Flood rings

This is an NSF-funded project to use tree-rings for the reconstructions of paleoflooding and associated large-scale climate forcing in the Mississippi River drainage basin. Jon Remo in the Department of Geography and Environmental Resources, Southern Illinois University is a co-investigator on the project. Below you can read some details about the project.

The first reports of destructive flooding on the Mississippi began with the founding of New Orleans in 1718 and catastrophic floods such as those in 1785 and 1844 severely affected many early settlements in the region. Major 20th century floods such as those in 1927  and 1937 are well documented and more recent floods such as those in 1993, 2008 and 2011 have spurred recent research emphasizing understanding the underlying mechanisms that cause major flooding including the effects of climate variability.

Determining the true natural variability of flood frequency and magnitude is an important issue not only as is relates to traditional areas of concern such as hazards to life, property and infrastructure, but also in terms of placing extreme climate events experienced in the modern period, into a long-term context. Prior to the mid-to-late 19th century, instrumental records of flooding are limited in the region, particularly in the western tributaries. This lack of long high-resolution records of flooding hampers attempts to quantify the potential range of flood severity and temporal patterns of occurrence (e.g., Klemes, 1989). The development of quantitative tree-ring reconstructions of flooding in the MCR will provide the data necessary to understand the nature and causes of long-term flood variability in the MCR that instrumental period observations cannot.

Paleoflood Hydrology is the study of the frequency and magnitude of pre-instrumental floods using geological or botanical evidence (such as tree rings). Paleoflood hydrology can provide hydrological scientists and engineers with unique information about flood intervals, maximum flood magnitude, and the impact of climate variability.

 

Floor ring photo

Photomicrograph of an increment core sample of Quercus lyrata from Big Oak Tree State Park, MO showing the 1973 flood ring anomaly resulting from 28 consecutive days of flooding (Stage height >12.19 m). Note the unusually small earlywood vessels, which are common anatomical features of flood damage.

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