• Title/Summary/Keyword: coastal plain

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The Distribution and Geomorphic Changes of Natural Lakes in East Coast Korea (한반도 동해안의 자연호 분포와 지형 환경 변화)

  • Lee, Min-Boo;Kim, Nam-Shin;Lee, Gwang-Ryul
    • Journal of the Korean association of regional geographers
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    • v.12 no.4
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    • pp.449-460
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    • 2006
  • This study aims to analyze distribution of natural lakes including lagoonal lake(lagoon) and tributary dammed lake(tributary lake) and calculate the size, morphology in order to interpret time-serial change of lakes using methodology of remote sensing images(1990s), GIS and topographic maps(1920s) in east coast of Korean Peninsular. Analysis results show that in 1990s, there are 57 natural lakes, with the total size of $75.62km^2$ over size $0.01km^2$. marine-origin lagoons are 48 with total size of $64.85km^2$, composing 85% of total natural lake, and the largest lagoon is Beonpo in Raseon City. Tributary lakes have been formed by damming of tributary channels by fluvial sand bars from main stream, located nearby at coastal zone, similar to lagoon sites. Large tributary lake, Jangyeonho, is developed in lava plateau dissection valley of Eorang Gun, Hamnam Province. There are more distributed at Duman River mouth$\sim$Cheongjin City, Heungnam City$\sim$Hodo Peninsular and Anbyeon Gun$\sim$Gangreung City. Geomorphometrically, correlation of size to circumference is very high, but correlation of size to shape irregularity is very low. The direction of lagoonal coast, NW-SE and NE-SW are predominated due to direction of tectonic structure and longshore currents. The length of the river into lake are generally short, maximum under 15km, and lake size is smaller, degree of size decreasing is higher. Geomorphic patterns of the lake location are classified as coast-hill range, coastal plain, coastal plain-channel valley, coastal plain-hill range and channel valley-hill range. During from 1920s to 1990s, change with lake size decreasing is highest at coastal plain-channel valley, next is coastal plain. Causes of the size decreasing are fluvial deposition from upper rivers and human impacts such as reclamation.

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Recycling of Suspended Particulates by Atmospheric Boundary Depth and Coastal Circulation (대기경계층과 연안순환에 의한 부유입자의 재순환)

  • Choe, Hyo
    • Journal of Environmental Science International
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    • v.13 no.8
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    • pp.721-731
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    • 2004
  • The dispersion of suspended particulates in the coastal complex terrain of mountain-inland basin (city)-sea, considering their recycling was investigated using three-dimensional non-hydrostatic numerical model and lagrangian particle model (or random walk model). Convective boundary layer under synoptic scale westerly wind is developed with a thickness of about I km over the ground in the west of the mountain, while a thickness of thermal internal boundary layer (TIBL) is only confined to less than 200m along the eastern slope of the mountain, below an easterly sea breeze circulation. At the mid of the eastern slop of the mountain, westerly wind confronts easterly sea breeze, which goes to the height of 1700 m above sea level and is finally eastward return flow toward the sea. At this time, particulates floated from the ground surface of the city to the top of TIBL go along the eastern slope of the mountain in the passage of sea breeze, being away the TIBL and reach near the top of the mountain. Then those particulates disperse eastward below the height of sea-breeze circulation and widely spread out over the coastal sea. Total suspended particulate concentration near the ground surface of the city is very low. On the other hand, nighttime radiative cooling produces a shallow nocturnal surface inversion layer (NSIL) of 200 m thickness over the inland surface, but relatively thin thickness less than 100m is found near the mountain surface. As synoptic scale westerly wind should be intensified under the association of mountain wind along the eastern slope of mountain to inland plain and further combine with land-breeze from inland plain toward sea, resulting in strong wind as internal gravity waves with a hydraulic jump motion bounding up to about 1km upper level in the atmosphere in the west of the city and becoming a eastward return flow. Simultaneously, wind near the eastern coastal side of the city was moderate. Since the downward strong wind penetrated into the city, the particulate matters floated near the top of the mountain in the day also moved down along the eastern slope of the mountain, reaching the. downtown and merging in the ground surface inside the NSIL with a maximum ground level concentration of total suspended particulates (TSP) at 0300 LST. Some of them were bounded up from the ground surface to the 1km upper level and the others were forward to the coastal sea surface, showing their dispersions from the coastal NSIL toward the propagation area of internal gravity waves. On the next day at 0600 LST and 0900 LST, the dispersed particulates into the coastal sea could return to the coastal inland area under the influence of sea breeze and the recycled particulates combine with emitted ones from the ground surface, resulting in relatively high TSP concentration. Later, they float again up to the thermal internal boundary layer, following sea breeze circulation.

Ear and Kernel Characteristics of Korean Indigenous Maize Lines Collected in Pusan and Kyungnam (부산, 경남지역에서 수집된 한국 재래종 옥수수의 이삭 및 낟알의 특성)

  • 이인섭;박종옥
    • Journal of Life Science
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    • v.11 no.2
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    • pp.159-165
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    • 2001
  • In order to reserve abundant germplasm for breeding new corn varieties, major characteristics of ears and kernels were evaluated with a total of 210 Korean indigenous maize lines collected from various parts of Pusan City and Kynugnam Province, Korea The average ear length and ear diameter of indigenous maize lines collected was 12.52cm and 3.33 cm, respectively. The average ear weight of the maize lines was 63.70g. The ears collected from the north-west mountainous region were the heaviest, and The ears from the south coastal region were the lightest. The average kernel weight per ear was 50.54g, and the kernel weight per ear by region showed a tendency similar to the ear weight. The kernels of maize lines collected in the north-west mountainous region were the longest, and kernel width and thickness were the largest in the west plain region. 100 kernel weight and embryo weight the largest in the lines collected in the north-west mountainous region. The degree of pericarp thickness was the smallest in the lines collected in the south coastal region, and largest in the lines collected in the west plain region. Except for the correlation coefficient width and 100 kernel weight, all correlation coefficients between the characteristics of the lines showed highly significant differences.

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An Alternative Strategy on Minor Rural Road Improvement Project (농어촌도로 정비사업의 정책적 전개방향)

  • Choi, Soo-Myung;Choi, Dong-Jin
    • Journal of Korean Society of Rural Planning
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    • v.8 no.2 s.16
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    • pp.42-49
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    • 2002
  • Since legislation of Rural Minor Road Improvement Act 1990, a quarter of its total length had been paved now. However, over 80% of arterial road length(national+provincial roads) had been paved, so, road improvement policy should be focussed on the local road(county+rural minor roads) from now. Generally, in the greater part of coastal plain and island areas, arterial road intensity(total road length/total catchment area) is relatively low, but local road intensity is relatively high. So, in terms of balanced development, much more efforts for rural minor road improvement should be concentrated in coastal plain and islands areas. In Chonnam Province, the maximum differentials of minor rural road improvement ratio was over 20%(the lowest; 14.1% in Goheung, the highest; 35.6% in Goksung) in 1999, but the improvement budget have been allocated in proportion to unpaved road length of each county by the provincial government. However, the differentials should not be fairly narrowed in the near future if the present budget allocation policy be maintained. To solve this problem, target differentials of rural minor road improvement between regions should be set up for each planning year and road improvement budget be allocated according to this policy change.

Distribution and Traditional Practice on Neem in the Rural Homesteads of Chittagong Coastal Plain of Bangladesh

  • Miah, Md. Danesh;Hossain, Mohammed Anwar;Muhammed, Nur;Sin, Man Yong
    • Journal of Korean Society of Forest Science
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    • v.95 no.5
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    • pp.524-531
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    • 2006
  • Neem tree (Azadirachta indica), native to the Indian sub-continent, has been known since the ancient time for its medicinal and insect repellent properties. In recent years, Neem has attracted global attention due to its potential as a source of natural drugs and also environment-friendly pesticides. In the households. The distribution and traditional practice on Neem can be important to the agriculturist, ethno-pharmaceutical developers and to the rural development practitioners in Bangladesh. An exploratory survey on the distribution and traditional practice on Neem tree in the rural homesteads of Chittagong coastal plain, Bangladesh, was conducted over a period of three months from September 2002 to November 2002. It was found that maximum, 64% households used seedling as planting material having 40% maximum sources Within the major tree species present in the homesteads, Neem accounted for 12% among the total individuals. It was found that the availability of Neem trees was found maximum, 31%, in the homesteads of medium sized households. Maximum, 42% individuals of Neem were found within the DBH of 10.1 to 20 cm; and 37% within the 3.1 to 6 m height classes. Neem trees were found to be used maximum, 88% for furniture. The findings of the study will be of immense importance for the rural development practitioners and ethno pharmacological developers in Bangladesh.

Long-term Investigation of Soil Chemical Properties in Paddy Fields Located in Different Topographic Areas of Jeonbuk Province

  • Ahn, Byung-Koo;Ko, Do-Young;Lee, Chang-Kyu;Kim, Jin-Ho;Song, Young-Ju;Lee, Jin-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.3
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    • pp.275-281
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    • 2016
  • The aim of this study was to examine the selected soil chemical properties of paddy fields in different topographic areas to efficiently manage nutrient valances of the paddy fields in Jeonbuk Province. Three-hundred soil sampling sites in paddy fields were selected from the different topographic areas in Jeonbuk Province. The soil samples were collected every four years from 1999 to 2015. Soil pH and exchangeable K and Mg concentrations declined during the experimental periods. However, almost all the chemical properties were within the proper levels for paddy soil, except exchangeable Mg concentration. Distributed areas of the paddy fields with soil pH below 5.5 continuously increased, but the paddy fields with lower concentrations of soil organic matter and available $P_2O_5$ than the proper levels declined after 2007. In addition, the paddy fields with available $SiO_2$ below the proper concentration decreased from 83.3% of the total paddy fields studied in 1999 to 61.0% of the total fields investigated in 2015. The paddy fields with lower exchangeable K and Mg than the proper levels increased after 2003 whereas the fields with lower exchangeable Ca concentration decreased. Dominant landform of coastal and plain areas was fluvio-marine plains that was distributed in 53.7% and 40.9%, respectively. Local valley and fans was a dominant landform of mountainous and middle-mountainous areas, which was 51.8% and 67.6%, respectively. Dominant soil textures distributed in coastal and plain areas were silty loam and loam. Those in mountainous and middle-mountainous areas were sandy loam and loam, respectively. Soil pH was relatively higher in coastal area and the comparatively higher content of soil organic matter was found in costal area than other areas. The concentrations of available $P_2O_5$, exchangeable Ca, and exchangeable Mg were generally higher in mountainous, coastal, plain areas, respectively, but available $SiO_2$ and exchangeable K concentrations were not significantly different among the different topographic areas.

The Geomorphology and the Sediment Characteristics of Sagye Coastal Dune, Jeju Island, Korea (제주도 사계 해안사구의 지형과 퇴적물 특성)

  • Seo, Jong-Cheol;Sohn, Myung-Won
    • Journal of the Korean association of regional geographers
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    • v.12 no.6
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    • pp.631-644
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    • 2006
  • The study area is a pocket beach which consisted of sandy beach, dune, agricultural land and residential area etc. The coastal dune area is classified to foredune, dune plain, secondary (or back) dune. The foredune area is covered by herbaceous dune plants(ex. Carex kobomugi, Wedelia prostrata, etc.), whereas the dune plain area is covered by herbs and shrubs(Vitex rotundifolia). The most inner area, secondary dune, is planted by pine forest(Pinus thunbergii). The mean size of the beach and dune sediments ranges from 1.1 to $1.8{\Phi}$, which mean these values are higher than normal sediments. Sorting and Skewness is $0.6{\sim}-1.2{\Phi}$ and $-2.7{\sim}1.6{\Phi}$ respectively. We found that the soil formation process in the secondary dune area has been progressed rapidly from the analysis of fine grain content, organic matter content, and CEC.

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Wave Reflection and Transmission from Buoyant Flap Typed Storm Surge Barriers - Hydraulic Experiments (부유 플랩형 고조방파제의 파랑 반사 및 전달 - 수리실험)

  • Jeong, Shin-Taek;Kim, Jeong-Dae;Ko, Dong-Hui;Kim, Dong-Hyawn;Park, Woo-Sun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.2
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    • pp.238-245
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    • 2008
  • To evaluate wave reflection and transmission from buoyant flap-typed storm surge barriers, hydraulic experiments were performed by using regular and irregular wave conditions. Buoyant flap-typed storm surge barriers consist of buoyant main body connected with foundation structure in the seabed by hinge. The characteristics of wave reflection, transmission and dynamic response of the structure were investigated for 36 regular and 4 irregular wave conditions. It was also evaluated the usage of plain plate attached on the buoyant main body as one of alternatives to control wave reflection and transmission. From the hydraulic experiments, it was found that the case of plain plate attached on the offshore side is very effective to improve the wave transmission as well as reflection. But, the effect of the case on the harbor side might be negligible.

An Expremental Study on Connections Friction Test of Improvement for Coastal Environment Block (Coastal Environments 블록의 개발을 위한 연결부 마찰 실험)

  • Kim, Chun-Ho;Kim, Sang-Hoonq
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.49-52
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    • 2008
  • The plain and simple shape water front structure were designed and installed for wave protection and wave resistance. But the installation of these plain and simple structure cause deficiency of environmental affinity. Also the resonance phenomena from the reflective wave and shipwave of the harbor incident wave caused high tide and wave, consequently maintaining the tranquility of inside harbor, give difficulty for mooring the ship and loading-unloading, increase the possibility of ship collision at the quray wall and landing place To solve these problems, we develop the environmentally friendly wave dissipation block. And installation efficiency, stability of the blocks through experiment of C.E Block Joint.

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