• Korean Journal of Agricultural and Forest Meteorology
• /
• v.9 no.1
• /
• pp.61-70
• /
• 2007

This study was conducted to investigate nutrient dynamics and water quantity of throughfall and stemflow in natural oak stands in Korea. The ratio of the total throughfnll and stemflow to the amount of precipitation varied with locations. It was considered that the ratio was affected not only by the characteristics of tree species but also by regional, weather and other environmental conditions. It was, therefore, necessary to set up a water control system to launch a tending project for natural oak stands. Comparisons of nutrient amount in throughfall among regions reflected regional characteristics. $Ca^{2+},\;Mg^{2+}$ and $K^+$ ions were leached from the canopy and yellow sand accumulation. $Na^+$ and $Cl^-$ were marine-borne. $NO_3^-$ and $SO_4^{2-}$ resulted from dry deposition of air pollutants. Nutrient amount in the stemflow was as low as about 10% of that in the total throughfall and stemflow. The pH of stemflow in natural oak stands in urban areas ranged from 3 to 5. Influx of the acidic stemflow to soil could, in the long term, affect pH in soil solution and nutrient dynamics around root zones.

• Journal of Korea Water Resources Association
• /
• v.41 no.2
• /
• pp.149-162
• /
• 2008

The Soil and Water Assessment Tool (SWAT) developed by the USDA-Agricultural Research Service for the prediction of land management impact on water, sediment, and agricultural chemical yields in a large-scale basin was applied to Daecheong Reservoir basin to estimate the amount of soil losses from different land uses. The research outcomes provide important indications for reservoir managers and policy makers to search alternative watershed management practices for the mitigation of reservoir turbidity flow problems. After calibrations of key model parameters, SWAT showed fairly good performance by adequately simulating observed annual runoff components and replicating the monthly flow regimes in the basin. The specific soil losses from agricultural farm field, forest, urban area, and paddy field were 33.1, $2.3{\sim}5.4$ depending on the tree types, 1.0, and 0.1 tons/ha/yr, respectively in 2004. It was noticed that about 55.3% of the total annual soil loss is caused by agricultural activities although agricultural land occupies only 10% in the basin. Although the soil erosion assessment approach adopted in this study has some extent of uncertainties due to the lack of detailed information on crop types and management activities, the results at least imply that soil erosion control practices for the vulnerable agricultural farm lands can be one of the most effective alternatives to reduce the impact of turbidity flow in the river basin system.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.5
• /
• pp.927-940
• /
• 2017

Landslide has been a major disaster in Indonesia, and recent climate change and indiscriminate urban development around the mountains have increased landslide risks. Java Island, Indonesia, where more than half of Indonesia's population lives, is experiencing a great deal of damage due to frequent landslides. However, even in such a dangerous situation, the number of inhabitants residing in the landslide-prone area increases year by year, and it is necessary to develop a technique for analyzing landslide-hazardous and vulnerable areas. In this regard, this study aims to evaluate landslide susceptibility of Java, an island of Indonesia, by using GIS-based spatial prediction models. We constructed the geospatial database such as landslide locations, topography, hydrology, soil type, and land cover over the study area and created spatial prediction models by applying Weight of Evidence (WoE), decision trees algorithm and artificial neural network. The three models showed prediction accuracy of 66.95%, 67.04%, and 69.67%, respectively. The results of the study are expected to be useful for prevention of landslide damage for the future and landslide disaster management policies in Indonesia.

• Journal of Environmental Impact Assessment
• /
• v.22 no.3
• /
• pp.219-230
• /
• 2013

Species distribution modeling is one of the most effective habitat analysis methods for wildlife conservation. This study was for evaluating the suitability of species distribution to distance between forest patches in Seoul city using tits. We analyzed the distribution of the four species of tits: varied tit (Parus varius), marsh tit (P. palustris), great tit (P. major) and coal tit (P. ater), using the landscape indexes and connectivity indexes, and compared the resulting suitability indexes from 100m to 1,000m. As factors affecting to the distribution of tits, we calculated landscape indices by separating them into intra-patch indices (i.e. logged patch area (PA), area-weighted mean patch shape index (PSI), tree rate (TR)) and inter-patch indices (i.e. patch degree (PD), patch betweenness (PB), difference probability of connectivity (DPC)), to analyze the internal properties of the patches and their connectivity by tits occurrence data using logistic regression modeling. The models were evaluated by AICc (Akaike Information Criteria with a correction for finite sample sizes) and AUC (Area Under Curve of ROC). The results of AICc and AUC showed DPC, PA, PSI, and TR were important factors of the habitat models for great tit and marsh tit at the level of distance 500~800m. In contrast, habitat models for coal tit and varied tit, which are known as forest interior species, reflected PA, PSI, and TR as intra-patch indices rather than connectivity. These mean that coal tit and varied tit are more likely to find a large circular forest patch than a small and long-shaped forest patch, which are higher rate of forest. Therefore, different strategies are required in order to enhance the habitats of the forest birds, tits, in a region that has fragmented forest patches such as Seoul city. It is important to manage forest interior areas for coal tit and varied tit, which are known as forest interior species and to manage not only forest interior areas but also connectivity of the forest patches in the threshold distance for great tit and marsh tit as adapted species to the urban ecosystem for sustainable ecosystem management.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.44 no.6
• /
• pp.51-59
• /
• 2016

The purpose of this study is to improve interaction with the construction subject by analyzing the contents and contents of users' involvement in landscaping works. For this purpose, this study selected the Gwanggyo Residential Land Development District Public Landscape Project in Suwon, Gyeonggi Province. For four years before and after the completion, the opinions of tenants were used as research data. Both qualitative and quantitative analyses of 412 complaints received by the project implementation office and local government were conducted. As a result, first, the main purpose of suggesting opinions was 'demanding and expressing complaints', and there were many 'parks' and 'rivers'. In terms of content, "quality" was the most pointed out, but many kinds of trees, such as tree planting, ecological river construction, and pavement construction were also mentioned. Second, the extraction of key words from content analysis was the most common method. Followed by 'additional foodstuff' and 'moving to the toilet and management building'. Much of the point of view about dead wood has continued to be conspicuous in the process of waiting to be dealt with at the time of transplanting. Third, the validity of the contents of the complaints was evaluated as a five - point scale. Therefore, the opinions raised were unreasonable, but overall, there were more complaints with certain objectivity.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.17 no.1
• /
• pp.1-16
• /
• 1989

^x As mentioned above, I consider the change of role that is related with Japanese thought of Natural Environmental Conservation, and I divide each part of periods into forest, farmland, open space, urban planning, environmental conservation etc. To summary the content of each period of Natural Environmental Conservation thought is as follows. 1) Previous period before formation(before 1919) In the previous period of Meiji, it could be said that the consciousness of the Natural Environmental Conservation was coming to existence. In this, so called, Natural Environmental Conservation, the thought of Forest Preservation was the main current and it was the thought of territorial integrity for the security of resource, the forestry conservancy and flood control in the forestry farmland. Since the age of Meiji, the theory of Natural Conservation appears from the theory of Japanese landscaping and systematic management about public parks was enforced, but the regular theory of Natural Environmental Conservation did not attain full growth. 2) The period of formation(1919~ 1954) In the period of formation, the base of Natural Environmental Conservation had been established. Parks and Open spaces were admitted as a public facilities in each city, and legislations which supported it had been continuously enacted and so on. In this period, the afforestation counter plan was emphasized on the side of territorial integrity. In the mountainous district. tree planting was emphasized to recover the forest which had been destroied by war. 3) The period of development(1955~ 1974) In the period of development, varied policies was institutionalized for the Natural Environmental Conservation. However, all sorts of development policy had performed simultaneously, thus development had complicated relation with preservation. But after 1970's the framework of system of Natural Environmental Conservation improvement was constituted to control the many kinds of development, and the spontaneous campaign of nature preservation by private lead was being taken root. This is the more progressive period. 4) The pried of root(after 1975) After the latter of 1970's, the role of Natural Environmental Conservation began to take root not in the direction of control but inducement, and, getting out of development - oriented policy, aimed at relation between human being and natural environment and the side of amenity of human environment. Besides, the current of Natural Environmental Conservation had been seperately progressed in the cities and forests. Since this period, it was the character that cities and forests began to be unified as 'amenity'space of man.

• Korean Journal of Environment and Ecology
• /
• v.23 no.3
• /
• pp.258-271
• /
• 2009

Various environmental parameters change and ecological succession often lead to decline of Pinus densiflora forest in Seoul. Due to decline of it, we proposed the ecological management for conserving and improving from decrease of its dominant area on there. We analysed the P. densiflora forest's classification and suggested its ecological management that based on relation to competition between dominant species in the upper tree layer, the presence of competitive species in shrub layer and vegetation management standard. The Pinus densiflora forest types has been classified 6 types by ecological characteristics. The results from categorized its types are following as; 1) Pinus densiflora pure forest type; edaphic climax Pinus densiflora forest(26.1%), Pinus densiflora pure forest(21.5%). 2) the forest of Pinus densiflora and other species that compete with each other type; Pinus densiflora-Quercus mongolica forest(28.0%), Pinus densiflora-Pinus rigida forest(13.1%), Pinus densiflora-Quercus acutissima(4.2%). We conclude that the results in these kind of 4 types; Pinus densiflora pure forest type where possible to maintain the forest by edaphic climax, human trampling damage, vegetation management(e.x. remove the competition species, shrub layers management etc.) are mainly need to negative management. Whereas, the others 4 types; Pinus densiflora and other species(Quercus variabilis, foreign species, naturalized species etc.) that compete with each other types are need to positive management such as manage the same niche competition species, shrub layers management, remove the foreign species, naturalized species etc.. In these kinds of ecological management are very necessary to maintain Pinus densiflora forest.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.36 no.1
• /
• pp.45-54
• /
• 2018

This study aims to study the flora and identify the naturalized plants of the 4 ancient palace (Gyeongbokgung, Changdeokgung, Changgyeonggung, Deoksugung) and Jongmyo Shrine, which are national cultural heritage and urban cultural centers in Seoul. The plants found consisted of 315 taxa in total, belonging to 82 families, 201 genera, 285 species, 1 subspecies and 29 varieties. The naturalized plants were shown as follows: in the Deoksugung Palace(33 taxa), the Jongmyo Shrine(14 taxa) and the Gyeongbok Palace(21 taxa) and the Changdeokgung Palace complex(11 taxa). The results of the analysis based on the place of origin showed a higher rate of distribution of species based in North America, Europe and Eurasia, with higher rates of grass than tree. In addition, except for Gyeongbokgung Palace, the annual rate is higher than the perennial rate. As a result of naturalization analysis, the percentage of naturalized plants corresponding to naturalization degree 3 and naturalization degree 5 was high. According to the moment of the invasion, the naturalized plants recently introduced were higher than the first species. In addition, it was found that the similarity between the sites was more than 40%, and the diversity of species of naturalized plants common to the five sites was very low. The purpose of this study is to provide basic data for cultural heritage landscaping and naturalized plant management.

• Nuclear Engineering and Technology
• /
• v.53 no.8
• /
• pp.2534-2546
• /
• 2021

Nuclear emergency preparedness and response is an essential part to ensure the safety of nuclear power plant (NPP). Key support technologies of nuclear emergency decision-making usually consist of accident diagnosis, source term estimation, accident consequence assessment, and protective action recommendation. Source term estimation is almost the most difficult part among them. For example, bad communication, incomplete information, as well as complicated accident scenario make it hard to determine the reactor status and estimate the source term timely in the Fukushima accident. Subsequently, it leads to the hard decision on how to take appropriate emergency response actions. Hence, this paper aims to develop a method for rapid source term estimation to support nuclear emergency decision making in pressurized water reactor NPP. The method aims to make our knowledge on NPP provide better support nuclear emergency. Firstly, this paper studies how to build a Bayesian network model for the NPP based on professional knowledge and engineering knowledge. This paper presents a method transforming the PRA model (event trees and fault trees) into a corresponding Bayesian network model. To solve the problem that some physical phenomena which are modeled as pivotal events in level 2 PRA, cannot find sensors associated directly with their occurrence, a weighted assignment approach based on expert assessment is proposed in this paper. Secondly, the monitoring data of NPP are provided to the Bayesian network model, the real-time status of pivotal events and initiating events can be determined based on the junction tree algorithm. Thirdly, since PRA knowledge can link the accident sequences to the possible release categories, the proposed method is capable to find the most likely release category for the candidate accidents scenarios, namely the source term. The probabilities of possible accident sequences and the source term are calculated. Finally, the prototype software is checked against several sets of accident scenario data which are generated by the simulator of AP1000-NPP, including large loss of coolant accident, loss of main feedwater, main steam line break, and steam generator tube rupture. The results show that the proposed method for rapid source term estimation under nuclear emergency decision making is promising.

• Journal of Wetlands Research
• /
• v.21 no.2
• /
• pp.173-180
• /
• 2019

This study was conducted to understand factors affecting TSS and heavy metals transport on the road, parking lot and roof. During storm events, heavy metals, which were mostly attached to TSS, were also transported when TSS was washed off in the road, parking lot and roof. This finding may be supported by the significant correlations between TSS load and total and soluble heavy metals load including Cr, Fe, Cu, and Pb (Pearson r value: 0.52 to 0.73; probability p value<0.01). Generation and transport of TSS and heavy metals were greater in the road and parking lot compared to the roof due to vehicular activities, slope and greater catchment areas of these sites. It was found that TSS transport during peak flows of storm events ranges from 65% to 75% implying that by controlling peak flows, TSS transportation to nearby water bodies may be decreased. Depending on the target TSS and heavy metal reduction, sizing of low impact development (LID) technologies and green infrastructures (GI) such as infiltration trench, tree box filter, and rain garden may be calculated. Future researchers were recommended to assess the limitations of the systems and determine the design considerations for these types of facilities.