• Journal of Applied Biological Chemistry
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• v.50 no.1
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• pp.22-28
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• 2007

Most of the uplands in alpine regions during off-season are left as bare soil and thus vulnerable to severe erosion due to the inherent topographical conditions. Appropriate management strategy to cope with this problem is urgently needed, yet few researches have been reported on the effects of winter cover crop and management on soil erosion. We assessed effects of ryegrass (Lolium multiflorum) as cover crop, green manure or mulching residue on soil erosion and quality through field and segment plot lysimeter experiments in alpine uplands. Ryegrass successfully adopted to winter in alpine region based on biomass, nutrient contents, and vigors of top and root systems. Incorporation of ryegrass into soil maintained soil fertility, nutrient uptake, and yield of cabbage exerting potential use as green manure. Cultivation of ryegrass suppressed occurrence of Chinese cabbage pests. Surface coverage by ryegrass as cover crop and mulching residue significantly reduced soil loss up to 96%, when combined with soil conservation management practices. Results revealed maintaining cover crop over winter was beneficial in reducing soil erosion, and sustaining soil quality and Chinese cabbage productivity. This study suggested winter cover crop, followed by green manure and mulching, and conservation tillage system could be one of the best management practices in alpine sloping uplands cultivating Chinese cabbage.

• Korean Journal of Environmental Agriculture
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• v.22 no.2
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• pp.111-117
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• 2003

Treatment of secondary effluent was investigated using sandy soil as a possible alternative to the tertiary treatment of municipal wastewater. Secondary effluent was applied with three different flow rates to the surface of pilot scaled lysimeters, which were filled with sandy soil. Some of the lysimeters were covered with osd, while others were kept bare in order to investigate the role of plantation on the treatment. The concentration changes in COD and nitrogen were measured along the unsaturated soil depth. The same set of experiment as with the secondary effluent was performed using tap water to investigate the dissolution of the contaminants from the soil. from the results it was found that when sandy soil was used for tertiary treatment of municipal wastewater COD removal efficiency reached about 70% regardless of the application rate. The soil depth needed to obtain such efficiency increased along with the application rate, which was about 60 cm at the application rate of 50 L/day. Results also showed that nitrification occurred rapidly. The process was completed in soil depth of first $10{\sim}20\;cm$. Nitrogen removal efficiency was as low as about 20% regardless of the application rate. Some supplementary means should be considered to improve the efficiency. Sod on the soil surface had no significant influence on the contaminant treatment but was helpful to keep the infiltration rate undiminished. Finally, the organic soil was found to release significant amount of contaminants when it was in contact with soil water.

• Korean Journal of Organic Agriculture
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• v.9 no.2
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• pp.101-115
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• 2001

Nitrogen applied as fertilizer for crop production is partly absorbed by plant , and the remaining nitrogen in soil might be leached out through complicated processes to the subsoil layer Especially, NO$_3$-N in leachate causes environmental pollution. The purpose of this study was focused on understanding of uptake of nutrients by plants, the behaviors of nutrients in soil and the possibility of leaching loss when nitrogen fertilizer and completely decomposed compost were applied. Lysimeters(Volume 0.15㎥, Diameter 62cm, Height 62.8cm) were installed for collecting leachate in the Jeju volcanic ash soils. Lysimeter study consisted of thirteen treatments : fallow, fallow with weeding, cropping without fertilizer and compost, three N fertilizer soil surface applications(16, 32, 64kg/10a), three N fertilizer and compost soil surface applications(16+800, 32+1600, 64+32kg/10a), two water dissolved N fertilizer applications(16, 32kg/10a), and low and high plant densities. N fertilizer was applied as urea. The growth of com(preceding crop) and potatoes(succeeding crop) and leaching loss were determined during the experimental period. The results obtained were summarized as follows ; With Increased N, pH of leachate tended to decrease and NO$_3$-N concentration of leachate increased. NO$_3$-N leaching loss was remarkably greater in soil from the bare plot without fertilization and the weed control than from plots with medium N rate and was least in the cropping plot without fertilization. NO$_3$-N concentration in leachates from the water dissolved N fertilizer application plots was 64% of that from the soil surface application plots. The concentration of Ca and K ions and the leaching loss of these ions were least from the cropping plot without fertilization and were greatest from bare plots(T1 and T2) without fertilization. The proportion of leaching and residual N in soil increased as N rate increased indicting that higher N rates increase the possibility of N leaching to subsoil layer The proportion of N leaching losses was lower at the low N rate and the high plant density. In future, fertilization prescription which can maximize fertilizer use efficiency and minimize the pollution of ground water will be needed for conserving the environments.

• Korean Journal of Remote Sensing
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• v.28 no.3
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• pp.277-285
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• 2012

The GOCI imagery can be an effective alternative to monitor short-term changes over terrestrial environments. This study aimed to assess the radiometric characteristics of the GOCI multispectral imagery for land applications. As an initial approach, we compared GOCI at-sensor radiance with MODIS data obtained simultaneously. Dynamic range of GOCI radiance was larger than MODIS over land area. Further, the at-sensor radiance over various land surface targets were tested by vicarious calibration. Surface reflectance were directly measured in field using a portable spectrometer and indirectly derived from the atmospherically corrected MODIS product over relatively homogeneous sites of desert, tidal flat, bare soil, and fallow crop fields. The GOCI radiance values were then simulated by radiative transfer model (6S). In overall, simulated radiance were very similar to the actual radiance extracted from GOCI data. Normalized difference vegetation index (NDVI) calculated from the GOCI bands 5 and 8 shows very close relationship with MODIS NDVI. In this study, the GOCI imagery has shown appropriate radiometric quality to be used for various land applications. Further works are needed to derive surface reflectance over land area after atmospheric correction.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.5
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• pp.53-58
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• 2020

The purpose of this study is to build a database of Spatial information Bigdata of cities using satellite images and spatial information, and to examine the correlations with the surface temperature. Using architectural structure and usage in building information, DEM and Slope topographical information for constructed with 300 × 300 mesh grids for Busan. The satellite image is used to prepare the Normalized Difference Built-up Index (NDBI), Normalized Difference Vegetation Index (NDVI), Bare Soil Index (BI), and Land Surface Temperature (LST). In addition, the building area in the grid was calculated and the building ratio was constructed to build the urban environment DB. In architectural structure, positive correlation was found in masonry and concrete structures. On the terrain, negative correlations were observed between DEM and slope. NDBI and BI were positively correlated, and NDVI was negatively correlated. The higher the Building ratio, the higher the surface temperature. It was found that the urban environment DB could be used as a basic data for urban environment analysis, and it was possible to quantitatively grasp the impact on the architecture and urban environment by adding local meteorological factors. This result is expected to be used as basic data for future urban environment planning and disaster prevention data construction.

• Journal of Korean Society of Forest Science
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• v.83 no.3
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• pp.391-399
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• 1994

This study was carried out to investigate the water storage charateristics of surface soil by different forest floor conditions and to measure water storage capacity of forest Land at the Yeungnam University forest in Yongjang-ri, Nenam-myoen, Kyongju-gun, Kyongsangbuk-do. The study was conducted for 4 months, from June to September, 1993. The results were summarized as follows ; 1. Infiltration capacity of surface soil for each. forest floor condition was in the order : Oak forest>Oak forest removed $A_o$ layer>Pine forest removed $A_o$ layer>Pine forest>Bare land>Grasses. 2. The absolute values of infiltration capacity were increased as the rain intensity increased, while the order of infiltration capacity for each floor condition was not changed. 3. Infiltration capacity was highly correlated with surface soil hardness and todal pores. 4. Infiltration formula based on the Horton's could be estimated at each forest floor condition. 5. The model for water storage capacity of forest land expressed by infiltration capacity was estimated using total pores and soil hardness. This study indicates water storage capacity of different forest floor conditions depends on infiltration capacity. Using these formula, it was possible to calculate and estimate water storage capacity of forest land. Therefore, the result of this study will be helpful to increase water storage capacity of forest land and to manage water resources effectively.

• Journal of Korean Society of Forest Science
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• v.24 no.1
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• pp.1-24
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• 1974

A national programme of erosion control for soil and water conservation needs to be based on factual information about rates and quantities of soil erosion and of water runoff. The best and simplest way of reducing sedimentation pollution is to prevent or control the erosion at its sources. Steeply sloping earth banks are liable to both surface erosion and land-slides and the key to the control of these form of erosion lies with drainages and dense vegetation establishment including surface mulching on the slopes. Micro-plots having $1.6m^2$ (1 metre in width and 1.6 metres in slope length, and 1:1.2 in gradient) of banking slopes on the coarse sand soil are used to establish the order of magnititude of the difference in controlling of soil erosion and water runoff, and in potentiality of execution in consideration of the values of landscapes, performed on the 2 repetetions of six-experiment plots consisted of five surface mulches including seedings and one bare slope as a control treatment. The main results obtained may be summarized as follows: 1. The significant difference is realized in the quantities of soil erosion between the measures of six treatments. 2. Excepting the differences between treatment III and VI, the significant difference is realized in the rate of surface runoff between each treatment measures. 3. Both measures of treatment II and IV are recognized as the most effective measures in controlling the soil erosion and water runoff and also in establishing the ground vegetation. (Treatment II is a measures of the coarse straw-mat mulchings on the micro-strip seedings, Treatment IV is a measures of the "SPRAY-ON method" on the micro-strip seedings). In consideration of the potentiality of execution as well as the value of landscapes, the measures of treatment II could be recommendable for establishing the vegetation cover on the denuded gentle slopes in hillsides while the measures of treatment IV could be suitable for accelerating the establishment of vegetation on steeply sloping earth banks and cuts.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.257-259
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• 2003

Landuse maps are prepared from satellite imagery and field observations were conducted at various locations in the study area. Compared to the field data and NDVI and RVI thematic maps, NDVI is better than RVI, because it compensates for changing illumination conditions, surface slope, aspect and other factors. Clouds, water and snow have negative values for RVI and NDVI. Rock and bare soils have similar reflectance in both NIR and visible band, so RVI and NDVI are near zero. In forest areas with good vegetation cover, NDVI is high and landslide occurrence is less. But if annual and biennial vegetations are present and if cultivation practices are changed frequently, NDVI is medium and landslide occurrence is moderate. In areas where deforestation and settlement is in progress, NDVI is less and landslide occurrence is more. The NDVI FCC thematic map may be used as an important layer in GIS application for landslide studies. Analyzing other layers such as slope, rainfall, soil, geology, drainage, lineament, etc with NDVI FCC layer will give a better idea about the identity of landslide prone areas.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.4
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• pp.39-50
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• 1998

The object of this study was to examine and analyze the environmental deterioration of three major trails and around peak area of Moaksan Provincial park in 1996. Trails are mostly made up at ridgeline and the slope of them is gentle. Mean trail width is 3.6m, and total length of branch trails is 982m in survey area. The environmental deterioration is derived from trail extension. Maximum eroded depth and cross-section area loss are 89cm and 14,050cm2 respectively, and gully erosion type appears at many sites. The environmental deterioration of trails is very heavy at the sections from Khui to Moaksan peak and from Moakchong to ascent part around the peak. The entire width, branch trail, maximum depth, cross-sectional area loss and surface roughness, as the indexes of trail conditions, are significantly greater at the more heavily used trails. Amount of erosion is influenced by eroded depth, longitudinal slope, runoff influence and entire width in descending order as well as the amount of use. Safety and protection facilities on the trail such as stone and soil stairs, rope handrail, stone channel and soil ditch work are built, but they are very deficient. Bared lands about 4,900m2 and fill slopes are caused and formed by recreation activities and constructions around peak area. It is required to carry the recess system and to conserve and rehabilitate the destroyed trail sites and bare fill slopes as soon as possible, before the environmental deterioration becomes critical because of increased used amount in consequence of construction of recreation parks.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.29-36
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• 2013

The objective of the research was to describe the effect of straw mat cover and soil amendments on the reduction of runoff and non-point source load from steep sloped highland agricultural fields. Four $5{\times}30$ m plots on sandy loam soil with 28 % slope were prepared. Experimental treatments were bare (control), rice straw mat cover (3,000 kg/ha) (S), PAM (5 kg/ha)+Gypsum (1 ton/ha) (PG) and rice straw mat cover+PAM+Gypsum (SPG). A variety of lettuce was cultivated and runoff was monitored during a growing season in 2011. Natural monitoring was conducted to three times. Runoff rate of S, PG and SPG plots were significantly lower than those of control plot. Especially, the runoff rate is zero in SPG plot at a first rainfall events. The reduction rate of runoff from the S, PG and SPG plots was 30.8 %, 29.0 % and 81.8 % compared to control plots, respectively. The reduction rate of NPS pollution load of S, PG and SPG was ranged of 50~90 %, 30~70 % and 90~100 %, respectively. Yield of lettuce from S, PG and SPG plots was respectively 400 (567 kg/ha), 320 (453 kg/ha) and 760 (1,067 kg/ha) that of compared to control plots greater than that from control plots (140 kg/ha). We speculated that the experimental treated plots could hold more nutrients and moisture than the control and helped the crop grow healthier. When analyzing the above results, in terms of reduction of runoff and NPS pollution load and crop yields, SPG experimental treatment had the best effect. It was concluded that the use of rice straw mats cover and soil amendments on soil surface could not only reduce the NPS pollution loads in receiving waters but also help increase the crop yield.