• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1277-1290
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• 2020

Water resources which is formed of surface and groundwater, are considered as one of the pivotal natural resources worldwide. Since last century, the rapid population growth as well as accelerated industrialization and explosive urbanization lead to boost demand for groundwater for domestic, industrial and agricultural use. In fact, better management of groundwater can play crucial role in sustainable development; therefore, determining accurate location of groundwater based groundwater potential mapping is indispensable. In recent years, integration of machine learning techniques, Geographical Information System (GIS) and Remote Sensing (RS) are popular and effective methods employed for groundwater potential mapping. For determining the status of the integrated approach, a systematic review of 94 directly relevant papers were carried out over the six previous years (2015-2020). According to the literature review, the number of studies published annually increased rapidly over time. The total study area spanned 15 countries, and 85.1% of studies focused on Iran, India, China, South Korea, and Iraq. 20 variables were found to be frequently involved in groundwater potential investigations, of which 9 factors are almost always present namely slope, lithology (geology), land use/land cover (LU/LC), drainage/river density, altitude (elevation), topographic wetness index (TWI), distance from river, rainfall, and aspect. The data integration was carried random forest, support vector machine and boost regression tree among the machine learning techniques. Our study shows that for optimal results, groundwater mapping must be used as a tool to complement field work, rather than a low-cost substitute. Consequently, more study should be conducted to enhance the generalization and precision of groundwater potential map.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.111-120
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• 2016

The objective of this study was to provide basic information for selecting the right timing and the right place of erosion control of stream on Gyeongsangnam-do. In order to achieve this objective, a total of 526 erosion control dams and 230 mountains stream conservation facilities on the constructed places and construction planned places for the erosion control were investigated on site, forest physiognomy, and hydrologic conditions. The erosion control dams and mountain stream conservation facilities were mostly constructed in the area, which has the sedimentary rock, 200-400m of altitude, a slope of 21~30°, and II of landslide hazard map. Among the forest environmental factors, it was only similar to the construction frequency in the areas that have small diameter class, III age class. Also, we investigated the hydrological environmental factors that determine the size and numbers of erosion control dam. The places constructed to the highest frequency were below 50ha in the area, 2.1~4.0km/㎢ of drainage density, longitudinal water system, 61~90mm of maximum precipitation per hour, and 201~300mm of day maximum precipitation. As the results, the sites and floodgate conditions between the constructed places and stream conservation facilities for the erosion control showed to be very similar. Therefore, these results indicate that the erosion control of the stream of the areas, which have the disruption of mountain peaks and the high erosion risk areas, should be used on both the erosion control dam and stream conservation facilities.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.187-194
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• 1986

Present stadies were carried out to obtain fundermental data for effective management of the soils by investigating the physicochemical characteristics rubber fiber, humification grade and bearing power of peats and muck which were included in Geongdeog series, and Gimje series in Honam area. The results abtained were as follows; 1. Humification grade of peats were about 23, while that of muck soils was about 45-71 and those were higher in Gimje series than Bongnam series. 2. The organic tiers which humification grade was higher were high pH, bulk density, and contents of K, $P_2O_5$, B.S and while were low OM, T-C, T-N, Na, $SiO_2$ and rubbed fiber. 3. In peats and mucks, bulk density, pH, contents of T-N $P_2O_5$ and ash were negatively correlated with rubbed fiber and OM, CEC, T-C, PAC, C/N, C/P were positively correlated with one, while these physicochemical characteristics were oppositely correlated with humification grade. 4. Cone bearing power of each soil tiers was low in every Geongdeog series which had the thick organic tiers and showed poorly drainage and it was the highest in Gimje series which was similar to in organic soils because of its thin organic tiers.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.3
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• pp.139-144
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• 2000

This study was conducted to obtain the basic information to increase the practical use of soil survey data through the subdividing of valley shapes with soil sequences due to different parent rocks, and to study the relationship between the valley shapes and parent rock. The various rocks such as sedimentary(gray shale and sand stone) and igneous rocks(granite, granite gneiss and andesite porphyry) which are the major parent rocks in Yeongnam area were investigated. The characteristics of valleys formed and the kinds of soils derived from different rocks were analysed by using aerial photographs and topographical maps scaled 1:5,000. The rill density in igneous rock area was as high as 40. But the rill bifurcation ratio of first order stream was higher in the sedimentary than the igneous rocks except granite area. The mean slope of valleys in igneous areas was about 8%, which was higher than that of the sedimentary areas. The variability of valley width in the complexly metamorphosed rock, such as granite gneiss, and andesite porphyry, was greater than in sedimentary and in granite rocks. Based on the variability of valley widths and valley slopes, it was possible to classify the valleys into two types. The "Uterus-shaped valleys" had wide variability of valley width and were located in the areas of granite gneiss and andesite porphry rocks. while the "Roots-shaped valleys" had narrow variability of valley width and were located in the sedimentary areas. "Uterus-shaped valleys" were typified by having land forms of mountain foot slopes and alluvial fans, and the soil drainage sequences also had complexities. So that, we concluded that the variability of valley width and valley slopes was associated with kinds of parent rocks and metamorphism which influences soil sequence and characteristics.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.80-87
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• 2010

This study was conducted to develop a reservoir modelling workflow to reproduce the heterogeneous distribution of effective permeability that impacts on the performance of SAGD (Steam Assisted Gravity Drainage), the in-situ bitumen recovery technique in the Athabasca Oil Sands. Lithologic facies distribution is the main cause of the heterogeneity in bitumen reservoirs in the study area. The target formation consists of sand with mudstone facies in a fluvial-to-estuary channel system, where the mudstone interrupts fluid flow and reduces effective permeability. In this study, the lithologic facies is classified into three classes having different characteristics of effective permeability, depending on the shapes of mudstones. The reservoir modelling workflow of this study consists of two main modules; facies modelling and permeability modelling. The facies modelling provides an identification of the three lithologic facies, using a stochastic approach, which mainly control the effective permeability. The permeability modelling populates mudstone volume fraction first, then transforms it into effective permeability. A series of flow simulations applied to mini-models of the lithologic facies obtains the transformation functions of the mudstone volume fraction into the effective permeability. Seismic data contribute to the facies modelling via providing prior probability of facies, which is incorporated in the facies models by geostatistical techniques. In particular, this study employs a probabilistic neural network utilising multiple seismic attributes in facies prediction that improves the prior probability of facies. The result of using the improved prior probability in facies modelling is compared to the conventional method using a single seismic attribute to demonstrate the improvement in the facies discrimination. Using P-wave velocity in combination with density in the multiple seismic attributes is the essence of the improved facies discrimination. This paper also discusses sand matrix porosity that makes P-wave velocity differ between the different facies in the study area, where the sand matrix porosity is uniquely evaluated using log-derived porosity, P-wave velocity and photographically-predicted mudstone volume.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.66-73
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• 2004

As one of the typical farming practices in the sloped upland in Pyeongchang and Hongcheon area, application of piling with coarse saprolite materials has been practiced by farmers for several reasons such as reduction of damage by monocropping, better development of plant roots, and better drainage. However, adverse effect on application of coarse saprolite soil materials to environmental aspects should not be ignored. Therefore, this research was conducted to evaluate the physicochemical properties of coarse saprolite materials in upland fields in Pyeongchang area. According to particle size distribution of coarse saprolite materials, averaged gravel contents for Pyeongchang and Hongcheon county were 16.7 and 25.3%, respectively. There was no significant difference in gravel contents by soil depth, and CV values for each particle size ranged from 20 to 40%, which implied that application of coarse material with similar properties. When we compared CEC values of dressed soil with or without considering gravel content, CEC values decreased as increasing gravel contents. The penetration resistances were 0.04-7.48 MPa at the 0 to 10 cm surface soil, and 0.10 to 8.80 MPa at the depth below 11 cm. The bulk density of the soil was $1.15g\;cm^{-3}$ at the surface soil and 1.29 to $1.35g\;cm^{-3}$ at the soil depth below 10 cm. The organic matter content, cation exchange capacity, and avaliable $P_2O_5$ concentrations of soil in upland where piling with saprolite materials of Pyeongchang area applied were $12.4g\;kg^{-1}$, $7.1cmol_c\;kg^{-1}$, and $526mg\;kg^{-1}$, respectively. Cation exchange capacity was lower than that of averaged Korean upland soil, while available $P_2O_5$ concentration was relatively higher than that of averaged Korean upland, which indicated high input of various fertilizers.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.246-250
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• 2003

In order to preserve the soundness of agro-ecosystem and products safety in agriculture, this study was evaluated environmental impact in relation to the INM (Integrated Nutrient Management) and IPM (Integrated Pest Management) at paddy fields at Ok-Chun and Yang-Pyung region. By introduction of INM with the application of BB(bulk-blanded) fertilizer based on soil analysis and IPM, the application rate of fertilizer was reduced to about $28.6{\sim}39.4%$ and the yield of brown rice was increased to about $3{\sim}10%$ compared to conventional practices. The concentrations of COD, $NH_4-N$, and $NO_3-N$ in irrigation water flowed to the environmental-friendly agriculture practices were 15.0, 0.67, and 1.39 mg/L, respectively. The concentrations of COD, $NH_4-N$, and $NO_3-N$ from paddy fields in drainage water were 12.4, 0.29, and 2.42 mg/L, respectively. The total number of the freshwater invertebrates was higher in field treated with fertilization by prescription with soil testing. Also, the population density of aquatic insects was higher than the other fields at both demonstration villages. In conclusion, it was possible to reduce the amount of fertilizer and agricultural chemicals application, and increase the yield of rice by application of the environmental-friendly agriculture practices.

• Journal of Environmental Policy
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• v.12 no.3
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• pp.21-47
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• 2013

The aim is to analysis landslide vulnerability in Inje, Korea, using GCI(Geospatial Correlative Integration) and probability rainfalls based on geographic information system (GIS). In order to achieve this goal, identified indicators influencing landslides based on literature review. We include indicators of exposure to climate(rainfall probability), sensitivity(slope, aspect, curvature, geology, topography, soil drainage, soil material, soil thickness and soil texture) and adaptive capacity(timber diameter, timber type, timber density and timber age). All data were collected, processed, and compiled in a spatial database using GIS. Karisan-ri that had experienced 470 landslides by Typhoon Ewinia in 2006 was selected for analysis and verification. The 50% of landslide data were randomly selected to use as training data, while the other 50% being used for verification. The probability of landslides for target years (1 year, 3 years, 10 years, 50 years, and 100 years) was calculated assuming that landslides are triggered by 3-day cumulative rainfalls of 449 mm. Results show that number of slope has comparatively strong influence on landslide damage. And inclination of $25{\sim}30^{\circ}C$, the highest correlation landslide. Improved previous landslide vulnerability methodology by adopting GCI. Also, vulnerability map provides meaningful information for decision makers regarding priority areas for implementing landslide mitigation policies.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.501-508
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• 2012

This study was carried out to compare species diversity of soil bacteria from Baekdudaegan mountain forests (Bonghwa-gun, Mungyeong-si and Sangju-si) in Gyeongsangbuk-do and to analyze the effects of soil environments on diversity and population of soil bacteria. Soil bacteria were isolated from soil samples by streak plate method, and identified by DNA extaction and 16S rDNA sequence analyses. The population of soil bacteria from the soil samples of Bonghwa-gun was the highest with $5.1{\times}10^5cfu/g$, and followed by those from Mungyeong-si and Sangju-si with $1.9{\times}10^5cfu/g$ and $1.1{\times}10^5cfu/g$, respectively. The population of soil bacteria from surface layer soil was the highest, and then gradually decreased according to soil depth. The increase in population of soil bacteria from soil samples of different sites was correlated with the increase of the altitude of soil sampling site, depth of A horizon, liquid phase among three phases of soil, water content and bulk density of soil. Two hundreds and sixty eight bacterial colonies from Bonghwa-gun were classified into 10 species, 8 genera. One hundred and thirty four bacterial colonies from Mungyeong-si were classified into 15 species, 9 genera. Forty four bacterial colonies from Sangju-si were classified into 5 species, 2 genera. The dominant species (occupancy rate) from Bonghwa-gun and Mungyeong-si were Bacillus weihenstephanensis (36% and 40%, respectively), and Sangju-si was Bacillus cereus (39%). The relationships between soil environment and community structure of soil bacteria were analyzed statistically by using ecological indices. The diversity, evenness and dominance indices of soil bacteria were 6.30, 2.04 and 0.59 in Bonghwa-gun, 9.09, 2.94 and 0.51 in Mungyeong-si, and 4.55, 2.34 and 0.71 in Sangju-si, respectively. The diversity and evenness indices were increased by the increase of water content, drainage condition and gravel content of soil, while the dominance index was decreased.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.4
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• pp.57-68
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• 1982

The paddy fiels slope located in Kangweon province Hwyongsung gun Gonggeun myon Shinchonri was considerably steep and so it was impossible to economically consolidate the field up to date. But for the porpose of farm mechanization, the field (32. 27ha) was consolidated by the auther under the assitance of the Ministry of Agriculture and Fishery and,;the Administration of Kangweon province. This paddy field consolidation was caused by the treatise on "Land-consolidation methods for farm mechanization in the steep-sloped paddy field", of which the auther is the same. The constrution was carried out from September, 1981 to April, 1982. During the 4esign and construction, some Peculiarities were found and discussed. That is, in design, besides the common condititions for a design, some special conditions were considered and written below; (1) The ranges of field slope in this design were 1/100-1/30. (2) Long sides of the land readjustment blocks must be arranged abreast contour line, and so they make the amount of cutting and banking decreased so as to take the maximum advantage of the configuration of the field. (3) In design, the main principles of dividing blocks were written below; i) First of all, long side of a block should be drawn straight abreast a contour line. ii) Long side of a block should arrange abreast contour line and make its length 100-150m, if not, l)reak the side in order to make a bended rectangle. iii) Length of a short side should be determinded within differences of elevation (0.6 -1. 2m) between the two adjacent blocks toward the normal to a contour line. iv) Length of a short side should be above 15m and the ratio of long and short side should be slso kept 1: (4-6). v) A new field surface leveling was determinded from the elevation which produce the least amount of cuttingand banking within the range of 0.6-1. 2m diffe rences of elevation between the two adjacent blocks. vi) In the course of dividing blocks with the same width along the line which was normal to a contour line, all blocks connot keep their shape in a retangle because of steep slope of the field and so on, and so it was also necessory to make some non-retanglar and small blocks such as a trianglar or trapezoidal shape, which was impossible to use some of farm machinery. But because this non-rectanglar and small blocks were divided, larger and many rectanglar blocks can be divided and construction cost can also be lowered. According to the conditions discussed above, the paddy field consolidation project designed and constructed. And the results of this study were obtained as below; (1) Three-forth of total cost of this paddy field consolidation was not construction cost, and these cost consist of land grading (1/4), road and canal construction cost (1/4) and the other cost (1/4) such as surveying or materials and 56 on. (2) The steeper the land slope, the greater cost was assigned for road and canal construction, and than land grading. (3) Curtailment of the road and canal construction cost depended on simplificating their strutures. (4) In the case of the land slopes were low, the land grading cost was high by 1: 1.4 in comparison with the road and canal construction cost, and conversely when the slops were steep, the road and canal construction cost was high by 1 : 5 in compa- rison with the land grading cost. (5) The densities of irrigation canal, drainage canal and trunk and branch road were 150. Sm/ha, 60. im/ha and 17. 4m/ha respectively. The density of irrigation canal of the area was high by 2 times in comparison with the average one of Kangweon Province, and the others were nearly the same. (6) Most farmers (above 85%) knew the effects of paddy field consolidation. The effects are; 1) Improvement of irrigation 2) Improvement of farm management 3) Improvement of transportarion 4) farm mechanization and 5) grouping of the scattered land. And the more farm modernization was accomplished by these projects, the more farmers wanted to live in their land. (7) In spite of the very steep sloped paddy field, the diminution rate of the net farm land caused by consolidation was 7.7% which was nearly the same as the one of Chulweon plain of Kangweon province. Land grading cost was 971, OOOwon/ha which was rather cheap by 13.2% than the one of Ghulweon plain, and unit construction cost was 5, 341, OOOwon/ha (included soil addition) which was also nearly the same as the one of Chulweon plain and FNFIA (The federation of national farmland improvement association).