• Journal of Korean Society of Forest Science
• /
• v.100 no.4
• /
• pp.664-671
• /
• 2011

Random Walk Model can predict the sediment areas of debris flow but it must be extracted three parameters fitted topographical environment. This study developed the method to extract the optimal values of three parameters - Once flowing volume, Stopping slope and Gravity weight - for Random Walk Model. And the extracted parameters were validated by aerial photographs of the debris flowed area. To extract the optimal parameters was randomly performed, limiting the range values of three parameters and developing an accuracy decision method that is called the rate of concordance. The set of the optimal parameters was decided on highest the rate of concordance and a consistency. As a result, the optimal parameters in Bonghwa county were showed that the once flowing volume is $1.0m^3$, the stopping slope is $4.2^{\circ}$ and the gravity weight is 2 when the rate of concordance is -0.2. The validating result of the optimal parameters showed closely that the rate of concordance is average -0.2.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.29 no.4
• /
• pp.40-48
• /
• 2011

Mt. Hee-yang is located in Mungyeong-si, Gyeongsangbuk-do, South Korea. Through the analysis and interpretations of twenty-two different ancient writings which covers Mt. Hee-yang, and three times of field studies, I tried to analyze the cognition of our ancestors in those days regarding Mt. Hee-yang. Since Mt. Hee-yang goes very deep in the mountain range, Mt. Hee-yang was recognized as appropriate place for seclusion or operating Byeolseo. From the era of Silla, in terms of Fengshui, Mt. Hee-yang was also interpreted as an image of either a phoenix flying into the sky(鳳凰登天) or a valley of a phoenix and dragon(鳳巖龍谷). This cognition comes from its formations of topographical features, and continued to the era of Joseon Dynasty. The purposes of excursion were to retrace the course of predecessors, to attain one's long-cherished desire to visit, or to enjoy holidays. From the analysis of Mt. Hee-yang's visitors, the average social status of them is lowered a lot around the end of Joseon Dynasty, compared with the early period of Joseon Dynasty. Studying the visitor's route of Mt. Hee-yang, I could see the places that are highly-recognized were the top of Mt. Hee-yang, Seonyudong(仙遊洞), Bakundae(白雲臺), Yayuam(夜遊岩). Mt. Hee-yang was recognized as Sun-kyung(仙境) where Sin-seon(a taoist hermit with miraculous powers; the sage of old) lives, and mostly it was main destination of visit while Bakundae(白雲臺) was perceived diversely on each visitor because of its strange scenery.

• Journal of The Geomorphological Association of Korea
• /
• v.20 no.4
• /
• pp.1-13
• /
• 2013

Padori beach is one of the representative composite mixed beach in Korea and shows divert geomorphic landscape change. It belongs to the Taean National Park. The purpose of this study is to clarify movement mechanism of sediments from sediment distribution of Padori beach associated with morphology. In addition, it is to explain morphological landscape change under different wave and tide condition in the composite mixed beach consisting of a dissipative low tide terrace and a reflective beach face with a high tide range of 5 to 7m. The results of this study are: First, the mean grain size of sediments becomes smaller from the south of the beach, where there is a wide wave-cut platform, to the north because gravels are supplied from the wave-cut platform as well as sea-cliff in the south of the beach. A sedimentation pattern of the sandy gravel on the beach face and gravel on the berm, and gradation phenomena of grain size on cross-shore and alongshore direction in the beach can be explained with a pattern of sediment movement, overpassing, in the composite mixed beach. Second, micro-topography on beach face and berm were changed depending on effects of wave height and tide. As a result, in low-wave energy environments, a berm is developed in large size, and beach cusps are formed on the upper beach face, while in high-wave energy environments, a berm is built up in relatively small size, and mixture of sediments occur on the upper beach face.

• (The)Study of the Eastern Classic
• /
• no.50
• /
• pp.29-54
• /
• 2013

Mun Il-pyeong(1888-1939) is famous for a nationalist historian led history into popular style to enlighten the public. This paper aims to overview the characteristic of Mun Il-pyeong's history based on prior studies on Mun Il-pyeong's works. The characteristic of Mun Il-pyeong's history shows us people centric trend based on a struggle of classes. For the people, he insisted that description of history should be easy and scientific for the people who are host of history. And Mun Il-pyeong insisted the harmony of nationalist history and positive history. This was a progressive attitude in writing history at that time. Another characteristic of Mun Il-pyeong's history is that he considered cultural history as important. Mun Il-pyoeng wanted to overcome the ashamed political history by cultural history. In this intention, Korean history was again born proudful by him. Mun Il-pyoeng pursued open nationalism, not ultra-nationalism by connecting with other world. This paper focused on the essential part of Mun Il-pyoeng's history. Many scholars think Mun Il-pyeong focused on Korean modern history or history of foreign relation. But I think Mun Il-pyeong attached importance to Practical Learning, Sirhak in late Joseon dynasty. Because Sirhak contained Mun Il-pyeong's academic intention, Modernism and Culturism dreamed from his youth age. Therefore he led so-called Joseonhak Undong meaning study of Sirhak. Studying Sirhak made Mun Il-pyeong open a new direction Korean modern history have to go.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.23 no.2
• /
• pp.122-133
• /
• 2021

Cultivar parameter calibration can be affected by the reliability of the input data to a crop growth model. In South Korea, two sets of weather stations, which are included in the automated synoptic observing system (ASOS) or the automatic weather system (AWS), are available for preparation of the weather input data. The objectives of this study were to estimate the cultivar parameter using those sets of weather data and to compare the uncertainty of these parameters. The cultivar parameters of CERES-Rice model for Shindongjin cultivar was calibrated using the weather data measured at the weather stations included in either ASO S or AWS. The observation data of crop growth and management at the experiment farms were retrieved from the report of new cultivar development and research published by Rural Development Administration. The weather stations were chosen to be the nearest neighbor to the experiment farms where crop data were collected. The Generalized Likelihood Uncertainty Estimation (GLUE) method was used to calibrate the cultivar parameters for 100 times, which resulted in the distribution of parameter values. O n average, the errors of the heading date decreased by one day when the weather input data were obtained from the weather stations included in AWS compared with ASO S. In particular, reduction of the estimation error was observed even when the distance between the experiment farm and the ASOS stations was about 15 km. These results suggest that the use of the AWS stations would improve the reliability and applicability of the crop growth models for decision support as well as parameter calibration.

• Journal of the Korean earth science society
• /
• v.42 no.1
• /
• pp.88-101
• /
• 2021

The purpose of this study was to qualitatively examine the meaning of students' drawings in outdoor classes and modeling-based learning cycles. Ten students were observed in a gifted education center in Seoul. Under the theme of the Hantan River, three outdoor classes and three modeling activities were conducted. Data were collected to document all student activities during field trips and classroom modeling activities using simultaneous video and audio recording and observation notes made by the researcher and students. Please note it is unclear what this citation refers to. If it is the previous sentence it should be placed within that sentence's punctuation. Hatisaru (2020) Ddrawing typess were classified by modifying the representations in a learning context in geological field trips. We used deductive content analysis to describe the drawing characteristics, including students writing. The results suggest that students have symbolic images that consist of geologic concepts, visual images that describe topographical features, and affective images that express students' emotion domains. The characteristics were classified into explanation, generality, elaboration, evidence, coherence, and state-of-mind. The characteristics and drawing types are consecutive in the modeling-based learning cycle and reflect the students' positive attitude and cognitive scientific domain. Drawing is a useful tool for reflecting students' thoughts and opinions in both outdoor class and classroom modeling activities. This study provides implications for emphasizing the importance of drawing activities.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.24 no.1
• /
• pp.12-25
• /
• 2021

Land cover maps are used in various fields in urban expansion and development. This study analyzed the amount of land cover change over time using multi-sensor information, focusing on the waterfront area of the Taehwa River. In order to apply high-accuracy aerial hyperspectral images, patterns with Field-spectral were reviewed and compared with time series Digital map. The hyperspectral image was set as 13 land cover grades, and the time series digital map was classified into 7 and the waterfront area was classified into 5-6 grades and analyzed. As a result of analysis of the change in land cover of the digital map from the 1990s to 2010, it was found that forest areas were rapidly decreasing and Farmland and grassland were becoming urban. As for the land cover change(2010~2019) in the waterfront area(set 500m) analyzed through hyperspectral images, it was found that Farmland(1.4㎢), Forest(1.0㎢), and grassland (0.8㎢) were converted into urbanized and dried areas, and urbanization was accelerating around the Taehwa River waterfront. Recently, a lot of research has been conducted on the production of land cover maps using high-precision satellite images and aerial hyperspectral images, so it is expected that more detailed and precise land cover maps can be produced and utilized.

• Korean journal of applied entomology
• /
• v.59 no.4
• /
• pp.433-441
• /
• 2020

This study was conducted to understand the distribution characteristics of aquatic insects in ecologically different ponds in terms of the disruption. We investigated the fauna of aquatic insects in three artificial ponds (pond 1, 2 and 3) and two natural ponds (pond 4 and 5) located within 1 km each other around Gungdaeoreum in Jeju Island, from March 2018 to June 2020. A total of 50 species belonging to 15 families were found in the surveyed ponds: total 850 individuals with 14 species in 4 families of the order Odonata, total 4,391 individuals with 14 species in 6 families of the order Hemiptera, and total 2,014 individuals with 22 species in 4 families of the order Coleoptera. In overall, total abundance and species numbers were relatively higher than those of artificial pond in natural ponds in which animal and plant ecosystems were well established. In the case of artificial ponds, the number of individuals and species recovered rapidly when reconstituted by introducing aquatic plants, etc. (Pond 1). The nymphs of Odonata were observed largely in ponds without natural enemies such as large fish, and where adults could freely access without interception by artificial structure. Phytophagous Corixidae of the order Hemiptera were abundant, and Haliplidae populations of the order Coleoptera were affected by the distribution of the plants. Accordingly, the major factors affecting aquatic insect abundance were identified as the presence of refuges such as the topography and aquatic plants and presence of predators. Species of the order, Odonata were vulnerable based on these factors. Our results can be useful as basic information for the restoration of wetlands and construction of artificial wetlands or for conservation of species diversity in the future.

• Journal of Wetlands Research
• /
• v.23 no.1
• /
• pp.1-6
• /
• 2021

The average annual rainfall in Busan to increase, and in case of Oncheon-Chen in Busan, frequent flooding occurred frequently. The middle and lower reaches of the Oncheon-Chen are relatively flat and urban areas are developed. Therefore, due to the frequent flooding of rivers and the large flood damage, a method of effectively eliminating the flow rate of Oncheon-Chen in the event of heavy rain is needed. In this study, underground waterway was established in the east of Hoedong-Reservoir as a measure to reduce floods in hot springs and simulated with EPA-SWMM. The information needed to construct the basin was utilized by GIS. In middle part of the Suyeong-Gang, there is a Hoedong-Reservoir and a dam is installed and has better conditions than the Nakdong-Gang. It also analyzed the effect of the Oncheon-Chen flow through the underground waterway on the Suyeong-Gang when it was transferred to the Hoedong-Reservoir. It was analyzed that the flood reduction rate at the flood risk points set up in this study was reduced by 24.64% on average when the underground waterway was installed, and the inflow of the water into the Suyeong-Gang increased by 1% on average when the flow rate was excluded by the Suyeong-Gang.

• Korean Journal of Environment and Ecology
• /
• v.35 no.4
• /
• pp.398-407
• /
• 2021

This study intended to identify causes of poor tree vigor in the Hanbando coastal forest by investigating its geographical environment, climate condition, soil physicochemical characteristics, and growth condition of Pinus thunbergii. It divided the forest into an area with poor tree vigor or dead standing trees and a control area with good tree vigor and examined them separately. The survey showed that stand density was significantly higher in the area with poor tree vigor. In contrast, the crown width in the area with good tree vigor was wider. The number of dead standing trees and the stand density showed a negative correlation. The stand density and diameter at breast height (DBH), tree height, crown height, and crown width also showed a negative correlation. The result indicated that, as the tree's stand density increases, the crowns of individual trees overlapped and the lower branches died. Then crown height and crown width decreased, and the number of leaves and photosynthesis was reduced, leading to lower tree height and weaker growth of breast diameter. As a result, tree vigor weakened, and combined with environmental pressures from the lack of moisture and nutrients in coastal soil and salty wind, P. thunbergii in coastal areas is expected to die massively. Although the causes of dead standing trees and poor tree vigor of P. thunbergii in the Hanbando coastal forest are complicated, poor management of adequate tree density in response to the growth of P. thunbergii is the primary cause. The secondary cause is external environmental pressures, including unfavorable soil conditions and salty and strong wind that obstruct the growth of P. thunbergii.