• Journal of Korean Society on Water Environment
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• v.27 no.5
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• pp.680-688
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• 2011

This study was performed to find out the distribution aspect of benthic macroinvertebrates according to altitude in a mountain stream (a main stream: Buk stream, a tributary: Hangye stream) of Seoraksan. The survey was conducted from August to November in 2010. All survey sites were very sound because the mountain was being maintained as a protection area of the national park. Water quality and the composition of substrata were similar in all sites. Benthic macroinvertebrates of 3 phyla, 4 classes, 9 orders and 84 species occurred in the stream. Along with the decline of altitude, shredders of the functional feeding groups (FFGs) decreased, while collector filterers increased. In particular, collector filterers increased sharply at the altitude of 600 ~ 500 m (S.E.L.). Benthic macroinvertebrates showed low similarity between the uppermost site and the lower sites. Altitude appeared to be a significant factor that influence the structure and distribution of benthic macroinvertebrate community.

• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.415-424
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• 2006

This study was carried out to analyze the characteristics of forest watershed factors by using the quantification theory(I) for evaluation and prediction of the failure hazard area. Present $sediment(m^3/yr/ha)$ of erosion control dams were investigated in 95 sites of erosion control dam constructed during 1986 to 1999 in Gyeongnam province. The results obtained from this study were summarized as follows; General condition of class I(Very hazard area) were as follow; Igneous rock in parent rock, coniferous in forest type, below 20year in stand age, below 30cm in soil depth, SCL in soil texture, $31{\sim}40%$ in gravel contents, $S{\sim}E$ in aspect, $2,501{\sim}3,600m$ in length of main stream, $26{\sim}30$ in number of total streams, $6,601{\sim}10,000m$ in length of total streams, over 3 in stream order, over 16 in number of first streams order and over $31^{\circ}$ of slope gradient. General condition of class IIl(hazard area) were as follow; Metamorphic rock in parent rock, hardwood in forest type, over $21{\sim}24year$ in stand age, $31{\sim}40cm$ in soil depth, SiCL or SCL in soil texture, $11{\sim}20%$ in gravel contents, $S{\sim}W$ in aspect, $1,501{\sim}2,600m$ in length of main stream, $6{\sim}10$ in number of total streams, $3,501{\sim}5,500m$ in length of total streams, 2 in stream order, $6{\sim}10$ in number of first streams order and over $31^{\circ}$ of slope gradient. General condition of class III(Un hazard area) were as follow; Sedimentary rock in parent rock, mixed in forest type, over 25year in stand age, $41{\sim}50cm$ in soil depth, SiCL in soil texture, below 10% in gravel contents, $N{\sim}W$ in aspect, below 500m in length of main stream, below 5 in number of total streams, below 1,000m in length of total treams, below 1 in stream order, below 2 in number of first streams order and below $25^{\circ}$ of slope gradient. The prediction method of suitable for failure hazard area divided into class I, II, and III for the convenience of use. The score of class I evaluated as a very hazard area was over 4.8052. A score of class II was 4.8051 to 2.5602, it was evaluated as a hazard area, and class III was below 2.5601, it was evaluated as a un hazard area.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.3
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• pp.10-20
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• 2014

The purpose of this study is to define criteria for landscape restoration of palace gardens. The case study on Gyeongbokgung and Changdeokgung was used not only to evaluate effectiveness of the criteria, but also to propose solutions to issues of current restoration process of both palace gardens. Following three pairs of different concepts were chosen as criteria to determine on the original form: Diachrony vs. Synchrony, Originality vs. Contemporary Characteristics, and Invariance vs. Deformability. Gyeongbokgung has been restored based on its contemporary characteristics of Year 1888 and the main focus is on its architectural features rather than both architecture and landscape. However, in-depth complementary work on landscape restoration is necessary to restore its originality in Year 1395 such as analyzing photos of Gyeongbokgung taken in modern era. In case of Changdeokgung, we analyzed separately by region or landmark such as Jondeok-Pavilion(尊德亭), Yeonkyung-Hall(演慶堂), and Okryu-Stream(玉流川). Original form of Jondeok-Pavilion Area was changed in 1884. Since diachronic invariance that lasted for 240 years is more important criterion than its contemporary characteristics, it should be restored as how it was painted in Donggwoldo(東闕圖). In Yeonkyung-Hall Area, both original characteristics at the time of Hyomyung Crown Prince and contemporary characteristics of Emperor Kojong Era appear. Therefore, different solution is required for such area to be restored appropriately. Starting from era of King Injo(1636), diachrony and invariance of Okryu-Stream Area were continued throughout the era of King Sukjong and King Jeongjo(1800). It is more than 250 years before Okryu-Stream Area was altered under the rule of Emperor Kojong in 1884. In fact, alterations made to Okryu-Stream Area after 1884 doesn't hold much significance. Therefore, water landscape of Okryu-Stream Area, which was altered in the era of Emperor Kojong, needs to be restored based on Donggwoldo.

• Journal of Environmental Science International
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• v.16 no.11
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• pp.1301-1312
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• 2007

The objective of this study is to propose a critical storm duration forecasting model on storm runoff in small river basin. The critical storm duration data of 582 sub-basin which introduced disaster impact assessment report on the National Emergency Management Agency during the period from 2004 to 2007 were collected, analyzed and studied. The stepwise multiple regression method are used to establish critical storm duration forecasting models(Linear and exponential type). The results of multiple regression analysis discriminated the linear type more than exponential type. The results of multiple linear regression analysis between the critical storm duration and 5 basin characteristics parameters such as basin area, main stream length, average slope of main stream, shape factor and CN showed more than 0.75 of correlation in terms of the multi correlation coefficient.

• Korean Journal of Environment and Ecology
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• v.20 no.2
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• pp.259-266
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• 2006

Community analysis based on functional feeding groups of aquatic insects in Wonju stream was assessed with the composition of aquatic insects collected for four times at the area from May to November, 2004. The total 92 species of aquatic insects in 62 genera, 37 families, and 8 orders were collected during the period of the investigation. The distribution of the numbers and movements of aquatic insects proved the Woniu stream to be healthy except for St. 7 and St. 9. In the main streams, the occupancy ratio of shredders and scrapers of the functional feeding groups(FFGs) gradually decreased from St. 1 to St. 9 while collectors-gathering and collectors-filtering remarkably increased. In St. 2, the shredders and scrapers posted a higher ratio compared to those in tributaries, and it had the quality of mountain streams. With the results of analysis on the similarity matrix(UPGMA) between each sites of Wonju stream, St. 1, 2, St. 3-8 and St. 9 were classified as the upper stream, the middle stream, and the lower stream area, respectively.

• Journal of The Geomorphological Association of Korea
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• v.28 no.4
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• pp.1-13
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• 2021

In this study is aerial photos and UAV(Unmanned Aerial Vehicle) images were used to analyzed the characteristics of depositional landform changes in the Geum river channels before and after the opening gate of Gongju weir. Based on the depositional landform classification result, the main stream and the bare land occupied most of the area in all periods, and also found that the main stream, mid-channel island, and sand bar occupied a greater degree of area increase or decrease compared to other landforms in the classification items. As a result of analyzing the characteristics of depositional landform changes before and after the opening gate of Gongju weir, it is judged that the depositional landforms have changed due to the decreased water level of the Geum river after the opening of the weir, the summer rainy season and typhoons, river stabilization after the effluence of Daecheong dam, supply and deposition of river sediments and fixation of vegetation. The results derived from this study can be used as basic data for the study of river depositional landforms and the establishment of management and conservation plans for the landforms in river channels.

• Journal of the Korean association of regional geographers
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• v.12 no.1
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• pp.1-15
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• 2006

This study is to review the site of Seoul and its urbanized area expansion in relation with a geomorphic environments. Surveying on the urbanized area of Seoul by period and related geomorphic conditions found the following conclusions. Seoul urbanized area had been expanded from the cheonggyecheon drainage basin to its surrounding hills and marshland. The marshland development began during the Japanese period from around the tributaries of the Hangang river and expanded to the areas by the main stream of the river. The extensive marshland at the point where the main stream and its tributaries of the river join has been developed relatively new. The marshland development, which took advanced engineering skills and a huge investment, is comparatively later and also involves large additional expenses to keep the areas from food damages. Judging from the above findings, this study concluded that the urbanized area expansions in a big metropolitan city such as Seoul, are greatly influenced by geomorphic environments and the importance of geomorphic conditions still hold true even today when scientific and technological developments have reached unprecedented heights.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.555-562
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• 2004

This paper presents the development and application of a riparian buffer zone design model(RBZDM). The model was developed as a decision-making tool for watershed management, by integrating geographic information system(GIS) and analytical hierarchy process(AHP) theory. Several factors for watershed management, such as pollution removal capacity, land aquisition cost, distribution of point and non-point pollution sources, and possibility of new pollution source location, were analyzed based on AHP theory. The vegetated buffer zone width was designed using GIS-based riparian buffer analysis. The developed model was applied to the Kyoungan Stream watershed, which is an important part of Paldang lake catchment area. The Kyoungan stream watershed was divided into sixteen subbasins. Six of them belong to the main stem, where the model was applied. Ten alternatives of buffer zone width and five hierarchial levels were designed. The relative importance and the relative preference were computed by pair-wise comparison of evaluation criteria given in hierarchial levels. The buffer zone width was determined by linear function of the given alternatives and relative preferences. From this study, it was determined that the six buffer zone widths of Kyoungan main stems would be 1,594, 1,744, 1,856, 1,782, 1,338, 1,780 meter, from upstream to downstream.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.3
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• pp.51-62
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• 2013

The importance of environmental water has been risen in terms of river ecosystem soundness with preventing stream flow depletion in rural area, while enlarging agricultural reservoir project is conducted under the 4 main river restoration project for supplying more water to 4 main rivers. The aim of this study was to estimate the amount of environmental water release and analyze the release pattern during non-irrigation season in enlarged agricultural reservoirs. The 4 reservoirs (Dansan, Samga, Geumbong, Changpyeong) located on the upper region of Nakdong river were simulated applying the operation rule which was determined by release criteria curves. The simulated results indicated that the more environmental water could be released than the spillway release and continuous release was achieved with smaller range of fluctuation. In case of Changpyeong reservoir, average 506.0 thousand $m^3$ environmental water could be released on Feb., and it was about twice as much as the spillway release before the enlargement, and also, the 18 thousand $m^3$/day environmental water could be supplied to a stream consistently after enlargement. From the results, it was expected that the additional environmental water release will improve stream water flow during dry season in terms of quantity and quality of water.

• Journal of Environmental Impact Assessment
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• v.15 no.2
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• pp.157-163
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• 2006

The purpose of this study is to understand imperviousness impact for the characteristics of stormwater runoff and water temperature. The land-use map was used to estimate the watershed imperviousness(percent of impermeable area) and the RMS(Remote Monitoring System) was used to evaluate the stormwater runoff of watershed. This study was investigated for two streams(Jiam and Gongji) in Chunchon City. The detailed results of these studies are as follows; The imperviousness(%) of two watersheds(Jiam and Gongji) estimated by spatial analysis which is main function of GIS were 0.24% and 24.16%. So, Gongji watershed as urban area was about 100 times than jiam watershed as forest area. In case of rainfall of low intensity, stormwater runoff flowrate in higher imperviousness area(Gongji) was more than it in forest area(jiam). Also, The time to peak flowrate(Tp) was short in Gongji stream and the water temperature difference between Gongji and Jiam stream was about $4.4^{\circ}C$ in summer.