• 상하수도학회지
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• 제35권6호
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• pp.477-487
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• 2021

Due to the global climate change, Korean peninsula is has been experiencing flooding and drought severely. It is hard difficult to manage water resources sustainably, because due to intensive precipitation in short periods and severe drought has increased in Korea. Reused water from the wastewater treatment plant (WWTP) could be a sustainable and an alternative water source near the urban areas. In order to understand the patterns of water reuse in Korea, annual water reuses data according to the times and regional governments were investigated from 2008 to 2019. The reused water from WWTP in Korea has been mainly used for river maintenance flow and industrial use, while agricultural use of water reuse has decreased with time. Metropolitan cities in Korea such as Seoul, Busan, Daegu, Ulsan, and Incheon have been mainly used reused reusing water for river maintenance flow. Industrial water reuse has been limitedly applied recently for the planned industrial districts in Pohang, Gumi, Paju, and Asan. By using the collected annual water reuse data from the domestic sewerage statistics of sewerage, the optimistic and pessimistic future estimations of for future annual water reuse were suggested from 2020 to 2040 on a five year interval for every five years.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.345-345
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• 2021

기상청에 따르면 2018년 강수량은 평년보다 높으나 시기 및 지역에 따른 편차로 인해 강수 부족 지역이 발생하였고 7월 중순부터 8월말까지 최저 강수로 인한 국지적 가뭄이 발생하였다. 특히 전국적으로 영농기 시점(3~5월) 및 영농기 종점(10월)에 평년보다 많은 비가 왔으나 7~8월말 평년보다 적은 강수로 인한 여름철 농업가뭄이 발생하였다. '73년 이후 두 번째로 짧은 장마기간을 기록하였고 장마기간 강수량은 평년대비 72% 수준으로 일부 지역 저수지 저수율은 지속적인 심각단계를 초래했다. 2018년 강우기준 가뭄빈도 분석을 위해 '18년 1월~8월까지 누적 강수량을 기준으로 분석, 7월 중순에서 8월 중순까지 극심한 강수 부족이었으나 1월~8월까지 누적 강수량은 평년 수준을 나타내었다. 강우기준 가뭄빈도 분석 결과 10년 이상 가뭄빈도 해당 지역은 전남 강흥군과 강진군으로 분석되었다. '18년 7월 강수량을 기준으로 분석결과 전국 대부분 지역이 극심한 강우 부족에 따른 가뭄이 발생한 것으로 200년 이상 가뭄빈도 해당 지역은 107개 시군으로 분석되었다. 저수율기준 가뭄 빈도 분석을 위해 '18년 8월 저수지 저수율 기준 가뭄빈도 분석결과 벼작물 생육기간 중 필요수량 높은 시기에 용수 부족으로 200년 이상 가뭄빈도 해당 지역은 45개 시군으로 나타났다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.207-207
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• 2021

The Vietnamese Mekong Delta(VMD) covers an area of 62,250 km² in the lowest basin of the Mekong Delta where more than half of the country's total rice production takes place. In 2016, an estimated 1.29 million tonnes of Vietnam's rice were lost to the country's biggest drought in 90 year and particularly in VMD, at least 221,000 hectares of rice paddies were hit by the drought and related saltwater intrusion from the South China Sea. In this study, 3D numerical simulations using Delft3D hydrodynamic models with calibration and validation process were performed to examine flow characteristics, climate change scenarios, water level changes, and salinity concentrations in the nine major estuaries and coastal zones of VMD during the 21^st century. The river flows and their interactions with ocean currents were modeled by Delft3D and since the water levels and saltwater intrusion in the area are sensitive to the climate conditions and upstream dam operations, the hydrodynamic models considered discharges from the dams and climate data provided by the Coupled Model Intercomparison Project Phase 6(CMIP6). The models were calibrated and verified using observational water levels, salinity distribution, and climate change data and scenarios. The results agreed well with the observed data during calibration and validation periods. The calibrated models will be used to make predictions about the future salinity intrusion events, focusing on the impacts of sea level rise due to global warming and weather elements.

• 한국토양비료학회지
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• 제8권3호
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• pp.161-170
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• 1975

Status of agriculture in Jeju province were investigated to find out problems and solutions in view of weather, soils and crop productions. Two hundred harmful windy days per year force to build strong wind-break forest near to farm. Somewhat severe drought situation in croping could be completely avoided by good irrigation system using abundant underground water resources. Poor fertility of soils should be improved by using much compost, lime, fused phosphate, and high dose fertilizers. Optimum fertilizer level for each crop should be determined with special consideration on characteristics of volcanic ash soil.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.259-262
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• 2003

Surveyed effluent capacities for potential wastewater resources through the surveying of the sewage treatment plants its capacity is up to 10,000 tonnes per day located 4 provinces (kyunggi, gangwon, chungbuk, chungnam) in this year. The total effluent capacities in this provinces are 423 thousand $m^3/day$, which may be used to irrigated paddy fields of 2,310ha A GIS database for wastewater resource inventory was developed for 4 provinces (kyunggi, gangwon, chungbuk, chungnam) to explore the feasibility of the wastewater reuse for drought mitigation. And it is to be extended to the other wastewater treatment plants.

• 상하수도학회지
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• 제30권1호
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• pp.51-58
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• 2016

On account of the increase in water demand and climate change, droughts are in great concern for water resources planning and management. In this study, rainfall characteristics with stationary and non-stationary perspectives were analyzed using Weibull distribution model with 40-year records of annual minimum rainfall depth collected in major cities of Korea. As a result, the non-stationary minimum probable rainfall was expected to decrease, compared with the stationary probable rainfall. The reliability of ${\xi}_1$, a variable reflecting the decrease of the minimum rainfall depth due to climate change, in Wonju, Daegu, and Busan was over 90%, indicating the probability that the minimal rainfall depths in those city decrease is high.

• 아시안잔디학회지
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• 제11권4호
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• pp.271-280
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• 1997

The short green period of zoysiagrass has been a problem in using for turf. This study was performed to check growth response of several wintergrasses under sunny and shady area in Korea. Wintergrasses of 5 species, 27 cultivars introduced from U.S.D.A., were used in this study. After establishment, two fluctuations of top growth were observed which varied according to the species; first, due to drought in May, second, due to high temperature and humidity from July to August. Red fescues and perennial ryegrasses showed severe growth retardation in sunny area during summer period. Kentucky bluegrasses and tall fescues maintained good Qualities nearly all the year round arid showed slight disease infections. Kentucky bluegrass 'Kenblue' and red fescue 'Agram' grown under shady area showed higher photosynthetic ability than under sunny area, except the temperature range from 30˚C to 40 ˚C under 40,000 lux light in red fescue 'Agram'. And the phorosynthesis was decreased at the temperature range from 35 ˚C to 40 ˚C. Key words: Wintergrass, Top growth, Visual rating, Photosynthesis, Poa pratensis. Festuca arundinacea, Pestuca rubra. Lolium perenne, Agrostis stolonifera.

• 한국조경학회지
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• 제33권5호통권112호
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• pp.69-82
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• 2005

These studies were carried out (1) to investigate the growth characteristics of Sedum album L. in the field, (2) to propose a suitable shallow peen roof system for this plant, and (3) to evaluate plant growth in the proposed system over the long term. The growth characteristics, such as morphological properties, growth habit, shade tolerance, and flowering, were surveyed. In experimental shallow green-roof systems, the effects of drainage type, substrate type, and soil depth on plant growth were investigated. Then drought tolerance was investigated. After planting Sedum album L. in the proposed system survival rate, cover, and resistance to insects, heal and cold were evaluated for about 2 years. The results of these studies are summarized below. 1. In the field, the aboveground part of Sedum album L. did not die back during the winter. Plant height was 4$\sim$7 cm. Roots were distributed to a depth of 5$\sim$7 cm. Sedum album L. is a compact ground-cover plant that spreads vigorously. Shading condition of less than $30\%$ of full sunlight didn't cause any trouble, but shading conditions above $87\%$ made the shape of the shoots and leaves abnormal. The plant bloomed from June to August and had a rather large compound umbel of white, star-shaped flowers. 2. Two systems, a drainage-blend-10 cm soil depth and a reservoir$\cdot$drainage-blend-15 cm soil depth, performed best in terms of cover, fresh weight, and dry weight. The first has an advantage for green roofs because it is lighter than the latter. 3. In drainage-blend-10 m soil depth and modified reservoir · drainage-blend-10 cm soil depth system no plants died for about 4 months after stopping the irrigation. The visual quality of the latter system was above 5 for 4 months and that of the former was under 5 after 2 months. In the field, however, the drought tolerance of Sedum album L. grown in the former would be enough to withstand the dry season. Considering the urban ecosystem and the importance of healthy growth the modified reservoir $\cdot$ drainage-blend-10 cm soil depth system was finally recommended. This system was composed of a 4 cm thick drainage layer and drain outlets placed at a height of 2.5 cm. 4. In the proposed system, the survival rate was $100\%$, and there was no injury induced by insects and heat. The leaf density decreased a little in winter. Cover increased throughout the year. Sedum album L. was planted with a cover of 72$cm^{2}$ on 3 April 2003; on 16 June 2003 and 15 June 2004, cover was $132.66\pm$5.87 $cm^{2}$(1.8 times) and $886.98\pm$63.51 $cm^{2}$(12.3 times), respectively.

• 한국습지학회지
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• 제21권4호
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• pp.312-320
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• 2019

남조류의 대발생은 대량 번성 및 사멸에 따라 수체 내 산소 고갈 및 유기물 증가와 같은 문제를 야기하고 있다. 매년 여름철 폭염 및 가뭄의 영향으로 조류대경보가 발령되고 있으며, 낙동강 본류 구간의 선제적 녹조관리를 위해 남조류 발생특성을 정량적으로 규명할 필요가 있다. 본 연구에서는 시각화 분석 및 상관관계 분석을 이용한 남조류 발생 주요 영향인자 분석과 더불어 머신러닝 기법인 의사결정나무를 이용하여 영향인자에 따른 남조류 발생조건을 정량적으로 분석하였다. 8개 보 모든 지점에서 기상학적 요인인 기온과 SPI 가뭄지수는 남조류 세포수와 유의한 상관관계 특성을 보였다. 이는 폭염일수 증가 및 가뭄에 따른 수체 내 물의 혼합 차단 및 성층현상이 지속되어 남조류 발생을 촉진시키는 것으로 보여지며, 장기적으로 기상학적 영향을 고려한 남조류 발생의 선제적 관리도 필요할 것으로 판단된다.

• 한국수자원학회논문집
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• 제51권10호
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• pp.839-852
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• 2018

본 연구의 목적은 기상자료(강수량, 최고기온, 최저기온, 평균기온, 평균풍속) 기반의 다중선형 회귀모형을 개발하여 농업용저수지 저수율을 예측하는 것이다. 나이브 베이즈 분류를 활용하여 전국 1,559개의 저수지를 지리형태학적 제원(유효저수량, 수혜면적, 유역면적, 위도, 경도 및 한발빈도)을 기준으로 30개 군집으로 분류하였다. 각 군집별로, 기상청 기상자료와 한국농어촌공사 저수지 저수율의 13년(2002~2014) 자료를 활용하여 월별 회귀모형을 유도하였다. 저수율의 회귀모형은 결정계수($R^2$)가 0.76, Nash-Sutcliffe efficiency (NSE)가 0.73, 평균제곱근오차가 8.33%로 나타났다. 회귀모형은 2년(2015~2016) 기간의 기상청 3개월 기상전망자료인 GloSea5 (GS5)를 사용하여 평가되었다. 현재저수율과 평년저수율에 의해 산정되는 저수지 가뭄지수(Reservoir Drought Index, RDI)에 의한 ROC (Receiver Operating Characteristics) 분석의 적중률은 관측값을 이용한 회귀식에서 0.80과 GS5를 이용한 회귀식에서 0.73으로 나타났다. 본 연구의 결과를 이용해 미래 저수율을 전망하여 안정적인 미래 농업용수 공급에 대한 의사결정 자료로 사용할 수 있을 것이다.