• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.17-26
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• 1987

To develop the rehabilitation measures for rockily denuded forest lands which are widely distributed in Seoul metropolitan area, erosional characteristics of denudation should, first of all, be evaluated and analysed. As a fundamental study for developing such technical measures, the rockily denuded lands were classified into 6 types according to denudation features of the mountain land, and also movements of stone debris-and-sand on rock-exposed hillslopes were measured and analysed. The 6 basic types of denudation features include a) natural rock-outcrop-exposed land, b) stone debris-and-sand scattered land, c) stone debris-and-sand deposited land, d) coarse sand producing bare land susceptible to weathering and erosion, e) dwarfed pine growing land, and f) torrential valley susceptible to the debris slides. In the stone debris-and-sand scattered hillslopes (type b), average amount of moved-down debris reached to about 3.9 ton/ha/yr due to surface washing and slidings. In the particle size distribution of the moved-down debris, it amounts to about 25% of 10-25mm, about 15% of 5-10mm, about 24% of 2-5mm, and about 36% of less than 2mm in diameter class, respectively. The detailed experimental studies should be accomplished further more about the denudation processes including weathering, erosion and debris slides on rock-exposed hillslopes.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.1
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• pp.9-16
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• 1987

In Seoul metropolitan area, rockily denuded fores lands are widely distributed. Out of the rock-exposed hillslopes, Kwanak-Samsung mountains and Bookhan-Dobong mountains areas are the most severely eroded land at present To develope the rehabilitation measures for the rock-exposed hillslopes, it is essentially required that mechanisms of rock debris production and movement from the rock-exposed hillslopes should be studied. And also, suitable experiments for planting techniques should be practised at the field level. In this context, some experiments for the on-site fixation of the unstable stone-debris including plantation establishments on the rock-exposed hillslopes, have been carried out for 4 years from 1983 to 1986 at Kwanak mountain hillslopes. The results may be summarized as follows : 1) The soil environment-tolerable tree species for plantation extablishment on rock-exposed hillslopes include Buxus microphylla var. koreana, Forsythia koreana, Juniperus chinensis var. sargentii, Alnus hirsuta and Pinus rigida. These trees have, however, been showed fairly good growth performence at the places having more than about 30cm of soul layer depth above rock-bed. 2) In raising of seedlings to plant on the rock-exposed hillslopes, containerized seedling practices knave been appeared as the most adoptable measures. 3) In fixation of the unstable stole debris-and-sands on the on-site of rock. exposed hillslopes, the stone-lined barrier measures are more effective at comparatively large-sized places of rock-exposed hillslopes while the stone-bowed barrier measures are more effective at small-sifted isolated sold-debris places. The stone-buttressed terraces measures are more effective at the soil-composed hillslopes rather than rock-exposed hillslopes.