• Title/Summary/Keyword: Land covers

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Spatial Interpolation of Hourly Air Temperature over Sloping Surfaces Based on a Solar Irradiance Correction (일사 수광량 보정에 의한 산악지대 매시기온의 공간내삽)

  • 정유란;윤진일
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.4 no.2
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    • pp.95-102
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    • 2002
  • Spatial interpolation has become a common procedure in converting temperature forecasts and observations at irregular points for use in regional scale ecosystem modeling and the model based decision support systems for resource management. Neglection of terrain effects in most spatial interpolations for short term temperatures may cause erroneous results in mountainous regions, where the observation network hardly covers full features of the complicated terrain. A spatial interpolation model for daytime hourly temperature was formulated based on error analysis of unsampled site with respect to the site topography. The model has a solar irradiance correction scheme in addition to the common backbone of the lapse rate - corrected inverse distance weighting. The solar irradiance scheme calculates the direct, diffuse and reflected components of shortwave radiation over any surfaces based on the sun-slope geometry and compares the sum with that over a reference surface. The deviation from the reference radiation is used to calculate the temperature correction term by an empirical conversion formula between the solar energy and the air temperature on any sloped surfaces at an hourly time scale, which can be prepared seasonally for each land cover type. When this model was applied to a 14 km by 22 km mountainous region at a 10 m horizontal resolution, the estimated hourly temperature surfaces showed a better agreement with the observed distribution than those by a conventional method.

A Study on the Identity of the Korean Landscape Architectural Award (대한민국조경대상의 정체성 해석)

  • Hong, Youn-Soon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.5
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    • pp.91-100
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    • 2011
  • This study aimed at the identity of the landscape architectural award, which is the highest authority award system in landscape architecture; the establishment of cooperation between the landscape architecture and urban public sector, which deals with infrastructure is significantly requested nowadays. The identity characteristic of a detailed concept which configures the sameness in the shape of inner self-cognition and individuality as external and correlative cognition are utilized as the research methodology, and the findings are summarized as follows. The Korean Landscape Architectural Award holds an internal value as the only award in landscape architecture that is granted municipalities and public agencies. However, when it is compared with several correlated award systems, the vulnerable sides such as short origin and partly limping in terms of sustainability, the possibilities of losing the interest in the public sector due to management's reform program and insufficient participants and responses regarding social authority have been found. In addition, according to the today's paradigm tha taims for green cities, the aspect that shares the large portion with the values set by detailed categories of city planning that enforces metropolis awards is also in the spotlight. Hence, the landscape architectural award should construct specialization and development strategies by strengthening the superiority compared with the city award in the field of city planning. In other words, the Ministry of Land, not limited to the systematic cooperation with various administrative areas will be strengthened and it will communicate with the aspect that reinforces characters as an academic and practical area that covers various districts and disciplines. Thus, the identity is directly connected to the landscape architectural award's competitive reinforcement as a detailed characteristic variously combined, and it requires huge interest and discussions regarding internal and external landscape architecture areas and the democratic public discussion process.

Compatibility of MODIS Vegetation Indices and Their Sensitivity to Sensor Geometry (MODIS 식생지수에 미치는 센서 geometry의 영향과 센서 간 자료 호환성 검토)

  • Park, Sunyurp
    • Journal of the Korean Geographical Society
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    • v.49 no.1
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    • pp.45-56
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    • 2014
  • Data composite methods have been typically applied to satellite-based vegetation index(VI) data to continuously acquire vegetation greenness over the land surface. Data composites are useful for construction of long-term archives of vegetation indices by minimizing missing data or contamination from noise. In addition, if multi-sensor vegetation indices that are acquired during the same composite periods are used interchangeably, data stability and continuity may be significantly enhanced. This study evaluated the influences of sensor geometry on MODIS vegetation indices and investigated data compatibility of two difference vegetation indices, the Normalized Difference Vegetation Index(NDVI) and the Enhanced Vegetation Index(EVI), for potential improvement of long-term data construction. Relationships between NDVI and EVI turned out statistically significant with variations among vegetation covers. Due to their curvilinear relationships, NDVI became saturated and leveled off as EVI reached high ranges. Correlation coefficients between Terra- and Aqua-based vegetation indices ranged from 0.747 to 0.963 for EVI, and from 0.641 to 0.880 for NDVI, showing better compatibility for EVI compared to NDVI. In-depth analyses of VI outliers that deviated from regression equations constructed from the two different sensors remain as a future study to improve their compatibility.

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The Role of Cover Material in Soil Water Retention and Growth of Tropaeolum majus and Fragaria spp. by Vertical Farming using Hanging Baskets in Urban Agriculture (도시농업을 위한 저관리 용기형 수직녹화에서 피복재가 토양수분 및 한련화와 딸기의 식물생장에 미치는 영향)

  • Ju, Jin-Hee;Yang, Ji;Park, Ju-Young;Yoon, Yong-Han
    • Journal of Environmental Science International
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    • v.27 no.5
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    • pp.291-297
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    • 2018
  • Vertical farming systems offer many advantages in urban spaces. They have also been proposed as an engineering solution to increase the productivity per unit area of cultivated land by extending crop production in the vertical dimension. However, soil water retention is a major constraint affecting the plant environment. This study analyzed the effects of growth environment of Tropaeolum majus and Fragaria spp., on the vertical farming system, by using four different types of cover material types including sphagnum moss (Control), a shading net (S.N.), multi-layered fabric (M.L.F.), and non-woven fabric (N.W.F.). The volumetric soil moisture contents and plant characteristics were investigated from May to September 2014. Plant materials were individually cultivated in hanging baskets measuring $30{\times}17{\times}17cm$, filled with a mixture of soil and perlite, and placed at 1.5m height. Each treatment was performed in quadruplicate and consisted of five plants, amounting to a total of 20 plants. The analysis indicated that different covers were associated with multiple functions and soil water retention improvements may have a positive impact on the vertical farming system. The difference in soil water retention increased in the following order: M.L.F. > Control > N.W.F. > S.N.. Furthermore, the differences in plant height and survival rate increased in the following order: M.L.F. > Control > N.W.F. > S.N. Therefore, M.L.F yielded satisfactory good response for the vertical farming system of cover materials. Our results clearly demonstrate that vertical spaces represent an attractive alternative to urban farming and suggest that further increases in yield may be achieved via different cover materials in vertical farming using hanging baskets.

Groundwater Recharge Estimation for the Gyeongan-cheon Watershed with MIKE SHE Modeling System (MIKE SHE 모형을 이용한 경안천 유역의 지하수 함양량 산정)

  • Kim, Chul-Gyum;Kim, Hyeon-Jun;Jang, Cheol-Hee;Im, Sang-Jun
    • Journal of Korea Water Resources Association
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    • v.40 no.6 s.179
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    • pp.459-468
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    • 2007
  • To estimate the groundwater recharge, the fully distributed parameter based model, MIKE SHE was applied to the Gyeongan-cheon watershed which is one of the tributaries of Han River Basin, and covers approximately $260km^2$ with about 49 km main stream length. To set up the model, spatial data such as topography, land use, soil, and meteorological data were compiled, and grid size of 200m was applied considering computer ability and reliability of the results. The model was calibrated and validated using a split sample procedure against 4-year daily stream flows at the outlet of the watershed. Statistical criteria for the calibration and validation results indicated a good agreement between the simulated and observed stream flows. The annual recharges calculated from the model were compared with the values from the conventional groundwater recession curve method, and the simulated groundwater levels were compared with the observed values. As a result, it was concluded that the model could reasonably simulate the groundwater level and recharge, and could be a useful tool for estimating spatially/temporally the groundwater recharges, and enhancing the analysis of the watershed water cycle.

Evaluations on the Compaction Energy Effects on the Soil Compaction at Sub-Zero Temperature (영하에서의 다짐에너지에 따른 다짐 효과 평가)

  • Lee, Jeonghyeop;Hwang, Bumsik;Chae, Deokho;Cho, Wanjei
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.8
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    • pp.13-20
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    • 2015
  • Due to the population growth and exhaustion of resource, the development on the harsh environment such as cold weather is emerging as an alternative for new resource development. The permafrost area covers about 14 percent of the world's land area and the global construction market for such area is rapidly expanded. Whereas the developed countries have already recognition of the need for research of coldest place and invested heavily in technology development, the domestic technology for the coldest place development is less developed and related research has rarely been performed. There is not a detailed national specification standard for the strength and deformation properties of the earthworks at sub-zero temperature but simple field directions. Therefore, the D compaction tests were conducted on the sand with fine contents of 0%, 5%, 10% and 15% at room temperature ($18^{\circ}C$), $-3^{\circ}C$ and $-8^{\circ}C$ to investigate the effect of the compaction energy on the compacted soils at sub-zero temperatures. Based on the test results, the larger compaction energy, the larger maximum dry unit weight under sub-zero temperature and D type compaction at $-3^{\circ}C$ show similar max. dry unit weights as those obtained from the compaction at the room temperature. However, compaction at $-8^{\circ}C$ showed significant performance degradation regardless of the compaction energy.

Analysis of Topographic Environment for Urban Forest Area in Taejon City Using Landsat - 5 TM and Digital Terrain Elevation Data (Landsat-5 TM과 수치지형데이타를 이용한 도시내 산림의 지형환경 분석 - 대전시를 중심으로 -)

  • 장관순
    • Korean Journal of Environment and Ecology
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    • v.10 no.1
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    • pp.58-65
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    • 1996
  • The environment in urban are becoming worse and forest is being recognized the major part of city by the increase of population and facilities. This study was carried out to analyze topographic environment as the basis for reasonable management and utility of forest situated in Taejon city and its vicinities using Sandst-5 TM and digital terrain elevation data(DTED). Forest area was extracted by Landsat-5 TM data. Distribution of elevation, slope and aspect was derived from digital terrain elevation data. The research area to analyze ropographic environment for urban forest were Bomumsan, Bongsan, Kabhasan, Sikchangsan, and Kyechoksan. Forest, the largest area in Taejon covers 55.1% of totaf area. This is more 5 times than urban area. 70.8% of forest area in Taejon city is located in elevation of lower than 200m and 4.8% of that is located in elevation of upper than 400m. Distribution of elevation is 45.7% of total area for 100m to 200m in Kyechoksan and is 92.4% of total area for lower than 300m in Bomumsan. Elevation of upper than 300m is 20.4% of total area in Kabhasan and is 46.6% of total area in Sikchangsan. The slope of more 20 digree is over 50% of total area in every area except for Bonsan and 35.2% of total area in Sikchangsan and Kahasan than in Bomumsan and Kyechoksan.

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The Study of the Influence on Long Term Streamflow Caused by Artificial Storage Facilities Based on SWAT Modeling Process (SWAT모형을 이용한 인공저류시설물의 하류장기유출 영향분석 기법에 관한 연구)

  • Shin, Hyun-Suk;Kang, Du-Kee
    • Journal of Korea Water Resources Association
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    • v.39 no.3 s.164
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    • pp.227-240
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    • 2006
  • In the several decades, various storage facilities have been developed and operated to supply water resource, flood control or environmental preservation etc. Then, how those man-maid storage facilities affect on the downstream water and environment and how the hydrologists can evaluate those features for water resources problem-solving are high-concentrated problems in this field. Most large watersheds in Korea contain various types of artificial facilities such dams, reservoirs, in-land ponds, wetlands etc. But the study to develop the technology for achieving the effect of the variances and properties of the long term streamflow caused by the artificial storage facilities have been on the simple watershed models and experimental modeling in the real fields. In this paper, we introduce the procedure and methods to consider the above problems based on continuous and semi-distributed featured SWAT model. At the first, we describe the elements and mechanisms of storage facilities in SWAT model to see how we can apply that in proper and appropriate manner for real field problems. Then, we applied the process to a sample watershed, Taewha River basin which covers the most of Ulsan region. Specially, we concentrate on our effort to the effect of upper reservoirs on down stream long term flows based on various scenario basis. The result was described and analysed in spacial and temporal variations on that basin using the precise manner.

Influence of Playground Land Covers on the Human Thermal Sensation (운동장 포장재료가 인간 열환경에 미치는 영향)

  • Hyun, Cheolji;Jo, Sangman;Park, Sookuk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.3
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    • pp.12-21
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    • 2019
  • In order to investigate the effect of various pavement materials (artificial grass, natural grass, and clay sand) on the human thermal environment, the microclimate data in early autumn (air temperature, humidity, wind speed, and shortwave and longwave radiation) were measured and compared on each surface. The mean air temperature, humidity and wind speed of the pavement materials did not differ significantly and showed the greatest difference in the mean radiant temperature. Natural grass, which has the highest albedo, has the highest amount of shortwave radiation. The artificial turf had the highest surface temperature and the highest amount of longwave radiation. In the human thermal environment index PET, artificial grass > clay sand > natural grass. Natural grass had a maximum 2/3 level lower and a mean 1/2 level lower in PET as compared to artificial grass. The clay sand pavement had a maximum 2/3 level lower and a mean 1/3 level lower than the artificial grass. Natural grass had a maximum 1/3 level lower than the clay sand pavement. Their UTCIs showed smaller differences than the PETs. Therefore, it is necessary to carefully choose materials from the planning stage when designing outdoor spaces, including playgrounds.

Calculation of Surface Broadband Emissivity by Multiple Linear Regression Model (다중선형회귀모형에 의한 지표면 광대역 방출율 산출)

  • Jo, Eun-Su;Lee, Kyu-Tae;Jung, Hyun-Seok;Kim, Bu-Yo;Zo, Il-Sung
    • Journal of the Korean earth science society
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    • v.38 no.4
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    • pp.269-282
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    • 2017
  • In this study, the surface broadband emissivity ($3.0-14.0{\mu}m$) was calculated using the multiple linear regression model with narrow bands (channels 29, 30, and 31) emissivity data of the Moderate Resolution Imaging Spectroradiometer (MODIS) on Earth Observing System Terra satellite. The 307 types of spectral emissivity data (123 soil types, 32 vegetation types, 19 types of water bodies, 43 manmade materials, and 90 rock) with MODIS University of California Santa Barbara emissivity library and Advanced Spaceborne Thermal Emission & Reflection Radiometer spectral library were used as the spectral emissivity data for the derivation and verification of the multiple linear regression model. The derived determination coefficient ($R^2$) of multiple linear regression model had a high value of 0.95 (p<0.001) and the root mean square error between these model calculated and theoretical broadband emissivities was 0.0070. The surface broadband emissivity from our multiple linear regression model was comparable with that by Wang et al. (2005). The root mean square error between surface broadband emissivities calculated by models in this study and by Wang et al. (2005) during January was 0.0054 in Asia, Africa, and Oceania regions. The minimum and maximum differences of surface broadband emissivities between two model results were 0.0027 and 0.0067 respectively. The similar statistical results were also derived for August. The surface broadband emissivities by our multiple linear regression model could thus be acceptable. However, the various regression models according to different land covers need be applied for the more accurate calculation of the surface broadband emissivities.