This research was conducted to investigate methods of coir-block cut-slopes greening, which enable the reduction of non-point pollution, as well as the assessment of its performance. Research was conducted to inspect greening and landscape improvement effects on 6 construction sites that have already installed coir-blocks. Furthermore, by conducting on 4 experiment groups, the reduction effects of non-point pollution were analyzed on 4 different components: COD, SS, T-N and T-P.
As the result of experimenting on landscape improvement and greening effects from coir-blocks, the seeding of coir-blocks was shown to be beneficial as safety measures rather than for its use in seeding or on vegetation mats. In addition, outstanding effects were demonstrated in accelerating the plants’ growth and maintaining favorable growth and development conditions. Furthermore, the coir-blocks showed an average post-construction survival rate of 90%, which also demonstrated favorable constructability. Therefore, coir-blocks improved the weak points that occurred in seeding and vegetation mats in the past, from which it is assessed that it accelerates greening at an early stage. Lastly, it is believed to have positive effects on greening, landscape improvement and restoration effects on slopes, rivers and other slanted landscapes.
With regards to the results of the non-point pollution reduction experiment, in the case of COD, the number of pollution sources converged with the soil on the slopes, resulting in a rise in the overall level of pollution. Afterwards, significant differences in the other 4 experiment groups were not seen. It was found that the number of non-point pollution converged with the soil on slopes, resulting in a massive rise in the level of pollution. Therefore, to reduce the amount of non-point pollution leaking into water, it is considered crucial that slopes be well-arranged.
On the other hand, SS massively increased as pollution sources flowed into common soil slopes. However, a decrease in the experimental group where coir-blocks were set up was shown. Furthermore, T-N and T-P were found to decrease gradually in non-point pollution sources in 4 experiment groups, which are believed to have high restoration effects on slopes made up of gravel and plants, compared to common soil slopes.
As an analysis on the significance, 3 factors excluding COD have shown high significance. In particular, the T-N and T-P experiment groups have clearly been distinguished in the grouping as the experiment groups changed. Moreover, it has been demonstrated to show a gradual rise in the reduction of non-point pollution in slopes of common soil, slopes where coir-blocks have been installed and slopes made up of gravel and plants. In the case of SS, as the values increased extraordinarily when the number of pollution sources met with soil slopes, it is identified that treating the slopes and oppressing the leakage of earth vastly influenced the reduction of non-point pollution.
Thus, for the reduction of non-point pollution that are generated on land, it is important to control it before it is introduced into rivers, wetlands and aquatic ecosystems. Furthermore, biodegradable materials such as coir-blocks and plant roots have been shown to reduce non-point pollution that are introduced in waters. Therefore, based on the results of this research, the experiment can be applied to various fields other than that of river construction, such as road slopes, slopes that are generated from civil engineering and artificial greening in cities, which are accepted as an eco-friendly subject for green growth all across the city.

Keywords : Coir-blocks, Non-point pollution, Cut-slopes, Landscape improvement