• Current Research on Agriculture and Life Sciences
• /
• v.29
• /
• pp.11-19
• /
• 2011

This research gives weight to establish practical improvement based on analysis of the landscape ecological character and value to realize the importance of small wetland and stream in cultivated areas functioning as a residual landscape element in rural landscape and to deal with ecological depression effectively. The results of summary are as follows. 1) The results of landscape ecological character analysis of wetlands biotop in total of 7 sites, for example, size of surface in site 5 was widely formed about $10,600m^2$, which was assessed satisfactory in terms of slope of waterfront, width of hedgerow, vegetation condition of composition and so on. Also, The number of flexibility showed 2 in site 8-1, the highest, and morphological diversity showed 1.47, the highest. 2) The results of problem analysis of wetland biotop, most of wetlands are analyzed that the width of hedgerow was below 1m. Also, the 4 wetlands in site 8 are appeared that hard to live slope vegetation in there because of slope of waterfronts are above $45^{\circ}$. 3) The results of landscape ecological character analysis of stream in total of 6 sites, for example, width of waterfront in site 4 showed 55m, the widest, and investigated consist of natural ingredients such as soil, rock, gravel. However, width of waterfront in site 2-2 showed 4m, the narrowest, and inclined angle of slope was formed a right angle. 4) The results of problem analysis of stream, width of waterfront hedgerow in site 2-1 showed about 5m, which was very narrower than width of waterfront, and toxic chemicals discharged from near cultivated area without any filtering. Also, all areas of site 2-2 was formed concrete, and was assessed dissatisfactory in terms of capacity of nature purification, flood control, habitat living space because of straight stream. 5) Based on the result above landscape ecological character and problem analysis, main improvement guidelines are set in terms of shape, vegetation, topography in case of wetlands, and which are set in terms of vertical, horizontal structure in case of stream.

• Water for future
• /
• v.28 no.3
• /
• pp.197-204
• /
• 1995

The runoff from an urban catchment is increased because of the gravitation of the population towards cities. For this reason, water level increment in confluence area makes it impossible to drain internal water and thus produces flood out in upstream areas. In this study, flow variations of main channel are measured which is caused by combining storm sewer into main channel in small watershed. Depth increment in main stream is analyzed due to flowrate and slope in main channel and flowrate, slope is getting steeper, and also due to low flowrate in main stream and high flowrate in tributrary channel. For the degree of confluence, depth ratio decreases when the degree is getting small. As mentioned above, main factors influencing the depth ratio increment of confluence channel are in the order of the degree of confluence, and the flowrate of tributary channel and main channel.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.27 no.2
• /
• pp.41-50
• /
• 1999

The purpose of this study is to find out the changes in geomorphic characteristics of a small watershed when a golf course is constructed. The research site is a set of seven small watersheds including an 18-hole golf course that were randomly selected. The size, shape, and drainage network of watersheds were measured by using planimeter, watershed eccentricity, and stream order, respectively. In addition, a 25m$\times$25m mesh was used on topographic maps and grading plans in order to obtain the slope, elevation, and aspect of the watersheds. The major results of this research, while investigating of the changes in geomorphic characteristics of watersheds when a golf course is constructed, are as follows: 1. The size of watersheds is increased in accordance to the difference in elevation between the golf course site and the small watershed. 2. The watershed eccentricities are in general similar except for a few low-valued cases. 3. The changes in the average altitude and the gradient are more drastic with their bigger original values. 4. The aspects are changed more with decreasing elevation. 5. The stream order decreases in the case of a low watershed eccentricity. 6. The surface modification has a closer relationship to the slope rather than the size of effective use area. 7. With a steeper gradient and an excessively low gradient, the height of cutting/filling is increased.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.21 no.3
• /
• pp.67-81
• /
• 2018

We tried to analyze qualitatively a total of 110 the research papers which were related domestic ecological restoration technologies about 15 years through semantic network analysis in social network analysis. In order to understand the research trends of ecological restoration technologies, we analyzed the degree centrality and betweenness centrality of the Stream/Wetland, Slope, Soil/Others fields selected as Word Cloud. As a result, ecological restoration technologies have been changed. They were focused on the restoration of species or their habitats in the past. However, they have been evolved into the detailed systems to respond in unpredictable natural disasters and climate change, high-resolution image implementation technology to accurately grasp the practical environment and methods related to environmental restoration for human in urban ecosystem. In the future, investment and technology for the ecosystem restoration field will be continuously demanded for the symbiosis of human beings and species in the damaged ecosystem. Therefore, the research trend of ecological restoration technologies should be provided as reliable guidelines when decision makers establish the policy direction or when researchers select their subjects.

• Journal of Korea Water Resources Association
• /
• v.51 no.3
• /
• pp.183-193
• /
• 2018

Channel-forming discharge for downstream section of Yeongju dam in Naesung stream was calculated to analyze stable channel geometry. Determined channel-forming discharge was applied to design stable channel slope, depth, and base width at Yonghyeol station. Used data for channel-forming discharge and stable channel analysis were collected in downstream section of Yeongju dam in Naesung stream before the dam construction. Specified recurrence interval discharge, effective discharge, and bankfull discharge were analyzed and compared to decide final channel-forming discharge which was $260m^3/s$ of bankfull discharge. Stable channel analysis and design program was applied to predict stable channel section of width, depth, and slope with various sediment transport equations of Ackers and White, Brownlie, Engelund and Hansen, and Yang's equations. As a result, all equations of sediment transport produced milder slopes compared to current bed slope of 0.00177 and Ackers and White equation presented the most similar flow depth of current section with the design constraint of current channel width.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.12 no.2
• /
• pp.101-108
• /
• 1992

A careful re-examination has been conducted on the applicability of the concept of equilibrium riverbed slope to river engineering practice and on the validity of Aki's and Mononobe's formulas that are widely used in Korea for determination of equilibrium riverbed slope. A stream in equilibrium is one in which, over a period of years, slope is naturally adjusted to provide, with available water discharge and with prevailing channel characteristics, just the velocity required for transportation of the sediment load supplied from the upstream. The equilibrium riverbed slope is the bed slope of such river. The present river engineering practice to analyze the riverbed characteristics by applying so called 'the equilibrium riverbed slope formula' to such rivers, therefore, should be avoided. Also, the validities of Aki's and Mononobe's formulas, that are presently used for determination of stable channel slope, are very dubious and should not be used in river engineering practice.

• Journal of The Geomorphological Association of Korea
• /
• v.18 no.4
• /
• pp.247-259
• /
• 2011

This research aimed to analyse geomorphic resources of Mt. palgong(in Daegu city and Gyeongbuk province) through some field surveys, and then to clarify geomorphic features. The main results are as follows. 1) The geological boundary of the south slope(granite) is more clear than one of the north slope(granite bedrock and metamorphic sedimentary rock). Small basins are along with fault line between granite bedrock and metamorphic sedimentary rock. 2) It is estimated that relatively big valleys on the north slope are due to local climate, geomorphic and geological features. 3) Tor, sheeting joint, gutter are well developed both on the south slope and on the north slope, however the development of polygonal cracking and boulder stream are more dominant on the south slope; river cliff, pool, waterfall are more dominant on the north slope with valleys that well developed. 4) Scenic geomorphic landscapes are mainly developed in Dongsan valley and Chisan valley on the north slope. 5) There are many interesting geomorphic resources in the viewpoint of storytelling in Mt. Palgong. So the specific design to utilize such resources is required

• Journal of the Korean Institute of Landscape Architecture
• /
• v.28 no.1
• /
• pp.83-91
• /
• 2000

This study was carried out to develop the close-to nature construction technology for the stream which has been improved just for the flood control with artificially straightened and concrete covered, losing the various functions of the stream such as wild-life habitat, polluted water purification and waterscape. Jungpyung stream in youngin City, Kyunggi Province was selected as a case study site. The results were as follows; 1. Existing stream improvement planning could accept the close-to-nature techniques of the low-flow revetment, keeping the capability of flood control and water use. 2. The low-flow revetment was planned and executed to the bottom of the stream without damaging the existing bank, and the slope of the low-flow revetment was adjusted as 1:1.2∼1.5. Consequently it would not disturb the water flow when the flood occurred and it would keep the constant water flow even at the drought with providing a stable ecosystem and water purification. 3. Low-flow revetement was planted with Salix species and perennials naturally, and it would be a precious biotope for the diverse floras and faunas. 4. Some furnitures such as stepping stone bridge, wooden bridge and step were installed to the suitable locations for the convenience of users, and it will be ot only the sound stream environment but also easy access to the waterscape. 5. This case study site will be monitored for 3 years systematically after the construction was finished in September, 1999 to get the exact results for the scientific approvement

• Journal of the Korean Society of Hazard Mitigation
• /
• v.4 no.4 s.15
• /
• pp.13-19
• /
• 2004

The tremendous flood damage caused by Typhoon Rusa(2002) was occurred at GangNeung City in GangWon Province. Almost of the city region was inundated and most of the stream channel facilities were damaged by flash flood with heavy rainfalls. We have investigated seriously damaged parts of stream bank and tried to analyze the causes of damages focused on flow characteristics in curved channel. We analyzed the damage aspects of curved channel by examining geomorphological survey and hydrographical characteristics. Strong correlation was shown according to the regression analysis between length of stream and meander wave length, and meander belt and length of stream. Furthermore, enveloped curve was presented between bottom slope of channel and meander belt, and meander ratio and channel width. As a result, special consideration about stream flow characteristics are needed for engineers who design stream banks and channels.

• Journal of Korean Society of Rural Planning
• /
• v.17 no.2
• /
• pp.23-32
• /
• 2011

The purpose of this study is to produce basic planning criteria required in ecological restoration and improvement works of streams in rural area through the application of stream assessment methods (water quality, soil environment, and ecological function assessment) at 6 study sites of Han River basin. The investigation results were as followings; 1) There were the evaluation items like a manure use, salt degree, river peripheral tree, which did not fitted to apply to domestic streams, in the SVAP (Stream Visual Assessment Protocol) and NRCS Riparian Assessment that were evaluation models developed in USDA. The area inhabitants with a little knowledge and education personally seems to utilize the evaluation methods through improvement partly with an aspect that evaluation is slightly easy. 2) From the stream assessment results, the construction of diverse pools, large woody debris and isolated backwater pool are needed to improve a few of problems observed at the mostly study sites. The result of NRCS Riparian Assessment showed that the improvement of stream bank vegetative communities is needed by planting tree with deep-binding root masses, and managing of noxious weeds and exotic undesirable plants. 3) Summing up, the assessment results showed that the assessment scores were higher at upstream than downstream, the stream with totally maintenance than that with partly maintenance, the stream with slope bank than that with vertical bank, and the stream with a flood plain than that without a flood plain. So, the direction of stream maintenance projects must be set by consideration of those results.