• Title/Summary/Keyword: Tropical Area

Search Result 497, Processing Time 0.027 seconds

Relationships between Summer Droughts in Korea and Activities of Tropical Cyclones over the Northwestern Pacific (한국 여름가뭄과 북서태평양 태풍활동의 연관성)

  • Choi, Ki-Seon;Kim, Do-Woo;Byun, Hi-Ryong
    • Atmosphere
    • /
    • v.18 no.4
    • /
    • pp.279-286
    • /
    • 2008
  • In the tropical western Pacific (especially, west of 135oE, including South China Sea and the Philippines), during boreal summer, it was found that a strong correlation exists between the tropical cyclone activity and the drought conditions in Korea. During the summer drought, firstly, there were strong ascending flows over the tropical western Pacific with more tropical cyclone genesis, and to compensate for this, descending flows develop in the mid-latitudes, thereby causing drought; in other words, a secondary circulation is formed between the tropical western Pacific and mid-latitudes of East Asia. Secondly, the developments of both the subtropical western Pacific high and the Manchurian low are suppressed. As a result, both the land-sea pressure gradient and the southerly flow from low-latitudes to Korean area are also weakened, which reduces approaches of tropical cyclones to this area despite the high frequency of their geneses.

A Study on the Thermal Characteristics of Midsummer in Daegu Metropolitan Area

  • Park, Myung-Hee;Lee, Joon-Soo;Ahn, Won-Shik;Kim, Hae-Dong;Oh, Sung-Nam
    • Journal of Environmental Science International
    • /
    • v.22 no.6
    • /
    • pp.667-677
    • /
    • 2013
  • This study aims to examine the actual status of the urban heat island in Daegu by analyzing the data of 17 automatic weather stations installed in the Daegu area. And the results can be summarized as follows: First, regarding the temperature distribution in Daegu by summer time zones, for the 31 days(August 1st till 31st), 18 days showed daily maximum temperature over $30^{\circ}C$, and 11 days indicated daily minimum temperature over $25^{\circ}C$. The day that showed the highest daily maximum temperature was August 5th, which indicated $36^{\circ}C$. Second, about the spatial distribution of time ratio exceeding $30^{\circ}C$ and $25^{\circ}C$, the area with the highest time ratio exceeding $30^{\circ}C$ is mostly the downtown(central area), eastern area, and northern area. Meanwhile, regarding the time ratio exceeding $25^{\circ}C$, the downtown area centering around the central area were high as over 70%, and the outskirts were low as under 65%. Third, considering the temporal distribution of daily maximum temperature and daily minimum temperature, daily maximum temperature was shown around 14:00 to 15:00 while the daily minimum temperature was indicated around 17:00 to 18:00. Daily maximum and minimum temperature were appeared at northeast and downtown, respectively. Fourth, regarding the spatial distribution of tropical days and tropical night days, tropical days showed 77% and tropical night days indicated 42% before and after the 24th and also the 13th each. Tropical days were occurred up to 24 days at northeastern area. And the southwestern area of Daegu showed under 22 days. The downtown showed the 14 days of the tropical night. However, the outskirts indicated relatively few days as under 10 days. Fifth, about the spatial distribution of the average daily temperature range (the difference between the highest temperature and lowest temperature), the central area, the central part of the city, showed the smallest as $7.2^{\circ}C$, and as it was closer to the northern area, it became larger, so in the eastern and northern area, it was over $8.8^{\circ}C$ or so.

Estimation of Probable Maximum Depth-Area-Duration by Moisture Maximization over the Geumgang River Basin (금강유역에 내린 호우의 수분최대화에 의한 가능 최대 DAD의 산정)

  • Lee, Kwang-Ho
    • Atmosphere
    • /
    • v.16 no.2
    • /
    • pp.55-65
    • /
    • 2006
  • The characteristics of Depth-Area-Duration (DAD) for 50 storms over the Geumgang river basin have been analysed in terms of various storm causes using the precipitation data during the period from 1984 to 2003. Results show that the ratio of the precipitation depth to duration, and the ratio of decrease in the precipitation depth to area are the largest in the case of the tropical cyclone. Storm maximization ratios are in the range 1.03 to 2.66 for the 50 selected heavy precipitation cases over Geumgang river basin, with the largest value for the tropical cyclone case, suggesting that the tropical cyclone could cause heavier precipitation than the other storms. In addition, the 24-hour probable maximum precipitation for the Geumgang river basin is estimated to be about 745 mm in the maximum precipitation area.

Monitoring of Deforestation and Fragmentation in Sarawak, Malaysia between 1990 and 2009 Using Landsat and SPOT Images

  • Kamlun, Kamlisa Uni;Goh, Mia How;Teo, Stephen;Tsuyuki, Satoshi;Phua, Mui-How
    • Journal of Forest and Environmental Science
    • /
    • v.28 no.3
    • /
    • pp.152-157
    • /
    • 2012
  • Sarawak is the largest state in Malaysia that covers 37.5% of the total land area. Multitemporal satellite images of Landsat and SPOT were used to examine deforestation and forest fragmentation in Sarawak between 1990 and 2009. Supervised classification with maximum likelihood classifier was used to classify the land cover types in Sarawak. The overall accuracies of all classifications were more than 80%. Our results showed that forests were reduced at 0.62% annually during the two decades. The peat swamp forest suffered a tremendous loss of almost 50% between 1990 and 2009 especially at coastal divisions due to intensified oil palm plantation development. Fragmentation analysis revealed the loss of about 65% of the core area of intact forest during the change period. The core area of peat swamp forest had almost completely disappeared during the two decades.

Pattern on Enterobius vermicularis in Korea (한국(韓國)에 있어서의 요충감염상(蟯虫感染相))

  • Lee, Joon-Sang;Kim, Kyu-Ho;Ryu, Jong-Cheol;Hong, Kyung-Sook;Lee, Hae-Jung;Rim, Han-Jong
    • Journal of agricultural medicine and community health
    • /
    • v.3 no.1
    • /
    • pp.18-26
    • /
    • 1978
  • Enterobius vermicularis (pinworm) infestation in present day Korea has become one of nationwide problems. But, the incidence of pinworm infestation having been reported by many workers was almostly the data for specific groups. The incidence of pinworm infestation for 208 families of 760(male; 30, female;420) middle class inhabitant of Seoul, 238 subrural inhabitants in Gyeonggi Province and 150(male;77, female;73) rural primary students in three different districts were examined by modified Gralam's scotch-tape swab method. The results are summarized as follows; 1. The incidence of nationwide infestation a. The nationwide incidence of pinworm infestation of the 1,148 specimens examined was 28.7% (male; 27.5%, female; 29.6%). b. The highest incidence was found among 5-14 years of age. c. In comparison of the incidence by the area, the highest incidence was found among subrural area, next among rural area and the lowest among urban area. 2, Urban area a. The incidence of the 760 inhabitants examined was 23.2% (male; 24.1%, female; 22. 3%). b. The incidence of the parents group was 12.2% and children group was 30. 30.3%. c. In the parents who hold one or more pinworm poitive cases among children, the incidence of father group was 13.2% and mother group was 29.7%.3. Subrural area a. The incidence of the 238 inhabitants examined was 42.9% (male, 40.8%, female; 44.4%). b. The cumulative positive rate of anal swabs showed increasing tendency. c. Worm collection rates after chemotherapy of 98 inhabitants were 54, 0%. d. In scotch tape anal swab only one times, diagnostic value was 74.0%. e. Mother group infested with pinworm seemed to play an important role for the high incidence in individual family. f. In comparison of the incidence by the examination method, the highest incidence was found among scotch tape method. 4. Rural area The incidence of the 150 primary students examined was 34. 5% (male ; 24. 7%, female; 43.8%).

  • PDF

Yield Potential of Improved Tropical Japonica Rice under Temperate Environment in Korea

  • Lee, Kyu-Seong;Ko, Jae-Kwon;Kim, Jong-Seok;Lee, Jae-Kil;Shin, Hyun-Tak;Cho, Soo-Yeon
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.44 no.3
    • /
    • pp.214-220
    • /
    • 1999
  • Rice production in Korea has markedly increased during the last two decades due to newly developed high yielding varieties and improved production technology. This experiment was conducted to determine the potential of tropical japonica germplasm in enhancing the yield of temperate japonica. The yield performance of two tropical japonicas (IR 65597-29-3-2 and IR66154-52-1-2) and one temperate japonica (Dongjinbyeo) was compared at different plant densities and nitrogen levels under Korean environmental conditions. Although tropical japonicas showed low tillering habit and large panicles, they had similar leaf area index and dry weight at heading stage to Dongjinbyeo of the high tillering type indicating that there was not much difference between tropical and temperate japonica in terms of biomass production. The highest milled rice yield of 6.15 t/ha was obtained from Dongjinbyeo at a high nitrogen level with less planting density (220 kg N/ha and 30 $\times$ 15 cm). However, those of the two tropical japonicas were 5.36 t/ha at the condition of 165 kg N/ha and 30 x 10 cm planting density and 5.06 t/ha at the condition of 165kgN/ha and 15 x 15 cm planting density, respectively. Ripened grain of tropical japonicas ranged from 65 to 87%, while that Dongjinbyeo ranged from 82 to 97% under Korean conditions.

  • PDF

Effect of an Urban Thermal Environment on the Air Quality in Two Cities

  • Lee, Kwi-Ok;Lee, Hwa-Woon;Lee, Hyun-Ju;Park, Jong-Kil;Jung, Woo-Sik
    • Asian Journal of Atmospheric Environment
    • /
    • v.5 no.1
    • /
    • pp.29-40
    • /
    • 2011
  • In this study, the effects of an urban thermal environment on air quality were investigated using hourly surface weather observation data and air quality data over six summers from 2000 to 2005 in two cities on the Korean Peninsula. One, the city of Daegu, is representative of basin topography and the other, the city of Busan, represents a coastal area. It is known that the characteristics of an urban thermal environment are represented as an "urban heat island". Here, we focus on the nighttime urban thermal environment, which is called a "tropical night", during the summer. On tropical nights in Busan, the temperature and cloud cover levels were higher than on non-tropical nights. Wind speed did not appear to make a difference even on a tropical night. However, the frequency of southwestern winds from the sea was higher during tropical nights. The prevailing southwest winds in all areas meant an inflow of air from the sea. So at most of the air quality stations, the ozone concentration during tropical nights was lower than during non-tropical nights. In Daegu, the tropical nights had higher temperatures and cloud covers. Despite these higher temperatures, the ozone concentration during the tropical nights was lower than that on non-tropical nights at most of the air quality stations. This feature was caused by low irradiance, which in turn caused an increased cloud cover. Wind speed was stronger during the tropical nights and dispersed the air pollutants. These meteorological characteristics of the tropical nights reduced ozone concentrations in the Daegu Basin.

Epidemiological Note on the Clonorchiasis in Samrangjin Eup, Milyang Gun, Kyongsang Nam Do (=province) (경상남도(慶尙南道) 밀양군(密陽郡) 삼랑진읍(三浪津邑)에 있어서의 간흡충(肝吸虫) 감염실태조사(感染實態調査))

  • Rim, Han-Jong;Joo, Kyoung-Hwan;Eom, Kee-Seon;Park, Soo-Bae
    • Journal of agricultural medicine and community health
    • /
    • v.7 no.1
    • /
    • pp.80-89
    • /
    • 1982
  • In order to observe the endemic status of Clonrchis sinensis infection in Samrangjin eup, Milyang gun, Kyongsang nam do, a total number of 294 stool specimens were collected from the inhabitants who lived in the basin of the Nakdong river. The specimens were examined by cellophane thick smear technique and Stoll's egg dilution technique during the period from May to June 1983. The epidemiological status was analysed statistically by the regression equation and catalytic curv with the results obtained from this area. The results are as follows : 1) The infestation rate of Clonorchis sinensis in 294 was 49.0%. 2) No remarkable difference was observed between male (52.5%) and female (44.8%). 3) Average E.P.G. by Stoll's egg dilution technique in this area was 9,597. 4) The degree of the intensity of Clonorchis infection by E.P.G. count was distributed as 10.5% in very heavy infection, 14.7% in heavy infection, 47.4% in moderate infection, and 29.3% in light infection. 5) The intensity of endemicity in this area was represented with the regression equation calculated with the cumulative percentages of E.P.G. counts. Regression equation was y=3.40+1.23 log x and Cs. $D._{50}$ was 19.99. 6) The two stage catalytic model was applied and the calculation lead to the equation $y=1296(e^{-0.008t}-e^{-0.035t})$ ; a=0.035 > b=0.008 in this surveyed area. 7) Other helminthic infection rate in this area was 7.1% in A. lumbricoides, 9.5% in T. trichiura and 4.1% in E. vermicularis respectively.

  • PDF

Observational Study of Thermal Characteristics by Distribution Ratio of Green Area at Urban in Summer Season (하절기 관측을 통한 도시의 지역별 공간녹지분포율에 따른 열환경 특성 연구)

  • Jung, Im-Soo;Choi, Dong-Ho;Lee, Bu-Yong
    • Journal of the Korean Solar Energy Society
    • /
    • v.31 no.3
    • /
    • pp.8-16
    • /
    • 2011
  • The objective of this study is to analyze the characteristic of thermal environment in the summer season by conducting the field observation of temperature, relative humidity, and globe temperature in some parts of the city. Observation point was divided to a densely populated area, a residential area, a green area, a waterfront green area and a suburban district by the distribution ratio of green area. In this study, the correlation between maximum temperature and globe temperature, study on index for intensity of the tropical night and the temperature distribution characteristic of measurement points by the distribution ratio of green area were analyzed. The results of this study are as follows. (1) The difference between temperature and globe temperature by the distribution ratio of green area is confirmed. The difference of nighttime is more clearly that of daytime. (2) The average temperature and globe temperature of the densely populated area($29.2^{\circ}C$, $33.7^{\circ}C$) are higher than that of the waterfront green area($27.9^{\circ}C$, $32.0^{\circ}C$) by $1.3^{\circ}C$ and $1.7^{\circ}C$, respectively. (3) The number of tropical nights has different days of tropical nights by the distribution ratio of green area of 17days for the Daegu weather station, 14days for adensely populated area, 14days for a residential area, 6days for a green area, 2days for a waterfront green area, and 2days for a suburban district. (4) The results of the slope of trend line for the effects of the temperature on globe temperature change and the intercept for the size of the impact of radiant energy gained around by the analysis of the correlation between the maximum temperature and globe temperature can be utilized objective evaluation index of the each point's artificial effects.

Haplorchis taichui as a Possible Etiologic Agent of Irritable Bowel Syndrome-Like Symptoms

  • Watthanakulpanich, Dorn;Waikagul, Jitra;Maipanich, Wanna;Nuamtanong, Supaporn;Sanguankiat, Surapol;Pubampen, Somchit;Praevanit, Rangson;Mongkhonmu, Srisuchat;Nawa, Yukifumi
    • Parasites, Hosts and Diseases
    • /
    • v.48 no.3
    • /
    • pp.225-229
    • /
    • 2010
  • The aim of this study is to clarify the clinical features of Hap/orchis taichui infection in humans in Nan Province, Thailand, and to correlate the clinical features with irritable bowel syndrome (IBS)-like symptoms. In this study area, only H. taichui, but neither other minute intestinal flukes nor small liver flukes were endemic. The degree of infection was determined by fecal egg counts and also by collecting adult worms after deworming. The signs and symptoms of individual patients together with their hematological and biochemical laboratory data were gathered to evaluate the relationship between the clinical features and the severity of infection. Special emphasis was made to elucidate the possible similarities of the clinical features of H. taichui infection and IBS-like symptoms. The results showed useful clinical information and the significant (> 50%) proportion of haplorchiasis patients complained of abdominal pain, lassitude, and flatulence, which were the important diagnostic symptoms of IBS. This study has reported a possible link between H. taichui and IBS, and H. taichui might probably play a role in the etiology of these IBS-like symptoms.