• 물과 미래
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• 제20권2호
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• pp.139-150
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• 1987

본 연구는 우리나라의 확율강우량도 작성을 위한 수문해석기법을 개발제시하는 것을 내용으로 하고 있다. 강우량계열의 적정분포형검정과정에서는 변수변환정규분포(Y-k법)등 11개의 연속확율분포형을 적용하였으며, 각 지속기간별 연최대강우량자료에 대한 수문해석을 실시하였다. 최적분포형 선정을 위한 적합도검정은 $-test와 Kolmogorov-Smirnov test에 의거하였으며 계급구간은 등간격으로 취하였다. 서울, 인천, 부산 및 광주지점의 강우지속기간 10분, 60분, 6시간 및 24시간에 대한 연최대 강우량에 각종 확율분포를 적용하고, 분포형의 적용상 특성과 강우량 자료집단의 특성을 고려하여 최적확율분포형을 설정하였다. 이와같은 해석기법으로 설정된 최적확율분포형은 종전의 방법으로 얻어진 적정분포형 보다도 자료면에서 확장된 자료집단일 뿐 아니라 확대검정된 합리적인 결과라고 생각된다.

• 한국물환경학회지
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• 제35권1호
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• pp.72-77
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• 2019

Soil type in LID infiltration practices plays a major role in runoff reduction efficacy. In this study, the effects of infiltration rate of foundation ground under bioretention on annual runoff reduction rate was evaluated using LIDMOD3 which is a simple excel based model for evaluating LID practices. A bioretention area of about 3.2 % was required to capture surface runoff from an impervious area for a 25.4 mm rainfall event. The relative error of runoff from bioretention using LIDMOD3 is 10 % less than that of SWMM5.1 for a total rainfall event of 257.1 mm during the period of Aug. 1 ~ 18, 2017, hence, the applicability of LIDMOD3 was confirmed. Annual runoff reduction rates for the period 2008 ~ 2017 were evaluated for various infiltration rates of foundation ground under the bioretention which ranged from 0.001 to 0.600 m/day and were converted to annual runoff reduction for hydrologic soil group. The runoff reduction rates within hydrologic soil group C and D were steeply increased through increased infiltration rate but not steep within hydrologic A and B with reduction rates ranging from 53 ~ 68 %. The estimated time required to completely empty a bioretention which has a storage depth of 0.632 m is 3.5 ~ 6.9 days and we could assume that the annual average of antecedent rainfall is longer than 3.5 ~ 6.9 days. Therefore, we recommended B type as the minimum hydrologic soil group installed LID infiltration practices for high runoff reduction rate.

• Water Engineering Research
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• 제3권1호
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• pp.31-44
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• 2002

The effect of diurnal cycle, intermittent visit of observation satellite, sensor installation, partial coverage of remote sensing, heterogeneity of soil properties and precipitation to the soil moisture estimation error were analyzed to present the global sampling strategy of soil moisture. Three models, the theoretical soil moisture model, WGR model proposed Waymire of at. (1984) to generate rainfall, and Turning Band Method to generate two dimensional soil porosity, active soil depth and loss coefficient field were used to construct sufficient two-dimensional soil moisture data based on different scenarios. The sampling error is dominated by sampling interval and design scheme. The effect of heterogeneity of soil properties and rainfall to sampling error is smaller than that of temporal gap and spatial gap. Selecting a small sampling interval can dramatically reduce the sampling error generated by other factors such as heterogeneity of rainfall, soil properties, topography, and climatic conditions. If the annual mean of coverage portion is about 90%, the effect of partial coverage to sampling error can be disregarded. The water retention capacity of fields is very important in the sampling error. The smaller the water retention capacity of the field (small soil porosity and thin active soil depth), the greater the sampling error. These results indicate that the sampling error is very sensitive to water retention capacity. Block random installation gets more accurate data than random installation of soil moisture gages. The Walnut Gulch soil moisture data show that the diurnal variation of soil moisture causes sampling error between 1 and 4 % in daily estimation.

• 한국농공학회지
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• 제24권4호
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• pp.99-108
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• 1982

This thesis aims to estimate the rainfall runoff from paddy field in a small watershed during irrigation period. When the data observed at the proposed site are not available, the Monthly Runoff Equation of Korean Rivers which was derived from data observed under the following assumptions is used to study the water balance. a. Monthly base flow was assumed as 10. 2mm even if these is no mouthly rainmfall. b. Monthly comsumption of rainfall was ranged from 100 to 2OOmm without relation to the rainfall depth. However, the small watershed which consists mainly of paddy fields encounters severe droughts and accordingly the baseflow is negligible. Under the circumstances the author has developed the following equation called "Flood Irrigation Method for Rainfall Runoff "taking account of the evapotranspiration, precipitation, seepage, less of transportation, etc. R= __ A 7000(1 +F) -5n(n+1)+ (n+1)(Pr-S-Et)] where: R: runoff (ha-m) A: catchment area (ha) F: coefficient of loss (o.o-0. 20) Pr: rainfall (mm) S: seepage Er: evapotranspiration (mm) To verify the above equation, the annual runoff ratio for 28 years was estimated using the Monthly Runoff Equation of Korean Rivers the Flood Irrigation Method and the Complex Hydrograph Method based on meteorological data observed in the Dae Eyeog project area, and comparison was made with data observed in the Han River basin. Consequently, the auther has concluded that the Flood Irrigation Method is more consi- stent with the Complex Hydrograph Method and data observed than the Monthly Runoff Equation of Korean Rivers.

• 물과 미래
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• 제13권1호
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• pp.39-48
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• 1980

우리나라 5대 하천유역 즉 한강, 낙동강, 금강, 영산강 및 섬진강에 대한 지역최대일 강우량의 실측기록을 써서 지역강우빈도 분석을 실시한바 분석방법으로는 다섯가지 방법을 활용하여 비교 검토하였다. 지역강우에 대한 빈도분석은 많이 이루어졌으나 지역강우에 대한 연구는 찾아 볼 수 없었기 때문에 이 성과를 쓴다면 홍수해석에 도움을 줄 수 있겠다 하겠다. 본 연구에서 제시한 강우량의 빈도별 산정식을 쓴다면 수문관측 기록이 나와 있지 않은 기타 지역에도 지역확률 강우량을 산정 할 수 있다.

• 한국토양비료학회지
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• 제45권4호
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• pp.484-491
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• 2012

The hydrological components of a sandy loam soil of nearly level in Chuncheon over 30 years were computed using the E-DiGOR model. Daily simulations were carried out for each year during the period of 1980 to 2009 using standard climate data. Reference evapotranspiration and potential soil evaporation based on Penman-Montheith model were higher during May to August because of the higher atmospheric evaporative demand. Actual soil evaporation was mainly found to be a function of the amount and timing of rainfall, and presumably soil wetness in addition to atmospheric demand. Drainage was affected by rainfall and increased with a higher amount of precipitation and soil water content. Excess drainage occurred throughout rainy months (from July to September), with a peak in July. Therefore, leaching may be a serious problem in the soils all through these months. The 30-year average annual reference evapotranspiration and potential soil evaporation were 951.5 mm and 714.2 mm, respectively. The actual evaporation from bare soil varied between 396.9-528.4 mm and showed comparatively lesser inter-annual variations than drainage. Annual drainage rates below 120 cm soil depth ranged from 477.8 to 1565.9 mm. The long-term mean annual drainage-loss was approximately two times higher than actual soil evaporation.

• 한국수자원학회논문집
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• 제33권3호
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• pp.307-314
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• 2000

본 연구에서는 조선시대부터 최근까지의 약 200년간의 서울지점 연강수량 자료를 이용하여 다우해 및 과우해의 재현특성에 대해서 살펴보았다. 기본적으로 원자료에 나타난 자기상관특성을 분석함은 물론 몇 개의 절단수준(truncation level)에 대해 다우해 및 과우해의 재현경향이 어떤지를 살펴보았다. 또한 각각의 절단수준에 대해 연강수량을 평년, 다우해 및 과우해로 나누고 각각의 전이확률을 조사하여 봄으로서 궁극적으로는 각각의 경우에 대해 평년, 다우해 및 과우해의 평균재해기간이 얼마나 되는지를 추정해 보았다. 이러한 분석은 조선시대의 측우기기록과 근대의 강우관측기록을 포함한 전체의 기록뿐만 아니라 측우기 관측기록 및 근대 관측기록에 대해 각각 적용해 봄으로서 비교 분석될 수 있도록 하였다. 전체자료를 이용한 결과의 경우 1900년 전후의 건조기의 영향을 제외한다면 건조기의 전반부 및 후반부만을 이용한 결과와 어느 정도 유사한 결과를 줌을 알 수 있었다. 아울러 건조기의 전반부와 후반부에 대한 비교에서는 건조기 후반부의 기록에서, 특히 상대적으로 큰 절단수준에 대해, 과우해의 재현기간이 상대적으로 크게 나타나는 차이를 살펴볼 수 있었다. 대략 평균에서 표준편차(약370mm)정도가 벗어난 수준을 다우해 및 과우해의 기준으로 본다면 다우해의 재현기간은 5∼6년, 과우해의 재현기간은 6∼7년 정도로 과우해의 재현기간이 다우해의 재현기간 보다 약간 길게 나타나고 있음을 알 수 있었다.

• 대한지리학회지
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• 제42권3호
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• pp.405-420
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• 2007

본 연구에서는 기후변화에 따른 수문요소의 변동을 파악하기 위해 섬진강댐과 소양강댐 유역의 물순환 과정에 미치는 영향을 분석 평가하였다. 그 결과를 정리하자면 다음과 같다. 먼저 지난 30년간 기온과 강수량은 점차 증가하는 경향이 뚜렷하게 나타나고 있으나 증발산량은 지역에 따라 상이하게 나타나고 있으며 연평균 기온상승과 연증발산량의 증가가 정의 관계에 있다고 볼 수 없었다. Penman-FAO24법에 기초한 기후학적 물수지방법과 실측값은 서로 유의한 것으로 밝혀져 국내 물수지 연구에 사용가능한 것으로 사료된다. 한편 연강수량 증대에 따라 연유출량의 증가는 인정되나 연유출률에 대한 변동은 실측값과 계산값 간의 변동이 상이하게 나타나고 있어 기후변화의 영향이 유역의 유출특성에 크게 영향을 미치고 있다고 단정하기 어렵다. 기후변화에 의한 수자원관리와 재난관리에 큰 어려움이 예상되고 있다는 것은 이미 널리 알려진 사실이다. 이에 대한 적절한 대응방안을 강구하기 위해서는 유역의 기후학적 조건과 수문학적 변동성에 대한 깊은 이해가 필요하며 보다 조밀한 수문관측망의 구축과 신뢰도 높은 자료의 축적이 전제되어야 할 것이다.

• 생태와환경
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• 제42권4호
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• pp.487-494
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• 2009

We compared spatial and temporal variations of water chemistry between high-flow year ($HF_y$) and low-flow year ($LF_y$) in an artificial lentic ecosystem of Daechung Reservoir. The differences in the rainfall distributions explained the variation of the annual inflow and determined flow characteristics and water residence time and modified chemical and biological conditions, based on TP, suspended solids, and chlorophylla, resulting in changes of ecological functions. The intense rainfall and inflow from the watershed resulted in partial disruption of thermal structure in the metalimnion depth, ionic dilution, high TP, and high suspended solids. This condition produced a reduced chlorophyll-a in the headwaters due to low light availability and rapid flushing. In contrast, reduced inflow and low rainfall by drought resulted in strong thermal difference between the epilimnion and hypolimnion, low inorganic solids, high total dissolved solids, and low phosphorus in the ambient water. The riverine conditions dominated the hydrology in the monsoon of $HF_y$ and lacustrine conditions dominated in the $HF_y$. Overall data suggest that effective managements of the flow from the watershed may have an important role in the eutrophication processes.

• 한국농공학회지
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• 제42권1호
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• pp.57-65
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• 2000

The objective of this paper are to present a realistic methodology to estimate the daily water supply rates form irrigation pumping stattions, to validate it with the field data, and to report the daily irrigation pumping rates from the Han river basin. Five-year historical pumping records were collected from seventy-three pumping stations in the Han river basin. And the daily pumping rates were estimated from the electrical consumption records. The pumping patterns from the stations were analyzed and the results were applied to ungauged pumping stations in the basin. The method was appliedto five stations which were field monitored during the irragation periods in 1998. The relative errors between the observed and simulated water pumpage ranged from 1.4 to 7.0 percent. This indicates that the proposed method is valid to apply for estimating the pumping rates for agricultural lands. During 1993 to 1997, the annual average water pumpaging from the Han river and the tributaries were 350 million cubic meter. The annual water supply from the pumping stations varied from 973 to 1.377 mm in depth and the mean was 1,170 mm. The major factor affecting the annual variations was attributed to the rainfall during the growing seasons.