• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2001년도 학술발표회 발표논문집
• /
• pp.324-329
• /
• 2001

Sediment yields from the reservoir watershed areas and raising of the spillway crest for the agricultural reservoir capacity enlargement were investigated and analysed through the 21 pilot reservoirs, have irrigated areas 200has. and over in the Kyoungpook province. In these studies, (1), the correlation analysis between various watershed characteristics and annual specific sediment yields were derived and (2), the excess effective reservoir capacity of the over 0.5m above the spillway crest could be estimated. In brief, catchment area should strongly be correlated with the annual specific sediment yields (R=0.90), the other side, average slope of the main stream is less than catchment area. The excess effective capacity of reservoir enlargement by the raising of spillway crest at 0.5m-height was resulted 12.1% of increasing capacity compare with the original reservoir capacity.

• 한국환경과학회지
• /
• 제10권5호
• /
• pp.315-321
• /
• 2001

This study was conducted to estimate the decomposition capacity for organic matter by microbe of tidal flat sediments (Hajae, Dongjin and Mankyung). The decomposition rate constants (K') have been determined by Thomas slope method and compared with the values of each tidal flats. The decomposition rates of organic matter by microbe were initially very slow, but at the end of 12 hours, very sharply increased. The values of decomposition rate constant for Dongjin, Mankyung and Hajae tidal flat sediment were 1.364$day^{-1}$/, 1.080d$day^{-1}$ and 0.735$day^{-1}$, respectively. The decomposition rate constant of Dongjin tidal flat sediment which affected by livestock wastewater was higher than others. The decomposition quantity (mg/g/day) of organic matter by microbe of tidal flat sediments was 0.4mg/g/day for Dongjin, 0.36mg/g/day for Mankyung and 0.36mg/g/day for Hajae. The average of decomposition quantity was 0.37mg/g/day. To calculate purification capacity (kg/ha) of organic matter by microbe, we applied to two assumption ; 1) biological action by microbe is occur within 0.1cm under surface 2) specific gravity of sediment are 2.5g/$\textrm{cm}^2$. The purification capacity of organic matter by microbe of tidal flat sediment was calculated to 9.25kg/ha. The relationships between decomposition rate constant (K') and ignition loss (I. L), chemical oxygen demand by sediment (CO $D_{sed}$), total carbon(TC), silt and clay as index of organic matter were a high positive($R^2$=0.97~1.00).

• 물과 미래
• /
• 제9권2호
• /
• pp.67-75
• /
• 1976

With 9 existng reservoirs selected in the Sab-Gyo River Basin, the sedimentation of the reservoirs has been calculated by comparing the present capacity with the original value, which revealed its reduced reservoirs capacity. The reservoirs has a total drainage area of 6,792 ha, with a total capacity of 1,204.09 ha-m, and are short of water supply due to reduction of reservoirs capacity. Annual sedimention in the reservcire is relation to the drainage area, the mean of annual rain fall, and the slop of drainage area. The results of obtained from the investigation are summarized as follow; (1) A sediment deposition rate is very high, being about $9.19{m}^3/ha$ of drainage area, and resulting in the average decrease of reservoir capacity by 19.1%. This high rate of deposition could be mainly attributed to the serve denvdation of forests due to disor derly cuttings of tree. (2) An average unit storage of 415.8mm as the time of initial construation is decreesed to 315.59mm at present, as resultting, we could'nt supply water at 566.24ha. (3) A sediment deposition rate as a relation to the capacity of unit drainage area is as follow; $Qs=1.43 (c/a)^{0.531}$ (4) A sediment deposition rate as a relation to the mean of annval rainfall is as follow; $Qs=672.61 p^{0.024}$ (5) A sediment deposition rate as a relation to the mean slop of drainage area is follow; $Qs=267.21 S^{0.597}$

• 한국농공학회지
• /
• 제10권1호
• /
• pp.1413-1419
• /
• 1968

Yochon reservoir was consturcted with an original storage capacity of 202.7 chung-meters. This reservoir receives the water from watershed area of 933.0 chungbo and has irrigated area of 478.0 chungbo. In 1967 a detailed capacity survey of this reservoir was carried out by a new depth-recorder under the scheme of reservoir sedimentation of Agricultural Engineering Research Center. Significant findings are 1. The capacity of the reservoir for the water storage has been reduced by 8.9%(18.066 chung-meters out of the 202.7 chung-meters) since its construction, a period of just 39.0 years. 2. The sediment accumulation in the reservoir represents an average annual soil loss of 0.496mm depth(0.463 chung-meters) of soil from the watershed area of 933.0 chungbo. Eventually the capacity of the reservoir for the water storage will be reducing by about 25%(50.7 chung-meters out of the 202.7 chung-meters)in one hundred years since its construction. We have to set up controlling projects for those reservoir protections from the sediment, soil loss, and other failures. The depth recorder is very useful, convenient, and accurate machine for surveys of reservoir capacity and other river surveys.

• International Journal of Internet, Broadcasting and Communication
• /
• 제15권4호
• /
• pp.199-204
• /
• 2023

Periodic assessment of reservoir capacity is essential for better water resources management and planning for the future water use. Reservoirs and water storage structures raised on the rivers are subjected to sedimentation and he sedimentation is caused by deposition of eroded sediment particles carried by the streams. Knowledge of reservoir sedimentation is important to estimate avaliable storage capacity for optimum reservoir operation and scheduling water release. In recent years, remote sensing and GIS techniques have emerged as an important tool in carrying out reservoir capacity analysis and water management. The reduction in storage capacity as compared to the original capacity at the time of reservoir impounding is indicative of sediment deposition. In this study, the application of GIS and remote sensing techniques were applied to assess the sediment deposition, losses in the reservoir storage and the revised cumulative capacity. Satellite images covering Pyodongdong reservoir were analyzed using Erdas Imagine and ArcGIS softwares.Cumulative capacities at different levels were also calculated and we estimated that the revised live storage was 84.2Mft3 in 2021 and 64.3Mft3 in 2022 while the original capacity was 22.8 and 53.6Mft3 in 2021 and 2022.

• 한국지리정보학회지
• /
• 제14권1호
• /
• pp.94-106
• /
• 2011

본 연구에서는 GIS 기반 토사유실모델과 유사전달률 그리고 유효저수용량을 고려하여 댐 저수지별 흙탕물 발생 가능성을 분석하였다. 이를 위해 DEM, 토양도, 토지피복도 등의 공간자료를 기반으로 RUSLE 모델의 입력인자를 평가하여 유역대책 수립시 필요한 각 유역별 취약인자를 분석하였으며, 고랭지밭 특성을 고려한 토사유실량 평가를 통해 강우시 유역내 토사발생 잠재성을 분석하였다. 또한 유역면적을 고려한 유사전달률을 통해 유역별 토사유출량을 계산한 결과 충주댐과 소양강댐이 가장 높은 값을 나타내었으며, 유효저수용량을 고려한 유사농도 분석결과에서는 임하댐과 충주댐이 각각 0.791 $kg/m^3/yr$와 0.526 $kg/m^3/yr$로 가장 높게 나타났다. 특히 임하댐의 토사유출량은 소양강댐유역에 비해 약 2.36배 낮게 나타났으나 임하댐 저수지의 유효저수용량이 소양강댐에 비해 약 4.48배 작아 유사농도는 오히려 임하댐 저수지가 1.90배 높게 분석되었다. 본 연구에서는 10년 평균 강우사상을 이용하여 유사농도를 계산하였으며, 이를 통해 각 유역별 토양, 지형, 식생, 경작상태 그리고 유효저수용량 측면을 검토할 수 있었다. 따라서 이러한 정량화된 유사농도 자료들은 저수지의 고탁수 발생 잠재성을 평가할 수 있고 저수지 관리를 위한 효과적인 도구로도 활용될 수 있으리라 판단된다.

• 한국농공학회지
• /
• 제17권3호
• /
• pp.3840-3847
• /
• 1975

With 30 excisting reservoirs in the Chin-Young area, the Sedimentation of the reservoirs has been calculated by comparing the present capacity with the original value, which revealed its reduced reservoir capacity. The reservoirs has a total drainage area of 3l4l ha, with a total capacity of 43.23 ha-m, and are short of water supply due to reduction of reservoir capacity, Annual sedimentation in the reservoir is relation to the drainage area, the mean of annual rainfall, and the slop of drainage area. The results of obtained from the investigation are summarized as follows: (1) A Sediment deposition rate is high, being about 7.03㎥/ha of drainage area, and resulting in the overage decrease of reservoir capacity by 16.1%. This high rate of deposition coule be mainly attributed to the serve denudation of forests due to disorderly cuttings of tree. (2) An average unit storageof 116mm as the time of initial construction is decreased to 95.6mm at present. This phenomena cause a greater storage of irrigation water, sinceit was assumed that original storage quantity itself was already in short. (3) A sediment deposition rate as a relation to the capacity of unit drainge area is as follow: Qs=1.27(C/A)0.6 and standard deviation is 185.5㎥/$\textrm{km}^2$/year. (4) A sediment deposition rate as a relation to the mean of annual rainfall is as follow: Qs=21.9p10.5 and the standard deviation is 364.8㎥/$\textrm{km}^2$/year. (5) A sediment deposition rate as a relation to the mean slop of drainage area is follow: Qs=39.6S0.75 and the standard deviation is 190.2㎥/$\textrm{km}^2$/year (6) Asediment deposition rate as a relation to the drainage area, mean of rainfall, mean of slope of drainage area is: Log Qs=0.197+0.108LogA-6.72LogP+2.20LogS and the standard deviation is 92.4㎥/$\textrm{km}^2$/year

• 기술사
• /
• 제3권10호
• /
• pp.7-17
• /
• 1970

Fourteen reservoirs maintained by the local land improvement associations in the province of Chullabuk-Do and 20 reservoirs maintained by those in the province of Chullanam-Do, were surveyed in connection with a correction between storage capacity and sediment deposit. In addition to this survey, 3347 of small scale reservoirs, that lie scattered around in the above mentioned two provinces were investigated by using existing records pertaining to storage capacity in the office of City and Country, respectively. According to this inrestigation. the following conclusions are derived. 1. A sediment deposition rate is high, being about 10.63m$^3$/ha of drainage area, and resulting in the average decrease of storage capacity by 27.5%. This high rate of deposition could be mainly attributed to the severe denudation of forests due to disorderly cuttings of trees. Especially, in small scale reservoirs, an original average design storage depth of 197mm in irrigation water depth is decreased to about 140mm. 2. An average unit storage depth of 325.6mm as the time of initial construction is decreased to 226mm at present. This phenomena causes a greater shortage of gation water, since it was assumed that original storage quantity itself was already in short.

• 한국환경과학회지
• /
• 제1권2호
• /
• pp.59-69
• /
• 1992

In order to predict the distribution of chemical species of copper and cadmium in water, conditional stability constant and complexation capacity between copper or cadmium and natural aquatic sediment have been determined in a shallow lake in Haman, Kyungnam. Kinetic parameters were calculated by Langmuir isotherm equation. Conditional stability constant was log $K_{cuSed}=4.78 and log K_{cdSed}=4.45$. Complexation capacity was $1.70{\times}10^{-4}$moles/g for copper and $5.54{\times}10^{-5}$moles/g for cadmium. Accuracy of experimental values of conditional stability constant was checked by comparing the calculated concentration of the metals with the measured one. Relatively good agreement between these values was obtained. Relative errors were 8.9% for copper and 6.5% for cadmium. Data of the measured conditional stability constant were put into data base of MINEQL computer program, and concentration of various chemical species of copper and cadmium in a model aquatic system was calculated. Aquatic sediment was associated with copper at the concentration of $10^{-5M}(0.059g/\ell)$10-5M(0.059g/l) and with cadmium at the concentration of $10^{-6M}(0.018g/\ell)$, and it significantly influenced on the distribution of chemical species of the metals. This result showed that prediction of chemical species of the heavy metals in an aquatic system should be taken into account the influence of the sediment.

• Journal of applied mathematics & informatics
• /
• 제41권1호
• /
• pp.181-192
• /
• 2023

This work deals with the numerical modeling of dam-break flow over erodible bed. The mathematical model consists of the shallow water equations, the transport diffusion and the bed morphology change equations. The system is solved by central upwind scheme. The obtained results of the resolution of dam-beak problem is presented in order to show the performance of the numerical scheme. Also a comparison of central upwind and Roe schemes is presented.