• Journal of the Korean Institute of Landscape Architecture
• /
• v.49 no.2
• /
• pp.27-40
• /
• 2021

This study was carried out for the description of the conflicts on the measurement of the root collar diameter of the landscape trees that are currently being produced, distributed, and planted in S. Korea, and for determination of the standard for root collar diameter measurement. The difference in consciousness of appropriate measurement of root collar diameter among different ages of landscape practitioners was statistically significant at p<0.05 level. It seemed to be due to the difference in the amount of field experiences among different age groups. On "the ambiguity of measuring the root collar diameter' of landscape trees", the consciousness was significantly different at p<0.05 level among job positions. On "Improvement of measurement criteria for landscape trees," it was significantly different at p<0.05 level among job types. This was thought to be due to the disagreement between the client and the contractor. On "prevention of topsoil removal" when excavating landscape trees, the consciousness was significantly different at p<0.001 level among different age groups, and different at p<0.01 level among different occupations, and different at p<0.05 level among different working area. The consciousness on "removing top soil when excavating landscape trees and rooting after transplantation" was not significantly different. The consciousness on the conflict caused by "ambiguity in root collar diameter measurement criteria" was high with an average of 3.85 for job type, occupation, jop position, and work experience. It was higher for landscape contractors than public institutions. The higher job positions and more experiences, the more conflicts. The consciousness on the appropriate position of root collar diameter measurement for landscape trees revealed that measuring at above-ground part (66.5%) was prefered to the underground part (33.0%). During the excavation of landscape trees for transplant, topsoil removal up to average depth of -2cm to -4cm was favored by 84.0%, and the purpose of removing topsoil was recognized as 'to increase the size and unit cost' by 59.7%.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.47 no.1
• /
• pp.39-48
• /
• 2019

Based on the bidding data of the national marketplace for public procurement service from 2003 to 2015, this study investigated and analyzed the bidding trends of the landscape management public consignment service by analyzing total bidding, type, client, region, license. The results are as follows. First, the total number of bids for civilian consignment services in landscape management increased by 1,112 cases, corresponding to a 487.7% increase over 10 years, and the total bidding amount increased by 144,504 million won, corresponding to a 382.5% increase. Second, in 10 years, the proportion of landscape management in landscaping works increased by 10%, and the bidding amount increased by 3%. Third, in the analysis of bidding trends by type, green areas showed the greatest growth in the number of bids, while the greenery of buildings showed the highest increase in the bid amount. Fourth, local autonomous entities, Gyeonggi province, and the landscaping planting construction industry showed the highest increase in the number of bids and the amount in each field such as client, region, and license. In summary, the number of cases and the bidding amount is increasing year by year. Considering the increasing number of users and demands thereof, the number of bids and the amount of consignment service for landscape management will continue to increase. The purpose of this study is to investigate and systematically analyze the tendency of bidding for 10 years for the private consignment service of landscape management in the current situation, where the importance of landscape management is increasingly emphasized. Another purpose of this study is to discern the necessity of the landscape management business and to provide the basis for incorporating the landscape management business into the professional construction industry in the future, thus providing opportunities for widening the expertise and diversity of the landscaping field. For the following study, the legal basis of landscape management, qualification, equipment standards, calculation of management cost per unit, and the appropriateness of the management cost should be considered.

• Ocean and Polar Research
• /
• v.25 no.2
• /
• pp.183-200
• /
• 2003

In order to assess the ecological changes induced by organic pollutants of the Shihwa Lake, BPI (Benthic Pollution Index) based on the benthic faunal community was employed. It was modified from Infaunal Trophic Index (ITI), and recommended as a pollution detecting method for the environmental assessment. The BPI values were calculated from the benthos data, which were collected for three terms: in 1980, before the Shihwa Lake was built up; in 1994-1997, which the Shihwa Lake was completely isolated from the outer seawater; in 1997-1999, after inflow of the outer seawater. Since the Shihwa Dike was constructed in February 1994, the pollution intensity of the lake had been increased from the narrow and inner part of the former Gyeonggi Bay and spread fast along the coast line of the Shihwa Lake. Then, in 1996 it showed the very high BPI levels all around the Lake. This serious polluted condition had been lasted till 1997, when the inflow of the seawater was begun. In 1998, from the nearest part of the Shihwa Gate, the BPI levels gradually became low in most area of the Lake, except its inner and narrow part. These greatly lowered BPI levels mean that the seawater inflow could be assumed to affect positively in the lake. Furthermore, BPI gave the same results from the other environmental assessment based on the abundance and the species richness of macrobenthic community. It shows that BPI could be useful as an effective method to assess the marine environment and evaluate the status of environmental conditions.

• Journal of Wetlands Research
• /
• v.19 no.4
• /
• pp.403-408
• /
• 2017

This study aims to set up the basic data to manage the waterfowl habitat through the analysis of the changes of physical structure according to the time series of Hangang(Riv.) as water birds' habitat. Study area was 41.5km in length from Paldang bridge to Hangju bridge. during total length of 497.52km and horizontal boundary was based on the protected lowland in year 1975. As the analysis result of land use from the center of water to adjacent road to the river, ratio of year 1975 was in order of sedimentary land(22.7%), surface water(20.7%), built-up area(16.9%), field(16.2%), paddy field(15.9%), and afterwards most of the areas were changed through the construction of arterial highway and submerged weir in order to use Hangang(Riv.). In year 1985, the area ratio of protected lowland(57.8%) and surface water(32.8%) dramatically increased. After construction of river bank the recreational areas continually increased and relatively natural areas decreased. In year 2005, the area ratio of protected lowland was enlarged to 57.6% and surface water also to 33.3%. While the length of both riversides and naturalness decreased by 10.9%, 91.5% respectively in year 2005 compared to year 1975, the depth of water increased by 1.46m. Comprehensively, the flow of changes by physical structure in Hangang(Riv.) for 30 years was divided into two periods. The main characteristics in the first period were decrease of riverside area and enlargement of the surface water through the massive construction before middle of year 1980, and afterwards revetments were intensively artificialized with changes of land use for amusement area. In terms of water fowl habitat, Hangang(Riv.) which previously had various types of habitat condition was changed into simplified habitat for few of species, and the active improvement apporach was needed for habitat diversity.

• Journal of Cadastre & Land InformatiX
• /
• v.47 no.2
• /
• pp.233-254
• /
• 2017

The purpose of this study is to analyze the main factors influencing the severity of traffic accidents and to visualize spatiotemporal characteristics of traffic accidents in Seoul. To do this, we collected the traffic accident data that occurred in Seoul for four years from 2012 to 2015, and classified as slight, serious, and death traffic accidents according to the severity of traffic accidents. The analysis of spatiotemporal characteristics of traffic accidents was performed by kernel density analysis, hotspot analysis, space time cube analysis, and Emerging HotSpot Analysis. The factors affecting the severity of traffic accidents were analyzed using decision tree model. The results show that traffic accidents in Seoul are more frequent in suburbs than in central areas. Especially, traffic accidents concentrated in some commercial and entertainment areas in Seocho and Gangnam, and the traffic accidents were more and more intense over time. In the case of death traffic accidents, there were statistically significant hotspot areas in Yeongdeungpo-gu, Guro-gu, Jongno-gu, Jung-gu and Seongbuk. However, hotspots of death traffic accidents by time zone resulted in different patterns. In terms of traffic accident severity, the type of accident is the most important factor. The type of the road, the type of the vehicle, the time of the traffic accident, and the type of the violation of the regulations were ranked in order of importance. Regarding decision rules that cause serious traffic accidents, in case of van or truck, there is a high probability that a serious traffic accident will occur at a place where the width of the road is wide and the vehicle speed is high. In case of bicycle, car, motorcycle or the others there is a high probability that a serious traffic accident will occur under the same circumstances in the dawn time.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.5
• /
• pp.815-825
• /
• 2017

Visibility of lane marking is impaired at night or in the rain, which thereby threatens traffic safety. Recently, various studies and technologies have been developed to improve lane marking visibility, such as the extension of lane marking life expectancy (up to 1.5 times), improvement of lane marking equipment productivity, improvement of lane marking visibility by applying phosphorescent material mixed paint. Cost-benefit analysis was performed with considering various benefit items that can be expected. About 45% of traffic accidents would be prevented by improving lane marking visibility. Additionally, accident reduction benefit and traffic congestion reduction benefit were calculated as much as 246 billion KRW per year and 12 billion KRW per year, respectively, by reducing repaint cycle due to enhanced durability. 45 billion KRW per year is expected to reduced with improved lane detection performance of autonomous vehicle. Meanwhile, total increased cost when introducing phosphorescent material mixed paint to 91,195km of nationwide road is identified as 1922 billion KRW per year. However, economic feasibility could not be secured with 0.16 of cost-benefit ratio when applied to the road network as a whole. In case of "Accident Hot Spot" analyzing section window (400m), one or more fatality or two or more injured (one or more injured in case of less than 2 lanes per direction) per year were caused by pavement marking related accident, economic feasibility was secured. In detail, 3.91 of cost-benefit ratio is estimated with comparison of the installation cost for 5,697 of accident hot spot and accident reduction benefit. Some limitations and future research agenda have also been discussed.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.28 no.2
• /
• pp.127-136
• /
• 2010

This study is aimed at reviewed and analyzed in order to suggest the improved plans related to natural monuments. The summary of this study is as followings; First, Replacing the current term 'cultural properties', which denotes the meaning of 'goods', we need to devise an new categorization that separates such properties into cultural heritage and natural heritage under the national heritage framework. Second, the designation criteria for natural monuments should be divided into the individual realm for animals and plants respectively, since they are not divided in the current Act. Third, the guidelines for naming of natural monuments should be established with the following new categories in accordance with the clear standards. Fourth, such imbalances require us to give priority to the relatively neglected types and areas. Fifth, as the big and old trees account for more than a half of the designated plants, it is necessary to search out new resources(wet plant communities, seashores, sand dune plant communities, etc.) such as geological resources, mineral springs, hot springs, and fossils that are in danger of completely being exploited and exhausted. While most of the designated animals are protected nationally, the existing designation system is required to protect habitats and breeding places for the systematic and efficient conservation. Sixth, as long as we need to preserve those historical and cultural resources for the future generations from national and global perspectives, we should enhance their values by designating them as natural monuments even though they are protected by other regulations such as the natural environment area. Seventh, as a result of the survey, we found that more budgets and experts in the local governments, more empowered organizations, more active public participation should be provided for the better Natural Monument management in Korea. Eighth, the Lap of Natural Heritage in the National Research Institute of Cultural Heritage needs to be developed to the Natural Heritage Institute to conduct the diverse activities such as researches, restoration, exhibition and education programs in a systematic and efficient way. Ninth and the last, major damages to natural monuments can be generally categorized into the artificial one and natural one, respectively. The artificial damages include toxics, soil covering, excessive humidity, fire, construction and management works, unlawful damages, fishing, oil spillage, etc, and the natural ones include lightning, storms(typhoons), heavy snowfalls, damage by insects and diseases, lack of prey, etc. This study will become meaningful in that it proposes specific measures for the improvement of the institutions, designation, and management of natural monuments on the basis of the comprehensive analysis on natural monuments. We wish to leave the other subjects related with this study to the future researches.

• Korean Journal of Heritage: History & Science
• /
• v.42 no.3
• /
• pp.26-47
• /
• 2009

This study examined dwelling site from among the sites of the Neolithic age found in the Asan Bay(牙山灣) area, and the temporal-spatial location and meaning of the dwelling site (settlement). The majority of the settlements in the area are of a square style but some coexist with rectangular-style settlements, which is noteworthy. The dwelling sites of the Neolithic age found in Asan Bay area are mostly located in a ridge of hilly areas, divided into gentle, low areas (20~50 meters above sea level) and relatively high areas (50~80 meters above the sea level). Although location strongly corresponded to the residents' subsistence and the technical levels within the culture, it likely was greatly affected by natural environment where they lived, as well. In examining radiocarbon dating results and the excavated artifacts, the settlements found in Asan Bay were determined to belong to the period II(3,500~3,000 B.C.) stated in the Relative Chronological table of Dwelling sites in the Neolithic age, written by the author. Said Dwelling sites are proven to have a close relationship with those found on the coast of Gyeonggi Province(京畿道) and in the Geum River(錦江) valley. This is deemed to be the result of expansion and interchange between Gyeonggi Province(京畿道) group and Geum River(錦江) valley group, who constituted the large settlements. Additionally, the Daecheon-ri type dwelling sites in the Geum River valley were verified to be the result of exchange, and spread to the Asan Bay area in the same era. Two forms of Dwelling sites coexisted dynamically in the Asan Bay area around 3,500 B.C. Such a phenomenon resulted primarily from the expansion of the dwelling site due to the introduction of primitive agriculture, as well as environmental (temperature), biological and social changes at those times.

• Korean Journal of Ecology and Environment
• /
• v.53 no.4
• /
• pp.365-373
• /
• 2020

Biomonitoring Survey and Assessment Manual for lake ecosystem suggest zooplankton collection methods to compare relatively the number of species, population density, and community indices, taking into account the convenience of the field sampling according to the sites' water depth. In this study, the oblique towing and 20 m vertical towing methods presented in the manual were respectively compared with the whole water column-vertical towing and we analyzed the differences and characteristics of zooplankton community information gathered by each collection method. For community indices, there was no difference in the comparison of oblique/vertical towing methods in the shallow lake, but in the deep lake, the diversity and richness indices increased when vertically towing through whole water column rather than when limiting the towing depth to 20 m. In addition, the total zooplankton density collected by the oblique/20 m vertical towing methods was about three times higher than the whole water column-vertical towing method, which means that the density of zooplankton community can be overestimated depending on the collection methods. It appears to be results of differences in the zooplankton density by water layer arising from their vertical distribution and in filtered raw water quantity according to the towing depth/distance. Hence, for zooplankton community information to be used as a functional quantitative indicator representing the entire lake, it would be more appropriate to apply the whole water column-vertical towing method with considering the distribution of zooplankton density by depth and contribution rate of each water layer when converting total zooplankton density.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.50 no.2
• /
• pp.23-40
• /
• 2022

Many constructed wetlands have been installed in dam reservoirs nationwide for ecological purification of watershed pollutants, but aging and reduced efficiency are becoming issues. To improve the management of constructed wetlands, an objective evaluation of structural suitability is required. This study evaluated 39 constructed wetlands of 15 dams. First, through fogus group interview(FGI), survey analysis, and analytic hierarchy process(AHP), eight evaluation items in the physical and vegetative aspects were selected and the evaluation criteria applied with weights were prepared. Second, as a result of the structural suitability evaluation, the average score of the overall constructed wetlands was 80.8, with 10 sites rated as 'good grade(91~100)', 22 sites rated as 'normal grade(71~90)' and 7 sites rated as 'poor grade(70 or less)'. The average score of physical structure evaluation was 52.6, with 14 sites rated as 'good', 21 sites as 'normal' and 4 sites as 'poor'. The suitability of location was good level in most constructed wetlands, but the water supply system, depth of water, ratio of length-to-width, and slope of flow channel were evaluated as 'normal' or less in constructed wetlands of 50% or more. Therefore, it was found that overall improvement was necessary for stable flow supply and flow improvement in the constructed wetland. The average score of vegetative structure evaluation was 28.2, and about 84% of them were identified as 'normal' or lower. As a result of analyzing the Spearman's correlation coefficient between the physical structure evaluation score and the vegetation structure evaluation score, there was a significant correlation(r = 0.728, p < 0.001), and it was found that each evaluation factor also influences each other. As a result of the case review of 6 constructed wetlands, the appropriateness of the evaluation results was confirmed, and it was found that the location, flow rate supply, and type of wetland had a great influence on the efficiency and operation of the wetland. Through this study, it will be possible to derive structural weaknesses of constructed wetlands in dam reservoirs as a nature-based solution, to prepare types and practical alternatives for improved management of each constructed wetland in the future, and to contribute to enhancing various environmental functions.