摘要

After a wildfire the soil is covered by ash. Ash properties depend on vegetation type, amount of fuel and fire intensity. The ash layer controls the post-fire soil hydrologic response, but little is known about the effect of ash thickness and ash type on infiltration, which is relevant for post-fire runoff and soil losses and for ecosystems rehabilitation and restoration. This paper analyses the role of i) ash type (black or white), ii) thickness (5, 15 and 30 mm-thick) and iii) temporal variation (0, 15 and 40 days) under three simulated rain events (55 mm for 1 h) on soil surface hydrology. The rainfall was simulated on 025 m(2) plots, and time to ponding, runoff and runoff discharge were measured. The infiltration rates, the initial infiltration rate (f(0)), the steady-state infiltration rate (f(c)), and the infiltration decay factor (k), were calculated and the Horton infiltration equation applied. The results show that soils covered with white ash doubled the runoff rates of soils covered with black ash. In general, runoff decreases as the ash thickness increases and the runoff decreases with the number of rainfall events after the fire in plots covered with white ash. Ponding time and k are positively correlated by the ash thick

  • 出版日期2013-11