Flood Reconstruction in Southern Illinois Using Tree Rings

摘要

Water management is a crucial element in directing future land development acrossthe United States. Measures are often taken to minimize flood hazards while at the same time maintaining an adequate water supply for consumption, irrigation, sewage treatment and aquifer regeneration. Water resource management activities directed at regulating stream runoff must address a wide variety of considerations, including the frequency and magnitude of floods. The confidence of flood frequency analysis is dependent on the existence and length of gaged records. A lack of long-duration hydrologic records for United States steams has limited the confidence of flood frequency estimates, and created an opportunity for data contributions by proxy methods. The science of tree-ring analysis, or dendrochronology, can provide a value source of paleoflood information. The year and, often, magnitude of significant floods can be determined from the annual ring by considering the geomorphic situation and biological response of trees to flooding. The growth of tree rings primarily depends on soil nutrients (nitrogen, phosphorous, potassium, calcium, magnesium, and sulfur), and climatic factors (mainly temperature and soil moisture). By calibrating ring growth to recorded weather and discharge data, tree-ring information can be used to reconstruct yearly variations in climate.