• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.26-37
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• 1992

Fifty-five field experiments were conducted in order to find out some useful indices for the prediction of N-supplying capability(NSC) of soils under cultivation of corn in Pennsylvania over 3 years from 1986. Contents of $NO_3-N$, absorbance at 200 nm of the extract from soil with 0.01M $NaHCO_3$ were identified to be used as indices before planting. Methods for the estimation of organic nitrogen available later in the growing season(KCLA-N, PBBA-N, UV260 nm absorbance of $NaHCO_3$ extract) were not to be used as good indices individually, but when those are combined together with inorganic $NO_3-N$ showed a highly significant correlationship with the NSC. The year of an even distribution of rainfall, 1987, gave the highest significant correlationship between NSC and the indices. For soils of the same texture with slightly different physical properties, combined indices obtained from physico-chemical factors improved the degree of predictability when the grades of soil slope, depth of Ap were considered at the same time. More futher researches such as this need to be done before any conclusive result can be drawn.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.4
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• pp.274-281
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• 2005

The climate of the Uisong Area is wet in the heat of summer and cold and dry in winter, The climate is highly consistent. The typical forest soil of the Uisong Area has an acidity of pH 4.5-5.6. The thickness of soil A layers is thin to an average of 10-20 cm and is a typical brown forest soil type. The growth characteristic of this climate and soil environment is as follows. In the case of Larix leptolepis, it takes 5-9 years to reach 6 cm diameter, The annual growth rate falls off greatly at an age of 17-19 years. The change of annual rings is more apparent on the north slopes compared with the east and northeast slopes. Pinus rigida takes 7-9 years to reach a 6 cm diameter. Annual growth rates of Pinus rigida fall greatly when age reaches 19 years. The change of annual ring growth of Pinus rigida was most apparent in the west and northeast slopes compared with the south and east slopes. In the case of Pinus koraiensis, the change of the annual ring width according to the characteristics of the slope is not important. Pinus koraiensis takes 6 yearsto reach the 6cm diameter, and annual growth rate fell off at age 19 years. In the case of Quercus acutissima, the growth of the valley trees is more stable than for trees grown at the mountain base. Annual growth rate of Quercus autissima fell off 19 years after planting. Ring growth of Robinia pseudo-acasia on northeast slopes appears much like that on northwest slopes. In conclusion, the main silviculture species reaches a 6 cm diameter in 5-9 years of growth, and the annual growth rate begins to fall between years 13 and 19 in the Uisong Area.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.1
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• pp.1-7
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• 2000

Management of phosphorus availability in the plastic film house soils in Korea merits attention because salts have been accumulated for last decades due to the heavy application of fertilizers and intensive cropping practices. In an attempt to characterize the P availability, available phosphorus contents and electrical conductivity of the saturated extracts ($EC_e$) were measured for soils collected from the 169 plastic film houses in Kangwon-do. Soil phosphorus contents were analyzed by methods of Lancaster, Bray No. 1, Olsen, Truog, water extractable and saturation extracts. Phosphorus concentrations in the saturated extracts of the plastic film house soils ranged from 0.02 to $34mg\;L^{-1}$, with the average of $8mg\;L^{-1}$. The available $P_2O_5$ of the soils ranged from 136 to $3,689mg\;Kg^{-1}$, with the average of $1,261mg\;Kg^{-1}$. The water soluble $P_2O_5$ ranged from 2 to $118mg\;L^{-1}$, with the average of $39mg\;L^{-1}$. A significant correlation existed between saturation extract P (Y) and available $P_2O_5$ (X) [Y = -5.075 + 0.018X, $r=0.662^{***}$] indicating $1.0mg\;P\;L^{-1}$ of in the saturated extract was equivalent to $337mg\;Kg^{-1}$ of the available $P_2O_5$ by Lancaster method. Electrical conductivity of the saturated pastes ($EC_e$) was highly significantly correlated with EC (1:5), yielding the slope of 12.2 for the coarse textured plastic film house soils. Results of higher concentrations of available P in soil solution and dilution factor of 12.2 for $EC_e$ demonstrate that a special care must be taken in terms of fertilizer management and data interpretation for soils under this specific condition.

• Journal of the Korean Geographical Society
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• v.28 no.1
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• pp.1-15
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• 1993

This research aims to investigate some respects of chemical weathering processes, espcially the amount of solute leaching, formation of clay minerals, and the chemical weathering rate of granite rocks under present climatic conditions. For this purpose, I investigated geochemical mass balance in a small catchment and the mineralogical composition of weathered bedrocks including clay mineral assemblages at four res-pective sites along one slope. The geochemical mass blance for major elements of rock forming minerals was calculated from precipitation and streamwater data which are measured every week for one year. The study area is a climatically and litholo-gically homogeneous small catchment($3.62Km^2$)in Anyang-shi, Kyounggi-do, Korea. The be-drock of this area id Anyang Granite which is composed of coarse-giained, pink-colored miner-als. Main rock forming minerals are quartz, K-Feldspar, albite, and muscovite. One of the chracteristics of this granite rock is that its amount of Ca and Mg is much lower than other granite rock. The leaching pattern in the weathering profiles is in close reltion to the geochemical mass balance. Therefore the removal or accumulation of dissolved materials shows weathering patterns of granite in the Korean peninsula. Oversupplied ions into the drainage basin were $H^+$, $K^+$, Fe, and Mn, whereas $Na^2+$, $Mg^2+$, $Ca^2+$, Si, Al and $HCO-3^{-}$ were removed from the basin by the stream. The consumption of hydrogen ion in the catchment implies the hydrolysis of minerals. The surplus of $K^+$ reflects that vegetation is in the aggravation stage, and the nutrient cycle of the forest in study area did not reach a stable state. And it can be also presumed that the accumulation of $K^+$ in the top soil is related to the surplus of $K^+$. Oversupplied Fe and Mn were presumed to accumulate in soil by forming metallic oxide and hydroxide. In the opposite, the removal of $Na^+$, Si, Al resulted from the chemical weathering of albite and biotite, and the amount of removal of $Na^+$, Si, Al reflected the weathering rate of the bedrock. But $Ca^2+$ and $Mg^2+$ in stream water were contaminated by the scattered calcareous structures over the surface. Kaolinite is a stable clay mineral under the present environment by the thermodynamical analysis of the hydrogeochemical data and Tardy's Re value. But this result was quite different from the real assemblage of clay miner-als in soil and weathered bedrock. This differ-ence can be explained by the microenvironment in the weathering profile and the seasonal variation of climatic factors. There are different clay forming environments in the stydy area and these differences originate from the seasonal variation of climate, especially the flushing rate in the weathering profile. As it can be known from the results of the analysis of thermodynamic stability and characteristics of geochemical mas balance, the climate during winter and fall, when it is characterized by the low flushing rate and high solute influx, shows the environmental characteristics to from 2:1 clay minerals, such as illite, smectite, vermiculite and mixed layer clay minerals which are formed by neoformation or transformation from the primary or secondary minerals. During the summer and spring periods, kaoli-nite is a stable forming mineral. However it should consider that the other clay minerals can transformed into kaolinite or other clay minerals, because these periods have a high flushing rte and temperature. Materials which are directly regulated by chemical weathering in the weathered bedrock are $Na^+$, Si, and Al. The leaching of Al is, however, highly restricted and used to form a clay mineral, and that of Si falls under the same category. $Na^+$ is not taked up by growing veget ation, and fixed in the weathering profile by forming secondary minerals. Therefore the budget of $Na^+$ is a good indicator for the chemical weathering rate in the study area. The amount of chemical weathering of granite rocks was about 31.31g/$m^2+$/year based on $Na^+$ estimation.

• Journal of Korean Society of Forest Science
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• v.23 no.1
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• pp.29-33
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• 1974

U-Reuk, a laureate musician in the days of King Jin-Heung, Silla Dynasty, built the Eui Rim Reservoir about 1,400 years ago. This was one of the oldest man-made reservoir. The embankment of the reservoir collapsed by the clumsy artificial drainage on August 19, 1972 when the heavy rainfall of 462 mm/day caused a dangerous overflow of the reservoir. The result of the study on the mystic ancient embankment techniques are as follows: 1. Sandy loam derived from the weathering of granite which is the most widely distributed rock type in the area, was used in the embankment. Large size logs (embankment core) of 30-50 cm in diameter were buried lengthwise along the embankment. 2. The six stocks of Pinus densiflora, 3 stocks of Quercus acutissima, 1 stock of Quercus variabilis and 1 stock of Popolus maximowiczii, altogether 11 stocks are identified. Forest types in the nearby area during the days of the reservoir construction seem to be includde a considerable number of Pinus densiflora, Quercus and Populus species. 3. The angle of repose of the earth materials is taken into account during the embankment. On top of the embankment double layers of clay (20-30 cm indepth) were spread and consolidated. Layer of litter of 20-40 cm in deep covered on the clay layer of the embankment completely, and another layer of clay was consolidated over the litter. Finally, a layer of stones of 10-30 cm in diameter and clay (yellow soil layer) toped the embankment. 4. At the lower part of the embankment clay layer was thicker and became thinner as it goes upwards. At every layer, soil was consolidated and burned. When embankment was completed, it was covered evenly with heavy clay, and finally it was topped with general soil. 5. The heavy clay layer on the inner slope of the embankment showed gray phenomena and litter remained raw humus layer. The clay layer functioned as rubber in the water, and raw humus layer prevented water from seepages. Thus, the embankment was solidly built in this way. 6. The ancient embankment techniques used soils conveyed from nearby area taking the angle of repose into account. Once embankment was completed, clay and litter layers were added to have a plasticity and to withstand the water pressure. 7. It is an excellent technique that the reservoir was constructed with least labor for maximum effects while the recent embankment techniques requires a large amount of labor.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.74-85
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• 2020

Darangnon in Gachon Village, Namhae-gun, Gyeongsangnam-do, is the first designated environment among Korea's industrial-based historical and cultural sites and is still the only one that involves agricultural activities. Although the stonework, which is the infrastructure environment here, has limitations that inevitably lead to natural and artificial deformation due to its nature, there has been no research to consider the situation so far. As of the end of May 2020, this study investigated and analyzed the damage in the sub-area of the survey, which is approximately 30% of the scope of the designation of the scenic spot, from a quantitative and qualitative perspective. As a result of the study, the state of loss, which reveals the physical damage of the arctic rice paddy stone retaining wall in the environment under investigation, was particularly serious around the coast, in the northern area with high slopes, and near tourist information centers and parking lots. On the other hand, the qualitative aspect of the damage to the stonework was noticeable in the repair of heterogeneous materials on the stone retaining wall adjacent to the village and parking lot, and the landscape damage caused by the cladding of plants was found in an environment far away from the residence. In addition, natural environmental factors such as slopes, elevations, and soil showed a close relationship with the degree of physical damage of the stone retaining wall, the higher the slope, the higher the elevation, and the better the soil drainage, the greater the impact. These results suggest that humanities environmental factors such as cultivation activities and management entities have important factors in the physical damage and management of stone retaining wall. Therefore, it is deemed essential to find management measures with local residents along with improving the agricultural environment, such as securing agricultural water and soil improvement, for the preservation of tuna paddies and stone retaining wall in the future.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.138-164
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• 2022

The Neolithic shell midden in Daejuk-ri, Seosan, is distributed on the gentle slope of a low hill close to the west coast. The bedrock of the area consists mainly of schist with various mafic minerals, but shows a partial gneiss pattern. The site consists of loamy topsoil and clay loam subsoil, and the degree of siallization is relatively low. Although the pottery excavated from the shell midden shares mostly similar features, a variety of shapes and patterns coexist. The surface colors, thickness and physical properties are slightly different. The pottery can be subdivided into three types (IA, IB and II) according to the composition of the body clay, the temper and the existence of a black core. Types IA and IB are colorless mineral pottery with a non-black or black core respectively. TypeII is colored mineral pottery with a non-black core. Type I pottery also contains non-plastic colored minerals, but type II contains a large amount of biotite, chlorite, talc, amphibole, diopside and tremolite, which include a large amount of Mg and Fe. The studied pottery contains a small amount of organic matter. Considering the grain size and relatively poor sorting and roundness of the non-plastic particles, the pottery appears to be made by adding coarse non-plastic tempers for special purposes to the untreated weathered soil around the site. The three types of pottery seem to have been incompletely fired in general. While type IB has the lowest degree of oxidation, typeII shows the highest degree of redness and oxidation. It can be interpreted that these differences depend on the firing temperature and the ratio of non-plastic particles. Through a synthesis of the minerals, geochemical data and thermal history, it can be determined that the firing temperature ranged from 600 to 700℃. The pottery types of the Daejuk-ri Shell Midden have slightly different production conditions, mineral compositions, and physical properties, but have undergone similar production processes with basically the same clay materials. The clay is almost identical to the composition of the bedrock and weathered soil distributed in the Daejuk-ri area. Currently, there is an industrial complex in the area, so it is difficult to confirm the soil and geological distribution of the site. However, it is highly probable that the area around the site was self-sufficient for the clay and tempers required for the production of the Neolithic pottery. Therefore, it can be interpreted that the group that left the shell midden in Daejuk-ri lived near the site, visited the site for the purpose of collecting and processing shellfish, and discarded the broken pottery along with shells.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.400-412
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• 2023

In this study, the biogeochemistry management (BGC-MAN) model was applied to North and South Korea pine and oak forest stands to evaluate the Net Primary Productivity (NPP), an indicator of forest ecosystem productivity. For meteorological information, historical records and East Asian climate scenario data of Shared Socioeconomic Pathways (SSPs) were used. For vegetation information, pine (Pinus densiflora) and oak(Quercus spp.) forest stands were selected at the Gwangneung and Seolmacheon in South Korea and Sariwon, Sohung, Haeju, Jongju, and Wonsan, which are known to have tree nurseries in North Korea. Among the biophysical information, we used the elevation model for topographic data such as longitude, altitude, and slope direction, and the global soil database for soil data. For management factors, we considered the destruction of forests in North and South Korea due to the Korean War in 1950 and the subsequent reforestation process. The overall mean value of simulated NPP from 1991 to 2100 was 5.17 Mg C ha^-1, with a range of 3.30-8.19 Mg C ha^-1. In addition, increased variability in climate scenarios resulted in variations in forest productivity, with a notable decline in the growth of pine forests. The applicability of the BGC-MAN model to the Korean Peninsula was examined at a time when the ecosystem process-based models were becoming increasingly important due to climate change. In this study, the data on the effects of climate change disturbances on forest ecosystems that was analyzed was limited; therefore, future modeling methods should be improved to simulate more precise ecosystem changes across the Korean Peninsula through process-based models.

• Proceedings of the Korean Geotechical Society Conference
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• 1991.10a
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• pp.87-102
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• 1991

It has been reported that the failure of Carsington Dam in Eng1and occured due to the existence of a thin yellow clay layer which was not identified during the design work, and due to pre-existing shears of the clay layer. The slope stability analyses during the design work, which utilized traditional circular arc type failure method and neglected the existence of the clay layer, showed a safety factor of 1.4. However, the post-failure analyses which utilized translational failure mode considering the clay layer and the pre-existing shear deformation revealed the reduction of safety factor to unity. The post-failure analysis assumed 10。 inclination of the horizontal forces onto each slice based on the results of finite element analyses. In this paper, Bishop's simplified method, Janbu method, and Morgenstern-Price method were used for the comparison of both circular and translational failure analysis methods. The effects of the pre-existing shears and subsquent movement were also considered by varying the soil strength parameters and the pore pressure ratio according to the given soi1 parameters. The results showed factor of safefy 1.387 by Bishop's simplified method(STABL) which assumed circular arc failure surface and disregarding yellow clay layer and pre-failure material properties. Also the results showed factor of safety 1.093 by Janbu method(STABL) and 0.969 by Morgenstern-Price method(MALE) which assumed wedge failure surface and considerd yellow clay layer using post failure material properties. In addition, dam behavior was simulated by Cam-Clay model FEM program. The effects of pore pressure changes with loading and consolidation, and strength reduction near or at failure were also considered based on properly assumed stress-strain relationship and pore pressure characteristics. The results showed that the failure was initiated at the yellow clay layer and propagated through other zones by showing that stress and displacement were concentrated at the yel1ow clay layer.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.219-232
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• 2012

The purpose of this study was to find characteristics of $Pinus$ $densiflora$ forests in previous records and cultural landscape regions and to establish a management method for recovery of $P.$ $densiflora$ landscape. A total of 16 landscape paintings were analyzed to study $P.$ $densiflora$ forests in Inwangsan(Mt.) shown in figure data. As a result of analyzing figure data, $P.$ $densiflora$ $forests$ were found to be distributed mainly in the ridge line of east slope side of Inwangsan(Mt.) from landscape paintings of Jung Seon, Jang Si Heung and Gang Hee Un. In order to analyze the landscape of $P.$ $densiflora$ forests shown in photograph data on Inwangsan(Mt.), photographs of Inwangsan(Mt.) since late 1800s were searched and a total of 24 photographs were used for analysis. As a result of photographic analysis, $P.$ $densiflora$ forests were found to be distributed mainly in the low area and ridge line of western slope side of Inwangsan(Mt.). As a result of analyzing the distribution status of 10 cultural heritages of Inwangsan(Mt.), cultural heritages in the mountain were mainly established with rocks and $P.$ $densiflora$ forests as the background and are establishing their landscape not only as a form of cultural heritage but also including the natural landscape in the background. A method of restoring cultural landscape of P. densiflora forests was necessary. As a result of analyzing 26 rock beds of Inwangsan(Mt.), most of $P.$ $densiflora$ forests were distributed nearby rock beds since the past. Among such regions, restoration and management of introduced species in the accumulated soil regions to $P.$ $densiflora$ forests were deemed necessary. As a result of analyzing current vegetation of $P.$ $densiflora$ forest areas of the past, 51.87% of areas maintained $P.$ $densiflora$ forest and 25.80% were changed to artificial forests. Most of low areas of the mountain were turned into urban area (10.16%). Management type for restoration of $P.$ $densiflora$ landscape of Inwangsan(Mt.) was classified into preservation, $P.$ $densiflora$ restoration and maintenance. Preservation management was configured as $P.$ $densiflora$ distribution and rocky area distribution. The targets of $P.$ $densiflora$ restoration were indigenous broad-leaf trees, vegetation areas with introduced species and damaged regions within the mountain. The targets of maintenance were urban area in the low area of Inwangsan(Mt.) and military base at the top of the mountain.