• Title/Summary/Keyword: forest fires

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Mechanical characteristic of overhead transmission lines by forest fires (화염에 노출된 가공송전선의 기계적.재료적 특성 검토)

  • Kang, J.W.;Jang, T.I.;Kim, B.K.;Park, C.G.;Bang, H.K.
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.339-341
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    • 2002
  • The remaining life of ACSR exposed to the atmosphere for a long period may rely on deterioration caused by environmental indices such as atmospheric corrosion, galvanic corrosion, crevice corrosion and fatigue corrosion. One of reduction of useful life in overhead transmission lines built on the ridge of mountain is often caused by forest fires. This paper deals with investigation of strength deterioration performance of ACSR due to fires through several testing and analyzing data for both tension load and material analysis. Test samples are ACSR $480[mm^2]$ conductors, which are artificially fired to regular durations. As a result, it can be verified that tension load of ACSR are reduced by increasing fro duration. Hence, it is obvious that ACSR due to forest fires may lead to mechanical deterioration.

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A FORECASTING METHOD FOR FOREST FIRES BASED ON THE TOPOGRAPHICAL CLASSIFICATION SYSTEM AND SPREADING SPEED OF FIRE

  • Koizumi, Toshio
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.311-318
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    • 1997
  • On April 27,1993, a forest fire occurred in Morito-area, Manba-city, Gunma-prefecture Japan. Under the prevailing strong winds, the fire spread and extended to the largest scale ever in Gunma-prefecture. The author chartered a helicopter on May 5, one week after the fire was extinguished, and took aerial photos of tile damaged area, and investigated the condition. of the fire through field survey and data collection. The burnt area extended. over about 100 hectares, and the damage amounted to about 190 million yen (about two million dollar). The fire occurred at a steep mountainous area and under strong winds, therefore, md and topography strongly facilitated the spreading, It is the purpose of this paper to report a damage investigation of the fire and to develop the forecasting method of forest fires based on the topographical analysis and spreading speed of fire. In the first place, I analyze the topographical structure of the regions which became the bject of this study with some topographical factors, and construct a land form classification ap. Secondly, I decide the dangerous condition of each region in the land form classification map according to the direction of the wind and spreading speed of f'kre. In the present paper, I try to forecast forest fires in Morito area, and the basic results for the forecasting method of forest fires were obtained with the topographical classification system and spreading speed of fire.

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Spatio-Temporal Analysis of Forest Fire Occurrences during the Dry Season between 1990s and 2000s in South Korea (1990년대와 2000년대 건조계절의 산불발생 시공간 변화 분석)

  • Won, Myoung-Soo;Yoon, Suk-Hee;Koo, Kyo-Sang;Kim, Kyong-Ha
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.3
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    • pp.150-162
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    • 2011
  • For the period between 1991 and 2009, the annual average of 448 forest fires occurred in Korea. Above all, approximately 94% of the total fires frequently occurred during the spring and fall seasons. Therefore, we need to minimize the damage of forest fire and manage them systematically. In this study, we analyzed the spatio-temporal distribution patterns for the frequency of forest fire occurrences by each city and gun during dry season between 1990s and 2000s using GIS. Then we compared to analyze the frequency of forest fire occurrence by ten-day intervals in 2000s with that in 1990s. As a result of analysis, early April showed the highest frequency of forest fire occurrence in both 1990s and 2000s. Compared to the 1990s and 2000s, the regional change of forest fire showed the most frequent fire events around Chungcheong province. Especially extra 27 fires increased in Daejeon city, and the second most frequent fire had more than 10 fires in Jeolla province and Incheon. However, the number of fire frequency decreased by 12 fires at the end of April in Hongcheon-gun(the province of Gangwon). This is the largest drop over the study period. We consider that this paper will utilize usefully to establish regional counterplan for forest fire prevention by understanding regional forest fire patterns from seasonal change.

Evaluating meteorological and hydrological impacts on forest fire occurrences using partial least squares-structural equation modeling: a case of Gyeonggi-do (부분최소제곱 구조방정식모형을 이용한 경기도 지역 산불 발생 요인에 대한 기상 및 수문학적 요인의 영향 분석)

  • Kim, Dongwook;Yoo, Jiyoung;Son, Ho Jun;Kim, Tae-Woong
    • Journal of Korea Water Resources Association
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    • v.54 no.3
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    • pp.145-156
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    • 2021
  • Forest fires have frequently occurred around the world, and the damages are increasing. In Korea, most forest fires are initiated by human activities, but climate factors such as temperature, humidity, and wind speed have a great impact on combustion environment of forest fires. In this study, therefore, based on statistics of forest fires in Gyeonggi-do over the past five years, meteorological and hydrological factors (i.e., temperature, humidity, wind speed, precipitation, and drought) were selected in order to quantitatively investigate causal relationships with forest fire. We applied a partial least squares structural equation model (PLS-SEM), which is suitable for analyzing causality and predicting latent variables. The overall results indicated that the measurement and structural models of the PLS-SEM were statistically significant for all evaluation criteria, and meteorological factors such as humidity, temperature, and wind speed affected by amount of -0.42, 0.23 and 0.15 of standardized path coefficient, respectively, on forest fires, whereas hydrological factor such as drought had an effect of 0.23 on forest fires. Therefore, as a practical method, the suggested model can be used for analyzing and evaluating influencing factors of forest fire and also for planning response and preparation of forest fire disasters.

Data Mining based Forest Fires Prediction Models using Meteorological Data (기상 데이터를 이용한 데이터 마이닝 기반의 산불 예측 모델)

  • Kim, Sam-Keun;Ahn, Jae-Geun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.8
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    • pp.521-529
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    • 2020
  • Forest fires are one of the most important environmental risks that have adverse effects on many aspects of life, such as the economy, environment, and health. The early detection, quick prediction, and rapid response of forest fires can play an essential role in saving property and life from forest fire risks. For the rapid discovery of forest fires, there is a method using meteorological data obtained from local sensors installed in each area by the Meteorological Agency. Meteorological conditions (e.g., temperature, wind) influence forest fires. This study evaluated a Data Mining (DM) approach to predict the burned area of forest fires. Five DM models, e.g., Stochastic Gradient Descent (SGD), Support Vector Machines (SVM), Decision Tree (DT), Random Forests (RF), and Deep Neural Network (DNN), and four feature selection setups (using spatial, temporal, and weather attributes), were tested on recent real-world data collected from Gyeonggi-do area over the last five years. As a result of the experiment, a DNN model using only meteorological data showed the best performance. The proposed model was more effective in predicting the burned area of small forest fires, which are more frequent. This knowledge derived from the proposed prediction model is particularly useful for improving firefighting resource management.

Mechanical and Electrical Properties of Aluminum Wires of ACSR Conductors due to Forest Fire (산불에 노출된 강심알루미늄연선 송전선 알루미늄 선재의 기계적 및 전기적 특성 거동)

  • Lee, Won-Kyo;Lee, Jung-Won;Kim, Byung-Geol
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.9
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    • pp.730-735
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    • 2010
  • Forest fire can cause a serious damage to overhead conductors. Therefore, detailed investigation on the changes of mechanical and electrical properties of damaged conductors should be carried out to understand the effect of forest fires on conductors. This is of critical importance in maintaining transmission line safely. This paper examines the changes of mechanical and electrical properties of flame exposed conductor. Tensile strength (TS) decreased according to increase of forest fire temperature and conductivity changed according to forest fire temperature. Specimens were aluminum conductors of aluminium conductor steel reinforced (ACSR) 410, 240, 480 $mm^2$. In this paper, the electrical and mechanical characteristics of forest fires exposed overhead conductors depending on the diameter of aluminum conductors are presented. It was possible to estimate the degree of deterioration caused by forest fires. The detailed results are given in the paper.

Implementation of YOLOv5-based Forest Fire Smoke Monitoring Model with Increased Recognition of Unstructured Objects by Increasing Self-learning data

  • Gun-wo, Do;Minyoung, Kim;Si-woong, Jang
    • International Journal of Advanced Culture Technology
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    • v.10 no.4
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    • pp.536-546
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    • 2022
  • A society will lose a lot of something in this field when the forest fire broke out. If a forest fire can be detected in advance, damage caused by the spread of forest fires can be prevented early. So, we studied how to detect forest fires using CCTV currently installed. In this paper, we present a deep learning-based model through efficient image data construction for monitoring forest fire smoke, which is unstructured data, based on the deep learning model YOLOv5. Through this study, we conducted a study to accurately detect forest fire smoke, one of the amorphous objects of various forms, in YOLOv5. In this paper, we introduce a method of self-learning by producing insufficient data on its own to increase accuracy for unstructured object recognition. The method presented in this paper constructs a dataset with a fixed labelling position for images containing objects that can be extracted from the original image, through the original image and a model that learned from it. In addition, by training the deep learning model, the performance(mAP) was improved, and the errors occurred by detecting objects other than the learning object were reduced, compared to the model in which only the original image was learned.

Development of Fire Weather Index Model in Inaccessible Areas using MOD14 Fire Product and 5km-resolution Meteorological Data (MODIS Fire Spot 정보와 5km 기상 재분석 자료를 활용한 접근불능지역의 산불기상위험지수 산출 모형 개발)

  • WON, Myoung-Soo;JANG, Keun-Chang;YOON, Suk-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.3
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    • pp.189-204
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    • 2018
  • This study has developed a forest fire occurrence probability model for inaccessible areas such as North Korea and Demilitarized Zone and we have developed a real-time forest fire danger rating system that can be used in fire-related works. There are limitations on the research that it is impossible to conduct site investigation for data acquisition and verification for forest fire weather index model and system development. To solve this problem, we estimated the fire spots in the areas where access is impossible by using MODIS satellite data with scientific basis. Using the past meteorological reanalysis data(5㎞ resolution) produced by the Korea Meteorological Administration(KMA) on the extracted fires, the meteorological characteristics of the fires were extracted and made database. The meteorological factors extracted from the forest fire ignition points in the inaccessible areas are statistically correlated with the forest fire occurrence and the weather factors and the logistic regression model that can estimate the forest fires occurrence(fires 1 and non-fores 0). And used to calculate the forest fire weather index(FWI). The results of the statistical analysis show that the logistic models(p<0.01) strongly depends on maximum temperature, minimum relative humidity, effective humidity and average wind speed. The logistic regression model constructed in this study showed a relatively high accuracy of 66%. These findings may be beneficial to the policy makers in Republic of Korea(ROK) and Democratic People's Republic of Korea(DPRK) for the prevention of forest fires.

Forest Fire Direction and Spread Characteristics by Field Investigations (사례 조사를 통한 산불 방향 및 확산 특성)

  • Lee, Byung-Do;Koo, Kyo-Sang;Lee, Myung-Bo
    • Fire Science and Engineering
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    • v.23 no.5
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    • pp.96-102
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    • 2009
  • Forest fire ignition and spread characteristics are needed as basic data in fire management. Slope aspect of ignition point, spread direction, and wind direction at that time were analyzed and regression equations were proposed for predicting burned area, fire perimeter, head spread rate, and flank spread rate using combustion time using 101 forest fires broken out between 2007 and 2009 spring. 57% forest fires of investigated numbers were ignited in south, southwest, and southeast aspects and 68% of forest fires were spreaded to east, southeast, and northeast influenced by westerly wind. About 11.8ha forest was burned and 0.5km fire perimeter increase was predicted per hour. Head and flank spread rate were calculated 0.13km and 0.05km, respectively.

A Study on Meteorological Elements Effecting on Large-scale Forest Fire during Spring Time in Gangwon Young-dong Region (강원 영동지역 봄철 산불대형화 영향 기상요소 분석)

  • Lee, Si-Young;Kim, Ji-Eun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.1
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    • pp.37-43
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    • 2011
  • In this study, we analyzed the meteorological elements, when large forest fires were occurred, The rate of precipitation was 13% of annual average precipitation. Especially, the stronger wind speed, lower humidity and rainfall than average annual record were the distinct feathers on the year when large forest fire occurred in east coast area in Kangwon region. The average, maximum and maximum instantaneous wind speed was 5.9 m/s, 11.3 m/s and 20.9 m/s when large forest fires occurred. The average, maximum and maximum instantaneous wind speed on large fire occurred were 1.8 m/s, 3.0 m/s and 6.9 m/s faster than and average wind speed when whole forest fires occurred. The results indicated that the large forest fire occurrence had a close correlation with meteorological elements.