• Title/Summary/Keyword: land surface

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Atmospheric Correction Issues of Optical Imagery in Land Remote Sensing (육상 원격탐사에서 광학영상의 대기보정)

  • Lee, Kyu-Sung
    • Korean Journal of Remote Sensing
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    • v.35 no.6_3
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    • pp.1299-1312
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    • 2019
  • As land remote sensing applications are expanding to the extraction of quantitative information, the importance of atmospheric correction is increasing. Considering the difficulty of atmospheric correction for land images, it should be applied when it is necessary. The quantitative information extraction and time-series analysis on biophysical variables in land surfaces are two major applications that need atmospheric correction. Atmospheric aerosol content and column water vapor, which are very dynamic in spatial and temporal domain, are the most influential elements and obstacles in retrieving accurate surface reflectance. It is difficult to obtain aerosol and water vapor data that have suitable spatio-temporal scale for high- and medium-resolution multispectral imagery. Selection of atmospheric correction method should be based on the availability of appropriate aerosol and water vapor data. Most atmospheric correction of land imagery assumes the Lambertian surface, which is not the case for most natural surfaces. Further BRDF correction should be considered to remove or reduce the anisotropic effects caused by different sun and viewing angles. The atmospheric correction methods of optical imagery over land will be enhanced to meet the need of quantitative remote sensing. Further, imaging sensor system may include pertinent spectral bands that can help to extract atmospheric data simultaneously.

Effect of Capillary Barrier on Soil Salinity and Corn Growth at Saemangeum Reclaimed Tidal Land

  • Lee, Sanghun;Lee, Su-Hwan;Bae, Hui-Su;Lee, Jang-Hee;Oh, Yang-Yul;Noh, Tae-Hwan;Lee, Geon-Hwi
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.6
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    • pp.398-405
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    • 2014
  • Salt accumulation at soil surface is one of the most detrimental factors for crop production in reclaimed tidal land. This study was conducted to investigate the effect of capillary barriers beneath the soil surface on dynamics of soil salts at coarse-textured reclaimed tidal land. A field experiment was conducted at Saemangeum reclaimed tidal land for two years (2012-2013). Capillary barriers ($3.5{\times}12m$) were treated with crushed-stone, oyster shell waste, coal briquette ash, coal bottom ash, rice hull and woodchip at 40-60 cm depth from soil surface. Silage corn (Zea mays) was cultivated during the experimental period and soil salinity was monitored periodically. Soil salinity was significantly reduced with capillary barrier compared to that of control. Oyster shell waste was one of the most effective capillary barrier materials to control soil salinity at Saemangeum reclaimed tidal land. At the first growing season capillary barrier did not influence on corn growth regardless of types of the material, but plant biomass and withering rate of corn were significantly improved with capillary barrier at the second growing season. The results of this study showed that capillary barrier was effective on the control of soil salinity and improvement of corn growth, which indicated that capillary barrier treatment can be considered one of the best management practices for stable crop production at Saemangeum reclaimed tidal land.

Landscape Ecology Concept, Principles and Its Rlation to Monothematic (e.g. Vegetation) Survey (경관생태학의 개념, 원리 및 식생조사와의 관계)

  • Isaak, S. Zonneveld
    • The Korean Journal of Ecology
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    • v.21 no.4
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    • pp.357-372
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    • 1998
  • Land (scape) ecology is a trans-disciplinary science studying the related systems at the earth surface, in their visual, structural and functional aspects. it serves as an umbrella under which abiotic and biotic sciences, in an integrated way, study the for each relevant land attributes and their interrelations. The spatial aspects of these relations have a special interest. Landscape ecology my have a pure scientific purpose, but usually is executed in an applied context, related to land evaluation for land use and conservation. Depending on the aim and application of the study, one of the land attributes may get special attention. Vegetation mapping may contribute to landscape ecological study but also benefit from it especially in case of reconnaissance surveys. This is because in less detailed surveys of any land attribute, like land form, soil, vegetation, one must necessarily apply landscape ecological principles in the survey methodology, including remote sensing.

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ESTIMATION OF HEAT ISLAND POTENTIAL BASED ON LAND-USE TYPE IN DAEGU

  • Ahn Ji-Suk;Kim Hae-Dong;Kim Sang-Woo
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.394-397
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    • 2005
  • This study aims to estimate a heat island potential distribution based on the land-use types using LANDSAT/TM(1100LST April 2000) and AWS data in Daegu. The heat island potential is defined as a difference between surface temperature and air-temperature at each place. The study area was selected as about $900k km^2$ square including Daegu metropolitan area. Land-use data obtained by dividing all of Daegu metropolitan area into l-km-square three types of maps were prepared, in the 1 960s, 1970s and 2000s respectively. The types of land-use were divided into 5. Forest and farm lands have been reduced at a wide range during 40 years, most of which changed to urban area. The heat island potential distribution presented a striking contrasts according to land-use types. For example, the heat island potential of urban area was higher than $14^{\circ}$ in comparison to those of water or paddy rice areas.

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Estimation of Sea Surface Temperature Change by Tide Embankment Construction

  • Shin Dong-hoon;Lee Kyoo-seock
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.146-148
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    • 2005
  • This study investigates to detect sea surface temperature (SST) and land cover change after tide embankment construction using Landsat Thematic Mapper (TM) thermal infrared (TIR) band data at Shihwa Lake and surrounding area. SST measurement is important for studies of both the structure of the ocean and as the thermal boundary between the ocean and the atmosphere. The TIR band of TM images can be used to detect SST change whose shoreline is complicated and narrow like the study site. The purpose of this study is to estimate SST and land cover change at Shihwa Lake and surrounding area.

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Histochemical and Ultrastructural Study on the Stomach of a Land Snail, Nesiohelix samarangae (동양달팽이의 위에 대한 조직화학적 및 미세구조적 연구)

  • 정계헌;이용석
    • The Korean Journal of Malacology
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    • v.13 no.2
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    • pp.175-184
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    • 1997
  • A histochemical and ultrastructural study on the stomach epithelium of a land snail Nesiohelix samarangae was carried out during the period of June 1996 to May 1997. The stomach epithelium is simple columnar dpithelium and is consisted of three types of columnar cells, Type 1 cell which is majority in number has a brush border with microvilli on the free surface of the cell and contains numerous secretory granules supposed to be neutral mucopolysaccharide. Type 2 cell, elongated conical in shape. is rarely found in the dpithelium. This cell also has a brush border with microvilli on its free surface and contains well developed rough surfaced endoplasmic reticulum, Golgi bodies, and secretory granules in various electron densities. This cell seems to produce both of acid and neutral mucopolysaccharides. Type 3 cell, which is morphologically similar to the Type 1 cell, has microvili and cilia on the free surface and exists in group only in the limited regions of the stomach.

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LONG TERM MONITORING OF HYDRARGYRUM POLLUTED SOIL USING PROJECTED IMAGE RECONSTRUCTION IN ELECTRICAL IMPEDANCE TOMOGRAPHY

  • Munkh-Erdne, Ts;Lee, Eunjung
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.18 no.2
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    • pp.167-180
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    • 2014
  • In this paper we consider a novel reconstruction method in electrical impedance tomography (EIT) and its application for monitoring and detecting a hydrargyrum (mercury) polluted soil near to the surface of underground. We use electrodes placed on the surface of land to collect the data which provides the relations of voltage and current map and to produce a projected image of interior conductivity distribution onto the surface of land. Here the projected image reconstruction method is used to monitor the pollution in soil underneath the ground without any destruction and any digging into a land.

Numerical Analysis of Meso-Scale Circulation with Inclusion of a Layer of Vegetation over Ulsan Area (식생의 영향을 고려한 울산지역의 중규모 지역기상장에 관한 연구)

  • Lee, Seong-Dae
    • Journal of Korea Water Resources Association
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    • v.30 no.2
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    • pp.119-129
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    • 1997
  • A three-dimensional numerical model for the simulation of meso-scale local circulation is developed and it is applied to the land and sea breezes which take place around Ulsan. The surface temperature and moisture on the land are determined by means of the surface heat budget with a layer of vegetation considered. The vertical diffusion coefficients of momentum, heat and specific humidity at the surface layer are obtained by the lever-2 model of the turbulence closure proposed by Yamada (1982). This model proved to be effective in simulating the structure of the land and sea breezes around Ulsan.

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Sub-grid study of scaling effects to evapotranspiration of heterogeneous forest landscape at the Volga source area in Russia

  • Oltchev, A.;G.Gravenhorst;A.P.Tishenko;Joo, Y.T.
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2001.06a
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    • pp.151-152
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    • 2001
  • A common problem of the model simulations of the land surface - atmosphere interaction is to choose the appropriate spatial scale and resolution at which the simulations are to be performed. The accuracy of energy and water exchange predictions between the land surface and the atmosphere in regional and global scale atmospheric models is mainly influenced by: model simplifications applied to describe the spatial heterogeneity of land surface properties within individual grid cells; ignoring the variability of sub-grid properties (e.g. relief, vegetation, soils), and; lacks of necessary input meteorological and biophysical data.(omitted)

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Analyzing off-line Noah land surface model spin-up behavior for initialization of global numerical weather prediction model (전지구수치예측모델의 토양수분 초기화를 위한 오프라인 Noah 지면모델 스핀업 특성분석)

  • Jun, Sanghee;Park, Jeong-Hyun;Boo, Kyung-On;Kang, Hyun-Suk
    • Journal of Korea Water Resources Association
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    • v.53 no.3
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    • pp.181-191
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    • 2020
  • In order to produce accurate initial condition of soil moisture for global Numerical Weather Prediction (NWP), spin-up experiment is carried out using Noah Land Surface Model (LSM). The model is run repeatedly through 10 years, under the atmospheric forcing condition of 2008-2017 until climatological land surface state is achieved. Spin-up time for the equilibrium condition of soil moisture exhibited large variability across Koppen-Geiger climate classification zone and soil layer. Top soil layer took the longgest time to equilibrate in polar region. From the second layer to the fourth layer, arid region equilibrated slower (7 years) than other regions. This result means that LSM reached to equilibrium condition within 10 year loop. Also, spin-up time indicated inverse correlation with near surface temperature and precipitation amount. Initialized from the equilibrium state, LSM was spun up to obtain land surface state in 2018. After 6 months from restarted run, LSM simulates soil moisture, skin temperature and evaportranspiration being similar land surface state in 2018. Based on the results, proposed LSM spin-up system could be used to produce proper initial soil moisture condition despite updates of physics or ancillaries for LSM coupled with NWP.