St. Louis is uniquely positioned in a region with many types (ranging from rural to urban) and sizes (ranging from small headwater streams up to the Mississippi River) of rivers. All of these rivers can feature flash flooding from transient storm events. Our group studies these flooding responses to understand the role of land use in hydrologic response to perturbations. We use chemical tracers to identify water sources and delivery during these events and have captured several extreme flooding events on the major rivers in the area.
Current studies include:
1. Water balance estimates in areas of varying land use.
2. Quantifying stream hydrologic responses to flooding along a rural to urban land use gradient, particularly the unique responses of suburban streams.
3. Understand water transport and delivery during extreme flood events in regional rivers.
Average lag times (A) and average percent baseflow contribution during floods (B) plotted against impervious surface area for small streams in the St. Louis metropolitan area (standard deviations are shown). Both figures quantitatively illustrate that as urbanization increases in a watershed, so does the amount of physical variability. Interestingly, the relationship between impervious area and baseflow during floods is not linear. Indeed, suburban streams show higher baseflow inputs than might be predicted by the impervious area in the watershed (from Hasenmueller et al., 2017).