• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.4
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• pp.8-16
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• 2004

The industrialization of central Europe more than 100 ago marked the beginning of densely concentrated buildings in quickly growing cities. A cheap type of roofing material of that time was tar. But it was dangerous because it was high inflammable. Then some roofer had a splendid idea. They used sandy material as a final layer atop the impermeable tar layer. These roofs were much more fire resistant than the typical roofs. In this sandy layer some plant species began to grow spontaneously. This was the beginning of the green roof history of modern Europe. A number of these green roofs survived both world wars. In the early 80's in Berlin alone, 50 such buildings existed and they continued to be waterproof until the present day. Since the 1992 Earth Summit of 1992 in Rio de Janeiro(http://www.johannesburgsummit.org/html/basic_info/unced.html) the term "sustainable development" became of central interest of urban designers. In city regions green roofs had become synonymous with this term. With a small investment, long-lasting roofs can be created. Further back in history, more exciting examples of green roofs can be found. The hanging gardens of antiquity are well-known. There are also green roofs built as insulation against cold and heat all over the world. For over 20 years, roof greening in central Europe has been closely examined for various reasons. Roof greening touches several different disciplines. Of primary interest is the durability of the roofs. But ecologists are also interested in green roofs, for instance in biodiversity research. The beneficial effect of greening on water proofing was also proven. For some time, the issue of fire protection was investigated. According to tests, green roofs received a harsh careful rating. Their fire protective property is considered similar to that of tile roofs. Another recent impulse for the green roof movement in Germany has come from the evident improvement of storm water retention and the reduced burden on the sewer system. The question of whether and how much energy green roofs can save has become an urgent question. The state of the research and also various open questions from a central European point of view will be discussed in the context of international collaboration. Apart from academic considerations, those who involve themselves in this issue take a predominantly positive view of the numerous existing green roofs in Germany. In some cities, green roofs are the typical construction technique for new buildings. A few outstanding examples will conclude this review. In Germany, about 20 companies, some of which operate internationally, specialize in green roof consulting. Learning from each other in an open-ended way with respect to different construction techniques and applications in various climatic regions can only be accomplished through such international collaboration as is taking place here.

• Journal of the Korean Geographical Society
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• v.41 no.4 s.115
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• pp.418-434
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• 2006

The study was investigated to runoff characteristics of non-point pollutants according to rainfall in Kokseong river watershed. The result of which is as follows : First of all, major reason which affect the formation of water quality of Kokseong River is judged to be caused by non-point pollution source which flows out from farmland and residential area. Flow of rainfall effluent in the downstream in which direct flow components of urban district and combined sewer overflows of farmland was intervened faster than that in the upstream reacted more promptly. Generation of pollutants by non-point source shows increasing trend in general in accordance with the increase in the intensity of rainfall but it was affected by SS, BOD, COD and T-P in the upstream part whereas BOD, COD and T-N were significantly affected by beginning period of rainfall in the downstream. EMC in the downstream increased approximately 3-315 times as compared to upstream, particularly the discharge of SS5 and T-P were extremely increased. While surface flow out of rainfall effluent in the upstream was only 4.7%, the surface flow in the downstream took up as much as 29%, which was major reason for the increase of EMC. From the above contents, we can see that the change in water quality according to the increase and decrease of effluent at the time of rainfall showed very complex pattern depending on the type of land use, and it is judged that the most important thing for the administration of non-point pollution source is to come up with the solution for the reduction of effluent at the beginning.