentdominant land covers within the 27.5 km² Clear Creek, IA watershedaffect key hydrologic indicators. Hydrologic output from two stream gages and acalibrated Soil Water Assessment Tool (SWAT) model were used as input to theIndicators of Hydrologic Alteration (IHA). Study results indicated that landcover plays a dominant role in controlling hydrologic variability at thesubbasin level within a watershed. Subbasins dominated by urban development hadnearly 30 more reversals than row crop or grass-dominated subbasins and theduration of small and large flood events were half as long. Row crop dominatedsubbasins had greater water yield and maximum flows and higher peak flows,whereas grass-dominated subbasins had lower rise and fall rates, fewer zerodays and fewer reversals. Hydrologic variations from land cover differenceswere more prominently expressed at the subbasin level than at the watershedlevel, as the dominant land cover represented a greater percentage of the totalland area. Study results suggest that future changes in LU/LC and climate willhave significant effects on the hydrology of Clear Creek Watershed.

Citation

Schilling, K., M. Streeter, K. Hutchinson, C.G. Wilson, B.K. Abban, K.M. Wacha and A.N. Papanicolaou (2015): Effects of Land Cover on Streamflow Variability in a Small Iowa Watershed: Assessing Future Vulnerabilities. American Journal of Environmental Sciences. DOI: 10.3844/ajessp.2015.186.198

This Paper/Book acknowledges NSF CZO grant support.