호우 방향성에 의한 유역 유출응답 특성 평가

박창열,유철상 한국수자원학회 2017 한국수자원학회논문집 Vol.50 No.5

본 연구에서는 호우 방향성에 의한 유역 유출응답 특성을 살펴보았다. 이를 위해 호우와 하천망의 방향적 특성을 확률밀도함수로 정량화하였고, 각 방향성 함수를 회선적분하여 호우 방향성의 고려 유무에 따른 유출응답 특성을 비교하였다. 그 결과, 호우 방향성을 고려한 유출모의 결과는 호 우 방향성을 고려하지 않은 경우에 비해 관측 유출자료와 더욱 유사함을 알 수 있었다. 이러한 결과는 호우 방향성을 고려한 유역 반응함수에 의해 유출모의 결과가 보다 개선될 수 있음을 나타낸다. 따라서 본 연구성과는 호우 방향성에 따른 유역 반응함수의 비선형성을 고려함으로써 유출모의 의 불확실성을 줄이는데 기여할 수 있을 것으로 기대된다. This study examined characteristic differences by the rainfall direction on the runoff responses. The directional characteristics of hydrological components in a basin were quantified by von Mises distribution. The runoff hydrograph was derived using the result of convolution integration of each distribution and this hydrograph was compared with GIUH model and observed data. As a result, it was found that runoff response by rainfall direction was more similar the observed rainfall-runoff data than the runoff result using GIUH model. These results implies that runoff modeling could be improved by considering directional components in hydrologic analysis. This study would be helpful to reduce uncertainties of hydrologic analysis considering a non-linearity of rainfall-runoff process by the rainfall direction.

수자원 측면에서의 봄비의 경제적 가치평가 사례 연구

박소연 ( So Yeon Park ),류경식 ( Kyong Sik Ryoo ),김정윤 ( Jung Yun Kim ),김백조 ( Baek Jo Kim ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.2

The direct-runoff of South Korea`s representative dams (Soyanggang, Chungju, Andong, Daecheong, and Seomjingang) and precipitation were analyzed mainly with the evenly distributed spring rainfall events across the country for the last five years. For precipitation, an increasing was presented during the period 2008-2011, but did not continue to increasing 2012. The average precipitation of the five dams displayed a similar trend. Except for Chungju and Andong Dams, the trend of runoff was similar to the one shown in the precipitation. Despite the precipitation of 2009 increased, the runoff volume decreased for Andong and Chungju Dams. In addition, Chungju Dam remarkably showed a bigger runoff volume compared to other dams. As for the Sumjingang Dam, the runoff volume was the smallest, and the difference is as great as over 15-fold when compared to other runoff values. After the result of analyzing the relation between a single runoff event and synoptic weather patterns, pattern 4 contributed to the greatest impact on this event and weather patterns. The total runoff volume of the five dams for spring rain event for the last five years that exhibited this characteristic was estimated at 5.68 billion tons(106m3). Lastly, the value of this estimation was assessed as approximately 273.1 billion KRW.

GIS 기법을 이용한 하천 유역분지 유출량 산출의 효율성 고찰

박의준,구자용,황철수 국토지리학회 2002 국토지리학회지 Vol.36 No.2

This study examines the applicability of the experimental method to integrate the traditional water-budget model with a GIS-based surface analysis technique, ArcView with spatial analysis extension. It confirms that the runoff analysis by ArcView, despite the fact that it has a strength of acquiring the runoff direction and the ratio of areal runoff, has a problem measuring the actual runoff because it converts the precipitation from atmosphere into ground runoff. The [resent investigation shows that the runoff estimation with the factor of water loss in water-budget model has an advantage of measuring water loss. In addition, the combination of the land convert types and the water loss offers the actual runoff from the urbanization. 초록 본 연구에서는 GIS 기법을 이용하여 특정 유역의 정확한 유출량을 산출하기 위하여 수분수지 기법에서 고려하는 각종 수문변수를 기존의 아크-뷰 수문분석에 적용하여 보정하고 이의 적용가능성을 검증하였다. 본 연구의 결과는 다음과 같다. 첫째, 연구지역으로 선정된 목포시 영산강 유역분지의 수분수지 분석결과 연간 강수량은 1,078mm, 저장량과 실재증발산량을 제외한 유출량은 286mm로 밝혀졌다. 둘째, 아크-뷰 수문분석 기법에서 이용된 강수량을 유출량으로 부여하여 계산한 결과, 연구지역의 유출량은 연간 5,133,436mm로 밝혀졌다. 그러나 이 방법은 대기에서 공급된 강수량이 100% 유출로 환산된 것이기 때문에, 연구지역의 유출의 방향과 구역별 유출의 비율을 구할 수 있다는 장점은 있으나 계산된 유출량을 실질적인 유출량으로 분석하는데에는 문제가 있는 것으로 확인되었다. 셋째, 수분수지 기법에서 고려하는 수분손실은 고려하되, 지표피복의 유형은 고려하지 않은 방법으로 유출량을 계산하였다. 그 결과 연구지역에는 연간 1,361,932mm의 유출량이 발생하는 것으로 분석되었다. 이 방법은 아크-뷰 유출량 계산법의 한계를 수분수지 분석 모델을 적용하여 보완한 것으로, 강수에서 유출로 이어지는 과정 속에서 일어나는 수분손실량을 파악할 수 있는 장점이 있는 것으로 판단되었다. 넷째, 수분수지 기법에서 고려하는 수분손실과 지표피복의 유형을 동시에 고려한 방법으로 유출량을 계산하였다. 이를 위해 위성사진을 이용한 연구지역의 토지피복자료를 이용하여 도시역을 추출하고 이를 계산에 이용하였다. 그 결과 연구지역에는 연간 2.1006,692mm의 유출량이 발생하는 것으로 확인되었다. 이 수치는 연구지역의 도시화에 따른 지표피복의 변화에 의하여 자연적인 상태보다는 유출량이 많아짐을 직접적으로 지시하는 것으로, 수분수지 기법의 한계점을 보완한 것으로 판단되었다.

L-THIA GIS 2013의 개선 및 적용

박윤식 ( Youn Shik Park ),임경재 ( Kyoung Jae Lim ),( Larry Theller ),( Bernard A. Engel ) 한국농공학회 2014 한국농공학회 학술대회초록집 Vol.2014 No.-

The Long-Term Hydrologic Impact Assessment (L-THIA) model is a quick and straightforward analysis tool to estimate direct runoff and nonpoint source (NPS) pollution. The model requires modest effort to collect input data and uses the Soil Conservation Service - Curve Number (SCS-CN) approach to estimate direct runoff. L-THIA was originally implemented as a spreadsheet application. GIS-based versions of L-THIA have been developed in ArcView 3 and upgraded to ArcGIS 9. However, a major upgrade was required for L-THIA to operate in the current version of ArcGIS and to provide more options in runoff and NPS estimation. An updated L-THIA interfaced with ArcGIS 10.0 and 10.1 has been developed in the study as an ArcGIS Desktop Add-in Model. The model provides a user-friendly interface, easy access to the model parameters, and an automated watershed delineation process. Also, the model allows use of precipitation data from multiple gauge locations for the watershed when a watershed is large enough to have more than one precipitation gauge station. The model was applied to a 4,410 square kilometer watershed in which seven precipitation gauge stations are located. The model estimated annual direct runoff well compared to separated direct runoff in the calibration and validation periods of ten and nine years. The NSE and R² for the calibration period were 0.59 and 0.62, and they were 0.72 and 0.84 for the validation period. The L-THIA GIS 2013, with a user-friendly interface and enhanced functions, is expected to be a decision support model requiring less effort for GIS processes or to be a useful educational hydrology model.

국가권력구조의 개편방향

임종훈(Lim Jong-Hoon) 한국헌법학회 2006 憲法學硏究 Vol.12 No.4

  This study elaborates how the current Korean Constitution should be amended in the field of government structure.<BR>  The bottom line to keep in mind in examining which system is the most suitable for the Republic of Korea is to take into consideration the constitutional and political experience we Koreans have.<BR>  I suggest that the current presidential system would offer the best hope for stable government and democratic continuity in Korea. Changing into the parliamentary cabinet system would be a political experiment the result of which no one can be sure of. The single term of five years for the presidential office should be amended to allow two terms of four years. A presidential candidate should attain a majority of votes to be elected the President. If no one attained a majority, the top two candidates would be put into a runoff. It would be better to have a vice president instead of a prime minister which is not well compatible with the presidential system.<BR>  The immunity and privilege clause for the members of the National Assembly might be amended so that the clause could not be misused. The regular parliamentary inspection of state affairs could be abolished on condition that the National Assembly facilitates its investigation of a specific matter of state affairs when it deems necessary and that the auditing function of the Board of Audit and Inspection is transferred to the National Assembly. Adding another chamber to the National Assembly, thus adopting a bicameral national legislature should be delayed until the unification of South and North Korea in the future.<BR>  Doubts about the capacity of elected representatives to address social problems, as well as fears that the National Assembly has often been captured by special interests and subject to corruption, led some scholars to propose to return the decision-making power to the populace. The initiative, referendum and recall are three major methods for direct democracy. As it was not until the last decade that the representative democracy began to function properly in Korea, it would be better to wait and see how it will work rather than adopting direct democracy methods.

Estimating Direct Runoff from Storm Rainfall Using NRCS Runoff Method and GIS Mapping in Vientiane City, Laos

Vannasy M.,Nakagoshi N. 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.4

The amount of direct runoff present in a watershed indicates the hydrological condition of the area, reflecting the characteristics of land use, soil and rainfall distribution. This study aims to measure the hydrological condition of Vientiane city by examining the runoff potential. This study obtained direct runoff from storm rainfall for the city area which covered the Mark-Hiao River watershed. The rainfall-runoff calculation is useful for future design of drainage networks within a watershed to support flooding management. The Geographical Information System (GIS) software is the main technology used in this study for the purposes of assigning the estimating process, watershed delineation, extracting hydrologic parameters and mapping. There are two main parts discussed with useful results in this study, delineating the river watershed and estimating weighted direct runoff for a watershed area. The result of delineating river watershed process, showing the changing elevation data achieved by combining the two elevation data, Shuttle Radar Topography Mission 30m Digital Elevation Model (STRM 30m DEM), and digital contour data (Vientiane database), performed well in terms of representing surface flow networks and their topography. The calculated average of direct runoff in each small sub-watershed estimated by using Weigh-Q method of the National Resources Conservation Service (NRCS) very well showed the poor to good hydrologic condition in each specific area in 1-to5-day durations of storm events.

산지계류에 있어서 홍수기의 강우사상에 대한 유출수문곡선 분리 및 특성 분석

남수연,전근우,이재욱,강원석,장수진 한국하천호수학회 2021 생태와 환경 Vol.54 No.1

We examined the flow characteristics by direct runoff and base flow in a headwater stream during observed 59 rainfall events of flood season (June~September) from 2017 to 2020 yrs. Total precipitation ranged from 5.0 to 400.8 mm, total runoff ranged from 0.1 to 176.5 mm, and runoff ratio ranged from 0.1 to 242.9% during the rainfall events. From hydrograph separation, flow duration in base flow (139.3 days) was tended to be longer than direct runoff (78.3 days), while the contribution of direct runoff in total runoff (54.2%) was greater than base flow (45.8%). The total amount and peak flow of direct runoff and base flow had the highest correlation (p<0.05) with total precipitation and duration of rain among rainfall and soil moisture conditions. Dominant rainfall events for the total amount and peak flow of base flow were generated under 5.0~200.4 and 10.5~110.5 mm in total precipitation. However, when direct runoff occurred as dominant rainfall events, total amount and peak flow were increased by 267.4~400.8 and 169.0~400.8 mm in total precipitation. Therefore, the unique aspects of our study design permitted us to draw inferences about flow characteristic analysis with the contribution of base flow and/or direct runoff in the total runoff in a headwater stream. Furthermore, it will be useful for the long-term strategy of effective water management for integrated surface-groundwater in the forested headwater stream.

대청호 상류 유역의 비점오염원 유출특성 분석 및 L-THIA 모형 적용성 평가

신민환,이재안,천세억,이열재,임경재,최중대,Shin, Min-Hwan,Lee, Jae-An,Cheon, Se-Uk,Lee, Yeoul-Jae,Lim, Kyoung-Jae,Choi, Joong-Dae 한국농공학회 2010 한국농공학회논문집 Vol.52 No.1

Generation and transportation of runoff and pollutant loads within watershed generated eutrophication at Daecheong reservoir. To improve water quality at Daecheong reservoir, the best management practices should be developed and applied at upper watersheds for water quality improvement at downstream areas. In this study, two small watersheds of upper Daecheong reservoir were selected. The Long-Term Hydrologic Impact Assessment (L-THIA) model has been widely used for the estimation of the direct runoff worldwide. To apply the L-THIA ArcView GIS model was evaluated for direct runoff and water quality estimation at small watershed. And the Web-based Hydrograph Analysis Tool (WHAT) was used for direct runoff separating from total flow. As a result, the $R^2$ (Coefficient of determination) value and Nash-Sutcliffe coefficient value for direct runoff comparison at An-nae watershed were 0.81 and 0.71, respectively. And the $R^2$ value and Nash-Sutcliffe coefficient value at Wol-oe were 0.95 and 0.93. The $R^2$ value of BOD, TOC, T-N and T-P at An-nae watershed were BOD 0.94, TOC 0.81, T-N 0.94 and T-P 0.89. And the $R^2$ value of BOD, TOC, T-N and T-P at Wol-oe watershed were BOD 0.80, TOC 0.93, T-N 0.86 and T-P 0.65. The result that estimated pollutant loadings using the L-THIA ArcView GIS model reflected well the measured pollutant loadings except for T-P in Wol-oe watershed. With L-THIA ArcView GIS model, the direct runoff and non-point pollutant (NPS) loadings in the watershed could be analyzed through simple input data such as daily rainfall, land uses, and hydrologic soil group.

선행강우를 고려한 제주하천 유출특성 분석

양성기 ( Sung Kee Yang ),김동수 ( Dong Su Kim ),정우열 ( Woo Yul Jung ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.4

The rainfall-runoff characteristics in Jeju Island significantly differ from those in inland, due to highly permeable geologic features driven by volcanic island. Streams are usually sustained in the dry conditions and thereby the rainfall-runoff characteristics changes in terms of initiating stream discharge and its types, depending highly on the antecedent precipitation. Among various the rainfall-runoff characteristics, lag time mainly used for flood warning system in river and direct runoff ratio for determining water budget to estimate groundwater recharge quantity are practically crucial. They are expected to vary accordingly with the given antecedent precipitation. This study assessed the lag time in the measured hydrograph and direct runoff ratio, which are especially in the upstream watershed having the outlet as 2nd Dongsan bridge of Han stream, Jeju, based upon several typhoon events such as Khanun, Bolaven, Tembin, Sanba as well as a specific heavy rainfall event in August 23, 2012. As results, considering that the lag time changed a bit over the rainfall events, the averaged lag time without antecedent precipitation was around 1.5 hour, but it became increased with antecedent precipitation. Though the direct run-off ratio showed similar percentages (i.e., 23%) without antecedent precipitation, it was substantially increased up to around 45% when antecedent precipitation existed. In addition, the direct run-off ration without antecedent precipitation was also very high (43.8%), especially when there was extremely heavy rainfall event in the more than five hundreds return period such as typhoon Sanba.

수질 및 유량자료를 활용한 직접유출에 따른 오염원 변화에 관한 연구

하돈우 ( Don-woo Ha ),김석규 ( Seok-gyu Kim ),박승호 ( Seung-ho Park ),김해성 ( Hae-sung Kim ),김영석 ( Young-suk Kim ) 한국환경기술학회 2015 한국환경기술학회지 Vol.16 No.2

우리나라는 수질개선 및 오염원 관리를 위해 오염총량관리제도를 시행하여 장래 오염원을 예측을 통한 체계적인 수질 관리를 하고 있다. 오염총량관리를 위해서 목표수질 지점을 지정하고 8일 간격으로 해당 지점의 수질 및 유량을 동시에 조사하고 있다. 영산강·섬진강수계는 24개의 목표수질 지점을 설정 하고 8일 간격으로 지속적이고 주기적으로 수질 및 유량에 대해 모니터링을 수행하고 있다. 이렇게 측정한 자료를 활용하여 본 연구에서는 섬진강수계 오수A 목표수질 지점의 측정된 유량을 활용·확장 하여 유출에 따른 오염원 배출 특성을 분석하였다. 기저유출과 직접유출을 분리는 Digital filtering방법을 이용하였으며, 유출의 특성으로 직접유출량은 19.60 ㎥/s, 기저유출량은 23.39 ㎥/s으로 기저 유출비는 54.4%이다. 기저유출에 비해 직접유출일 경우 BOD 219%, COD 148% 증가, SS 1,032%, T-N 118%, T-P 397%, TOC 161%가 증가한 결과를 나타내어 직접유출시에 기저유출시보다 하천에 오염원이 많이 유입됨을 확인할 수 있었다. Total Maximum Daily Loads(TMDL) is an advanced management method for water quality control which sets target water quality and allows pollutant discharge only within a range to meet the target water qualities. Ministry of Environment has produced directly or indirectly in the average interval of eight days 24 point for unit area in Yeongsan and Seomjin River stream. This study focuses on emission characteristics of pollution sources by runoff in OsuA target water quality point using surveyed discharge data. Separation of baseflow and direct runoff is used to digital filtering method. The results indicated that the direct runoff is increased each target water quality points with BOD 219%, COD 148%, SS 1,032%, T-N 118%, T-P 397%, TOC 161%. Consequently, direct runoff is much more inflow for pollution sources than baseflow.