Effects of Hurricanes Katrina and Rita on the Chemistry of Bottom Sediments in Lake Pontchartrain, Louisiana, USA
文摘
The effects of Hurricanes Katrina and Rita and thesubsequent unwatering of New Orleans, Louisiana, on thesediment chemistry of Lake Pontchartrain were evaluatedby chemical analysis of samples of street mud and suspendedand bottom sediments. The highest concentrations of urban-related elements and compounds (e.g., Pb, Zn, polycyclicaromatic hydrocarbons, and chlordane) in bottom sedimentsexceeded median concentrations in U.S. urban lakesand sediment-quality guidelines. The extent of the elevatedconcentrations was limited, however, to within a fewhundred meters of the mouth of the 17th Street Canal, similarto results of historical assessments. Chemical andradionuclide analysis of pre- and post-Hurricane Ritasamples indicates that remobilization of near-shore sedimentby lake currents and storms is an ongoing process. Theeffects of Hurricanes Katrina and Rita on the sedimentchemistry of Lake Pontchartrain are limited spatially andare most likely transitory.