Shallow and deep-seated regolith slides on deforested slopes in Canakkale, NW Turkey


Ekinci Y. L. , Turkes M., DEMİRCİ A., ERGİNAL A. E.

GEOMORPHOLOGY, cilt.201, ss.70-79, 2013 (SCI İndekslerine Giren Dergi)

Özet

This study deals with the stripping of regolith on a steep slope by surface wash and shallow landslides and a deep-seated landslide at a lower slope that took place on 17 February 2003 at the village of Mazilik, east of Canakkale, Turkey. Soil loss and shallow slides dominate on the deforested steep slopes in the study area and occur preferentially along slope-parallel sub-horizontal joint planes with clay coatings, particularly oxyhydroxides that are rich in Fe but poor in Mn as a result of weathering under well-drained conditions. Gully erosion also occurs where the regolith cover is relatively thick (up to similar to 4 m). The area of the deep-seated landslide, however, is dominated by silty clay (46%). A geoelectrical resistivity survey revealed a clay-rich zone at depths of similar to 3-10 m, corresponding to the slip surface of the slide, which was associated with excessive water content after the snowy day of 14 February 2003 with a daily precipitation of similar to 16.4 mm. Based on Thornthwaite's water budget analysis, the study area has a slide-prone condition with excess soil-moisture content, heavy rainfall events, snow accumulation and snow melting in winter months, and low soil permeability also favouring slope instability. (C) 2013 Elsevier B.V. All rights reserved.