• 제목/요약/키워드: Soil dam

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불포화 수리특성에 대한 댐체 침투 거동의 민감도 분석 (Sensitivity of Seepage Behavior of Dam to Unsaturated Soil Properties)

  • 조성은
    • 한국지반공학회논문집
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    • 제21권3호
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    • pp.119-131
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    • 2005
  • 댐 안정성 평가를 위하여 불포화 이론을 이용한 침투해석 기법이 널리 사용되고 있으나 지반의 불포화 거동에 대한 인식 부족과 실험절차의 번거로움으로 인하여 입력 물성치에 대한 체계적인 실험과 평가가 일반화되지 못하고 있는 실정이다. 불포화 수리특성에 따라 침투수량 및 간극수압 분포 등 댐체 및 제방의 침투거동이 달라지나 국내 지반에 대한 실험자료 부족으로 대부분 단순 추정에 의한 값을 사용하고 있다 본 연구에서는 불포화 수리특성이 댐체의 침투 거동에 미치는 영향을 살펴보기 위하여 함수특성곡선과 투수계수곡선에 대하여 고찰하고 수치해석을 수행하였다. 해석결과 변수 a와 n은 값이 클수록, m은 값이 작을수록 중력에 의한 침윤선의 하강이 빨리 발생하였다. 유한차분 형식에 의해 개략적으로 계산한 민감도는 침윤선 부근에서 가장 크게 나타났고 시간에 따른 민감도의 변화에는 함수특성곡선의 기울기와 관련된 n값이 가장 큰 영향을 주었다.

SATEEC 시스템을 이용한 객토 토양의 토성고려에 따른 도암댐 유역의 토양유실 및 유사량 분석 (Analysis of Soil Erosion and Sediment Yields at the Doam-dam Watershed considering Soil Properties from the Soil Reconditioned Agricultural Fields using SATEEC System)

  • 유동선;안재훈;윤정숙;허성구;박윤식;김종건;임경재;김기성
    • 한국물환경학회지
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    • 제23권4호
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    • pp.518-526
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    • 2007
  • There have been serious soil erosion and water pollution problems caused by highland agriculture practices at Doam-dam watershed. Especially agricultural activities, chemical and organic fertilizer and pesticide applications, soil reconditioning to maintain soil fertility are known as primary causes of soil erosion and water qaulity degradation in the receiving water bodies. Among these, soil reconditioning can accelerate soil erosion rates. To develop soil erosion prevention practices, it is necessary to estimate the soil erosion from the watershed. Thus, the Universal Soil Loss Equation (USLE) model has been developed and utilized to assess soil erosion. However, the USLE model cannot be used at watershed scale because it does not consider sediment delivery ratio (SDR) for watershed application. For this reason, the Sediment Assessment Tool for Effective Erosion Control (SA TEEC) was developed to assess the sediment yield at any point in the watershed. The USLE-based SA TEEC system can estimate the SDR using area-based SDR and slope-based SDR module. In this study, the SATEEC system was used to estimate soil erosion and sediment yield at the Doam-dam watershed using the soil properties from reconditioned agricultural fields. Based on the soil sampling and analysis, the US LE K factor was calculated and used in the SA TEEC system to analyze the possible errors of previous USLE application studies using soil properties from the digital soil map, and compared with that using soil properties obtained in this study. The estimated soil erosion at the Doam-dam watershed without using soil properties obtained in the soil sampling and analysis is 1,791,400 ton/year (123 ton/ha/year), while the soil erosion amount is 2,429,900 ton/year (166.8 ton/ha/year) with the use of soil properties from the soil sampling and analysis. There is 35 % increase in estimated soil erosion and sediment yield with the use of soil properties from soil reconditioned agricultural fields. Since significant amount of soil erosion are known to be occurring from the agricultural fields, the soil erosion and sediment yield from only agricultural fields was assessed. The soil erosion rate is 45.9 ton/ha/year without considering soil properties from soil reconditioned agricultural fields, while 105.3 ton/ha/year after considering soil properties obtained in this study, increased in 129%. This study shows that it is very important to use correct soil properties to assess soil erosion and sediment yield simulation. It is recommended that further studies are needed to develop environment friendly soil reconditioning method should be developed and implemented to decrease the speed of soil erosion rates and water quality degradation.

해안지역 지하수댐 염수침입 방지기술 개선 방안 (Countermeasure to Prevent Seawater Intrusion on Coastal Area)

  • 부성안;이기철;김진성;정교철;고양수
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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    • pp.148-154
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    • 2002
  • Groundwater Dam is one of the reliable techniques to get huge amount of groundwater abstraction for municipal, agricultural, drinking, industrial water supply system. It can be a major technique to solve water shortage problems when it based on the sufficient watershed, proper topology, and adequate aquifer distribution and pollution control. It is suggested that the two consecutive underground wall in the coastal area to prevent seawater intrusion beneath a single wall.

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Bhumipol Dam Operation Improvement via smart system for the Thor Tong Daeng Irrigation Project, Ping River Basin, Thailand

  • Koontanakulvong, Sucharit;Long, Tran Thanh;Van, Tuan Pham
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2019년도 학술발표회
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    • pp.164-175
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    • 2019
  • The Tor Tong Daeng Irrigation Project with the irrigation area of 61,400 hectares is located in the Ping Basin of the Upper Central Plain of Thailand where farmers depended on both surface water and groundwater. In the drought year, water storage in the Bhumipol Dam is inadequate to allocate water for agriculture, and caused water deficit in many irrigation projects. Farmers need to find extra sources of water such as water from farm pond or groundwater as a supplement. The operation of Bhumipol Dam and irrigation demand estimation are vital for irrigation water allocation to help solve water shortage issue in the irrigation project. The study aims to determine the smart dam operation system to mitigate water shortage in this irrigation project via introduction of machine learning to improve dam operation and irrigation demand estimation via soil moisture estimation from satellite images. Via ANN technique application, the inflows to the dam are generated from the upstream rain gauge stations using past 10 years daily rainfall data. The input vectors for ANN model are identified base on regression and principal component analysis. The structure of ANN (length of training data, the type of activation functions, the number of hidden nodes and training methods) is determined from the statistics performance between measurements and ANN outputs. On the other hands, the irrigation demand will be estimated by using satellite images, LANDSAT. The Enhanced Vegetation Index (EVI) and Temperature Vegetation Dryness Index (TVDI) values are estimated from the plant growth stage and soil moisture. The values are calibrated and verified with the field plant growth stages and soil moisture data in the year 2017-2018. The irrigation demand in the irrigation project is then estimated from the plant growth stage and soil moisture in the area. With the estimated dam inflow and irrigation demand, the dam operation will manage the water release in the better manner compared with the past operational data. The results show how smart system concept was applied and improve dam operation by using inflow estimation from ANN technique combining with irrigation demand estimation from satellite images when compared with the past operation data which is an initial step to develop the smart dam operation system in Thailand.

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Soil-Bentonite 혼합토의 투수 특성 연구 (A on Permeability Characteristics of Soil-Bentonite Mixture)

  • 임은상;신동훈;조성은;김재홍
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 춘계 학술발표회
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    • pp.852-857
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    • 2009
  • Recently the centrifuge test has been used increasingly to clarify a problem of seepage in dam. However, one of the most difficult challenges in the testing is to conform permeability properties of model ground to the prototype. In order to resolve the problem, a few solutions, such as an increase of pore water viscosity and a regulation of water permeability, are suggested. Although the use of prototype materials is principles if a model test is carried out, the materials of similarity gradation is used in the centrifuge model test because of the nature of the model test for dam. Therefore, we choose the latter method for model ground materials. In this study, the permeability properties of soil-bentonite mixtures are studied through the permeation test using triaxial compaction test apparatus.

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가뭄대비 농업용 지하댐 적지 평가 지표 개발 - 계층분석과정의 적용 - (Development of Suitable Sites Assessment Criteria for Agricultural Subsurface Dam for drought Management using Analytic Hierarchy Process (AHP))

  • 명우호;송성호
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제22권6호
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    • pp.37-47
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    • 2017
  • Climate change has often resulted in severe droughts in a rice-farming season (i.e., April to June), and the large amount of water resources were needed to cope with droughts during the season. Therefore, the subsurface dam, which is able to store groundwater resources in the alluvium aquifer, has been considered to be an alternative for securing more groundwater resources. In this study, suitable sites assessment criteria for agricultural subsurface dam using analytic hierarchy process (AHP) were established for adequate drought management. Moreover, the criteria were applied to the existing five agricultural subsurface dams to verify their applicability of groundwater supply for each subsurface dam. The assessment criteria were divided into three major categories (geology, hydrology and business condition) and classified to 12 individual sub-categories with weighting. From the assessment, Ian subsurface dam and Wooil subsurface dam were identified as the best and the worst suitable site, respectively, and this result was in accordance with the average amount of annual groundwater supply by each subsurface dam during the period of 2011-2017.

중부지역에 위치한 폐광산 주변의 오염물질 이동성 평가 (Evaluation about Contaminant Migration Near Abandoned Mine in Central Region)

  • 이종득;김태동;전기석;김휘중
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제15권6호
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    • pp.29-36
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    • 2010
  • Several mines including Namil, Solim and Jungbong which are located in the Gyeonggi and Kangwon province have been abandoned and closed since 1980 due to "The promotion policy of mining industry". An enormous amount of mining wastes was disposed without proper treatment, which caused soil pollution in tailing dam and ore-dressing plant areas. However, any quantitative assessment was not performed about soil and water pollution by transporting mining wastes such as acid mine drainage, mine tailing, and rocky waste. In this research, heavy metals in mining wastes were analyzed according to leaching method which used 0.1 N HCl and total solution method which used Aqua-regia to recognize the ecological effect of distance from hot spot. We sampled tailings, rocky wastes and soils around the abandoned mine. Chemical and physical parameters such as pH, electrical conductivity (EC), total organic carbon (TOC), soil texture and heavy metal concentration were analyzed. The range of soil's pH is between 4.3 and 6.4 in the tailing dam and oredressing plant area due to mining activity. Total concentrations of As, Cu, and Pb in soil near ore dressing plant area are 250.9, 249.3 and 117.2 mg/kg respectively, which are higher than any other ones near tailing dam area. Arsenic concentration in tailing dams is 31.0 mg/kg, which is also considered as heavily polluted condition comparing with the remediation required level(RRL) in "Soil environment conservation Act".

EARTH DAM의 비탈면 기울기 결정에 관한 연구 (A Study on Side Slope Determination of Earth Dam)

  • 이원희;김시원
    • 한국농공학회지
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    • 제23권1호
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    • pp.86-102
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    • 1981
  • The soil test data of 28 earth dams, scheduled to be constructed in Kore3, were selected for this study. The safety factors of their side slops were computed using Fellenius' "slice Method" by computer. The results summarized in this study are as follows; 1. Dam sections can be easily determined by fig.10 without a time consuming trial and error calculations of assumed sections. 2. For the economical design of earth dam sections, it was found that more cohesive soil was suitable for lower dams(dam height less than 25m) and soils with a higher friction angle was better for higher dams 3. In the case that used soil materials have the same Internal friction angle, side slope increase was almost same. 4. The relationship between side slope and friction angle was found as log.S=a tan ø+b (Fig. 7) 5. The relationship between side slope and cohesion (c) was also found as log. S=a c+b (Fig. 8) 6. The change of safety factors due to the change of central core materials was very little (Table-2) 7. The decrease of safety factors according to the unit weight increase of embankment materials was negligible. 8. In general the relationship between the wet unit weight and the saturated unit weight was r sat = (rt)$^2$+0. 140. This study will contribute to the determination of economic and safe planning and designing of earth dams, embankments and cutting side slopes.

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토양수분 저류 기반의 간결한 준분포형 수문분할모형 개발 (Development of Parsimonious Semi-Distributed Hydrologic Partitioning Model Based on Soil Moisture Storages)

  • 최정현;김령은;김상단
    • 한국물환경학회지
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    • 제36권3호
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    • pp.229-244
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    • 2020
  • Hydrologic models, as a useful tool for understanding the hydrologic phenomena in the watershed, have become more complex with the increase of computer performance. The hydrologic model, with complex configurations and powerful performance, facilitates a broader understanding of the effects of climate and soil in hydrologic partitioning. However, the more complex the model is, the more effort and time is required to drive the model, and the more parameters it uses, the less accessible to the user and less applicable to the ungauged watershed. Rather, a parsimonious hydrologic model may be effective in hydrologic modeling of the ungauged watershed. Thus, a semi-distributed hydrologic partitioning model was developed with minimal composition and number of parameters to improve applicability. In this study, the validity and performance of the proposed model were confirmed by applying it to the Namgang Dam, Andong Dam, Hapcheon Dam, and Milyang Dam watersheds among the Nakdong River watersheds. From the results of the application, it was confirmed that despite the simple model structure, the hydrologic partitioning process of the watershed can be modeled relatively well through three vertical layers comprising the surface layer, the soil layer, and the aquifer. Additionally, discussions were conducted on antecedent soil moisture conditions widely applied to stormwater estimation using the soil moisture data simulated by the proposed model.

GIS를 이용한 댐 저수지의 흙탕물 발생 가능성 비교 평가 (Comparative Evaluation of Muddy Water Occurrence Possibility in Dam Reservoir Using GIS)

  • 이근상;최연웅;박진혁
    • 한국지리정보학회지
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    • 제14권1호
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    • pp.94-106
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    • 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.