Effects of earthquake and cyclone sequencing on landsliding and fluvial sediment transfer in a mountain catchment

摘要: Patterns and rates of landsliding fluvial sediment transfer in mountain catchments are determined by the strength location rain storms earthquakes, sequence which they occur. To explore this notion, landslides caused three tropical cyclones a very large earthquake have been mapped Chenyoulan catchment Taiwan Central Range, where water discharges rock strengths well known. Prior to MW 7·6 Chi-Chi 1999, storm-driven landslide were modest. Landslides occurred primarily low within landscape shallow slopes, reworking older colluvial material. The wide-spread steepest bedrock slopes high due topographic focusing incoming seismic waves. After remained elevated, patterns closely tracking distribution coseismic landslides. These not strongly affected strength. Sediment loads River limited supply from hillslopes. earthquake, erosion budget was dominated one exceptionally flood, with anomalously concentrations, typhoon Herb 1996. concentrations much higher than normal intermediate size floods during first 5 years after giving yields. In 2005, had decreased values prevalent before 1999. hillslope response has stronger five-fold increase but since sources become increasingly disconnected channel system, 90 per cent reaching into channels. Downslope advection debris associated is driven impact cyclones, occurs on time-scale longer study. Copyright © 2008 John Wiley & Sons, Ltd.