Input and output considerations in estimating rates of chemical denudation

Abstract

Estimation of rates of solutional denudation in river basins necessitates some consideration of salt inputs as well as consideration of salt outputs. Recent work in nutrient cycling has stressed the complexity and importance of the input factor, particularly when throughfall chemistry is taken into account. Frequently the differences between rates of input and output of salt in a river basin are small, suggesting that many published rates of solutional denudation, which consider outputs alone, or inputs only in part, are excessive. The input of salts, which may take place in rain, snow, fog and throughfall are most important in coastal areas. Analysis of data, for both the semi-arid United States and the Cotswold Hills in England, illustrate the need for long-term sampling, and for a detailed spatial network of sampling points.