• Title/Summary/Keyword: Flooding factors

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The Effect of Soil Flooding on Photosynthesis and Water Relations of Carpinus cordata and Carpinus laxiflora (까치박달과 서어나무의 광합성과 수분관계에 미치는 토양 침수의 영향)

  • 박용목
    • The Korean Journal of Ecology
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    • v.20 no.3
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    • pp.175-179
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    • 1997
  • To explanin allopatric distribution of Carpinus cordata and C. laxiflora in the field the effect of soil flooding on photosynthesis and water relations was tested with field grown saplings. Under the flooding condition stomatal conductance of C. laxiflora decreased markedly from day two after flooding treatment and remanined low throughout the experiment. In contrast, flooding had no effect on stomatal conductance of C. cordata throughout the exper iment. The rate of photosynthesis of C. laxiflora was significantly suppressed under flooding conditions, whereas that of C. cordata was not affected in the flooded condition. On day seven after flooding treatment xylem pressure potential of C. laxiflora significantly decreased. Flooding, however, did not have any effect on the xylem pressure potential of C. cordata throughout the experiment. From these findings it is concluded that there is a difference in resistance to flooding between C. cordata and C. laxiflora and that one of the the factors responsible for allopatric distribution in the two species is flooding.

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Soybean Improvement for Drought, Salt and Flooding Tolerance

  • Pathan, Safiullah;Nguyen, Henry T.;Sharp, Robert E.;Shannon, J. Grover
    • Korean Journal of Breeding Science
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    • v.42 no.4
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    • pp.329-338
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    • 2010
  • Drought, salinity and flooding are three important abiotic factors limiting soybean production worldwide. Irrigation, soil reclamation, and drainage systems are not generally available or economically feasible for soybean production. Therefore, productive soybean varieties with tolerance are a cost effective means for reducing yield losses due to these factors. Genetic variability for higher tolerance to drought, salt and flooding is important. However, only a small portion of nearly 200,000 world soybean accessions have been screened to find genotypes with tolerance for use in breeding programs. Evaluation for tolerance to drought, salinity and flooding is difficult due to lack of faster, cost effective, repeatable screening methods. Soybean strains with higher tolerance to the above stresses have been identified. Crosses with lines with drought, salt and flooding tolerance through conventional breeding has made a significant contribution to improving tolerance to abiotic stress in soybean. Molecular markers associated with tolerance to drought, salt and flooding will allow faster, reliable screening for these traits. Germplasm resources, genome sequence information and various genomic tools are available for soybean. Integration of genomic tools coupled with well-designed breeding strategies and effective uses of these resources will help to develop soybean varieties with higher tolerance to drought, salt and flooding.

Classification and Analysis of Korea Coastal Flooding Using Machine Learning Algorithm (기계학습 알고리즘에 기반한 국내 해수범람 유형 분류 및 분석)

  • CHO, KEON HEE;EOM, DAE YONG;PARK, JEONG SIK;LEE, BANG HEE;CHOI, WON JIN
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.26 no.1
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    • pp.1-10
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    • 2021
  • In this study, Information for the case of seawater flooding and observation data over a period of 10 years (2009~2018) was collected. Using machine learning algorithms, the characteristics of the types of seawater flooding and observations by type were classified. Information for the case of seawater flooding was collected from the reports of the Korea Hydrographic and Oceanographic Agency (KHOA) and the Korea Land and Geospatial Informatics Corporation. Observation data for ocean and meteorological were collected from the KHOA and the Korea Meteorological Agency (KMA). The classification of seawater flooding incidence types is largely categorized into four types, and into 5 development types through combination of 4 types. These types were able to distinguish the types of seawater flooding according to the marine weather environment. The main characteristics of each was classified into the following groups: tidal movement, low pressure system, strong wind, and typhoon. Besides, in consideration of the geographical characteristics of the ocean, the thresholds of ocean factors for seawater flooding by region and type were derived.

Risk assessment for inland flooding in a small urban catchment : Focusing on the temporal distribution of rainfall and dual drainage model (도시 소유역 내 내수침수 위험도 평가 : 강우 시간분포 및 이중배수체계 모형을 중심으로)

  • Lee, Jaehyun;Park, Kihong;Jun, Changhyun;Oh, Jeill
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.6
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    • pp.389-403
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    • 2021
  • In this study, dual drainage system based runoff model was established for W-drainage area in G-si, and considering the various rainfall characteristics determined using Huff and Mononobe methods, the degree of flooding in the target area was analyzed and the risk was compared and analyzed through the risk matrix method. As a result, the Monobe method compared to the Huff method was analyzed to be suitable analysis for flooding of recent heavy rain, and the validity of the dynamic risk assessment considering the weight of the occurrence probability as the return period was verified through the risk matrix-based analysis. However, since the definition and estimating criteria of the flood risk matrix proposed in this study are based on the return period for extreme rainfall and the depth of flooding according to the results of applying the dual drainage model, there is a limitation in that it is difficult to consider the main factors which are direct impact on inland flooding such as city maintenance and life protection functions. In the future, if various factors affecting inland flood damage are reflected in addition to the amount of flood damage, the flood risk matrix concept proposed in this study can be used as basic information for preparation and prevention of inland flooding, as well as it is judged that it can be considered as a major evaluation item in the selection of the priority management area for sewage maintenance for countermeasures against inland flooding.

Assessment of Flooding Vulnerability Based on GIS in Urban Area - Focused on Changwon City - (GIS 기반의 도시지역 침수 취약성 평가 - 창원시를 대상으로 -)

  • Song, Bong-Geun;Lee, Taek-Soon;Park, Kyung-Hun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.4
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    • pp.129-143
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    • 2014
  • The purpose of this study is to evaluate flooding vulnerability considering spatial characteristics focused on Changwon-si, Gyeongsangnam-do. Assessment Factors are water cycle area ratio, surface runoff, and precipitation. And construction of assessment factors and vulnerability was analyzed by GIS program. Water cycle ratio and surface runoff were vulnerable in urban area. Precipitation was often distributed in agriculture of the northern region. Results of flooding vulnerability were low in agriculture and forest of the northern region. In contrast, urban area was high because there has covered impervious land cover. Analytical results of flooding vulnerability density using hotspot spatial cluster analysis were high in urban area. And these areas were situated in down stream so flooding were generated. Therefore, flooding vulnerability assessment of this study can help for selecting construction sites of pervious land cover and rainwater management facilities in urban and environmental planning.

Flooding Risk Assessment Using Flooding Characteristic Values (침수특성치를 이용한 침수위험성 평가)

  • Ahn, Jeonghwan;Kim, Kunwoo;Cho, Woncheol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.3
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    • pp.957-964
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    • 2013
  • This research is on the methodology of flood risk assessment using flooding characteristic values. Necessity of design magnitude for flood control considering floods was judged by plotting peak flow with respect to frequency and duration, and flooding magnitude was defined with 6 flooding characteristic values which were proposed to be significant factors when assessing flooding magnitude. Precipitation data used in the assessment modeling were applied by combining all the possible precipitation events. After overlapping the simulated results with precipitation matrix by flooding characteristic values, contour map was drawn, and Flooding characteristic contour graph for possible rainfall events were suggested in respect of all possible precipitation. Flooding characteristic contour graph for possible rainfall events was confirmed that reducing of damage magnitude of each flood characteristic value was figured out easily. The flood risk assessment methods suggested in this study would be a good reference for urban drainage system design, which only focuses on pipe conduit.

Analysis of the Vulnerable Area about Inundation on the Upriver Basin of Dam by Flood Simulation Using GIS (GIS 홍수 시뮬레이션에 의한 댐 상류 유역의 침수 취약지역 분석)

  • Um, Dae-Yong;Kim, Ji-Hye
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.6
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    • pp.723-731
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    • 2009
  • Recently, it has been strangely increasing rainfall and rainfall meter by global warming. so flood damage is being increase. It has happened there are so many damaged by influence by backwater of dam. However, the alleviative solutions of flood damages are focused on the lower river basin where the density of population is higher than upper river basin. This research proceeds based on design and build 3D topography model and reflects the topographical factors of upper river basin. It also simulated the circumstances of flooding by investigation of factors of outflow, hence, as a result, we would find out the vulnerable area for flooding and scale of damages effectively. This research suggests the solution and method of flooding for vulnerable area of the flooding to reduce the damages by predicting flooding. Thus, the suggestion may support to make a decision efficiently to prevent the damage of flooding.

Effects of environmental factors on the growth response of above- and below-ground parts of Mankyua chejuense, endangered endemic plant to Jeju province, in Korea

  • Kim, Hae-Ran;Shin, Jeong-Hoon;Jeong, Heon-Mo;You, Young-Han
    • Journal of Ecology and Environment
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    • v.37 no.2
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    • pp.61-67
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    • 2014
  • Mankyua chejuense is a native endangered plant distributed only in Gotzawal, a forested wetland, in Jeju Province, Korea. In order to determine the optimal environmental conditions for the growth and development of M. chejuense, we investigated the above- and below-ground growth responses and survival rate to various soil texture (sand and clay), water regimes (flooding and non-flooding), and $CO_2+T$ (ambient and elevated) conditions. All of the treatments had significant effects on aboveground growth parameters, while only the water regime and $CO_2+T$ treatments influenced belowground growth. The survival rate of M. chejuense was about twice higher under the sand, non-flooding and elevated $CO_2+T$ conditions than clay, flooding and ambient $CO_2+T$ conditions. These results indicate that M. chejuense grows in well-drained sandy soil conditions and elevated $CO_2$ concentration and temperature situations. Thus, there is a need to maintain M. chejuense under constant non-flooding soil conditions by implementing appropriate soil drainage strategies.

Correlation Analysis of Basin Characteristics and Limit Rainfall for Inundation Forecasting in Urban Area (도시지역 침수예측을 위한 유역특성과 한계강우량에 대한 상관분석)

  • Kang, Ho Seon;Cho, Jae Woong;Lee, Han Seung;Hwang, Jeong Geun;Moon, Hae Jin
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.97-97
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    • 2020
  • Flooding in urban areas is caused by heavy rains for a short period of time and drains within 1 to 2 hours. It is also characterized by a small flooding area. In addition, flooding is often caused by various and complex causes such as land use, basin slope, pipe, street inlet, drainage pumping station, making it difficult to predict flooding. Therefore, this study analyzes the effect of each basin characteristic on the occurrence of flooding in urban areas by correlating various basin characteristics, whether or not flooding occurred, and rainfall(Limit Rainfall), and intends to use the data for urban flood prediction. As a result of analyzing the relationship between the imperviousness and the urban slope, pipe, threshold rainfall and limit rainfall, the pipe showed a correlation coefficient of 0.32, and the remaining factors showed low correlation. However, the multiple correlation analysis showed the correlation coefficient about 0.81 - 0.96 depending on the combination, indicating that the correlation was relatively high. In the future, I will further analyze various urban characteristics data, such as area by land use, average watershed elevation, river and coastal proximity, and further analyze the relationship between flooding occurrence and urban characteristics. The relationship between the urban characteristics, the occurrence of flooding and the limiting rainfall amount suggested in this study is expected to be used as basic data for the study to predict urban flooding in the future.

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In Vitro Culture and Factors Affecting Population Changes of Ditylenchus destructor of Ginseng (인삼의 Ditylenchus destructor 선충의 인공배양 및 밀도에 영향을 주는 요인)

  • 김영호;오승환
    • Korean Journal Plant Pathology
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    • v.11 no.1
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    • pp.39-46
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    • 1995
  • Ditylenchus destructor isolated from diseased ginseng roots was cultured on ginseng calli, fungal mycelium (Fusarium solani), carrot discs and radish sprouts. Effects of temperature, organic material and flooding on the nematode population changes were examined. D. destructor multiplied readily on the culture media except radish sprout medium, and was cultured best on the fungal culture at 2$0^{\circ}C$. Feeding of the fungal hypha and radish root hairs, molting and mating in the fungal culture medium were observed. Addition of organic materials (perilla, sesame, soybean and ginseng leaves) in soil significantly increased Aphelenchus avenae and saprophytic nematode populations, while D. destructor populations changed little and the nematode population growths were limited by the organic amendments (except sesame leaves). The nematode populations in soil including D. destructor were decreased by flooding. The results indicate that D. destructor may survive but not multiply readily in soil without host plants and that it can be effectively controlled by flooding.

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