• 제목/요약/키워드: Excessive Rainfall

검색결과 69건 처리시간 0.021초

미계측 유역에서의 확률강우에 대한 돌발홍수지수 산정 (Estimation of the Flash Flood Index by the Probable Rainfall Data for Ungauged Catchments)

  • 김응석;최현일;지홍기
    • 한국방재학회 논문집
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    • 제10권4호
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    • pp.81-88
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    • 2010
  • 최근 들어 기상 이변에 따라 단시간 동안에 특정 소유역에 집중하는 호우 또는 초과우량에 의한 국지성 돌발홍수가 빈번히 발생함에 따라, 이로 인한 인명과 재산의 상당한 위험과 손실은 전 세계적인 것으로서 우리나라도 증가일로에 있다. 돌발홍수는 일반적으로 급경사 소유역에서 집중적인 강우에 의해 발생하여 빠른 유출과 토석류를 동반하기 때문에, 홍수피해를 대비하기 위한 사전 홍수예보시간이 부족할 정도로 급격히 빠른 홍수의 특성을 보인다. 본 연구의 목적은 대상유역의 확률강우량으로부터 돌발홍수지수(flash flood index, FFI)를 산정하여 돌발홍수의 심각성 정도를 정량적으로 분석하고자 한다. 특히 미계측 유역하천에서의 지역 홍수예 경보를 위한 기초자료를 제공할 수 있도록, 대상유역에 대하여 상대적인 돌발홍수심도를 제시할 수 있는 FFI-D-F(돌발홍수지수-지속시간-빈도) 관계곡선을 개발하였다. 또한 FFI-D-F 관계곡선은 현존 및 계획 방재시설물의 돌발홍수 대응능력 및 잔여홍수위험 평가에 활용될 수 있을 것으로 기대된다.

가축분뇨 액비 살포가 새만금유역에서의 논토양과 수질에 미치는 영향 (Effect of Livestock Liquid Manure Released at a Rice Field on Quality of Soil and Water in the Saemangeum Watershed)

  • 김미숙;곽동희
    • 상하수도학회지
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    • 제30권1호
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    • pp.19-31
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    • 2016
  • The Saemangeum watershed is required to manage water pollution effectively but the effect of liquid manure (LM) on soil and water quality in the basin is not clearly identified as yet. This study aims at assessing the effect on soil of a rice field and water quality of water bodies near the rice field during rice-crop time period to find out the effect of LM, the effect of rainfall, and the effect of rice-crop environment on soil and water quality by analyzing data of nitrogen components. As a result of the LM distribution, $NO_3-N$ was much higher than other N components in the entire soil layers and it was accelerated by rainfall right after the LM distribution. Compared to chemical fertilizer (CF), LM was slightly affected but still influenced on the surface water quality. During weak rainfall, low nitrogen concentration in topsoil was resulted as NH3-N decreased and Org-N and $NO_3-N$ increased. $NO_3-N$ concentration in the water of irrigation canals increased with time. During intensive rainfall, $NO_3-N$ and Org-N of the soil were measured highly in the submerged condition, while the water quality of the rice field was lower due to flooding into the irrigation canal as well as the growth of the rice plants. Also, total nitrogen was increased more than 7 times and it showed serious water quality deterioration due to LM and excessive fertilizer distribution, and rainfall during all rice-crop processes. The effect of LM on water quality should be studied consistently to provide critical data while considering weather condition, cropping conditions, soil characteristics, and so on.

시설재배지 토양의 염류축적 현상과 제염방안 (Effectivess of a salt extraction technique in soils under protected cultivation)

  • 홍성구;이남호;전우정;황한철;김진태
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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    • pp.447-453
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    • 1999
  • Salt accumulation is one of themajor problems in soils under protected cultivation . Since protected cultivation does not have rainfall or excessive irrigation, salt accumulaiton inthe soils is inevitable. In this study, characteristics of salt accumulation in soil column were ivestigated, and a salt-extracting method was tested to see its effectiveness. The results showed that the concentration of salt in top soil layers increased and electrical conductivity as thesalt concentration decreased especially in the top soil layer .When extraction medium was applied.

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화학비료와 유기비료 시비후 오염배출 농도 특성 비교 (Comparison of Pollutant Load Discharge Characteristics with Chemical Fertilizer and Organic Compost Applications)

  • 류창원;신용철;허성구;최예환;임경재;최중대
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2005년도 학술발표논문집
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    • pp.490-495
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    • 2005
  • Organic compost has been widely applied to the cropland because it has been thought as Environmentally Sound Agriculture (ESA) in Korea. However, many field researches have been done to investigate water quality impacts of organic compost uses, compared to those from chemical fertilizer applications. It was found that pollutant loads from organic compost applied croplands were higher than those from chemical fertilizer applied areas. However, there might be other unknown factors affecting the results since the experiments were performed at the outside fields. In this study, indoor rainfall experiments using the Norton rainfall simulator systems were done to minimize and exclude errors from unknown sources by controlling soil characteristics, rainfall amount, rainfall intensity, and fertilizer treatments. The amounts of surface runoff and groundwater percolated from 10% and 20% slope plots were measured and water quality samples were collected and analyzed for BOD, COD, and T-P. Flow weighted mean concentration (FWMC) values were computed to assess effects of different fertilizer treatments. It was found that average concentration values of BOD were 5.57 mg/L from chemical fertilizer treated plot and 8.08 mg/L from organic compost treated plots. For 10% slope, FWMC BOD values from organic compost treated plots were higher by 29.9% than those from chemical fertilizer treated plots. For 20% slope, FWMC BOD values from organic plots were higher by 38.8% than those from chemical fertilizer plots. FWMC BOD values for 20% slope plots were higher than those from those for 10% slope plots. The similar trends were found for COD and T-P. In Korea, excessive use of organic compost has caused extremely high levels of organic matter contents at the cropland. Organic compost are usually applied to the cropland to improve soil quality, while chemical fertilizer is applied to help crop growth. Since organic compost is very slow in releasing its nutrients to the soil, farmers usually apply excessive organic compost for immediate effects and maximum crop yields, which has been causing soil and water quality degradations. Therefore, thorough investigations for better nutrient management plans are needed to develop the ESA strategy in Korea.

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소규모 시험포에서의 비료처리별 오염배출 농도 특성 비교 (Comparison of Pollutant Load Discharge Characteristics with Fertilizer Treatments from Small Scale Plot)

  • 류창원;신용철;허성구;한윤수;임경재;최중대
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2006년도 학술발표회 논문집
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    • pp.997-1001
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    • 2006
  • Organic compost has been widely applied to the cropland because it has been thought as Environmentally Sound Agriculture (ESA) in Korea. In this study, two-year indoor rainfall experiments were performed. Surface runoff and groundwater volume from 10% and 20% slope plots were measured and water quality samples were collected and analyzed for BOD, COD, T-P and T-N. Flow weighted mean concentration (FWMC) values were computed to assess effects of various fertilizer treatments. FWMC BOD values for organic compost treated plots were higher than chemical fertilizer treated plots. FWMC BOD values for 20% slope plots were higher than those from those for 10% slope plots. The similar trends were found for COD and T-P. FWMC T-N values for chemical fertilizer treated plots were higher than organic compost treated plots. FWMC T-N values for 10% slope plots were higher than those for 20% slope plots. In Korea, excessive use of organic compost has caused extremely high levels of organic matter contents at the cropland. Since organic compost is very slow in releasing its nutrients to the soil, farmers usually apply excessive organic compost for immediate effects and maximum crop yields, which has been causing soil and water quality degradations. Therefore, thorough investigations for better nutrient management plans are needed to develop the ESA strategy in Korea.

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위험도 기반 지역별 정규 CSOs 곡선 설계에 관한 연구 (A Study on the Risk - based Local Normal CSOs Curve Designs)

  • 조덕준
    • 한국수자원학회논문집
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    • 제39권7호
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    • pp.575-581
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    • 2006
  • 본 연구에서는 강우로 인한 유출 유량의 수질 조절 시스템의 경제적인 설계절차를 제시하였다. 유출수의 수질 조절 시스템 계획을 위해서는 전 기간치의 국지 연속강우기록에 대한 강우-유출 과정의 모의를 하여야 한다. 본 연구에서 강우의 확률분포는 지수감소함수를 따른다고 가정하여 적용함으로서 비 초과확률 분포를 설명할 수 있는 정규곡선을 유도하였다. 또한 유출수의 수질 조절시스템의 저류용량 및 유량 결정을 위하여 월류 위험도를 기반으로 최적곡선을 유도하였다. 최적 저류용량 및 유량의 적용성을 강우 유출 모형인 ILLUDAS에 의한 분석결과와 비교하였으며 본 연구에서와 같이 최적 CSOs(Combined Sewer Overflows)을 지역별로 유도하게 되면 강우로 인한 유출 유량의 수질 조절시스템을 적은 노력과 시간으로 위험도를 기반으로 계획에 이용 될 수 있을 것으로 기대된다.

SSP 기후변화 시나리오에 따른 농업용 저수지 홍수조절능력 분석 (Analysis of Flood Control Capacity of Agricultural Reservoir Based on SSP Climate Change Scenario)

  • 김지혜;곽지혜;황순호;전상민;이성학;이재남;강문성
    • 한국농공학회논문집
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    • 제63권5호
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    • pp.49-62
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    • 2021
  • The objective of this study was to evaluate the flood control capacity of the agricultural reservoir based on state-of-the-art climate change scenario - SSP (Shared Socioeconomic Pathways). 18 agricultural reservoirs were selected as the study sites, and future rainfall data based on SSP scenario provided by CMIP6 (Coupled Model Intercomparison Project 6) was applied to analyze the impact of climate change. The frequency analysis module, the rainfall-runoff module, the reservoir operation module, and their linkage system were built and applied to simulate probable rainfall, maximum inflow, maximum outflow, and maximum water level of the reservoirs. And the maximum values were compared with the design values, such as design flood of reservoirs, design flood of direct downstream, and top of dam elevation, respectively. According to whether or not the maximum values exceed each design value, cases were divided into eight categories; I-O-H, I-O, I-H, I, O-H, O, H, X. Probable rainfall (200-yr frequency, 12-h duration) for observed data (1973~2020) was a maximum of 445.2 mm and increased to 619.1~1,359.7 mm in the future (2011~2100). For the present, 61.1% of the reservoirs corresponded to I-O, which means the reservoirs have sufficient capacity to discharge large inflow; however, there is a risk of overflowing downstream due to excessive outflow. For the future, six reservoirs (Idong, Baekgok, Yedang, Tapjung, Naju, Jangsung) were changed from I-O to I-O-H, which means inflow increases beyond the discharge capacity due to climate change, and there is a risk of collapse due to dam overflow.

분포형 유역유출모형의 홍수예보시스템 적용을 위한 최적해상도 결정에 관한 연구 - GRM 모형을 활용하여 금호강 유역을 중심으로 (A Study on the determination of the optimal resolution for the application of the distributed rainfall-runoff model to the flood forecasting system - focused on Geumho river basin using GRM)

  • 김수영;윤광석
    • 한국수자원학회논문집
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    • 제52권2호
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    • pp.107-113
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    • 2019
  • 한국에서 현재 사용되고 있는 홍수예보모형은 집중형 강우-유출모형을 적용하여 유역의 유출을 계산하고 하도 및 저수지 추적모형 등을 활용하여 하천의 수위를 예측한다. 집중형 모형은 유역을 동질의 배수구역으로 가정한다. 따라서 유역내의 다양한 공간적 특성을 고려하지 못한다는 단점이 있다. 또한, 사용되는 강우자료도 지점강우를 활용하기 때문에 공간적인 분포를 자세히 고려하지 못한다는 한계가 있다. 따라서 홍수예보모형에 분포형 모형을 적용하기 위한 연구가 다양하게 진행되고 있다. 본 연구에서는 GRM모형을 한국 홍수예보시스템에 적용하기 위해 모형의 다양한 해상도에 따른 유역유출의 결과의 차이를 분석하여 최적의 해상도를 결정하고자 한다. 모형의 격자가 너무 조밀한 경우 계산시간이 과다하게 되어 홍수예보모형에 적용하기에는 적합하지 않다. 너무 성길 경우에도 분포형 모형을 적용하여 공간적인 분포를 파악하고자 하는 목적에 맞지 않게 된다. 본 연구의 결과로 유역유출 예측의 정확성을 만족시키고 홍수예보에 적합한 계산속도가 나올 수 있는 최적 해상도를 제시하였다. 유출량 예측의 정확도는 Nash-Sutcliffe model efficiency coefficient (NSE) 값의 비교를 통해 분석하였다. 본 연구에서 도출된 최적해상도 산정 결과는 분포형 유역유출모형을 홍수예보모형에 적용하기 위한 기초자료로 활용될 것이다.

축산분뇨 농지환원을 위한 적정관리방안 (Development of Guidelines for Animal Waste Land Application to Minimize Water Quality Impacts)

  • 홍성구
    • 한국농공학회지
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    • 제44권5호
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    • pp.136-146
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    • 2002
  • Land application of manure compost is considered one of the widely-used animal waste management practices. Many livestock farms adopt composting for their animal waste disposal and apply the compost to crop fields. While standard rates have been established based on researches with respect to land application of manure compost recently, there have been few discussions on water quality impact of the application. Water quality impact should be taken into account in land applications of manure compost. In this study, management practices were proposed based on the investigation of water quality of leachate from manure compost under rainfall simulation, field studies, and monitoring runoff water quality from farm fields after land application of animal waste. The concentrations of major water quality parameters of the leachate were significantly high, whereas those of runoff from soils after tillage for soil incorporation, were not affected by the application based on a series of experiments. Runoff water from farm fields after land application also showed high concentrations of pollutants. Appropriate management practices should be employed to minimize pollutant loading from manure applied fields. Proposed major management practices include 1) application of recommended amounts, 2) proper tillage for complete soil and manure incorporation, 3) field management to prevent excessive soil erosion, 4) complete diversion of inflow into the field from outside, 5) implementation of vegetative buffer strips near boundaries, and 6) prevention of direct discharge of runoff water front fields Into streams.

기후변화에 따른 농경지 배수체계 개선에 관한 연구 (A Study on the Improvement of Rural Drainage System to cope with Climate Change)

  • 박명수;조진훈;윤동균;한국헌
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2012년도 학술발표회
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    • pp.823-823
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    • 2012
  • 최근 우리나라는 아열대성 기후로 변함에 따라 예측 불가능한 강우 형태가 자주 발생하고 있으며, 강우량의 경우 과거에는 발생하지 않았던 고강도의 강우가 빈번하게 발생하고 있는 실정이다. 그러나 기존 농경지 배수시설의 경우 고강도의 강우에 부족한 기준을 가지고 있어 침수에 불리한 구조를 가지고 있다. 또한, 국가경제발전과 국민 식생활 패턴 변화 등으로 논(수도작) 위주에서 원예 특용작물 등 밭작물 중심으로의 작부체계로 변화함에 따라 적정한 배수체계 개선방안이 요구된다. 따라서 현행 설계기준 강우보다 많은 강우가 단시간에 내리는 국지적 집중호우가 발생하여 배수시설물의 배제 능력 부족으로 인한 침수, 배수불량 등의 농경지 침수피해를 대비할 수 있는 배수설계기준이 필요한 상황으로, 기존 배수시설 설계기준에 대한 빈도별 계획강수량, 계획홍수량, 계획홍수위 등을 현재까지의 수문기상자료로 재검토하여 강우패턴변화를 고려한 적정 설계기준(안)을 평가하고 재해 대비 능력 부족한 농업기반시설(배수장, 배수문, 배수로 등)의 효율적인 관리 방안을 마련하겠다.

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