• Title/Summary/Keyword: Dry land

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Time series Analysis of Land Cover Change and Surface Temperature in Tuul-Basin, Mongolia Using Landsat Satellite Image (Landsat 위성영상을 이용한 몽골 Tuul-Basin 지역의 토지피복변화 및 지표온도 시계열적 분석)

  • Erdenesumbee, Suld;Cho, Gi Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.3
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    • pp.39-47
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    • 2016
  • In this study analysis the status of land cover change and land degradation of Tuul-Basin in Mongolia by using the Landsat satellite images that was taken in year of 1990, 2001 and 2011 respectively in the summer at the time of great growth of green plants. Analysis of the land cover change during time series data in Tuul-Basin, Mongolia and NDVI (Normalized Difference Vegetation Index), SAVI (Soil-Adjusted Vegetation Index) and LST (Land Surface Temperature) algorithm are used respectively. As a result shows, there was a decrease of forest and green area and increase of dry and fallow land in the study area. It was be considered as trends to be a land degradation. In addition, there was high correlation between LST and vegetation index. The land cover change or vitality of vegetation which is taken in study area can be closely related to the temperature of the surface.

A Study on Characteristic and Change of Agricultural Land Use for the Mountainous Village - The Case Study on Yowon-Village, Gyeongbuk Province - (산지촌의 농업토지이용 변화와 특성 -경북 영양군 석보면 요원리 지역을 사례로 -)

  • 오남현
    • Journal of the Korean Geographical Society
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    • v.37 no.1
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    • pp.93-110
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    • 2002
  • The purpose of this study is to analyse the change and characteristic of agricultural land use for the mountainous village which was linked to the development of arable land in the historic process as the case study on Yowon-village, Gyeongbuk province. The findings are summarized as fellows. First, most of arable land development had been developed from the late 16th century to the late 19th century and in the 1960s. A rice field was developed at the valley containing water resource and a dry field at the land close to a village before 1960 and at the gently sloped and wide hill after 1960. Second, the crops cultivated before the introduction of commercial agriculture were potato, foxtail millet, bean. After the 1970s, The vegetable, red pepper, tobacco were commercially cultivated. Third, the main group of land use change(choice of crops) result from effort of the inhabitant The significance of this study are as follows, explaining the change and characteristic of agriculture land use for the mountainous village which was linked to the development of arable land, studying as the case on small-scale village.

Development of calculating daily maximum ground surface temperature depending on fluctuations of impermeable and green area ratio by urban land cover types (도시 토지피복별 불투수면적률과 녹지면적률에 따른 지표면 일최고온도 변화량 산정방법)

  • Kim, Youngran;Hwang, Seonghwan
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.2
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    • pp.163-174
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    • 2021
  • Heatwaves are one of the most common phenomena originating from changes in the urban thermal environment. They are caused mainly by the evapotranspiration decrease of surface impermeable areas from increases in temperature and reflected heat, leading to a dry urban environment that can deteriorate aspects of everyday life. This study aimed to calculate daily maximum ground surface temperature affecting heatwaves, to quantify the effects of urban thermal environment control through water cycle restoration while validating its feasibility. The maximum surface temperature regression equation according to the impermeable area ratios of urban land cover types was derived. The estimated values from daily maximum ground surface temperature regression equation were compared with actual measured values to validate the calculation method's feasibility. The land cover classification and derivation of specific parameters were conducted by classifying land cover into buildings, roads, rivers, and lands. Detailed parameters were classified by the river area ratio, land impermeable area ratio, and green area ratio of each land-cover type, with the exception of the rivers, to derive the maximum surface temperature regression equation of each land cover type. The regression equation feasibility assessment showed that the estimated maximum surface temperature values were within the level of significance. The maximum surface temperature decreased by 0.0450℃ when the green area ratio increased by 1% and increased by 0.0321℃ when the impermeable area ratio increased by 1%. It was determined that the surface reduction effect through increases in the green area ratio was 29% higher than the increasing effect of surface temperature due to the impermeable land ratio.

Changes of Land Use Pattern due to Urbanization in Taejon Korea (도시화에 따른 대전시 토지이용의 변화)

  • 강신호
    • Korean Journal of Environment and Ecology
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    • v.14 no.2
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    • pp.154-161
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    • 2000
  • The objectives of this study were to determine how land use pattern in Taejon the sixth largest city in Korea has changed with urbanization. Degree of green naturalness (DGN) was used to analyze land use pattern from 1990 to 1998. Number of 1km$\times$1km grids numbers of satistical land use data and compared rate of population increase quantified land use pat-tern. The rate of population increase of Taejon was 27.8% from 1990 to 1998. Eight degrees of DGN were identified with secondary forest(grade 7) occupied the largest area (203 grids: 37.5%) of the total 541 grids in 1998. The changes in land use were compared among 1990, 1994 and 1998. Grade 1 increased by 9 grids while grade 2 decreased by 6 grids. Likewise paddy field decreased by 10km2 from 62 to 52km2 dry field and forest also decreased by 4km2 and 1km2 respectively while residence and factories increased by 10km2 and 0.5km2 respec-tively. The green space was mostly distributes in a national park and greenbelts in the outer zone of the city. As a result paddy and dry fields in central area of the city have been changed to residential and industrial areas. The city environment in term of DGN reduced its quality and quantity.

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Effect of Season and Fertilizer on Species Composition and Nutritive Value of Native Grasses

  • Khan, R.I.;Alam, M.R.;Amin, M.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.8
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    • pp.1222-1227
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    • 1999
  • Effect of three major cropping seasons and five fertilizer treatments on botanical composition, nutritional composition and in sacco digestibility of native grasses grown in 30 experimental plots of a medium fertile land was determined. It was observed that all the major grass species were grown in all seasons but their predominancy of growth was different. During the study the predominant grass species were Panicum repens (Angta), Fimvristylis miliacea (Joina), Cyanolis axillaries (Kanainala), Cynodon dactylon (Durba) and Cyperus iria (Phulchaise) which contributed about 27, 20, 13, 11 and 9% of the total grass yield, respectively. Dry matter (DM) contents was higher in dry followed by monsoon and summer seasons (p<0.05). Crude protein (CP) content in the summer and monsoon appeared to be higher (p<0.05) than that of dry season. Organic matter (OM) and neutral detergent fibre (NDF) were higher (p<0.05) in dry and monsoon than in summer season. Application of urea fertilizer and cowdung increased 28.2% of CP content of the grasses, but decreased 19.5 and 9.8% of DM and NDF contents, respectively. The potential degradation of DM and CP of the grasses grown in summer were 4.1 and 8.4% and 3.9 and 5.8% higher than those of monsoon and dry seasons, respectively, and both of these increased (11.3 and 5.9%, respectively) with the application of cowdung and urea fertilizer.

A Study on the Development of a Dry PFB Method with High Fire Resistance (고강도콘크리트 내화성능을 확보한 건식화 PFB 공법 개발에 관한 연구)

  • Kim, Woo-Jae;Jung, Sang-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.11a
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    • pp.49-52
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    • 2008
  • The present study was to develop a dry PFB method similar to the existing gypsum board construction method in order to apply the existing wet PFB method that uses fire-resistant adhesive. It was found that the existing wet method can produce concrete compressive strength of 80MPa and fire resistance of 3 hours with 30mm PF boards. The goal of development in this study was fire resistance of 3 hours through dry construction of 15mm fire-resistant boards. 1. Improved PF board was prepared by adding inorganic fiber to existing board and using aggregate with grain size of 3mm or less. Molding was done at temperature higher than that for existing PF board molding. While wet curing is used for existing PF boards, this study used dry curing in order to enhance heat insulation performance. 2. According to the results of fire resistance test, when the dry PF method was applied, the temperature of the main reinforcing bar was 116℃ in 15mm, 103.8℃ in 20mm, and 94℃ in 25mm, and these results satisfied the current standards for fire resistance control presented by the Ministry of Land, Transport and Maritime Affairs. When a 3-hour fire resistance test was performed and the external properties of the specimen were examined, the outermost gypsum board hardly remained and internal PF board maintained its form without thermal strain.

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Wood and Leaf Litter Decomposition and Nutrient Release from Tectona grandis Linn. f. in a Tropical Dry Deciduous Forest of Rajasthan, Western India

  • Kumar, J.I. Nirmal;Sajish, P.R.;Kumar, Rita.N.;Bhoi, Rohit Kumar
    • Journal of Forest and Environmental Science
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    • v.26 no.1
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    • pp.17-23
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    • 2010
  • The present study was conducted to quantify wood and leaf litter decomposition and nutrient release of a dominant tree species, Tectona grandis Linn. F. in a tropical dry deciduous forest of Rajasthan, Western India. The mean relative decomposition rate was maximum in the wet summer and minimum during dry summer. Rainfall and its associated variables exhibited greater control over litter decomposition than temperature. The concentrations of N and P increased in decomposing litter with increasing retrieval days. Mass loss was negatively correlated with N and P concentrations. The monthly weight loss was significantly correlated (P < 0.05) with soil moisture and rainfall in both wood and leaf litter. Tectona grandis was found to be most suitable tree species for plantation programmes in dry tropical regions as it has high litter deposition and decomposition rates and thus it has advantages in degraded soil restoration and sustainable land management.

Characteristics of Desiccation on the Stabilized Layer in Waste Landfill (쓰레기 매립지에서 표층고화처리층의 건조수축특성)

  • 천병식;임종윤;최창현;차용혁
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.301-308
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    • 1999
  • With the shortage of the land and NIMBY syndrome, it is issued recently that the capacity of waste-landfill site is needed though the decreasing tendency of waste landfill. From this point, the stability is the most essential problem in the landfill that will be constructed. Advanced design and construction are most important for that. In this paper, for the study of desiccation, dry-shrinkage crack from drying and chemical reaction in cement hydration, which is occurred when the surface layer stabilization method is applied in wast landfill, laboratory test of the ground and specimen according to the mixture ratio of stabilizer is performed. From the result, it is notified that the uni-axial strength increases with the stabilizer, but dry-shrinkage increases too, therefore, it is important and the goal of this study to find the optimal mixture ratio of each stabilizer. Analysis of variance for regression with acting variables is performed to find optimal mixture ratio of each stabilizer.

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Hydrothermal Pre-treatment and Gasification of Solid Wastes to Produce Electrical Power and Hydrogen

  • Yoshikawa, Kunio
    • Proceedings of the Korean Institute of Resources Recycling Conference
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    • 2006.09a
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    • pp.3-12
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    • 2006
  • The main feature of these total technologies is that we can constitute the optimum treatment scheme fitting to the property of wastes, amount of wastes and energy requirement. For high moisture content wastes or biomass resources, high pressure steam process (MMCS) for crush, dry and deodorize wastes to produce high quality fertilizer of fuel is most appropriate. For dry or semi-dry solid wastes, the STAR-MEET system can be applied to produce low-BTU gases for power generation using duel fueled diesel engines of Stirling engines, and the REPRES and HyPR-MEET systems can be applied to produce hydrogen rich medium-BTU gas. For waste plastics and oils, liquefaction technology is best fit to produce light oil or kerosene equivalent fuel oils. These total technologies are completely different from the existent waste treatment technologies based on land-filling or incineration, and are expected to disseminate all over the world in the near future.

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