• Title/Summary/Keyword: effect of rainfall

Search Result 888, Processing Time 0.027 seconds

A Case Study of Landslides due to Heavy Rainfall (집중호우시 산사태 원인분석에 관한 사례연구)

  • Yoo, Nam-Jae;Park, Byung-Soo
    • Journal of Industrial Technology
    • /
    • v.21 no.A
    • /
    • pp.303-315
    • /
    • 2001
  • This study is a research result of investigating causes of landslides occurred at Uijongbu in Kyonggi Province, Korea. For works of this research, informations and data about landslides occurred at the site, geological and topographical informations were collected to analyze causes of landslides, and mapping landslides was performed by using results of field investigation. Data about rainfall during occurrence of landslides around Uijongbu was also used to find the effect of intense rainfall on occurrence of landslides. Based on informations obtained from field investigation and collected data, the scale and the pattern of landslides were analyzed and influencing factors on landslide such as intensity and duration of rainfall, topography, geologic condition, geotechnical engineering properties of ground, forestry were investigated statistically to find causes of landslides. On the other hands, for geotechnical engineering respects, slope stability analysis was performed for the typical sites chosen from the sites where the landslides occurred, using informations obtained from detailed topographical survey with total stations, field reconnaissance and results from laboratory tests.

  • PDF

Variation of Non-Point Source Pollution according to AMC Condition Using Probable Rainfall (확률강우량을 이용한 AMC 조건에 따른 비점원 오염량의 변화)

  • 안승섭
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.42 no.3
    • /
    • pp.76-88
    • /
    • 2000
  • AGNPS model is applied in this study to analyze the changes of non-point source pollutant according to AMC condition using probable rainfall. Probable rainfall of H-dam area by Gumber's extreme value distribution is computed through frequency analysis for each return period. 35 coarse grids are subdivided into 134 find grids of finite differential network to analyze peak flow soil loss quantity and nutrients of study area and the modified CN estimation equation shows good result about rainfall events-peak flow relationship. And as the consequence of estimation of soil loss quantity for each rainfall event soil loss quantity shows 120%-170% of actual soil loss quantity Regression analysis for the observed and calculated values of flow T-P AMC has an important effect on nutrients concentration of outflow and it if found that the excessive fertilization under AMC III condition may cause eutrophication by nutrients because the range of increase of outflow concentration appears relatively high.

  • PDF

Analyses of Debris Flow by Heavy Rainfall of Sangnamri of Injegun in 2009 (2009년 집중호우에 의한 인제군 상남리 토석류 현장 분석)

  • Choi, Joon-Sik;Kwak, Cheol-Soo;Yoo, Nam-Jae
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2010.03a
    • /
    • pp.883-890
    • /
    • 2010
  • This study is a research results about flow characteristics of debris flow mobilized from landslides such as initiation, transportation and deposition. As results of slope stability analyses at sites studied, the safety factors in rainy period are decreased drastically in comparisons with those in dry period so that the effect of rainfall on initiation of debris flow is known to be significant. From results of analyzing rainfall data, debris flow occurred as previous rainfall accumulated during 2 weeks was more than 526mm, the maximum rainfall intensity being more than 34mm/hr and the day rainfall being more than 171mm/day. As results of analyzing topology of channel debris flow running, the angle of slope where debris flow initiated was in the range of $36{\sim}39^{\circ}$. For area of channel debris flow being transporting the angle of channel was in the range of $11{\sim}36^{\circ}$. The angle of channel where debris flow started to be deposited was found to be in the range of $5{\sim}10^{\circ}$.

  • PDF

Lake Water Quality Modelling Considering Rainfall-Runoff Pollution Loads (강우유출오염부하를 고려한 호수수질모델링)

  • Cho, Jae-Heon;Kang, Sung-Hyo
    • Journal of Environmental Impact Assessment
    • /
    • v.18 no.2
    • /
    • pp.59-67
    • /
    • 2009
  • Water quality of the Lake Youngrang in the Sokcho City is eutrophic. Jangcheon is the largest inflow source to the lake. Major pollutant sources are stormwater runoff from resort areas and various land uses in the Jangcheon watershed. A storm sewer on the southern end of the lake is also an important pollution source. In this study, water quality modelling for Lake Youngrang was carried out considering the rainfall-runoff pollution loads from the watershed. The rainfall-runoff curves and the rainfall-runoff pollutant load curves were derived from the rainfall-runoff survey data during the recent 4 years. The rainfall-runoff pollution loads and flow from the Jangcheon watershed and the storm sewer were estimated using the two kinds of curves, and they were used as the flow and the boundary data of the WASP model. With the measured water quality data of the year 2005 and 2006, WASP model was calibrated. Non-point pollution control measures such as wet pond and infiltration trench were considered as the alternative for water quality management of the lake. The predicted water quality were compared with those under the present condition, and the improvement effect of the lake water quality were analyzed.

Analysis on the effect of the forest fire and rainfall on landslide in Gangwon area (강원지역 산사태발생지의 산불발생이력과 강우특성에 관한 분석)

  • Jun, Kyoung-Jea;Lee, Seung-Woo;Yune, Chan-Young
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2009.03a
    • /
    • pp.1020-1025
    • /
    • 2009
  • Recently, unusual change of weather occurred in world wide region causes localized heavy rainfall and consequently disasters like landslide and debris flow in steep slope area. And the main factors of these disasters are rainfall and forest fire. To verify the existing landslide prediction and warning system, information about landslide and rainfall were collected for a data base system and analysed.

  • PDF

Analysis on disasters pattern of the railroad caused by heavy rainfall ($2002{\sim}2007$) (집중호우로 인한 철도재해 유형 분석($2002{\sim}2007$년도))

  • Choi, Chan-Yong;Lee, Jin-Wook;Shin, Min-Ho;Lee, Suk-Young
    • Proceedings of the KSR Conference
    • /
    • 2008.11b
    • /
    • pp.88-92
    • /
    • 2008
  • For more and more citizen safety and national security due to an unusual weather change and massive disaster, the atmospheric is one of the most major factors. According the Weather Service data that the rainfall intensity has been on the rise due to heavy rainfall in korea, and then daily precipitation expects to decline relative it. The characteristic climate of the domestic has a heavy rainfall due to 65% of mountain area in country and a regional declination as like seasonal effect, yearly. etc. In this paper, it was analyzed a disaster pattern and restoration cost based on occurred heavy rainfall from 2002 to 2007.

  • PDF

Analysis of Provincial road in National Highway Average Speed Variation According to Rainfall Intensity (강우 강도에 따른 일반국도 지방부 도로의 평균속도 변화 분석)

  • Kim, Tae-Woon;Oh, Ju-Sam
    • The Journal of the Korea Contents Association
    • /
    • v.15 no.4
    • /
    • pp.510-518
    • /
    • 2015
  • Weather condition has effect on traffic condition, but there is a lack of research between weather and traffic condition. So, in this study analyzes speed variation according to rainfall intensity in national highway provincial road. The results of the analysis, average speed is reduced about 3.2%. But average speed decrease by maximum 8.8% when traffic volume is below 200vph per direction. Because relatively, free flow traffic speed has greatly deceased according to rainfall intensity in provincial road. Also in this study estimates of speed reduction model according to rainfall and performs the statistical verification. Estimated speed reduction model's slops are gradual when rainfall increased, because average speed is reduced by rainfall when free flow.

Effects of the rainfall-rewetted paddy on the quality of the milledrice (벼의 재흡습이 도정미의 품질에 미치는 영향)

  • Chung, Chang-Joo;Jeon, Yong-Woon
    • Journal of Biosystems Engineering
    • /
    • v.4 no.1
    • /
    • pp.75-75
    • /
    • 1979
  • This study was conducted to find out the effects of rainfall occurring during the paddy sun-during process of traditional paddy harvesting operations on the quality of milld rice. Rice varieties used for the experiment were MINEHIJARI variety a japonica and SUWEON 264 vareity , a sister-line of TONG-IL . Sun-drying days after the paddy cutting, times of storm occurrance during sun-drying period, and storm duration were treated as variables. The results is summarised as follows : 1. Brown rice recovery exposed to rainfall during the sun-druing period were ranged 81.6-82.1% and 79.4-80.2% for MINEHIKARI and SUWEON 264 varieties, respectively. which showed negligible effect by rainfall. 2. Milling recovery of MINEHIKARI variety was not affected by storm duration but by the by the sun-drying days after cutting as the sun-drying days increased to eight and four days when the variety met the rainfall one and two times, respectively. The range of milling recoveries of MINEHIKARI variety were 75.18-74.07% and 75.24-73.46% as the variety met the rainfall one and two times, respectively, and it were estimated that up to 0.9% and 1.5% of milling recovery would be reduced by one and two times of rainfall during sun-drying period. 3. The milling recovery of SUWEON 264 variety was affected only by the increase of drying days after cutting when it met one time of rainfall during the sun-drying period, while it was begun to reduce by the storm duration more than 11hours as the drying paddy met two times of rainfall. The milling reveries of the paddy met one and two times of rainfall were ranged 74.24-73.21% and 74.02-72.36% which were estimated to be reduced up to 0.9 % and 1.8% by the increase of the drying days after cutting and storm duration , respectively. 4. The head rice recovery of MINEHIKARI rice variety showed notable decrease as the drying days after cutting increased, and also it was greatly reduced even by the five hours of storm duration when one time of rainfall occurred but it was not affected by storm duration when the rainfall occurred two times. Head rice recoveries of MINEHIKARI met one and two times of rainfall during the sun-drying period were 65. 15 -40.85% and 61.86 - 30.03 %, which showed terrible reduction as much as up to 25% and 35% compared to that which did not met rainfall during the sun-drying process. 5. Head rice recovery or SUWEON 264 variety was very much reduced as the sum-drying days after cutting increased. Storm duration less than five hours during the sun-drying process did not affect on the decrease of head rice recovery when the variety was exposed to one time of rainfall, while storm duration affected considerably on the reduction of head rice recovery of SUWEON 264 variety exposed to two times of rainfall. The range of head rice recovery, 56.43 - 33.94% and 51.28 - 21.03% , for the paddy exposed to rainfall one and two times were evaluated that up to 24% and 37% of reduction in head rice recovery would be brought about compared to the head rice recovery of the sundriedpaddy that did not met the rainfall.

Effects of the rainfall-rewetted paddy on the quality of the milledrice (벼의 재흡습이 도정미의 품질에 미치는 영향)

  • 정창주;김용운;강화석
    • Journal of Biosystems Engineering
    • /
    • v.4 no.1
    • /
    • pp.76-86
    • /
    • 1979
  • This study was conducted to find out the effects of rainfall occurring during the paddy sun-during process of traditional paddy harvesting operations on the quality of milld rice. Rice varieties used for the experiment were MINEHIJARI variety a japonica and SUWEON 264 vareity , a sister-line of TONG-IL . Sun-drying days after the paddy cutting, times of storm occurrance during sun-drying period, and storm duration were treated as variables. The results is summarised as follows : 1. Brown rice recovery exposed to rainfall during the sun-druing period were ranged 81.6-82.1% and 79.4-80.2% for MINEHIKARI and SUWEON 264 varieties, respectively. which showed negligible effect by rainfall. 2. Milling recovery of MINEHIKARI variety was not affected by storm duration but by the by the sun-drying days after cutting as the sun-drying days increased to eight and four days when the variety met the rainfall one and two times, respectively. The range of milling recoveries of MINEHIKARI variety were 75.18-74.07% and 75.24-73.46% as the variety met the rainfall one and two times, respectively, and it were estimated that up to 0.9% and 1.5% of milling recovery would be reduced by one and two times of rainfall during sun-drying period. 3. The milling recovery of SUWEON 264 variety was affected only by the increase of drying days after cutting when it met one time of rainfall during the sun-drying period, while it was begun to reduce by the storm duration more than 11hours as the drying paddy met two times of rainfall. The milling reveries of the paddy met one and two times of rainfall were ranged 74.24-73.21% and 74.02-72.36% which were estimated to be reduced up to 0.9 % and 1.8% by the increase of the drying days after cutting and storm duration , respectively. 4. The head rice recovery of MINEHIKARI rice variety showed notable decrease as the drying days after cutting increased, and also it was greatly reduced even by the five hours of storm duration when one time of rainfall occurred but it was not affected by storm duration when the rainfall occurred two times. Head rice recoveries of MINEHIKARI met one and two times of rainfall during the sun-drying period were 65. 15 -40.85% and 61.86 - 30.03 %, which showed terrible reduction as much as up to 25% and 35% compared to that which did not met rainfall during the sun-drying process. 5. Head rice recovery or SUWEON 264 variety was very much reduced as the sum-drying days after cutting increased. Storm duration less than five hours during the sun-drying process did not affect on the decrease of head rice recovery when the variety was exposed to one time of rainfall, while storm duration affected considerably on the reduction of head rice recovery of SUWEON 264 variety exposed to two times of rainfall. The range of head rice recovery, 56.43 - 33.94% and 51.28 - 21.03% , for the paddy exposed to rainfall one and two times were evaluated that up to 24% and 37% of reduction in head rice recovery would be brought about compared to the head rice recovery of the sundriedpaddy that did not met the rainfall.

  • PDF

A Case Study on the Estimation of Flooded Area using GIS (GIS를 이용한 홍수피해지역 분석에 관한 사례연구)

  • Ahn, Sang-Jin;Jun, Kye-Won;Kim, Jin-Guek
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2002.10a
    • /
    • pp.305-308
    • /
    • 2002
  • This study is that analyzes the flood damages caused by rainfall during typhoon and how inundated area should be affected. Using HEC-HMS for analyzing rainfall-runoff and GIS (Geography Information System) for analyzing inundated area and volume. Each model was applied to Seopyung area for runoff effect analysis. As the result, Damaged area was magnified gradually according to the increase of rainfall and GIS was good for calculating the exact flood damage area at varied time.

  • PDF