The the Mediterranean forest area of Israel, fires increase runoff and sediment yield rates relative to undisturbed forested land. The September 1989 fire covered an area of 4 km2 in the main recreation area of Mount Carmel, a typical Mediterranean forest area. the lithology is chalk and limestone, and about 40% of the burnt area has steep slopes, exceeding 30%. Three study plots were established in burnt and unburnt areas. Plots were located on 100-300 m2 areas with different slope exposures. Runoff and sediments were collected after each storm by a collector system. A hydrometric station was established, draining an area of 1 km2 in the burnt zone. Rainfall was measured by two recorders and several rain gauges at the experimental sites. In the first rainfall season after the fire, runoff and sediment yield were 500 and 100 000 times higher respectively in the burnt areas. Rainfall intensity is a dominant factor in runoff and sediment yield rates. In the measured basin, total runoff in the first year was 1.6%. Revegetation recovery of the area wa srapid, as shown by the results from the second season: runoff decreases by one order of magnitude, from an average of 10 mm to 1.5 mm; sediment yield decreased by two orders of magnitude, from 1200 g m-2 to 10 g m-1 The third season 1991/1992, was an exceptionally rainy year and therefore runoff and sediment yield increased, but to less than in the first year. Runoff and sediment yield are related to vegetation cover, rainfall intensity, soil properties, slope steepness and exposure and fire intensity. Logging activities after fire increase sediment yields. Through its effects on vegetation cover the soil, fire severity increases the potential for erosion.
|Number of pages||17|
|State||Published - Jul 1998|
Bibliographical noteFunding Information:
We thank students from the Laboratory of Geomorphology of the University of Haifa for their help during the field work seasons. The study was partly funded by the Carmel fund of the Ministry of Environment. We thank Ms. S. Mansfeld for the drawings.
ASJC Scopus subject areas
- Earth-Surface Processes