• 제목/요약/키워드: Unit Watershed

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분석단위 세분화에 따른 한강권역의 물수급 분석 비교 및 고찰 (Comparison and discussion of water supply and demand forecasts considering spatial resolution in the Han-river basin)

  • 오지환;김연수;류경식;배영대
    • 한국수자원학회논문집
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    • 제52권7호
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    • pp.505-514
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    • 2019
  • 우리나라는 효율적인 수자원 관리를 위해 노력하고 있으며, 향후 지역의 문제와 물이용 현황, 특성, 지형, 기후 등을 고려한 유역을 세분화한 후 계획을 수립하는 것이 필요하다. 이에 본 연구에서는 한강 권역을 대상으로 MODSIM 모형을 활용하여 중권역과 표준유역단위 물 수급 체계를 구축하고 분석 결과를 비교하였다. 분석 결과, 49개년(1967-2015)간 발생하는 평균 물 부족량은 중권역 단위 129.98 백만$m^3$, 표준유역단위 2,229.24 백만 $m^3$으로 약 21 억$m^3$ 가량의 차이가 나타났으나 물 부족이 발생하는 시기와 물 부족 발생 공간 분포에 대한 경향은 매우 유사하게 나타났다. 이러한 원인은 중권역 단위 분석의 경우, 모든 수량을 이용할 수 있다는 가정으로 대표 자연유량 값에 대한 생활, 공업, 농업용수 수요량에 대한 물 부족량이 산정된다. 그러나, 표준유역단위 분석에서는 분할된 공급량과 수요량의 차이로 인해 본류와 이격되어 있는 지류는 가용할 수 있는 수자원량이 상대적으로 작아져 물 부족이 크게 발생하는 것으로 나타났고, 본류는 오히려 회귀수량의 파급효과로 인해 물 부족이 나타나지 않는 것으로 분석되었다. 향후, 분석 단위의 세분화 뿐만 아니라 실제 물이용체계가 모형 내 고려된다면 지역적 특성이 반영된 물수급 평가가 가능할 것으로 판단된다.

Hydrological Consequences of Converting Forestland to Coffee Plantations and Other Agriculture Crops on Sumber Jaya Watershed, West Lampung, Indonesia

  • Manik, Tumiar Katarina;Sidle, Roy Carl
    • Journal of Forest and Environmental Science
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    • 제34권4호
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    • pp.293-303
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    • 2018
  • Sumber Jaya (54,194 hectares) is a district in West Lampung, Indonesia, located at the upper part of Tulang Bawang watershed. This watershed is one major water resource for Lampung Province, but has become a focal point of discussion because of the widespread conversion of forestland to coffee plantations and human settlements which lead to environmental and hydrological problems. This research aimed to evaluate Sumber Jaya watershed affecting by rapid land use change using hydrological methods as a base for watershed management. Nested catchment structure consisted of eight sub-catchments was employed in this research to assess scaling issues of land use change impacts on rainfall-runoff connections. Six tipping bucket rain gages were installed on the hill slopes of each sub-catchment and Parshall flumes were installed at the outlets of each sub-catchment to monitor stream flow. First, unit hydrograph that expressed the relationship of rainfall and runoff was computed using IHACRES model. Second, unit hydrograph was also constructed from observations of input and response during several significant storms with approximately equal duration. The result showed that most of the storm flow from these catchments consisted of slow flow. A maximum of about 50% of the effective rainfall became quick flow, and only less than 10% of remaining effective rainfall which was routed as slow flow contributed to hydrograph peaks; the rest was stored. Also, comparing peak responses and recession rates on the hydrograph, storm flow discharge was generally increased slowly on the rising limb and decreased rapidly on the falling limb. These responses indicated the soils in these catchments were still able to hold and store rain water.

부하지속곡선(LDC)을 이용한 영산강 · 탐진강수계 오염총량관리 목표수질 평가방법 적용 방안 (Application of the Load Duration Curve (LDC) to Evaluate the Rate of Achievement of Target Water Quality in the Youngsan · Tamjin River Watersheds)

  • 정은정;김홍태;김용석;신동석
    • 한국물환경학회지
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    • 제32권4호
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    • pp.349-356
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    • 2016
  • Total Maximum Daily Loads (TMDLs) System has been used to improve water quality in the Youngsan·Tamjin river basin since 2004. The Basic Policy of TMDLs sets up the standard flow based on the average dry condition or mid-range flow during the last 10 years. However, Target Water Quality (TWQ) assessment on TMDLs has been used to evaluate water quality through eight-day intervals over 36 times a year. The results for allocation evaluation and target water quality evaluation were different from each other in the same unit watershed during the first period. In order to improve the evaluation method, researchers applied Load Duration Curve (LDC) to evaluate water quality in nine unit watersheds of the Youngsan·Tamjin river basin. The results showed that achievement rates of TWQ assessment with the current method and LDC were 67~100% and 78~100%, respectively. Approximately 11% of the achievement rates with use of LDC were higher than those with use of the current method. In conclusion, it is necessary to review the application of the LDC method in all Four Major River Watersheds.

금강유역 산업계 특정수질유해물질 배출현황에 대한 탐색적 데이터 분석을 통한 전국오염원조사 결과 적합성 평가 (Quality Assessment of the Nationwide Water Pollution Source Survey Results on the Prioritized Toxic Water Pollutants from Industrial Sources in the Geum-River Basin by Exploratory Data Analysis)

  • 김은아;김연숙;김용석;류덕희;정제호
    • 한국물환경학회지
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    • 제30권6호
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    • pp.585-595
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    • 2014
  • The temporal trends of the prioritized toxic water pollutants generated and discharged from the industrial facilities in the Geum-River basin, Korea were analyzed with the results of the nationwide Water Pollution Source Survey conducted in 2001 - 2012. The statistical results indicated rapid increase in the volume of raw toxic wastewaters whereas the amount of each toxic pollutant kept fluctuating for 12 years. Serious discrepancies in the survey data of the same type of industries demonstrated a low reliability of the survey result, which stemmed from several error factors. A unit-load for each type of industrial facility was devised to estimate the amount of prioritized toxic water pollutant based on the total volume of industrial wastewater generated from the same type of industrial facilities. The supplementary measures with an effective permit issuance policy and adding survey parameters of terminal wastewater treatment plants to use them as references to the Water Pollution Source Survey were suggested as means to minimize the errors associated with the false reports from the industries.

소하천유역(小河川流域)의 계획홍수량(計劃洪水量) 산정방법(算定方法)의 개발(開發) (A Methodology for the Estimation of Design Flood of a Small Watershed)

  • 윤용남;안태진
    • 대한토목학회논문집
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    • 제4권1호
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    • pp.103-112
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    • 1984
  • 본(本) 연구(硏究)는 단위유량도이론(單位流量圖理論)에 근거하여 소하천유역(小河川流域)의 계획홍수량(計劃洪水量)을 결정할 수 있는 일련(一聯)의 경험적(經驗的)인 절차(節次)를 개발한 것이다. 특정재현기간(特定再現期間)의 홍수량(洪水量)은 유역면적(流域面積)에 재현기간(再現期間)에 해당되는 강우능계수(降雨能係數)와 강우특정기간별(降雨特精期間別) 유출능계수(流出能係數) 및 첨두홍수량(尖頭洪水量) 감소계수(減少係數)의 곱으로 표시(表示)하였다. 강우능계수(降雨能係數)와 유출능계수(流出能係數)의 결정방법(決定方法)은 본(本) 연구이전(硏究以前)에 수행된 연구(硏究)(13)에서 정립(定立)된 바 있어 본(本) 연구(硏究)에서는 첨두유량감소계수(尖頭流量減少係數)를 결정하는 방법(方法)을 개발(開發)한 후 경안천(慶安川)의 한 지점유역(地點流域)에 대한 50년홍수량(年洪水量)을 이 방법(方法)으로 산정(算定)하여 이를 타홍수량(他洪水量) 추정방법(推定方法)과 비교(比較) 검토(檢討)하였다. 첨두홍수량(尖頭洪水量) 감소계수(減少係數)는 면적집성법(面積集成法)에 의해 유도된 소유역별(小流域別) 단위도(單位圖)로부터 산정(算定)된 유역(流域)의 지체시간(遲滯時間) 대비(對比) 강우(降雨)의 특정시간(特精時間)을 변량(變量)으로 하여 상관관계(相關關係)가 수립되었으며, 지체시간(遲滯時間)은 유역(流域)의 지형인자(地形因子)인 유로연장(流路延長) 및 평균유로경사(平均流路傾斜)와 상관(相關)시켰다.

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한국에 있어서 제수문구조물의 설계의 기준을 주기 위한 수문학적 연구(류거, 홍수 편) (The furulamelllal study in order to obtain the hydrological design basis for hydrological structures in Korea (Run ofl estimate and Flood part))

  • 박성우
    • 한국농공학회지
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    • 제8권1호
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    • pp.1011-1034
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    • 1966
  • This thesis is the final report which has long been studied by the author to obtain the design basis for various hydrological constructions with the specific system suitable to the natural environmental conditions in Korea. This report is divided into two parts: one is to estimate runoff volume from watersheds and the other to estimate the peak discharge for a single storm. According to the result of observed runoff record from watersheds, it is known that Kajiyama formula is useful instrument in estimating runoff volume from watersheds in this country. But it has been found that this formula shows us 20-30% less than the actual flow. Therefore, when wihed to bring a better result, the watershed characteristics coefficient in this formula, that is, f-value, should be corrected to 0.5-0.8. As for the method to estimate peak discharge from drainage basin, the author proposes to classify it in two ways; one is small size watershed and the other large size watershed. The maximum -flood discharge rate $Q_p$ and time to peak Pt obtained from the observed record on the small size watershed are compared by various methods and formulas which are based upon the modern hydrological knowledge. But it was fou.d that it. was not a satisfied result. Therefore, the author proposes. tocomputate $Q_p$, to present 4.0-5.0% for the total runoff volume ${\Sigma}Q$.${\Sigma}Q$ is computed under the assumption of 30mm 103s in watershed per day and to change the theoritical total flow volume to one hour dura tion total flow rate when design daily storm is given. Time to peak Pt is derived from three parameters which are u,w,k. These are computed by relationship between total runoff volume (ha-m unit)and $Q_p$. (C.M.S. unit). Finally, the author checked out these results obtained from 51 hydrographs and got a satisfied result. Therefore the author suggested the model of design dimensionless unit-hydrograph. And the author believes that this model will be much available at none runoff record river site. In the large size watersheds in Korea when the maximum discharge occurs, the effective rainfall is two consequtive stormy days. So the loss in watershed was assutned as 6Omm/2days,and the author proposed 3-hour-daration hydrograph flow distribution percentage. This distribution percentage will be sure to form the hydrograph coordinate.

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경안천 유역 지적공부에 나타난 특정지목의 토지이용 특성 세분화를 통한 비점오염 부하량 산정 개선방안 (Unit-load Method for the Estimation of Non-point Pollution Loads by Subcategorizing the Land-use Category Reflected in the National Land Register Data : A Case Study of Kyeongan Watershed in South korea)

  • 이범연;이창희;하도;이수웅
    • 한국물환경학회지
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    • 제26권4호
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    • pp.598-607
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    • 2010
  • One of constraints in the application of unit-load method to estimate non-point pollution loads in the total water pollutant load management system (TWPLMS) is the limited numbers of applicable unit-loads. Since only 7 unit-loads are currently available for total 28 land-use categories in the national land register data, each unit-loads inevitably have to represent several land-use categories regardless of their actual land coverage characteristics. As a way to minimize the problem, this study suggested a nested application of the available unit-loads based on the analysis of high resolution aerial images taken in the Kyeongan watershed. Statistical analysis of three selected land-use categories such as school, apartment complex, and golf course showed that there exit significant (95% confidence level) relationships between the registered land-uses and actual land coverages. The school and apartment complex currently considered as 100% ground have only 65% and 80% of ground characteristics, respectively. Golf course, which is considered as 100% pasture, has about 5% of ground area. This indicates that the unit-load method using in TWPLMS can give over estimated non-point pollutant loads for the school and apartment complex (19.8~54.4%) but under estimation for the golf course (80.9%).

주민참여형 유역관리를 위한 하천모니터링 활동의 적용가능성 연구 - 무심천유역을 대상으로 - (A study on the application of River Monitoring Activities for Residents Participatory Watershed Management - Focusing on the Musim River Basins -)

  • 이은정
    • 환경영향평가
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    • 제26권1호
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    • pp.57-67
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    • 2017
  • 최근 우리나라 유역관리정책을 보면, 조류 중점관리 지류 선정, 지류총량제 시범적용 등 중앙정부 주도의 본류중심 관리에서 소단위 지류 지천 관리를 위한 기반을 마련하고 있다. 이러한 시점에 발맞춰 소단위 하천을 대상으로 일상적, 자발적, 맞춤형 관리가 가능하도록 주민참여형 유역관리방안을 설계 및 제안한 후, 주민이 참여하는 하천모니터링 활동을 무심천유역에 시범적으로 적용해 보았다. 총 30개 구간으로 구분하여 주민 1명씩 배치하여 격주로 총 10회동안 모니터링을 수행한 결과, 문서화되지 않은 실제 유역현황을 파악할 수 있었다. 특히, 사각지대의 오염원 실태를 통해 소단위유역별 관리의 필요성을 확인할 수 있었으며, 이러한 조사 내용이 각종 계획에 반영될 수 있는 상향식 접근이 가능한 발판을 마련하는 것이 유역관리를 위한 선행조건으로 판단된다.