• Title/Summary/Keyword: 기상요인

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Evaluating Impact Factors of Forest Fire Occurrences in Gangwon Province Using PLS-SEM: A Focus on Drought and Meteorological Factors (PLS-SEM을 이용한 강원도 산불 발생의 영향 요인 평가 : 가뭄 및 기상학적 요인을 중심으로)

  • Yoo, Jiyoung;Han, Jeongwoo;Kim, Dongwoo;Kim, Tae-Woong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.3
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    • pp.209-217
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    • 2021
  • Although forest fires are more often triggered by artificial causes than by natural causes, the combustion conditions that spread forest fire damage over a large area are affected by natural phenomena. Therefore, using partial least squares structural equation modeling (PLS-SEM), which can analyze the dependent and causal relationships between various factors, this study evaluated the causal relationships and relative influences between forest fire, weather, and drought, taking Gangwon Province as our sample region. The results indicated that the impact of drought on forest fires was 27 % and that of the weather was 38 %. In addition, forest fires in spring accounted for about 60 % of total forest fires. This indicatesthat along with meteorological factors, the autumn and winter droughts in the previous year affected forest fires. In assessing the risk of forest fires, if severe meteorological droughts occur in autumn and winter, the probability of forest fires may increase in the spring of the following year.

Meteorological Factors Influencing Breeding Biology of Kaloula borealis (맹꽁이(Kaloula borealis)의 번식에 영향을 주는 기상요인)

  • Ko, Sang-Beom;Chang, Min-Ho;Song, Jae-Young;Oh, Hong-Shik
    • Korean Journal of Environment and Ecology
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    • v.26 no.6
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    • pp.876-883
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    • 2012
  • In order to analyze the meteorological factors influencing breeding activities of the Kaloula borealis, spawning sites which are located in Daejung-Eub, Jeju Island were investigated for 4 years from 2008 to 2011. The factors for analysis were rainfall, humidity, temperature, barometric pressure and wind speed. Comparative analysis were done on the spawning activities on rainy days. The analysis shows that the main factors influencing breeding activities of the Kaloula borealis are rainfall, humidity, and barometric pressure. The most influencing factor among them is rainfall. According to the analysis, the Kaloula borealis participate in spawning activities when it rains hard and humidity and barometric pressure also have influence on their spawning activities to a certain degree. As for temperature, the breeding season is summer so it meets one of the conditions for breeding activities. As a result, like the previous studies on other anurans in temperate regions, rainfall and temperature have a great impact on breeding activities of the Kaloula borealis.

A Study on Development of Water Quality Prediction by Artificial neural network in Watershed of Nam River Using Probability Forecast (확률예보를 이용한 남강유역에서의 수질예측 ANN모형 개발 연구)

  • Jung, Woo Suk;Kim, Young Do;Kang, Boo Sik;Kim, Sung Eun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.26-26
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    • 2017
  • 우리나라는 하천 및 호수 등 지표수에 대한 수자원 의존도가 매우 높다. 지표수는 태양광에 노출되어 있고, 기온의 영향을 직접 받기 때문에 기후변화에 대해 매우 민감한 수체이다. 기후변화로 인한 이상 저온, 이상 고온, 홍수, 가뭄 등의 자연 현상은 하천, 호수의 물리화학적 및 생태학적 특성을 변화(교란)시키고 있다. 이러한 기상현상에 변동되는 수질특성을 고려하여 기상청 확률기상예보를 구축된 인공신경망 예측모형의 입력인자로 적용하여 수질예보시스템을 개발하고자 하였다. 모형구축은 실제 일어난 기상관측자료와 요인분석을 통해 분류한 수질인자를 반영하여 단위유역별 수질예측을 위한 ANN학습을 실시하였다. 각 단위유역마다 기상요인의 공간적 세밀화 적용을 위해 각각 남강A, 남강B는 산청기상대, 남강C, 남강D는 진주기상대, 남강E는 의령기상대 자료를 이용하였으며, 수질항목은 DO, BOD, COD, TOC, T-P, SS 총 6개로 단위유역 5개에서 총 30개 예측모형 구축을 위한 자료를 수집하였다. 학습된 인공신경망 예측모형에 기상청 확률예보 값을 입력인자로 사용하여 모형평가를 실시하였다. 5개 단위유역 중 상대적으로 유역관리의 시급성을 고려하여 남강댐 하류 단위유역인 남강D, 남강E 인공신경망 모형의 입력자료로 적용하여 평가하였다.

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Meteorological Constraints and Countermeasures in Major Summer Crop Production (하작물의 기상재해와 그 대책)

  • Shin-Han Kwon;Hong-Suk Lee;Eun-Hui Hong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.27 no.4
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    • pp.398-410
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    • 1982
  • Summer crops grown in uplands are greatly diversified and show a large variation in difference with year and location in Korea. The principal factor for the variation is weather, in which precipitation and temperature play a leading role and such a weather factors as wind, sun lights also influence production of the summer crops. Since artificial control of weather conditions as a main stress factor for crop production is almost impossible, it must be minimized only by an improvement of cultivation techniques and crop improvement. Precipitation plays a role as one of the most important factor for production of the summer crops and it is considered in two aspects, drought and excess moisture. This country, which belongs to monsoon territory, necessarily encounter one of this stress almost every year, even though the level is different. Therefore, the facilities for both drought and excess moisture are required, but actually it is not easy to complete for them. On this account, crops tolerant to drought, excess moisture and pests should be considered for establishing summer crops. For the districts damaged habitually every season, adequate crops should be cultured and appropriate method of planting, drainage and weed control should be applied diversely. Injuries by temperature is mainly attributed to lower temperature particularly in late fall and early spring, although higher temperature often causes some damages depending upon the kind of crops. Sometimes, lower temperature in summer season playa critical role for yield reduction in the summer crops. However, certain crops are prevented to some extent from this kind of stress by improving varieties tolerant to cold, hot weather or early maturing varieties. As is often the case, control of planting time or harvesting is able to be a good management for escaping the stress. Lodging, plant diseases and pests are considered as a direct or indirect damage due to weather stress, but these are characters able to be overcome by means of crop improvement and also controlled by other suitable methods. In addition, polytical supports capable of improving constitution of agriculture into modern industry is urgently required by programming of data for the damages, establishment of damage forecasting and compensation system.

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Examining Impact of Weather Factors on Apple Yield (사과생산량에 영향을 미치는 기상요인 분석)

  • Kim, Mi Ri;Kim, Seung Gyu
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.4
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    • pp.274-284
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    • 2014
  • Crops and varieties are mostly affected by temperature, the amount of precipitation, and duration of sunshine. This study aims to identify the weather factors that directly influence to apple yield among the series of daily measured weather variables during growing seasons. In order to identify them, 1) a priori natural scientific knowledge with respect to the growth stage of apples and 2) pure statistical approaches to minimize bias due to the subject selection of variables are considered. Each result estimated by the Panel regression using fixed/random effect models is evaluated through suitability (i.e., Akaike information criterion and Bayesian information criterion) and predictability (i.e., mean absolute error, root mean square error, mean absolute percentage). The Panel data of apple yield and weather factors are collected from fifteen major producing areas of apples from 2006 to 2013 in Korea for the case study. The result shows that variable selection using factor analysis, which is one of the statistical approaches applied in the analysis, increases predictability and suitability most. It may imply that all the weather factors are important to predict apple yield if statistical problems, such as multicollinearity and lower degree of freedom due to too many explanatory variables used in the regression, can be controlled effectively. This may be because whole growth stages, such as germination, florescence, fruit setting, fatting, ripening, coloring, and harvesting, are affected by weather.

A Study on the Constraints on North-east Chinese Ports (북중국 항만의 운영 제약 요인에 관한 연구)

  • Yoo Ju-Young;Kim Tae-Won;Nam Ki-Chan
    • Journal of Navigation and Port Research
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    • v.30 no.3 s.109
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    • pp.227-233
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    • 2006
  • As North-east Chinese parts including Shanghai port grow rapidly, competition among the Far-East parts to be a hub port is getting higher, somebody has even raised a crisis of Busan port. However there are same constraints an the North-east parts such as weather aggravation and long distance from main truck routes. When we consider the competitiveness of port, weather aggravation should be considered as one of the significant factors. But previous studies have rarely examined these kinds of external factors of port operation Therefore, this study analyze constraints an the North-east Chinese parts through a survey of same national flag shipping companies and agencies of foreign shipping companies. The result shows that the mast significant constraint in the North-east ports is weather aggravation which causes problems for regular schedules of shipping, operation cast and customer service qualities etc.