• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.6
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• pp.133-144
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• 2010

The objective of this planning proposal is to rehabilitate the urban stream which has been ecologically disturbed in the urban process. The experimental stream, Su-am stream located in Anyang City is typical urban stream in adjacent land use and the spatial condition. The stream in the watershed context, is the second tributary of Han River, in the Anyangcheon watershed. The Characteristics of the stream reach were analyzed by the river corridor survey. In the conceptual phase, Rehabilitation Programs were established based on the hydrological, ecological and spatial characteristics of the stream. Spatial zoning concept according to the characteristics of the stream and adjacent land use, was suggested 4 types of zoning; ecological preservation zone, natural landscape zone, neighborhood water-friendly zone and CBD water-friendly zone. Implementation Practices can be summarized as follow: For The longitudinal river continuum, some In-stream practices were suggested and implemented; such as channel alignment, step & pool, pool & riffle and low-flow channel bank. For latitudinal continuum and intimate spatial relationship between Sam-duk Park & Su-am stream, gentle sloped bank was planned and implemented. After stream improvement & ecological Implementation, follow-up monitoring and adaptive management programs will be a meaningful process for ecological rehabilitation.

• Economic and Environmental Geology
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• v.27 no.6
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• pp.579-592
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• 1994

A case study is presented where a fluvial system is modeled in three dimensions and compared to data gathered from a study of the Arkansas River. The data is unique in that it documents changes that affected a straight channel that was excavated within the river by the U.S. Army Corps of Engineers. Excavation plan maps and sequential aerial photographs show that the channel underwent massive deposition and channel migration as it returned to a more natural, meandering path. These records illustrate that stability of fluvial system can be disrupted either by catastrophic events such as floods or by subtle events such as the altering of a stream's equilibrium base level or sediment load. SEDSIM, Stanford's Sedimentary Basin Simulation Model, is modified and used to model the Arkansas River and the geologic processes that changed in response to changing hydraulic and geologic parameters resulting from the excavation of the channel. Geologic parameters such as fluid and sediment discharge, velocity, transport capacity, and sediment load are input into the model. These parameters regulate the frequency distribution and sizes of sediment grains that are eroded, transported and deposited. The experiments compare favorably with field data, recreating similar patterns of fluid flow and sedimentation. Therefore, simulations provide insight for understanding and spatial distribution of sediment bodies in fluvial deposits and the internal sedimentary structure of fluvial reservoirs. These techniques of graphic simulation can be contributed to support the development of the new design criteria compatible with natural stream processes, espacially drainage problem to minimize environmental disruption.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.3
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• pp.103-111
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• 2012

Works for dam heightening plan have dual purposes: flood disaster prevention by securing additional storage volume and river ecosystem conservation by supplying stream maintenance flow. Now, the dam heightening project is in progress and there are 93 dam heightened reservoir. After the dam heightening project, 2.2 hundred million ton of flood control volume in reservoirs will be secured. Thus it is necessary to evaluate the effects of the dam heightening project on watershed hydrology and stream hydraulics, and resulting flood damages. This study was aimed to assess the impact of outflow from the dam heightened reservoir group on the Whangryong river design flood. The HEC-HMS (Hydrologic Engineering Center-Hydrologic Modeling System) model was used for estimating flood discharge, while HEC-5 (Hydrologic Engineering Center-5) was used for reservoir routing. This study analysed flood reduction effect on 100yr and 200yr return periods about the before and after heightening of agricultural dams. Based on the results of this study, the reduction of flood peak discharge at downstream of the reservoir group was estimated to be about 41% and 53% for 100yr and 200yr frequencies, respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.69-69
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• 2021

From the unprecedented 2011 spring flood, the residens reside by Lake Champlain and Richelieu River encountered enormous damages. The International Joint Committee (IJC) released the Lake Champlain-Richelieu River (LCRR) Plan of Study (PoS). One of the major tasks for the PoS is to investigate the possible scenarios that might happen in the LCRR basin based on the stochastic simulation of the Net Basin Supplies that calculates the amount of flow into the lake and the river. Therefore, the current study proposed a novel apporach that simulate the annual NBS teleconnecting the climate index. The proposed model employed the bivariate empirical decomposition to contamporaneously model the long-term evolution of nonstationary oscillation embeded in the annual NBS and the climate signal (here, Artic Oscillation: AO). In order to represent the variational behavior of NBS correlation structure along with the temporal revolution of the climate index, a new nonstationary parameterization concept is proposed. The results indicate that the proposed model is superior performance in preserving long and short temporal correlation. It can even preserve the hurst coefficient better than any other tested models.

• Resources Recycling
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• v.12 no.6
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• pp.64-70
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• 2003

China is in the midst of readiness for the jump of the IT industry. It is generally esteemed in business circles that China will step up to the level which can be called the strong country of IT in the aspect of quality as well as the expansion of quantity China has put in operation the supporting policies of IT industry altogether through 'The 10th 5-year plan' which has begun since 2001 keeping pace with it, we are going to find out the desirable directions which we head for by looking into the present situation and policies for the development of Jung-kyung, where 'The master plan of the western development' is now Per-forming to balance the big economic disparity in the eastern and western areas.

• Journal of Environmental Science International
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• v.23 no.4
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• pp.595-603
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• 2014

Jeju Island, a volcanic island, is the region that shows the biggest rainfall and has a big elevation-specific deviation of precipitation, but Jeju Island River Maintenance Plan doesn't reflect the characteristics of Jeju Island as it only calculates probable precipitation from four weather stations with elevation less than 100m. Therefore, this study uses AWS observational data in four Jeju Island weather stations and other regions to calculate location-specific probable precipitation, review the elevation-probable precipitation correlation in southern and northern regions, and create a probable precipitation map for all regions of Jeju Island, in order to produce better outcomes. This study is expected to be the most basic data to establish a safe Jeju island from flood disaster in preparation for the future climate changes and widely used for Jejudo Basin Dimension Planning, River Maintenance Plan, Pre-Disaster Impact Review, etc.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.509-516
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• 2020

Since the 1960s, many rivers have been polluted and destroyed due to river repair projects for economic development and the covering of small rivers due to urbanization. Many studies have analyzed rivers using measured river topographic factors, but surveying is not easy when the flow rate changes rapidly, such as during a flood. In addition, the previous research has been mainly about the cross section of a river, so information on the longitudinal profile is insufficient. This research used informational entropy theory to obtain an equation that can calculate the average river slope, river slope, and river longitudinal elevation for a river basin in real time. The applicability was analyzed through comparison with measured data of a river's characteristic factors obtained from a river plan. The parameters were calculated using informational entropy theory, nonlinear regression analysis, and actual data. The longitudinal elevation entropy equation for each stream was then calculated, and so was the average river slope. All of the values were over 0.96, so it seems that reliable results can be obtained when calculating river characteristic factors.

• Journal of Environmental Impact Assessment
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• v.28 no.3
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• pp.215-230
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• 2019

The objective of this research is to evaluate the water quality characteristics using the statistical analysis of major tributaries in the Han River and to provide water quality improvement plan by selecting tributaries that should be preferentially managed by river grade classification method. The major 15 tributaries in Han River watershed were monitored for discharge and water quality during January-December 2017. As a result of the correlation analysis, the river discharge has been not correlation with other water quality constituents (p>0.05) but COD and TOC were significantly correlated (r=0.957, p<0.01). The main cause of water quality fluctuation was organic pollutants and nutrients in the principal component analysis (PCA) method. The BOD, COD, TOC, TN, and TP were found to be significantly different (p<0.05) by seasonal in result of one-way ANOVA analysis. Result of river grade classification by quantitative indicators the tributaries requiring improvement of water quality were Gulpocheon, Anyangcheon, Wangsukcheon, and Tancheon which affected by wastewater treatment plant.In this research, we determined tributaries that need to improve the water quality of Han River watershed and it can be used as an important data for efficient water quality management.

• Ecology and Resilient Infrastructure
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• v.11 no.2
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• pp.43-54
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• 2024

Recently, most of the rivers in Korea are experiencing various problems in dimension and river environment, such as expansion of stable area where disturbance does not occur during flood, increase of excessive trees in river channel, fixation of river channel, reduction of sand bar. When the soil supplied by the flood is deposited in the river, the plant is settled in the formed terrain, and when another disturbance of the scale that does not erode there occurs after the plant is settled, the river gradually grows and the vegetation zone is formed there. In particular, in terms of river management, river forestation and river aggradation are objects that must be managed because they are disadvantageous in terms of flood control by lowering the flow rate and raising the water level. Therefore, in this study, the area of vegetation occupied by the year of sandbar was analyzed in the process of river aggradation in Jang-Hang wetland. In addition, the correlation between the growth of Jang-Hang wetland was analyzed through the analysis of the flow rate and the flooding frequency that directly affect the growth of Jang-Hang wetland. Through this, the management plan of Jang-Hang wetland, which is registered in Ramsar Wetland but has been river forestation and is undergoing river aggradation, was proposed.

• Korean Journal of Agricultural Science
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• v.37 no.1
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• pp.105-112
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• 2010

The objective of this study is to develop a standardized model for analyzing water balances in large scaled water basin by considering agricultural water districts, and to evaluate the hydrological feasibility of applying this model to several water districts such as Nonbul, Geumbok, Daejeon 1, Daejeon 2, and Cheonggang in Geum river basin. Ten types of stream network were considered in developed model. Using this model, streamflows were simulated by major stations and water balances were analyzed by water districts. Simulated streamflows and measured streamflows were compared at check stations such as Gapcheon and Bugang stations in which Nash and Schcliffe's model efficiencies were 0.633, 0.902, respectively. This results showed its applicabilities to national water resources plan, rural water development plan, and total maximum daily load plan in Korea.