Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4572318 | CATENA | 2009 | 15 Pages |
Abstract
All soils were coarse, with â¼Â 20% gravel and â¼Â 94% sand; most fine material (â¤Â 0.063 mm) was silt, as clay content was negligible. Organic-matter percentage was low (1.65%). Bulk density and porosity were associated with moisture variation both in tephra-insulated and bare soils; 80% of field moisture was statistically (p < 0.001) accounted for by pore space. Air and soil temperatures were recorded at three sites during â¼Â one-week periods prior to moisture sampling. Tephra substantially decreased soil maxima and daily thermal amplitude in underlying soils, but did not noticeably affect nightly minima. Thin (5-6 cm) tephra layers were nearly as effective as thicker (9-15 cm) deposits in depressing soil maxima. Possible water-conservation mechanisms under tephra include: decreased evaporation due to ground shielding and lower maxima; reduced capillary flow; greater infiltration depth; nocturnal dew condensation; and fog interception by blocks.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Earth-Surface Processes
Authors
Francisco L. Pérez,