Syvitski, James P.M.1
(1) INSTAAR Univ of Colorado, Boulder, CO
ABSTRACT: The Influence of Climate on the Sediment Load of Rivers
The key factors that control the discharge dynamics of rivers and the material load they transport are 1) basin area: large basins integrate a variety of vegetation, geology, and hydrology, dampen out discharge variability, and have large ground water pools; 2) Relief: controls sediment dynamics (sediment transport, landslides) and water storage (permafrost, ice fields, snowfields); 3) Temperature: controls precipitation dynamics (frontal vs convective), water storage (permafrost, ice fields, snowfields), weathering dynamics (chemical vs physical), and human activity; 4) Discharge: influences transport capacity and provides material flux dilution; and 5) Perturbations: the number and size of lakes, unique geological terrain. Consequently the load of rivers is strongly impacted by climate (polar, temperate, tropical). One of the largest impacts of climate change is through changes in the overall water balance with subsequent impacts on land cover density and thus erosion rates. Relatively modest shifts in average climate conditions have large impacts on the behavior of a river’s flood response and thus sediment yield. Individual regions may respond differently to climate forcing, providing for a varied response of changes in sediment flux, for example, for a given climatic event. The response will depend on the duration of the climate fluctuation and the variability in spatial properties of such parameters as relief, geology and hydrological processes.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.