Figure 1 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
Source publication
Urban development naturally aggravates flood damage, causing severe damage yearly. Preparation for flood damage is a part of urban planning, but it is not easy to establish clear mitigation measures in densely populated urban areas. This study analyzed the applicability of trunk drainage sewers as an alternative to installing abatement facilities,...
Contexts in source publication
Context 1
... shown in Figure 1, the trunk drainage sewer system can be used to improve urban areas susceptible to increasing flood damage from excess runoff that occurs with rainfall exceeding the design frequency. It is expected to reduce the local flood damage risk in situations where typical measures, such as the installation of an underground storage tank and drainage pipe improvement projects, cannot be applied due to restrictions in urban planning and financial conditions, such as site acquisition and lack of project funds. ...
Context 2
... for the installation site of the trunk drainage sewer system, the area ratio of the upstream area of the watershed (hereinafter referred to as the DUAR) was calculated based on the trunk line, which is divided into 20, 40, 60, and 80%. Since two trunk pipelines are joined in the Dowon watershed, the trunk drainage sewer system was installed in a one trunk pipeline, with the DUAR set to only 20 and 40% ( Figure 10). The largest peak flow reduction in the Gunja watershed was 33.29% at the DUAR 40% point when the trunk drainage sewer capacity was 1000-5000 m 3 . ...
Context 3
... Seoul Metropolitan City, which manages flood damage in the Gunja watershed, established a plan to install a 25,000 m 3 underground storage tank in most downstream areas of the watershed [16]. The flood reduction effect was compared by setting the installation conditions for reviewing the applicability of the trunk drainage sewer system in the area at a 5000 m 3 capacity and 40% DUAR, as well as setting the discharge point of the trunk line at a 60% DUAR (Figure 11). Additionally, the rainfall conditions of the rainfall event from August 19 to 23, 2017, which caused flood damage in the watershed, were used. ...
Context 4
... shown in Table 5, as a result of installing a 25,000 m 3 underground storage tank, which is a typical flood damage reduction measure in Seoul, the number of inundated cells was reduced by 877, the inundation area by 98.956 m 2 , and the inundation volume by 25,227 m 3 , as compared to before installation. The spatial distribution of the inundation area in Figure 12 indicates that the inundation of the trunk line was reduced, but the inundation occurring in the branch rainwater conduit located in the northern part of the area was not reduced. By installing the trunk drainage sewer, the number of inundated cells was reduced by 935, the inundation area by 103,960 m 2 , and the inundation volume by 27,353 m 3 , as compared to before installation. ...
Context 5
... Seoul Metropolitan City has installed a 30,000 m 3 capacity underground storage tank for reducing the flood damage in the Dorim watershed, as was done in the Gunja watershed [16]. Figure 13 shows the installation location of the underground storage tank. According to the peak flow reduction rate analysis conditions in Table 3, the trunk drainage sewer in this study was installed with a capacity of 5000 m 2 at DUAR 40%, and the discharge point was set at DUAR 60%. ...
Context 6
... shown in Table 6, as a result of installing a planned 30,000 m 3 underground storage tank by Seoul Metropolitan City, the number of inundated cells was reduced by 21, the inundation area by 2594 m 2 , and the inundation volume by 11,098 m 3 , compared to before installation. The spatial distribution of the inundation area in Figure 14 showed no significant difference from before the installation of the reduction facility. ...
Context 7
... the case of the Dowon watershed, a plan to improve the rainwater conduit with insufficient water flow in the Dowon intersection area proposed in the "Establishment of Sewerage Maintenance Measures in the Dowon Intersection" has been promoted (Table 7) [17]. A 3000 m 3 trunk drainage sewer was installed at the DUAR 40% point in the Dowon watershed, and the junction of the two trunk lines was set as the discharge point ( Figure 15). Additionally, the rainfall conditions of the rainfall event from August 19 to 23, 2017, which caused flood damage in the watershed, were used. ...
Context 8
... installing the trunk drainage sewer, the number of inundated cells was reduced by 1451, the inundation time by 210 min, the inundation area by 144,996 m 2 , and the inundation volume by 13,472 m 3 , as compared to before installation. In view of the spatial distribution of the non-installation and inundation locations, the decrease in the inundation at the discharge point to the sea may be due to smooth drainage with a decrease in the discharge volume at the discharge point of the trunk drainage sewer (Figure 16). Further analysis is required according to the oceanic tide and the drainage conditions of the trunk line. ...
