• Title/Summary/Keyword: water deficit

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Development of a Monitoring Technique of Dryness and Wetness in Watershed using Climatic Water Budget (기후학적 물수지에 의한 유역의 건조 및 습윤 상황 감시 기법 개발)

  • Shin, Sha-Chul;Hwang, Man-Ha;Ko, Ick-Hwan
    • Journal of Korea Water Resources Association
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    • v.41 no.2
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    • pp.173-184
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    • 2008
  • Climatic water balance has been applied to obtain quantity of various hydrologic components. Hydrologic information is estimated by comparison between rainfall and evapotranspiration under complex terrain condition. Water deficit is defined as that subtraction of actual supply from climatic demand. The water deficit will occur, when monthly evapotranspiration exceed monthly rainfall. Contrary water surplus is defined as that surplus water after meeting the demand by plants. The water surplus will be occurred when monthly rainfall exceeds monthly evapotranspiration. Finally, the discrete moisture indices were calculated and mapped for the whole watershed to estimate dryness and wetness status using the climatic water balance approach. The result of this study can properly interpret the real drought and non drought. Based upon the results, it can be concluded that the climatic water balance model is useful to monitor water conditions for the watershed.

Comparison of Quality and Cell Enlargement of 'Nero' Black Chokeberry Fruits According to Different Soil Water Conditions (토양수분 조건에 따른 블랙쵸크베리 'Nero' 과실의 품질 및 세포 발달 비교)

  • Won, Jungyeon;Shin, Hyunsuk;Oh, Youngjae;Han, Hyeondae;Kim, Keumsun;Oh, Sewon;Kim, Daeil
    • Korean Journal of Plant Resources
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    • v.30 no.1
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    • pp.88-95
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    • 2017
  • Effects of different soil water conditions on fruit characteristics were investigated in 5-year-old 'Nero' black chokeberry trees (Aronia melanocarpa). Three kinds of drought stresses, including low water deficit, severe water deficit, and very severe water deficit, due to decline of soil water decreased the fruit quality of weight of 10 berries, soluble solid content, and anthocyanin, compared with the control (consistent water supply) during the harvest period. After longer drought stress, supply of soil water could induce berry cracking because cell size of epidermis of fruits contracted, whereas cell size of sub-epidermis and flesh expanded. Thus periodic water supply using water supply facility is needed for yield and quality of 'Nero' black chokeberry fruits.

Proposal and Application of Water Deficit-Duration-Frequency Curve using Threshold Level Method (임계수준 방법을 이용한 물 부족량-지속기간-빈도 곡선의 제안 및 적용)

  • Sung, Jang Hyun;Chung, Eun-Sung
    • Journal of Korea Water Resources Association
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    • v.47 no.11
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    • pp.997-1005
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    • 2014
  • This study evaluated hydrological drought the using the annual minimum flow and the annual maximum deficit method and proposed the new concept of water deficit-duration-frequency curves similar to rainfall intensity-duration-frequency curves. The analysis results of the annual minimum flow, the return periods of hydrological drought in the most duration of 1989 and 1996yr were the longest. The analysis results of the annual maximum deficit, the return periods of 60-days and 90-day deficit which are relatively short duration were the longest in 1995yr, about 35-year, Hydrological drought lasted longer was in 1995, the return period was about 20-year. Though duration as well as magnitude is a key variable in drought analysis, it was found that the method using the annual minimum flow duration not distinguish duration.

Antioxidant Enzymes and Photosynthetic Responses to Drought Stress of Three Canna edulis Cultivars

  • Zhang, Wen-E;Wang, Fei;Pan, Xue-Jun;Tian, Zhi-Guo;Zhao, Xiu-Ming
    • Horticultural Science & Technology
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    • v.31 no.6
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    • pp.677-686
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    • 2013
  • Edible canna is a productive starch source in some tropical and semitropical regions. In these regions, water deficit stress is one of factors that limit the crop yield. In the present study, we investigated seven physiological indexes and photosynthetic responses of three edible canna (Canna edulis Ker.) cultivars ('PLRF', 'Xingyu-1', and 'Xingyu-2') under 35 days drought stress. Our results indicated that drought treatment caused visible wilting symptoms in all cultivars, especially in 'Xingyu-1'. Coupled with the increase of wilting symptoms, relative water content (RWC) and chlorophyll content decreased progressively, malondialdehyde (MDA) content gradually increased, and key antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities increased first and then decreased in all three cultivars. The effect of water stress was more pronounced in 'Xingyu-1' than in 'PLRF' and 'Xingyu-2', and in lower leaves than in upper leaves. In addition, 35 days drought stress also significantly reduced the photosynthetic capacity. Consistent with antioxidant parameters, photosynthetic changes of 'Xingyu-2' were less than those of the other cultivars under water deficit stress. Drought stress caused a significant increase of water use efficiency (WUE) in 'Xingyu-2', but little in 'PLRF', and obvious decrease in 'Xingyu-1'. These results indicated that 'Xingyu-2' was more tolerant to drought stress than 'PLRF' and 'Xingyu-1' by maintaining lower lipid peroxidation and higher antioxidant enzyme activities.

Alteration in Pyridine Nucleotide Status in Cells as an Adaptive Response to Water Stress in Rice (Oryza sativa L.) Seedlings

  • Boo, Yong-Chool;Jung, Jin
    • Applied Biological Chemistry
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    • v.41 no.4
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    • pp.228-234
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    • 1998
  • An adaptive measure of photosynthetic cells to a condition identified with a reduction of cellular energy charge, caused by water deficit-induced impairment of photosynthetic ATP production, was investigated using hydroponically cultured rice seedlings. Water stress treatment of the seedlings resulted in a marked decrease in cellular ATP level, a significant increase in the content of NAD(H) and concurrent decrease in that of NADP(H) in shoots, which accompanied a decrease in the activity of NAD kinase (EC 2.7.1.23) that specifically converts NAD(H) to NADP(H). The decline in the enzyme activity was particularly evident in the $Ca^{2+}/calmodulin-dependent$ kinase, the major form of NAD kinase in plants, whereas the level of active calmodulin remained unchanged during water deficit. The ratio of $NADP^+$ to NADPH was maintained nearly constant and no increases were seen in the level of $H_2O_2$ and the activities of $superoxide/H_2O_2-detoxifying$ enzymes in shoots stress-treated for two days. Based on these results, it may be suggested that rice plants take a strategy to cope with an adverse situation of limited photophosphorylation created by water deficit in that cells facilitate ATP production through glycolysis and oxidative phosphorylation; in doing so, rice cells suppress NAD kinase activity, consequently up-sizing the NAD(H) pool at the expense of the NADP(H) pool. Several parameters associated with the stress symptoms are also of implicative that there is no overproduction of superoxide radical or the related active oxygen at least in rice seedlings.

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Drought Detection and Estimation of Water Deficit using NDVI (NDVI를 이용한 가뭄지역 검출 및 부족수분량 산정)

  • Shin, Sha-Chul;Jeong, Soo;Kim, Kyung-Tak;Kim, Joo-Hun;Park, Jung-Sool
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.2
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    • pp.102-114
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    • 2006
  • This study aims to develop a method to analyze droughts in Nakdong river area. Satellite imagery can be applied to droughts monitoring because it can afford periodic data for large area for long time. In this study, supposing that evapotranspiration and NDVI are closely related to each other, we presented a method to estimate evapotranspiration in large area with NDVI from MODIS data and temperature. For the final analysis of droughts, water deficit is calculated by climatological water balance using the distribution of evapotranspiration and precipitation. As the results of this study, we improved the usability of satellite imagery, especially in drought analysis.

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