Land cover change induced sediment transport behaviour in a large tropical Mexican catchment

Abstract

ABSTRACT The cause–effect relationship and rates of change of suspended sediment dynamics at catchment scales in the tropics remain poorly understood. This study used a chrono-sequence of remotely sensed land use and historical hydrometric data from 1985 to 2001 in three tropical streams of Mexico to analyse the temporal dynamics of land-use change and measured suspended sediment behaviour. The variations in measured suspended sediment concentrations (SSC) were related to land cover change using trend and hysteresis analysis. No statistically significant trends (p > 0.1) at a monthly scale were associated with the historical trajectories of stream sediment fluxes. However, intra-annual hysteresis allowed us to identify the climatic seasonality as a main driver for the discharge-sediment loops and to infer sediment source variations, related to land cover changes over time. The land cover change analysis, combined with statistical tests and hysteresis, was useful to identify temporal and spatial variations in sediment source dynamics.