• Title/Summary/Keyword: climatic properties

Search Result 106, Processing Time 0.024 seconds

Influence of New Town Development on the Urban Heat Islands - ln the Case of Pan-Gyo Area and Bun-Dang New Town - (신도시 개발이 도시열섬 형성에 미치는 영향 - 분당신도시와 판교지역을 중심으로 -)

  • 송영배
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.30 no.4
    • /
    • pp.37-46
    • /
    • 2002
  • The main purpose of this research is to discuss the urban heat island which will be caused by urbanization, especially by the construction of new town on a wide green zone. Over the last ten years, five new towns have been developed around the Seoul metropolitan area. However these new towns become bedroom communities and create traffic problems between Seoul and its surrounding areas because of an increase in population and a lack of roads and other infrastructures. The construction of another such new town is under consideration in the Pan-gyo area. But it is important that Pan-gyo remains a wide green zone. Many studies show that green space can play an important role in improving urban eco-meteorological, ameliorative capability and air hygiene. The objective of this study is to analyze the urban heat islands of Bund-Dang Si which was constructed in 1996 and of the Pan-Gyo area planned as new town. To investigate the local thermal environment and its negative effects caused by change of the land use type and urbanization we used LANDSAT TM images for extraction of urban surface temperature according to change of land use over 15 years. These data were analyzed together with digital land use and topographic data. As a study result, we found that the thermal island of this area from 1985 to 1999 rapidly increased with a difference of mean temperature of more than 12'E. Before construction of Bun-Dang Si the temperature of this area was the same as the forest, but during the new town construction in 1991, an urban heat island developed. The temperature of forest with a size of over 50% of the investigation area was lowest, which leads us to conclude that the forest cools the urban and its surroundings. The mean temperature of the residential and commercial area is more than +4.5$^{\circ}C$ higher then forest, so this method of land use is the main factor increasing the urban heat island. Urban heat islands and green space play an important role in urban wind systems, i.e. Thermal Induced Air Exchange and Structural Wind Circulation, because of their special properties with regard to energy balance between constructed urban and land. The skill to allocate land use types in urban areas is a very important planning device to reduce air pollution and induce the fresh cold air from green space. An urban climatic experiment featuring a numerical wind simulation study to show the air corridor will be published in a following research paper.

Reconstruction of the Paleo-environment during the Upper Pleistocene at Seongjeong-dong, Cheonan-si, inferred from Pollen Analysis (천안 성정동 지역의 화분분석 결과를 통한 Pleistocene 후기 고환경복원)

  • Kim, Hye-Ryung;Yoon, Soon-Ock;Hwang, Sang-Ill;Lee, Byeong-Cheol
    • Journal of the Korean Geographical Society
    • /
    • v.47 no.2
    • /
    • pp.179-192
    • /
    • 2012
  • Paleo-environments such as vegetation and climate changes from the Last Glacial Maximum to the Holocene are reconstructed by the results of pollen analysis in the floodplain of Cheonan River, Seongjeong-dong, Cheonan-si, Chungnam Province. In the pollen zone I (approximately 23,000-15,000 yr BP), the area studied was covered by the extensive grassland with sparse wood. The climatic conditions were very cold, but it might not be so severe compared to the intermontane area in the Yeongnam area. This zone corresponds to the 'very cold' stage of Woldstedt(1962) and Yoon and Jo(1996). No pollen horizon(pollen zone II) deposited between approximately 15,000 and 10,000 yr BP corresponds to the transitional stage from the Last Glacial Maximum to the Holocene. The horizon consists of the dark gray brown sand deposits different from the other horizons dominated by the silty deposits and these sedimentary properties may be attributed to the dramatic climate changes between the very cold stage and warm stage. The pollen zone III formed between approximately 10,000 and 6,000 yr BP shows clearly different pollen compositions indicative of temperate climate conditions.

  • PDF

Non-stationary Rainfall Frequency Analysis Based on Residual Analysis (잔차시계열 분석을 통한 비정상성 강우빈도해석)

  • Jang, Sun-Woo;Seo, Lynn;Kim, Tae-Woong;Ahn, Jae-Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.31 no.5B
    • /
    • pp.449-457
    • /
    • 2011
  • Recently, increasing heavy rainfalls due to climate change and/or variability result in hydro-climatic disasters being accelerated. To cope with the extreme rainfall events in the future, hydrologic frequency analysis is usually used to estimate design rainfalls in a design target year. The rainfall data series applied to the hydrologic frequency analysis is assumed to be stationary. However, recent observations indicate that the data series might not preserve the statistical properties of rainfall in the future. This study incorporated the residual analysis and the hydrologic frequency analysis to estimate design rainfalls in a design target year considering the non-stationarity of rainfall. The residual time series were generated using a linear regression line constructed from the observations. After finding the proper probability density function for the residuals, considering the increasing or decreasing trend, rainfalls quantiles were estimated corresponding to specific design return periods in a design target year. The results from applying the method to 14 gauging stations indicate that the proposed method provides appropriate design rainfalls and reduces the prediction errors compared with the conventional rainfall frequency analysis which assumes that the rainfall data are stationary.

The Development of the Hantan River Basin, Korea and the Age of the Sediment on the top of the Chongok Basalt (한탄강유역의 발달과정과 전곡현무암 위의 퇴적물의 연대)

  • Bae, Kidong
    • The Korean Journal of Quaternary Research
    • /
    • v.3 no.1
    • /
    • pp.87-101
    • /
    • 1989
  • The development of the Hantan river basin can be divided into three stages. The first stage include the ancient Hantan channel system prior to the Chongokni basalt which yield dates of about 0.6 mya from the K/Ar dating method. During this period the Baekuyri formation was formed. The Baekuyri formation is widely observed under the Chongokni basalt along the current river system. The second stage is the period when stream channels stayed on the top of the basalt plateau. Aggradation and deggradation were continued by meandering and braiding channel systems until major stream channel was formed. The currently remaining deposit on the top of the basalt was formed by lacustrine and fluvial systems in this period. During this period Pleistocene hominid was present on edge of water and flood plain and left Paleolithic material. This period was begun at the time of the final basalt flow dated about 300,000 BP. The third stage is designed for the time when the Hantan river channel was dropped down to a level from which the channel could not influence the top of the basalt any more No more deposit could be formed but erosion by surface water has been continued on the top of the basalt since then. The dropping of the Hantan river channel was probably not very long after the final flow of the basalt. Because of frost action and heavy concentrated precipitation in the basin area along with blocky and clumnar joint structure of the basalt, erosional process of the basalt is believed to have been carried out within a relatively short time. The lowering of the Hantan river channel was probably completed in a cycle of major fluctuation of world cimate. Also, the redclay on the top of the basalt is believed to have been formed during a warm period around 200,000 BP, which accords with the climatic change suggested above fair1y well. The Paleolithic materials in tile deposits fell accordingly into approximately same time period.

  • PDF

Stratigraphy and Paleoceanography of deep-sea core sediments from the Korea Deep Ocean Study (KODOS)-97 Area, Northeast Equatorial Pacific (북동태평양 KODOS-97지역 주상 퇴적물의 층서 및 고해양학적 연구)

  • Park, Jeong-Hee;Kim, Ki-Hyune
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.4 no.1
    • /
    • pp.50-62
    • /
    • 1999
  • Sediment core samples recovered from the Korea Deep Ocean Study (KODOS)-97 area were divided into two or three units according to their distinct changes in sediment colors and chemical and physical properties. Analyses of radiolarian faunas in the sediments and $^{10}Be$ ratios in each unit were performed to reveal stratigraphic and paleoceanographic history of the study area. In the upper part of the sediments, Tertiary radiolarians were mixed at various proportions with Quaternary assemblages probably by reworking process of bottom current and benthic animals. Dissolution of radiolarians was severe in deeper depth and in the Unit III, only few of the fragments of corroded Tertiary radiolarians were detectable. The mid layer of the Unit I belonged to Collosphaera invaginata Zone, the time period of 0.21 Ma. The Unit II belonged to Collosphaera tuberosa Zone with the time period younger than 0.42 Ma which was observed above the Stylatractus universus Zone. The Unit III is assigned to Tertiary, which is younger than the Late Eocene. Composition analyses of radiolarian assemblage and $^{10}Be$ ratio data indicated hiatus periods of more than 3 My between late of Middle Miocene and Pliocene resulting from erosion and dissolution caused by Antarctic Bottom Water. Stratigraphic evidence from radiolaria was well correlated with $^{10}Be$ data. Sedimentation rate during Quaternary can be suggested as 0.15-0.5 mm per 1000 years. Dominance of warm-water radiolaria species and the results reflected minimum climatic changes of tropical conditions.

  • PDF

Consequences of Water Induced Disasters to Livelihood Activities in Nepal

  • Gurung, Anup;Karki, Arpana;Karki, Rahul;Bista, Rajesh;Oh, Sang-Eun
    • Korean Journal of Environmental Agriculture
    • /
    • v.31 no.2
    • /
    • pp.129-136
    • /
    • 2012
  • BACKGROUND: The changes in the climatic conditions have brought potentially significant new challenges, most critical are likely to be its impact on local livelihoods, agriculture, biodiversity and environments. Water induced disasters such as landslides, floods, erratic rain etc., are very common in developing countries which lead to changes in biological, geophysical and socioeconomic elements. The extent of damages caused by natural disasters is more sever in least developing countries. However, disasters affect women and men differently. In most of the cases women have to carry more burden as compared to their male counterpart during the period of disasters. METHODS AND RESULTS: This study examines the impact of disasters on the local livelihood especially agriculture and income generating activities of women in three districts of Nepal. The study uses the primary data collected following an exploratory approach, based on an intensive field study. The general findings of the study revealed that women had to experience hard time as compared to their male counterpart both during and after the disaster happen. Women are responsible for caring their children, collecting firewood, fetching water, collecting grass for livestock and performing household chores. Whereas, men are mainly involved in out-migration and remained out-side home most of the time. After the disaster occurred, most of the women had to struggle to support their lives as well as had to work longer hours than men during reconstruction period. Nepal follows patriarchal system and men can afford more leisure time as compared to women. During the disaster period, some of the households lost their agricultural lands, livestock and other properties. These losses created some additional workload to women respondent, however at the same time; they learn to build confidence, self-respect, self-esteem, and self-dependency.Although Nepal is predominantly agriculture, majority of the farmers are at subsistence level. In addition, men and women have different roles which differ with the variation in agro-production systems. Moreover women are extensively involved in agricultural activities though their importances were not recognized. Denial of land ownership and denial of access to resources as well as migration of male counterparts are some of the major reasons for affecting the agricultural environments for women in Nepal. CONCLUSION: The shelter reconstruction program has definitely brought positive change in women's access to decision making. The gradual increase in number of women respondent in access to decision making in different areas is a positive change and this has also provided them with a unique opportunity to change their gendered status in society.Furthermore, the exodus out-flow of male counterparts accelerated the additional burden and workload on women.

Characteristics of chemical environment by changing temperature at the surface layer in the northeast Equatorial Pacific (북동적도태평양 표층 수온변화에 따른 화학적 환경 특성)

  • Son Seung-Kyu;Hyun Jung-Ho;Park Cheong-Kee;Chi Sang-Bum;Kim Ki-Hyune
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.4 no.1
    • /
    • pp.24-37
    • /
    • 2001
  • Physical and chemical properties of the northest Equatorial Pacific between 5° and 12° N along 131.5 °W wore investigated in association with changes in water column structures during the summer seasons of 1998 and 1999. Climatic disturbances such as El Nino and La Nina, should have affected this area during the study Period. In 1998, a thermocline where temperature rapidly decrease with depth, was formed at 90~110 m water depth. Nutrient depicting areas, specially for nitrate+nitrite and phosphate, or oligotrophic regions were extended down to approximately 100 m depth, which coincided with the surface mixed layer depth. However, in 1999, a very fluctuating thermocline was observed with latitudes. As a result of changes in the water column structures, nutrient concentrations also showed fluctuation parallel to the changes in other physical parameters. In the photic zone, depth integrated nitrogen and phosphorus values were 34 gN/m², 7 gP/m² in 1998 and 130 gN/m², 18 gP/m² in 1999, respectively. The results indicated that nitrogen (96 gN/m²) and phosphorus (11 gP/m²) are supported by up-welling and down-welling phenomena with convergence and divergence in the study area.

  • PDF

A Six-Layer SVAT Model for Energy and Mass Transfer and Its Application to a Spruce(Picea abies [L].Karst) Forest in Central Germany (독일가문비나무(Picea abies [L].Karst)림(林)에서의 Energy와 물질순환(物質循環)에 대(對)한 SLODSVAT(Six-Layer One-Dimensional Soil-Vegetation-Atmosphere-Transfer) 모델과 그 적용(適用))

  • Oltchev, A.;Constantin, J.;Gravenhorst, G.;Ibrom, A.;Joo, Yeong-Teuk;Kim, Young-Chai
    • Journal of Korean Society of Forest Science
    • /
    • v.85 no.2
    • /
    • pp.210-224
    • /
    • 1996
  • The SLODSVAT consists of interrelated submodels that simulate : the transfer of radiation, water vapour, sensible heat, carbon dioxide and momentum in two canopy layers determined by environmental conditions and ecophysiological properties of the vegetation ; uptake and storage of water in the "root-stem-leaf" system of plants ; interception of rainfall by the canopy layers and infiltration and storage of rain water in the four soil layers. A comparison of the results of modeling experiments and field micro-climatic observations in a spruce forest(Picea abies [L].Karst) in the Soiling hills(Germany) shows, that the SLODSVAT can describe and simulate the short-term(diurnal) as well as the long-term(seasonal) variability of water vapour and sensible heat fluxes adequately to natural processes under different environmental conditions. It proves that it is possible to estimate and predict the transpiration and evapotranspiration rates for spruce forest ecosystems on the patch and landscape scales for one vegetation period, if certain meteorological, botanical and hydrological information for the structure of the atmospheric boundary layer, the canopy and the soil are available.

  • PDF

A Study on Appropriate Tree Species and Crops for Agroforestry Using an Ecological Geographic Map of North Korea (북한의 생태지리구획을 활용한 임농복합경영 적정 수종 및 작물 고찰 연구)

  • Park, Sohee;Lim, Joongbin;Kim, Eun-hee;Yang, A-Ram
    • Journal of Korean Society of Forest Science
    • /
    • v.110 no.3
    • /
    • pp.355-368
    • /
    • 2021
  • This study aims to identify appropriate tree species and crops for agroforestry target sites in North Korea based on ecological geography and site properties. To this end, an ecological geographic map (13 regions and 4 zones) of North Korea was made using satellite images and North Korean academic journal articles. The target agroforestry sites were selected and mapped according to 18 site conditions depending on 3 site characteristics, and the sites were divided into short-term and long-term target sites depending on the agroforestry management period. Finally, optimal combinations of 30 tree species and 19 crops were selected by overlapping the ecological geographic map and agroforestry target site map. For regions within the same zone, tree species and crops were almost similar; however, compared to regions in other zones, they differed. This is likely because the geographical climatic characteristics reflected in the ecological geographic map vary greatly from zone to zone. These results will be used to propose a combination of suitable tree species and crops that takes into account both management purposes and management types for inter-Korean forest cooperation in the agroforestry sector.

Evaluation of Habitat Suitability of Honey Tree Species, Kalopanax septemlobus Koidz., Tilia amurensis Rupr. and Styrax obassis Siebold & Z ucc. in the Baekdudaegan Mountains using MaxEnt Model (MaxEnt 모형을 활용한 백두대간에 자생하는 주요 밀원수종인 음나무, 피나무, 쪽동백나무의 서식지 적합성 평가)

  • Sim, Hyung Seok;Lee, Min-Ki;Lee, Chang-Bae
    • Journal of Korean Society of Forest Science
    • /
    • v.111 no.1
    • /
    • pp.50-60
    • /
    • 2022
  • In this study, habitat suitability was analyzed for three major honey tree species, namely Kalopanax septemlobus, Tilia amurensis, and Styrax obassis, in the Baekdudaegan Mountains using MaxEnt models. The AUC values indicating the prediction accuracies of the models were 0.747, 0.790, and 0.755 for K. septemlobus, T. amurensis, and S. obassis, respectively. The most important variables for K. septemlobus and T. amurensis were elevation, mean annual temperature, and slope, whereas mean annual temperature, elevation, and mean annual precipitation were the most important predictors for S. obassis. For all three studied species, elevation and mean annual temperature were the most important topographic and climatic factors, respectively, indicating that such variables are crucial for explaining species distribution. Honey tree species are essential resources in forest beekeeping, a high value-added process for improving forest income, and this study identified sites with the potential for management of such species in the Baekdudaegan Mountains, where it may be possible to establish a honey forest. However, the accuracy of the models should be improved through comprehensive analysis with abiotic variables, such as soil properties and aridity, which affect the distribution of honey tree species, as well as biotic variables, such as interspecific competition.