• Title, Summary, Keyword: hydrologic condition

Search Result 115, Processing Time 0.052 seconds

Application Load Duration Curve for Evaluation of Impaired Watershed at TMDL Unit Watershed in Korea (수질오염총량 단위유역의 유량조건별 수체 손상 평가를 위한 부하지속곡선 적용성 연구)

  • Hwang, Ha-Sun;Yoon, Chun-Gyeong;Kim, Ji-Tae
    • Journal of Korean Society on Water Environment
    • /
    • v.26 no.6
    • /
    • pp.903-909
    • /
    • 2010
  • The purpose of this study was evaluated on the applicability of Load Duration Curve Method (LDC Method) using HSPF watershed model and sampling data for efficient TMDLs in Korea. The LDC Method was used for assessment pollutant characteristics in watershed and water quality variation in each water flow level. Load Duration Curve is applied for judge the level of impaired water-body and can be estimated the impaired level by pollutant, such as BOD, T-N, and T-P in this study depending on variation of stream flow. As a result, BOD, T-P was usually exceed the standard value at low flow and dry hydrologic period. Improvement of effluent concentration from WWTP and riparian buffer protection zone are effective to improve the water quality. T-N showed the worst condition at mid-range hydrologic period and moist hydrologic period. Therefore, soil erosion control program and BMPs for non-point source pollution control is effective for recovery the water quality, which can be useful method for management of water quality in the plan of recovery water quality spontaneously. Applicability of LDC Method was evaluated in the Nakbon A watershed. However, we need to consider more detailed and accumulated data set such as accurate GIS data and detail pollution data, and WWTP discharge water quality data for accurate evaluation of watershed. Overall, The LDC Method is adequate for evaluation of watersheds characteristics, and its application is recommended for watershed management and TMDL Implementation.

Sensitivity Analysis of Groundwater Model Predictions Associated with Uncertainty of Boundary Conditions: A Case Study (지하수 모델의 주요 경계조건에 대한 민감도 분석 사례)

  • Na, Han-Na;Koo, Min-Ho;Cha, Jang-Hawn;Kim, Yong-Je
    • Journal of Soil and Groundwater Environment
    • /
    • v.12 no.3
    • /
    • pp.53-65
    • /
    • 2007
  • Appropriate representation of hydrologic boundaries in groundwater models is critical to the development of a reliable model. This paper examines how the model predictions are affected by the uncertainty in the conceptualization of the hydrologic boundaries including groundwater divides, streams, and the lower boundaries of the flow system. The problem is analyzed for a study area where a number of field data for model inputs were available. First, a groundwater flow model is constructed and calibrated for the area using the Visual Modflow code. Recharge rate is used for the unknown variable determined through the calibration process. Secondly, a series of sensitivity analyses are conducted to evaluate the effects of model uncertainties embedded in specifying boundary conditions for streams and groundwater divides and specifying lower boundary of the bedrock. Finally, this paper provides some guidelines and discussions on how to deal with such hydrologic boundaries in view of developing a reliable conceptual model for the groundwater flow system of Korea.

Water Quality Management Measures for TMDL Unit Watershed Using Load Duration Curve (수질오염총량 단위유역별 LDC(Load Duration Curve, 부하지속곡선) 적용을 통한 수질관리 대안 모색 - 금호강 유역 대상)

  • Yun, Soyoung;Ryu, Jaena;Oh, Jeill
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.27 no.4
    • /
    • pp.429-438
    • /
    • 2013
  • This study was to develop effective water quality management measures using LDC (Load Duration Curve) curves for TMDL (Total Maximum Daily Loads) unit watershed. Using LDC curves, major factors for BOD and T-P concentration loads generation (i.e. point source or non-point source) in the case study area (Geumho river basin) were found for different hydrologic conditions. Different measures to deal with the pollutant loads were suggested to establish BMPs (Best Management Practices). It was found that the target area has urgent T-P management methods especially at moist and midrange hydrologic conditions because of point source pollutants occurred in developed areas. One example measure for this could be establishment of advanced treatment facility. This study proved that the use of LDC was a useful way to achieve TWQ (Target Water Quality) on the target watershed considered. It was also expected that the methodology applied in this study could have a wider application on the establishment of watershed water management measures.

The Variation of Hydrologic Performance Characteristics for Small Hydro Power Plant with Rainfall Condition (강우상태에 의한 소수력발전소의 수문학적 성능특성 변화)

  • Park, Wan-Soon;Lee, Chul-Hyung
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • /
    • pp.1369-1372
    • /
    • 2008
  • 소수력자원은 신재생에너지 중에서도 온실가스 배출량이 가장 적고 에너지밀도가 매우 높기 때문에 개발할 가치가 큰 청정부존자원으로 평가되고 있다. 강우상태의 변화는 Weibull분포의 축척모수와 형상모수를 인위적으로 변화시켜 소수력발전소의 설계인자들의 변화를 모사하였다. 분석 결과, 소수력발전입지의 수문학적 성능특성은 해당유역의 강우상태에 따라 변하는 것으로 밝혀졌다.

  • PDF

Flood Frequency Analysis with the consideration of the heterogeneous impacts from TC and non-TC rainfalls: application to daily flows in the Nam River Basin, South Korea

  • Alcantara, Angelika;Ahn, Kuk-Hyun
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • /
    • pp.121-121
    • /
    • 2020
  • Varying dominant processes, including Tropical Cyclone (TC) and non-TC rainfall events, have been known to drive the occurrence of precipitation in South Korea. With the changes in the pattern of the Earth's climate due to anthropogenic activities, nonstationarity or changes in the magnitude and frequency of these dominant processes have been separately observed for the past decades and are expected to continue in the coming years. These changes often cause unprecedented hydrologic events such as extreme flooding which pose a greater risk to the society. This study aims to take into account a more reliable future climate condition with two dominant processes. Diverse statistical models including the hidden markov chain, K-nearest neighbor algorithm, and quantile mappings are utilized to mimic future rainfall events based on the recorded historical data with the consideration of the varying effects of TC and non-TC events. The data generated is then utilized to the hydrologic model to conduct a flood frequency analysis. Results in this study emphasize the need to consider the nonstationarity of design rainfalls to fully grasp the degree of future flooding events when designing urban water infrastructures.

  • PDF

Impact Assessment of Climate Change on Hydrologic Components and Water Resources in Watershed (기후변화에 따른 유역의 수문요소 및 수자원 영향평가)

  • Kim Byung Sik;Kim Hung Soo;Seoh Byung Ha;Kim Nam Won
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • /
    • pp.143-148
    • /
    • 2005
  • The main purpose of this study is to suggest and evaluate an operational method for assessing the potential impact of climate change on hydrologic components and water resources of regional scale river basins. The method, which uses large scale climate change information provided by a state of the art general circulation model(GCM) comprises a statistical downscaling approach and a spatially distributed hydrological model applied to a river basin located in Korea. First, we construct global climate change scenarios using the YONU GCM control run and transient experiments, then transform the YONU GCM grid-box predictions with coarse resolution of climate change into the site-specific values by statistical downscaling techniques. The values are used to modify the parameters of the stochastic weather generator model for the simulation of the site-specific daily weather time series. The weather series fed into a semi-distributed hydrological model called SLURP to simulate the streamflows associated with other water resources for the condition of $2CO_2$. This approach is applied to the Yongdam dam basin in southern part of Korea. The results show that under the condition of $2CO_2$, about $7.6\% of annual mean streamflow is reduced when it is compared with the observed one. And while Seasonal streamflows in the winter and autumn are increased, a streamflow in the summer is decreased. However, the seasonality of the simulated series is similar to the observed pattern and the analysis of the duration cure shows the mean of averaged low flow is increased while the averaged wet and normal flow are decreased for the climate change.

  • PDF

On the Change of Hydrologic Conditions due to Global Warming : 2. An Analysis of Hydrologic Changes in Daehung Dam Basin using Water Balance Model (지구온난화에 따른 수문환경의 변화와 관련하여 : 2. 물수지 모형을 이용한 대청댐 상류 유역 수문환경의 변화 분석)

  • An, Jae-Hyeon;Yun, Yong-Nam;Yu, Cheol-Sang
    • Journal of Korea Water Resources Association
    • /
    • v.34 no.5
    • /
    • pp.511-519
    • /
    • 2001
  • Global warming has begun since the industrial revolution and it is getting worse recently. Even though the increase of greenhouse gases such as $CO_2$is thought to be the main cause for glogal warming, its impact on global climate has not been revealed clearly in rather quantitative manners. The objective of this research is to predict the hydrological environment changes in the Daechung Dam basin due to the global warming. A mesoscale atmospheric/hydrologic model (IRSHAM96 model) is used to predict the possible changes in precipitation and temperature in the Daechun Dam basin. The simulation results of IRSHAM96 model and a conceptual water balance model are used to analyze the changes in soil moisture, evapotranspiration and runoff in the Daechung Dam basin. From the simulation results using the water balance model for 1x$CO_2$and 2x$CO_2$situations, it has been found that the runoff would be decreased in dry season, but increased in wet season due to the global warming. Therefore, it is predicted that the frequency of drought and flood occurrences in the Daechung Dam basin would be increased in 2x$CO_2$condition.

  • PDF

Hydrologic Impact Assessment of land Cover Changes by 2002 Typhoon RUSA Using Landsat Images and Storm Runoff Model

  • Lee, Mi-Seon;Park, Geun-Ae;Kim, Seong-Joon
    • Korean Journal of Remote Sensing
    • /
    • v.22 no.5
    • /
    • pp.407-413
    • /
    • 2006
  • To investigate the streamflow impact of land cover changes by a typhoon, HEC-l storm runoff model was applied by using land cover information before and after the typhoon. The model was calibrated with three storm events of 1985 to 1988 based on 1985 land cover condition for a $192.7km^{2}$ watershed in northeast coast of South Korea. After the model was tested, it was run to estimate impacts of land cover change by the typhoon RUSA occurred in 2002 (31 August-1 September) with 897.5 mm rainfall. The land covers before and after the typhoon were prepared using Landsat 7 ETM+ of September 11 of 2000 and Landsat 5 TM of September 29 of 2002 respectively. For the $6.9km^{2}$ damaged area (3.6 % of the watershed), the peak runoff and total runoff by the changed land cover condition increased 12.5 % and 12.7 % for 50 years rainfall frequency and 1.4 % and 1.8 % for 500 years rainfall frequency respectively based on AMC (Antecedent Moisture Condition)-I condition.

HYDROLOGIC IMPACT ASSESSMENT OF LAND COVER CHANGES BY 2002 TYPHOON RUSA USING LANDSAT IMAGES AND STORM RUNOFF MODEL

  • Lee, Mi-Seon;Park, Geun-Ae;Kim, Seong-Joon
    • Proceedings of the KSRS Conference
    • /
    • v.2
    • /
    • pp.539-542
    • /
    • 2006
  • To investigate the streamflow impact of land cover changes by a typhoon, WMS HEC-1 storm runoff model was applied by using land cover information before and after the typhoon. The model was calibrated with three storm events of 1985 to 1988 based on 1985 land cover condition for a 192.7 $km^2$ watershed in northeast coast of South Korea. After the model was tested, it was run to estimate impacts of land cover change by the typhoon RUSA occurred in 2002 (31 August - 1 September) with 897.5 mm rainfall. The land covers before and after the typhoon were prepared using Landsat 7 ETM+ of September 11 of 2000 and Landsat 5 TM of September 29 of 2002 respectively. For the 6.9 $km^2$ damaged area (3.6 % of the watershed), the peak runoff and total runoff by the changed land cover condition increased 12.5 % and 12.7 % for 50 years rainfall frequency and 1.4 % and 1.8 % for 500 years rainfall frequency respectively based on AMC (Antecedent Moisture Condition)-I condition.

  • PDF

Hydrologic Regime Alteration Analysis of the Multi-Purpose Dam by Indicators of Hydrologic Alterations (수문변화 지표법에 의한 다목적댐의 유량변화 분석)

  • Park, Bong-Jin;Kang, Ki-Ho;Jung, Kwan-Sue
    • Journal of Korea Water Resources Association
    • /
    • v.41 no.7
    • /
    • pp.711-723
    • /
    • 2008
  • In this study, Hydrologic regime alterations(magnitude, magnitude and duration of annual extreme, frequency and duration of high and low pulse, rate and frequency of water condition changes, Range of Variability Approach) were analyzed by using Indicators of Hydrologic Alterations at the 11 major multi-purpose dam. The analysis result of the magnitude of monthly water conditions during drought season, inflow was $6.38m^3/sec{\sim}39.84m^3/sec$ and outflow was $20.36m^3/sec{\sim}49.43m^3/sec$, was increased $1.84%{\sim}200.98%$. The analysis result of the magnitude of monthly water conditions during flood season, inflow was from $79.06m^3/sec{\sim}137.12m^3/sec$ and outflow was from $65.32m^3/sec{\sim}80.16m^3/sec$, was decreased from $18.19%{\sim}40.39%$. The analysis result of the magnitude and duration of annual extreme, 1-day minimum was increased $82.86%{\sim}2,950%$, but 1-day maximum was decreased $34.78%{\sim}83.96%$. The analysis result of the frequency and duration of high and low pulse, low pulse count was decreased $29.67%{\sim}99.07%$ and high pulse count was also decreased $4.6%{\sim}92.35%$ after dam operation. Hydrograph rise rate was decreased $15.84%{\sim}79.31%$ and fall rate was $1.97%{\sim}107.10%$. RVA of 1-day minimum was increased $0.60{\sim}2.67$, also RVA of 1-day maximum was decreased $0.50{\sim}1.00$.