• Journal of the Korean association of regional geographers
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• v.18 no.4
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• pp.364-373
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• 2012

This study is to analyze distribution and change of montane meadows on the lava plateau in the east face of Mt. Baekdu. Process for aims carried out field survey, and analyzed landsat images of 1993, 1999, 2004, and year 2010. After research findings, the area of forests has increased by 33% from $636km^2$ to $848km^2$, montane meadow has decreased by 58% from $303km^2$ to $127km^2$ during 18 years. Montane meadows could be classified as 2 categories of wet meadow and dry meadow by the geomorphic environments and vegetation types. Wet meadow has decreased by 30%, dry meadow has decreased by 70% in the same period. Decreasing areas are replacing meadows with forests in invasion by trees and shrubs. According to the analysis with weather data for 16 years from 1993 to 2008, temperature has increased by $1.6^{\circ}C$, on the other hand, precipitation has decreased by 5.3mm. These kinds of climate change trends continue in the future, it could be change montane meadows into tree types.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.3
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• pp.145-156
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• 2024

Due to climate change and the expansion of cultivation areas through the use of reclaimed land, changes in the selection of Italian ryegrass (Lolium multiflorum L.) varieties are anticipated. This study was conducted to compare the growth characteristics before overwintering, productivity, and feed value of eight Italian ryegrass varieties with different maturing stages under the same cultivation conditions. The variety 'Lm4ho', a medium-maturing type, showed superior growth characteristics before overwintering, including plant height, leaf length, and leaf width. The heading date was advanced in all varieties, with a greater degree of advancement observed in varieties with earlier heading dates. When harvested at the heading stage of the early-maturing types, the dry matter yield of the medium-maturing types was not significantly different from that of the early-maturing types. However, when harvested at the heading stage of the medium-maturing types, the dry matter yield was higher than that of the early-maturing types. Specifically, 'Lm4ho' produced 2,518 kg/ha more than 'Kowinearly'. The late-maturing variety IR901 and the medium-maturing varieties 'Lm4ho' and 'Kowinmaster' showed statistically superior dry matter yields. In terms of forage value, including crude protein (CP), total digestible nutrients (TDN), and relative feed value (RFV), the medium- and late-maturing types outperformed the early-maturing types. Notably, 'Lm4ho', 'IR 901', and 'Hwasan 104' were evaluated as suitable varieties for high-quality forage production. These results suggest that medium-maturing varieties may be suitable for double cropping in the central regions due to climate change. We propose that future breeding of Italian ryegrass should expand from focusing on cold tolerance and early-maturing varieties to include medium- and late-maturing varieties that consider both productivity and quality.

• Journal of Ecology and Environment
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• v.39 no.1
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• pp.119-125
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• 2016

Mongolia has one of the strongest climate warming signals on Earth, and over 40% of the human population depends directly or indirectly on pastoral livestock production for their livelihoods. Thus, climate-driven changes in rangeland production will likely have a major effect on pastoral livelihoods . The loss of species dependent mostly on rainfall has resulted in adverse changes in the botanical composition of the steppes . Summer season in 2015 was completely dry until middle of July and, had not enough vegetation cover as last 15 years. The purpose of this study is to check plant community dynamics in Mongolia in relation to climate change in 2014 and 2015. The study sites were selected in mountain-steppe habitat in central Mongolia. In the 2014, there have been registered 81 plant species of 56 genera of 25 families on the investigated sites and, occurred 57 plant species of 44 genera of 21 families in the 2015. It is concluded that the abundance and richness of plants are directly connected to heavily affect by the climatic factor, i.e. amount of precipitation during growing season. As a same like result of climate change, in Mongolian land is going become desertification, and each spring, soil particles from Mongolia are swept up by a cold air mass into the atmosphere and blasts into south east China, Korea and Japan. The Koreans call this phenomenon the "Fifth season" or "Yellow sand", and the Chinese call it "Yellow dragon".

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.3
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• pp.785-794
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• 2014

Hydrologic responses in watershed are determined by complex interactions among climate, land use, soil and vegetation. In order to effectively investigate hydrologic response in watershed, one needs to analyze the characteristics of climate as well as other factors. In this study, the relative contribution of climate factors and watershed characteristics on hydrologic response is investigated by using hydrologic indexes such as the aridity index and the Horton index. From preliminary analysis, it is shown that the Horton index is proper in terms of classifying hydrologic responses in main natural watersheds of south Korea. While climate and watershed characteristics both contributes to hydrologic responses, the degree contributed from each factor is changed depending on annual climatic humid conditions. In dry conditions, the climate factor is the predominant influence on hydrologic responses. However, in wet conditions, the contribution of watershed characteristics on hydrologic responses is relatively increased.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.169-169
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• 2020

According to the IPCC analysis, severe climate changes are projected to occur in Korea as the temperature is expected to rise by 3.2 ℃, the precipitation by 15.6% and the sea level by 27cm by 2050. It is predicted that the occurrence of abnormal climate phenomena - especially those such as increase of concentrated precipitation and extreme heat in the summer season and severe drought in the winter season - that have happened in Korea in the past 30 years (1981-2010) will continuously be intensified and accelerated. As a result, the impact on and vulnerability of the water management sector is expected to be exacerbated. This research aims to predict the climate change impacts on streamflow of Daecheong Lake area of Geum River in South Korea during the summer and winter seasons, which show extreme meteorological events, and ultimately develop an integrated policy model in response. We projected and compared the streamflow changes of Daecheong Lake area of Geum River in South Korea in the near future period (2020-2040) and the far future period (2041-2060) with the reference period (1991-2010) using the HEC-HMS model. The data from a global climate model HadGEM2-AO, which is the fully-coupled atmosphere-ocean version of the Hadley Centre Global Environment Model 2, and RCP scenarios (RCP4.5 and RCP8.5) were used as inputs for the HEC-HMS model to identify the river basins where cases of extreme flooding or drought are likely to occur in the near and far future. The projections were made for the summer season (July-September) and the winter season(November-January) in order to reflect the summer monsoon and the dry winter. The results are anticipated to be used by policy makers for preparation of adaptation plans to secure water resources in the nation.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.516-516
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• 2022

Agricultural reservoirs are critical water resources structures to ensure continuous water supplies for rice cultivation in Korea. Climate change has increased the risk of reservoir failure by exacerbating discrepancies in upstream runoff generation, downstream irrigation water demands, and evaporation losses. In this study, the variations in water balance components of 400 major reservoirs during 1973-2017 were examined to identify the reservoirs with reliable storage capacities and resilience. A conceptual lumped hydrological model was used to transform the incident rainfall into the inflows entering the reservoirs and the paddy water balance model was used to estimate the irrigation water demand. Historical climate data analysis showed a sharp warming gradient during the last 45 years that was particularly evident in the central and southern regions of the country, which were also the main agricultural areas with high reservoir density. We noted a country-wide progressive increase in average annual cumulative rainfall, but the forcing mechanism of the rainfall increment and its spatial-temporal trends were not fully understood. Climate warming resulted in a significant increase in irrigation water demand, while heavy rains increased runoff generation in the reservoir watersheds. Most reservoirs had reliable storage capacities to meet the demands of a 10-year return frequency drought but the resilience of reservoirs gradually declined over time. This suggests that the recovery time of reservoirs from the failure state had increased which also signifies that the duration of the dry season has been prolonged while the wet season has become shorter and/or more intense. The watershed-irrigated area ratio (W-I_ratio) was critical and the results showed that a slight disruption in reservoir water balance under the influence of future climate change would seriously compromise the performance of reservoirs with W-I_ratio< 5.

• Journal of Astronomy and Space Sciences
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• v.41 no.1
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• pp.25-33
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• 2024

This paper evaluates the influence of rainfall on propagated signal at different time exceedance percentages of an average year, over the climate zones of the country. Specifically, it demonstrates critical and non critical signal fade or signal outage time exceedance (0.001% to 1%) for Ku, K, and Ka-band systems in an average year. The study was carried out using meteorological data made available by the Nigerian Meteorological Agency (NiMet) over a period of 10 years (2009-2018). The four climate zones in the country were represented by five (5) locations; Maidugiri (warm desert climate), Sokoto (tropical dry climate), Port Harcourt (tropical monsoon climate), Abuja and Enugu (tropical savanna climate). The parameters were simulated into the International Telecommunications Union Recommended (ITU-R) models for rain attenuation over the tropics and results presented using MatLab and Origin Lab. Results of Ku band propagations showed that only locations in the tropical savanna and tropical monsoon climates experienced total signal outage for time percentage exceedance equal to or below 0.01% for both horizontal and vertical polarizations. At K band propagations, the five locations showed to have experienced signal outage at time exceedance equal to and below 0.01%, almost same was recorded for the Ka-band propagation. It was also observed that horizontal and vertical polarization of signal had slightly different rain attenuation values for the studied bands at the five locations, with horizontal polarization having higher values than vertical polarization.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.5
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• pp.127-133
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• 2015

Recent worldwide trends are to develop the environmental friendly chemicals and processes in order to reduce the global warming and climate change phenomena. One of similar efforts in paper industry is to substitute the petroleum-based SBR latex by starch-based biobinder. The disadvantage of biobinder found through laboratory scale study was the lower dry pick strength than SBR latex. The objective of this study is to confirm the substitutability of SBR latex with biobinder through mill trial. Although biobinder itself gave lower dry pick strength, it was found that the use of SBR latex and biobinder mixture (50:50) could improve the dry pick strength. The introduction of biobinder into coating binder system improved the opacity of coated paper. Optical properties (brightness and whiteness), ink trapping, print gloss and mottling level of paper coated with biobinder system were similar to those of SBR latex.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.75-81
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• 1997

This study was wnducte to investigate the effects of treatment level and seasons of sluny hm bovine feces on the productivity of rye, N efficiency and improvement of soil fertility under the Korean climate condition. The results obtained fiom this study summarized as follows ; 1. The highest dry matter yield of rye was obtained in the partial fertilization of sluny in spring or autumn. There is no differences of dry matter yield between spring and autumn application. 2. With increasing the amount of slurry-N, the dry matter yield of rye was signigicantly increased up to 100Kg sluny Nha. As the level of slurry-N rises above about 100Kg N/ha, the maximal yield of dry matter was unchanged or declined. 3. As the level of sluny fertilization rises, the crude protein content of rye increases significantly. However the contents of crude protein was less affected by the application seasons. 4. The amount of nitrogen which produced 6om rye is dependent upon the level of slurry-N. The highest nitrogen yield of rye was obtained by the partial fertilization of sluny-N. 5. The season or amount of slurry treatments did not affect the organic matter content in soil. N-content in soil was the lowest by the partial fertilization of slurry in spring or autumn. However, N-content was increased with the higher level of sluny-N.

• Journal of Forest and Environmental Science
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• v.37 no.2
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• pp.128-140
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• 2021

Tropical dry forests are one of the most threatened, widely distributed ecosystems in tropics and estimation of forest biomass is a crucial component of global carbon emission estimation. Therefore, the present study was aimed to quantify the biomass and carbon storage in trees on large scale (10, 1 ha plots) in the dry mixed evergreen forest of Javadhu forest of Eastern Ghats. Biomass of adult (≥10 cm DBH) trees was estimated by non-harvest methods. The total biomass of trees in this tropical dry mixed evergreen forest was ranged from 160.02 to 250.8 Mg/ha, with a mean of 202.04±24.64 Mg/ha. Among the 62 tree species enumerated, Memecylon umbellatum accumulated greater biomass and carbon stocks (24.29%) more than the other species in the 10 ha study plots. ANOVA revealed that there existed a significant variation in the total biomass and carbon stock among the three plant types (Evergreen, brevi-deciduous and deciduous (F (2, 17)=15.343, p<0.001). Basal area and density was significant positively correlated with aboveground biomass (R² 0.980; 0.680) while species richness exhibited negative correlation with above ground biomass (R² 0.167). Finding of present study may be interpreted as most of the trees in this forest are yet to be matured and there is a net addition to standing biomass leading to carbon storage.