• Journal of the Korean Geographical Society
• /
• v.52 no.1
• /
• pp.15-24
• /
• 2017

Management of non-point sources for water quality control practice is complicating but very important. Sediments mainly from croplands are prioritized in non-point source management due to the sediment attached phosphorous. In this study, flow and sediment yields are modeled in Oenam watershed located in Hwasun, Jeollanam-do, a upstream of Juam Lake. A spatially distributed model and GIS(Geographic Information System) data was used to find out hot spots of sediment yields, to analyze the effectiveness of filter strips, and to visualize the effectiveness. The impacts of filter strips was estimated on the reduction of flow and sediments at 17.2% and 46.4% respectively when the filter strips were installed in the sub-watersheds with the most serious sediment yields.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.56 no.5
• /
• pp.21-27
• /
• 2014

Sediment-laden water is problematic in aquatic ecosystem and for hydraulic structures in a watershed, and agriculture area in a watershed is one of source areas of nonpoint source (NPS), since soil surface typically exposures due to agricultural activities. Especially, severe sediment might flow into stream when agricultural area is located near stream like the Imha-dam watershed. Soil erosion is affected by precipitation, therefore there is a need to consider precipitation characteristics in soil erosion and best management practices (BMPs) simulation. The Web-based Spreadsheet Tool for the Estimation of Pollutant Load (STEPL WEB) allows estimating long-term sediment loads and the impact of best management practices to reduce sediment loads. STEPL WEB and predicted precipitation data by MIROC-ESM model was used to estimate sediment loads and its reduction by filter strip and conversion of agricultural area to forest in the future 30 years. The result indicates that approximately 70 % of agricultural area requires filter strip installation or that approximately 50 % of agricultural area needs to be converted to forest, for 41 % of sediment load reduction.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.5
• /
• pp.584-593
• /
• 2021

The sediment makes up the sea floor and plays an important role as a habitats for living things in the sea. However, pollution of coastal sediment due to internal and external factors such as inflow of contaminants from land and self-pollution becoming more serious, the needs for management of sediment that play an important role in ecology, is increasing. In particular, the review and evaluation of the effects of sediment in marine development projects including reclamation and dredging, have significance in terms of proactive protection and management of surrounding ecosystems. This study proposed the improvement measures for marine sediment management standards on the sea area utilization consultation for the development of public water. For the purpose, The evaluation and management standards of domestic and overseas marine sediments were reviewed and compared. The sediment environment guidelines under the Marine Environment Management Act of Korea were reviewed. Accordingly, the cases of Canada and NOAA, which have various evaluation standards consist of comprehensive factors, were analyzed. For analysis of operational cases, the port and fishing port development projects for the last five years (2016-2020) that are considered to have the greatest impact on sediments among the sea area use consultations were also reviewed. Finally, this study suggested that the assessment factors for ecological hazards and potential human risks should be considered in the sediment environmental standards in the sea area utilization consultation system.

• Journal of Korean Society on Water Environment
• /
• v.22 no.6
• /
• pp.1094-1100
• /
• 2006

In this study, the reservoir sediment reduction methods for long-term operation are proposed by the analysis of both sediment deposit characteristics and sediment reduction effect by each method. To that end, a flowchart for sediment analysis in reservoir is established and sediment deposit is simulated by SMS-SED2D model. The sediment reduction methods which are sediment passing (sluicing), flushing, trapping, bypassing and mechanical removal are used. From the simulation results, the effective method for sediment reduction is operation which is coupled by both sediment passing with sand gate and sediment trapping with debris dam. And If sediment flushing will be used once a year after 50 years, conservation storage can be secured until 100 years after dam construction.

• Journal of Forest and Environmental Science
• /
• v.34 no.2
• /
• pp.192-195
• /
• 2018

To establish a management strategy of sediment-related disasters for adaptation to climate change, it is necessary to 1) understand the specific details and problems about the present status, 2) systematize related technologies by using exact numerical values obtained from physically-based analysis, and 3) ensure the basic guidelines are applied to field elastically. To achieve these successfully, detailed guidelines are required by scientifically considering the utilization and impact of related technology on the field. Here, detailed guidelines should include 1) the development of a basic plan, 2) enhancement of relevant technical instructions, 3) establishment of survey and inspection methods, 4) procedure of erosion control works in urban living sphere, and 5) proactive countermeasures against sediment-related disaster caused by earthquakes.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.40 no.4
• /
• pp.85-93
• /
• 1998

In the 2nd year study of a 5 year project to evaluate the soil quality and develop the best management practices for mountaineous soils, 11 runoff plots were treated and monitored with respect to physical property of the soil, runoff and sediment discharge, and the following results were obtained. 1. Bulk density and porosity did not show any siginificant difference between experimental treatments. 2. Runoff was basically dependent on the soil's physical property and tillage. Up-and-down plots showed the highest runoff while contour plots the lowest runoff. 3. Sediment yield in the mountaineous soils was directly related to tillage and residue cover. Residue covered plots showed the lowest sediment yield and up-and-down plots the highest sediment yield. And it is recommended that the best management practices using till_age and residue cover for the mountaineous soils must be developed to protect soil quality and maintain agricultural productivity.

• Korean Journal of Environmental Agriculture
• /
• v.38 no.4
• /
• pp.307-313
• /
• 2019

BACKGROUND: An intensive farming system may be of the most important source for agricultural non-point source (NPS) pollution, which is a major concern for agricultural water management in South Korea. Various management practices have therefore been applied to reduce NPS loads from upland fields. This study presents performances of sediment trap for reducing NPS and soil loss from rainfall runoff in cropland. METHODS AND RESULTS: In 2018 and 2019, three sediment traps (L1.5 m × W1.0 m × D0.5 m = 0.75 ㎥) and their controls were established in the end of sloped (ca. 3%) upland field planted with maize crops. Over the seasons, runoff water was monitored, collected, and analyzed at every runoff. Soils deposited in sediment traps were collected and weighed at the season end. Sediment traps reduced runoff amount (p<0.05) and NPS concentrations, though the decreased NPS concentrations were not always statistically significant. In addition, sediment traps had a significant prevention effect on soil loss from rainfall runoff in a sloped cropland. CONCLUSION: The results suggest that the sediment trap could be a powerful and the best management practice to reduce NPS pollution and soil loss in a sloped upland field.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.693-697
• /
• 2009

Physically-based WEPP watershed version was applied to a watershed, located at Jawoon-ri, Gangwon with very detailed rainfall data, rather than daily rainfall data. Then it was validated with measured sediment data collected at the sediment settling ponds and through overland flow. The $R^2$ and the EI for runoff comparisons were 0.88 and 0.91, respectively. For sediment comparisons, the $R^2$ and the EI values were 0.95 and 0.91. Since the WEPP provides higher accuracies in predicting runoff and sediment yield from the study watershed, various slope scenarios (2%, 3%, 5.5%, 8%, 10%, 13%, 15%, 18%, 20%, 23%, 25%, 28%, 30%) were made and simulated sediment yield values were analyzed to develop appropriate soil erosion management practices. It was found that soil erosion increase linearly with increase in slope of the field in the watershed. However, the soil erosion increases dramatically with the slope of 20% or higher. Therefore special care should be taken for the agricultural field with higher slope of 20% or higher. As shown in this study, the WEPP watershed version is suitable model to predict soil erosion where torrential rainfall events are causing significant amount of soil loss from the field and it can also be used to develop site-specific best management practices.

• Computers and Concrete
• /
• v.13 no.1
• /
• pp.83-96
• /
• 2014

Accumulated annual reservoir sedimentation in Taiwan was 14.6 million m3 in 2010, seriously endangering reservoir safety and the water supply. In addition, the sintering temperature of reservoir-sediment aggregates (RSAs) is very high, and very energy consuming consequently. Therefore, to explore the effects of admixtures on sintering behavior and performance of the aggregates, two different admixtures are blended, waste-glass and municipal sewage sludge, into reservoir sediment to make artificial aggregates. Experimental results show that the lightweight characteristics of waste-glass/reservoir-sediment aggregates (WGRSAs) are more significant than those of sewage sludge/reservoir-sediment aggregates (SSRSAs). Moreover, as sintering temperature increases, the specific gravity of WGRSAs drops more apparently. The optimum sintering temperature of pure reservoir-sediment aggregates (PRSAs), SSRSAs, and WGRSAs was $1150^{\circ}C$, $1100^{\circ}C$, and $1050^{\circ}C$, respectively. The PRSAs are normal weight with better strength; the WGRSAs are lightweight and energy-saving; and the SSRSAs are lightweight with normal strength.

• Journal of Korean Society on Water Environment
• /
• v.22 no.6
• /
• pp.1088-1093
• /
• 2006

In this study, the method of annual sediment estimation for reservoir long-term operation is proposed. Long-term daily precipitation and evaporation are predicted by Markov Chain. Using these values, reservoir inflow is simulated by NWS-PC model. Reservoir sediment load is estimated by sediment rating relation curve which is observed. From the simulation results, it was found that each simulated value by Markov Chain and NWS-PC was well compared to the observed ones and also estimated reservoir sediment was appropriate to the compared values using empirical equations. It is thought that the proposed method for estimation of reservoir sediment can be useful used to operate the reservoir.