• 제목/요약/키워드: rainfall

검색결과 6,222건 처리시간 0.032초

Effects of ILFs on DRAM algorithm in SURR model uncertainty evaluation caused by interpolated rainfall using different methods

  • Nguyen, Thi Duyen;Nguyen, Duc Hai;Bae, Deg-Hyo
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.137-137
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    • 2022
  • Evaluating interpolated rainfall uncertainty of hydrological models caused by different interpolation methods for basins where can not fully collect rainfall data are necessary. In this study, the adaptive MCMC method under effects of ILFs was used to analyze the interpolated rainfall uncertainty of the SURR model for Gunnam basin, Korea. Three events were used to calibrate and one event was used to validate the posterior distributions of unknown parameters. In this work, the performance of four ILFs on uncertainty of interpolated rainfall was assessed. The indicators of p_factor (percentage of observed streamflow included in the uncertainty interval) and r_factor (the average width of the uncertainty interval) were used to evaluate the uncertainty of the simulated streamflow. The results showed that the uncertainty bounds illustrated the slight differences from various ILFs. The study confirmed the importance of the likelihood function selection in the application the adaptive Bayesian MCMC method to the uncertainty assessment of the SURR model caused by interpolated rainfall.

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Effect of rainfall events on soil carbon flux in mountain pastures

  • Jeong, Seok-Hee;Eom, Ji-Young;Lee, Jae-ho;Lee, Jae-Seok
    • Journal of Ecology and Environment
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    • 제41권11호
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    • pp.302-309
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    • 2017
  • Background: Large-scale land-use change is being caused by various socioeconomic problems. Land-use change is necessarily accompanied by changes in the regional carbon balance in terrestrial ecosystems and affects climate change. Therefore, it is crucial to understand the correlation between environmental factors altered by land-use change and the carbon balance. To address this issue, we studied the characteristics of soil carbon flux and soil moisture content related to rainfall events in mountain pastures converted from deciduous forest in Korea. Results: The average soil moisture contents (SMC) during the study period were 23.1% in the soil respiration (SR) plot and 25.2% in the heterotrophic respiration (HR) plot. The average SMC was increased to 2.1 and 1.1% in the SR and HR plots after rainfall events, respectively. In addition, saturated water content was 29.36% in this grassland. The soil water content was saturated under the consistent rainfall of more than $5mm\;h^{-1}$ rather than short-term heavy rainfall event. The average SR was increased to 28.4% after a rainfall event, but the average HR was decreased to 70. 1%. The correlation between soil carbon flux rates and rainfall was lower than other environmental factors. The correlation between SMC and soil carbon flux rates was low. However, HR exhibited a tendency to be decreased when SMC was 24.5%. In addition, the correlation between soil temperature and respiration rate was significant. Conclusions: In a mountain pasture ecosystem, rainfall induced the important change of soil moisture content related to respiration in soil. SR and HR were very sensitive to change of SMC in soil surface layer about 0-10-cm depth. SR was increased by elevation of SMC due to a rainfall event, and the result was assumed from maintaining moderate soil moisture content for respiration in microorganism and plant root. However, HR was decreased in long-time saturated condition of soil moisture content. Root has obviously contributed to high respiration in heavy rainfall, but it was affected to quick depression in respiration under low rainfall. The difference of SMC due to rainfall event was causative of a highly fluctuated soil respiration rate in the same soil temperature condition. Therefore, rainfall factor or SMC are to be considered in predicting the soil carbon flux of grassland ecosystems for future climate change.

강우 및 식생에 의한 토질특성 변화 분석 (Analyzed Change of Soil Characteristics by Rainfall and Vegetation)

  • 이문세;김경수;송영석;류제천
    • 지질공학
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    • 제19권1호
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    • pp.33-41
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    • 2009
  • 이 연구는 산사태와 같은 지반재해를 초래하는 여름철의 집중호우가 실제 토층지반의 토질특성에 어떤 영향을 미치는 지를 분석하였다. 이를 위해 표토에 도달되는 강우량이 식생조건에 따라 어떻게 다른지를 조사하였으며, 토층에 침투한 강우로 인해 토질특성이 어떻게 변화되는지를 분석하였다. 연구지역은 식생조건이 다르나 동일한 지질 및 토질조건의 토층지반이 분포한 대덕연구단지내 자연사면이고 연구지역에서 발생한 2006년과 2007년 여름철의 집중호우를 대상으로 하였다. 강우자료는 연구지역에 인근한 대전지방기상청의 관측치를 기초로 하였으며, 식생조건별 강우량은 직접 제작한 강우량측정기를 이용하여 측정하였다. 또한, 집중호우 전 후에 채취한 토층시료를 대상으로 실내 토질시험을 실시하여 강우와 식생조건에 의한 토질특성 변화를 분석하였다. 연구결과 식생밀도는 실제 표토에 도달한 빗물의 양에 영향을 미치며 그 영향정도는 강우강도 및 지속시간에 따라 감소되는 경향성을 보였다. 또한, 집중호우의 영향으로 토층의 포화도, 함수비, 유동성 및 전단강도가 직접적으로 변화되는 것으로 나타났다.

Copula 모형을 이용한 이변량 강우빈도해석 (Bivariate Frequency Analysis of Rainfall using Copula Model)

  • 주경원;신주영;허준행
    • 한국수자원학회논문집
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    • 제45권8호
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    • pp.827-837
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    • 2012
  • 확률강우량은 수공구조물의 설계에 있어 중요한 역할을 하며 이러한 확률강우량의 산정은 일반적으로 일변량 빈도해석을 수행하고 최적의 확률분포형을 찾아냄으로써 계산된다. 하지만 일변량 빈도해석은 수행 시 지속기간이 제한적이라는 단점이 있으며 이를 보완하기 위해 본 연구에서는 이변량 빈도해석을 수행하였다. 다변량 모형인 copula 모형 중3가지의 분포형을 이용하여 5개 지점의 연최대강우사상에 대해 이 변량 빈도해석을 수행하였으며 확률변수로 강우량과 지속기간을 사용하였다. 주변분포형은 강우량에는 Gumbel (GUM), generalized logistic (GLO) 분포형, 지속기간에는 generalized extreme value (GEV), GUM, GLO 분포형이사용됐으며 copula 모형은Frank, Joe, Gumbel-Hougaard 모형을 이용하였다. 주변분포형의 매개변수는 확률가중모멘트법을 이용하여 추정하였으며, copula 모형의 매개변수는 준모수방법인 의사최우도법을 사용하여 구하였다. 이를 통해 얻어진 확률강우량을 주변분포형과 copula 모형을바꾸어가며 비교하였다. 그 결과, 주변분포형의 종류에 따른 변화에서는 지속기간의 분포형에는 크게 영향을 받지 않는 것으로 나타났다. 강우량의 분포형에 따라서는 조금씩 차이가 났으며 강우량의 분포형이 GUM일 경우, GLO일 때에 비해 재현기간이 증가할수록 확률강우량이 증가하는 경향이 두드러졌다. Copula 모형별로 비교해보았을 때, Joe, Gumbel-Hougaard 모형은 비슷한 경향을 나타내었으며 Frank 모형은 재현기간의 증가에 따른 확률강우량의 증가가 강하게 나타냈다.

집중호우시 발생된 삼척지역의 산사태 특성 (Landslide Characteristics induced by Heavy Rainfall in Samcheok Area)

  • 송영석;장윤호;김진석
    • 지질공학
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    • 제15권4호
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    • pp.435-445
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    • 2005
  • 본 연구에서 는 2002년 태풍 "루사(Rusa)"와 2003년 태풍 "매미(Meami)"에 의한 집중호우시 삼척 지역에 발생된 산사태를 조사하여, 대상지역의 강우와 산사태의 관계를 규명하였다. 삼척지역의 연평균강우량은 $1,200\~l,300mm$이며, 2002년 및 2003년에는 태풍 "루사" 및 "매미"로 인한 집중호우로 인하여 연평균강우량이 2,000mm이상으로 증가되었음을 알 수 있다. 최대시간강우강도와 2일간 누적 강우량이 상대적으로 큰 지역에서 산사태 발생 개소 및 붕괴 면적 이 크게 발생되고 있으므로, 산사태는 강우강도와 누적강우량에 직접적인 영향을 받고 있음을 확인할 수 있다. 삼척 지역에서 발생된 산사태는 태풍에 의한 집중호우에 의한 것이므로 산사태 발생 당일 최대 시간강우강도에 크게 영향을 미치는 것으로 나타났다. 합리적인 산사태 발생 규모를 예측하기 위하여 기존의 방법을 종합적으로 적용하여 최대시간강우강도와 산사태 붕괴 면적을 모두 고려할 수 있는 새로운 방법을 제안하였다. 기존의 방법 및 새로 제안된 방법을 적용한 결과 삼척지역의 산사태 발생규모는 대규모 산사태임을 알 수 있다.

확률 강우량을 이용한 고속도로 토석류 조기경보기준 제안 (1) : 강우기준 제안 (Proposal of Early-Warning Criteria for Highway Debris Flow Using Rainfall Frequency (1): Proposal of Rainfall Criteria)

  • 최재순
    • 한국방재안전학회논문집
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    • 제12권2호
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    • pp.1-13
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    • 2019
  • 본 연구에서는 강우재현주기의 내용을 포함하고 있는 고속도로 토석류 평가를 기초로 하여 고속도로 조기경보 시스템 개발을 위한 강우기준을 제안하였다. 강우기준은 주의경보와 위험경보로 구분하여 선행연구결과를 기초로 하여 적절한 강우기준이 추천되었으며 추천된 기준은 재현주기에 따른 토석류 평가등급별 1시간, 6시간, 3일 확률 강우량이다. 이때, 연구대상은 강원지역으로 하였으며 강원지역 8개 관측소의 확률 강우량을 수집하였다. 또한, 8개 자료의 확률 분석을 통해 강원지역 고속도로 토석류 조기경보에 이용될 1시간, 6시간, 3일 강우기준에 대한 확률분포를 산정하였다. 또한, 강우기준으로 선택된 3가지 강우정보와 실제 토석류 피해와의 연관성 분석을 실제 토석류가 발생한 강원지역 고속도로 7개 노선, 12개 지점의 피해발생시의 강우자료를 수집하여 검토에 이용하였다. 이때, 확률분포 상의 강우기준을 평균값과 하한값을 구분하여 검토하였다. 검토결과, 재현주기별 강우량의 하한값을 사용하는 경우가 실제 토석류 피해시의 상황을 잘 모사하는 것으로 나타났다.

Influence of Rainfall During the Ripening Stage on Pre-Harvest Sprouting, Seed Quality, and Longevity of Rice (Oryza sativa L.)

  • Baek, Jung-Sun;Chung, Nam-Jin
    • 한국작물학회지
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    • 제59권4호
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    • pp.406-412
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    • 2014
  • The influence of rainfall during the ripening stage on pre-harvest sprouting, seed viability, and seed quality was investigated in two Korean rice cultivars, Shindongjin and Hopum. When the rainfall was artificially treated in a greenhouse, HP started to pre-harvest sprouting at three days of rainfall treatment (DRT), but Shindongjin did not show pre-harvest sprouting at 40 DAH treatment and just 0.3~0.8% at 50 DAH, which was much lower than 15.3~25.8% of Hopum in the same treatment. After harvest, the seed germination of Hopum decreased about 10~25% compared to non-treated seeds, but that of Shindongjin decreased much little rate than that of Hopum. The seed longevity tested by accelerated aging decreased with prolonged rainfall period in both cultivars, but the varietal difference was clear; Shindongjin could withstand longer accelerated aging than Hopum. Shindongjin maintained its germination (>50%) ability after 15 days of accelerated aging regardless of the rainfall treatment period and time, but Hopum dropped below 50% germination ability after only 5 days of accelerated aging. In conclusion, rainfall during the ripening stage induced not only pre-harvest sprouting, but also reduced seed quality and longevity during storage, which varied between two cultivars.

수질오염총량관리 합류식지역의 우기시 관거이송 변화유형 (Patterns on Sewer Transfer Flow for Rain Weather Period in the Area with Combined Sewer System for the Management of TMDLs)

  • 박준대;오승영;김지태
    • 한국물환경학회지
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    • 제26권6호
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    • pp.1008-1015
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    • 2010
  • Discharged pollution load is varied as rainfall changes in the area with combined sewer system. Changes in discharged pollution load are directly related with those of sewer transfer flow. Therefore, it is important to identify the pattern of sewer transfer flow for the analysis of changes in discharged pollution load. This study reviewed the type of distribution of sewer transfer flow for 17 sewage treatment plants and developed simple formular to estimate sewer transfer flow as rainfall changes. 11 facilities showed to have some relation with rainfall in the change of sewer transfer flow but 6 facilities to have no relation. Relationships between rainfall amount and sewer transfer flow showed that 6 facilities out of 11 had relatively strong relationships above R2=0.5, which were considered to be affected directly by rainfall changes. The formular which explain the relationship between rainfall and sewer transfer flow can be applied in the analysis of rainfall effects on discharged pollution load, therefore, the more appropriate evaluation will be done.

19세기 원주감영, 함흥감영, 해주감영 측우기 강우량 복원 (Restoration of 19th-century Chugugi Rainfall Data for Wonju, Hamheung and Haeju, Korea)

  • 김상원;박준상;김진아;홍윤
    • 대기
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    • 제22권1호
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    • pp.129-135
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    • 2012
  • This study restores rainfall measurements taken with the Chugugi (rain gauge) at Wonju, Hamheung, and Haeju from the Deungnok (government records from the Joseon Dynasty). We restored rainfall data corresponding to a total of 9, 13, and 18 years for Wonju, Hamheung, and Haeju, respectively. Based on the restored data, we reconstructed monthly rainfall data. Restoration was most successful for the rainy season months of June, July and August. The restored rainfall data were compared with the summer rainfall data for Seoul as recorded by the Seungjeongwon (Royal Secretariat). In June, the variation in the restored rainfall data was similar to that of the Seungjeongwon data for Seoul. In July and August, however, the variations in the reconstructed data were markedly different from those in the Seoul data (Seungjeongwon). In the case of the worst drought in the summer of 1888, a substantial shortage of rainfall was found in both the Seungjeongwon data for Seoul and the restored data for the three regional locations.

재현기간별 확률 향우강도식 산정에 관한 수문통계학적 고찰-청주 지방을 중심으로- (A Review for Caluculation of the Formula for Probable Rainfall Intensities Following Return Periods in the Hydrological Statistics. -On Cheong-Ju district-)

  • 이순혁
    • 한국농공학회지
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    • 제17권3호
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    • pp.3848-3859
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    • 1975
  • The author attempted to find most suitable formulas for probable rainfall intensities with analysis and consideration for characteristics of rainfall intensities according to the short and long period return periods at Cheong-Joo district. Above mentioned formulas induced by this study can be contributed to the credibility of runoff estimation for urban sewerage system, drainage works in small catchment area and embankment works in the rivers. The results of this study are summarized as follows: 1 Calculation values by Gumbel-Chow method were selected as a mean values for the calculation of probable rainfall intensities according to return periods in the short period. 2. Calculations for probable rainfall intensities for long period are based upon to the result by Iwai's method. Talbot type, {{{{I= {a} over {t+b} }}}} is confirmed as a most suitable formula for probable rainfall intensities among calculation methods in the short periods at Cheong-Joo district. 4. Specific coefficient method, I24=RN24${\beta}$N was selected as a means of calculation for suitable formulas of probable rainfall intensities according to return periods in case of long period. 5. Runoff estimation with high credibility by rational formula can be anticipated by establishment for the most suitable probable rainfall intensities at Cheong-Joo district.

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