• Title/Summary/Keyword: environmental problems

Search Result 5,646, Processing Time 0.039 seconds

Neutralization of Acidity and Ionic Composition of Rainwater in Taean (태안지역 강우의 산성도 중화 및 화학성 평가)

  • Lee, Jong-Sik;Kim, Min-Kyeong;Park, Seong-Jin;Choi, Chul-Mann;Jung, Tae-Woo;Jung, Im-Young
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.42 no.5
    • /
    • pp.336-340
    • /
    • 2009
  • The issue of acid precipitation and related environmental problems in East Asia has been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during cultivation season from April to October were investigated at Taean in 2007. Also, to estimate the contribution of ions on its acidity, ion composition characteristics and neutralization effects by cation ions were determined. The ion balance between cations and anions values showed high correlation. The mean values of pH and EC were 4.9 and $32.9{\mu}S\;cm^{-1}$, respectively. The EC of rainwater showed seasonal characteristic, which was $91.4{\mu}S\;cm^{-1}$ with relatively low rainfall compared with other monitoring periods. $Na^+$ was the main cation followed by $NH_4{^+}$ > $Ca^{2+}$ > $H^{+}$ > $Mg^{2+}$ > $K^+$. Among these ions, $Na^{+}$ and $NH_4{^+}$ covered over 70% of total cations. In the case of anion, the order was $SO_4{^{2-}}$ > $NO_3{^-}$ > $Cl^{-}$. The mean value of sulfate, which is main anion component in the samples was $152.1{\mu}eq\;L^{-1}$. Also, 90% of soluble sulfate in rainwater was $nss-SO_4{^{2-}}$(non-sea salt sulfate). With fractional acidity and theoretical acidity of rainwater samples, $NH_4{^+}$ and $Ca^{2+}$ contributed greatly in neutralizing the rain acidity.

Overview and Prospective of Satellite Chlorophyll-a Concentration Retrieval Algorithms Suitable for Coastal Turbid Sea Waters (연안 혼탁 해수에 적합한 위성 클로로필-a 농도 산출 알고리즘 개관과 전망)

  • Park, Ji-Eun;Park, Kyung-Ae;Lee, Ji-Hyun
    • Journal of the Korean earth science society
    • /
    • v.42 no.3
    • /
    • pp.247-263
    • /
    • 2021
  • Climate change has been accelerating in coastal waters recently; therefore, the importance of coastal environmental monitoring is also increasing. Chlorophyll-a concentration, an important marine variable, in the surface layer of the global ocean has been retrieved for decades through various ocean color satellites and utilized in various research fields. However, the commonly used chlorophyll-a concentration algorithm is only suitable for application in clear water and cannot be applied to turbid waters because significant errors are caused by differences in their distinct components and optical properties. In addition, designing a standard algorithm for coastal waters is difficult because of differences in various optical characteristics depending on the coastal area. To overcome this problem, various algorithms have been developed and used considering the components and the variations in the optical properties of coastal waters with high turbidity. Chlorophyll-a concentration retrieval algorithms can be categorized into empirical algorithms, semi-analytic algorithms, and machine learning algorithms. These algorithms mainly use the blue-green band ratio based on the reflective spectrum of sea water as the basic form. In constrast, algorithms developed for turbid water utilizes the green-red band ratio, the red-near-infrared band ratio, and the inherent optical properties to compensate for the effect of dissolved organisms and suspended sediments in coastal area. Reliable retrieval of satellite chlorophyll-a concentration from turbid waters is essential for monitoring the coastal environment and understanding changes in the marine ecosystem. Therefore, this study summarizes the pre-existing algorithms that have been utilized for monitoring turbid Case 2 water and presents the problems associated with the mornitoring and study of seas around the Korean Peninsula. We also summarize the prospective for future ocean color satellites, which can yield more accurate and diverse results regarding the ecological environment with the development of multi-spectral and hyperspectral sensors.

Development of Carbon Dioxide Emission Factor from Resource Recovery Facility (폐기물자원회수시설의 이산화탄소 배출계수 개발)

  • Kim, Seungjin;Im, Gikyo;Yi, Chi-Yeong;Lee, Seehyung;Sa, Jae-Hwan;Jeon, Eui-Chan
    • Journal of Climate Change Research
    • /
    • v.4 no.1
    • /
    • pp.51-61
    • /
    • 2013
  • To address the problems associated with climate change and energy shortage, Korea has been making efforts to turn waste materials into usable energy. Due to the ongoing efforts to convert waste materials into energy, waste incineration is expanding to utilize the heat generated, and the subsequent greenhouse gas emissions from these waste material incineration are expected to increase. In this study, a municipal waste incineration plant that generates heat and electricity through heat recovery was selected as a subject facility. Methods for estimating the greenhouse gas emissions in the municipal waste incineration plant that was selected as a subject plant were sought, and the greenhouse gas emissions and emission factor were estimated. The $CO_2$ concentrations in discharge gas from the subject facility were on average 6.99%, and the result from calculating this into greenhouse gas emissions showed that the total amount of emissions was $254.60ton\;CO_2/day$. The net emissions, excluding the amount of greenhouse gas emitted from biomass incineration, was shown to be $110.59ton\;CO_2/day$. In addition, after estimating the emissions by separating the heat and electricity generated in the incineration facility, greenhouse gas emission factors were calculated using the greenhouse gas emissions produced per each unit of output. The estimated emission factor for heat was found to be $0.047ton\;CO_2/GJ$ and the emission factor for electricity was found to be $0.652ton\;CO_2/MWh$. The estimated emission factor was shown to be about 17% lower than the $0.783ton\;CO_2/MWh$ emission factor for thermal power plants that use fossil fuels. Waste material types and fossil carbon contents were evaluated as being the factors that have major effects on the greenhouse gas emissions and emission factor.

A Study on the Conditions of Natural Damage of Undesignated Cultural Heritages and the Plans to Reduce Damage through Vegetation Management - With Emphasis on Samcheonsaji Temple Site on Mt. Bukhansan - (비지정 문화유적의 훼손현황과 식생관리를 통한 저감방안 연구 -북한산 삼천사지를 사례로-)

  • Hong, Hee-taek;Kim, Hyeon-beom;Lee, Mun-haeng
    • Korean Journal of Heritage: History & Science
    • /
    • v.46 no.3
    • /
    • pp.114-133
    • /
    • 2013
  • This study aims to identify the natural damage of the Samcheonsaji Temple Site in Bukhansan National Park and to suggest the plans to minimize damage for the remains. The types of natural damage are classified into direct vegetation damage, indirect topographical damage, and artificial damage. The most popular causes of damage to temple sites include the roots of trees as direct vegetation damage and the soil erosion by rain or stream as topographical damage. Direct vegetation damage includes burial remains damaged by the root of trees and vines, but it is often observed that some trees have contributed to protection against collapse. Indirect topographical changes have damaged the ruins by soil erosion caused by floods or typhoons. Vegetation changes due to topographical reasons have also caused damage. Artificial reasons of damage include forestry operations and compaction by hikers. Based on the analysis of the findings, the following could be suggested as plans to resolve these problems: 1. Natural damage occurs slowly due to negligence. Therefore, it could be reduced by forestry improvement, including forest density control through thinning, planting to prevent landslides, maintaining grasslands nearby. 2. Deciduous broadleaf trees can be planted to reduce soil erosion by rainfall. It is necessary to maintain the density of forests at around $0.02{\sim}0.18trees/m^2$. 3. It would be good to grow Quercus spp and Carpinus spp or weaken the community of Robinia pseudoacacia and Pueraria lobata which disturb the ecosystem. Samcheonsaji Temple Site is located in Mt. Bukhan National Park that is a publicly owned property. Therefore, it is constantly maintained for natural preservation and vegetation management could be considered for the preservation of historical remains.

Accuracy Analysis of Target Recognition according to EOC Conditions (Target Occlusion and Depression Angle) using MSTAR Data (MSTAR 자료를 이용한 EOC 조건(표적 폐색 및 촬영부각)에 따른 표적인식 정확도 분석)

  • Kim, Sang-Wan;Han, Ahrim;Cho, Keunhoo;Kim, Donghan;Park, Sang-Eun
    • Korean Journal of Remote Sensing
    • /
    • v.35 no.3
    • /
    • pp.457-470
    • /
    • 2019
  • Automatic Target Recognition (ATR) using Synthetic Aperture Radar (SAR) has been attracted attention in the fields of surveillance, reconnaissance, and national security due to its advantage of all-weather and day-and-night imaging capabilities. However, there have been some difficulties in automatically identifying targets in real situation due to various observational and environmental conditions. In this paper, ATR problems in Extended Operating Conditions (EOC) were investigated. In particular, we considered partial occlusions of the target (10% to 50%) and differences in the depression angle between training ($17^{\circ}$) and test data ($30^{\circ}$ and $45^{\circ}$). To simulate various occlusion conditions, SARBake algorithm was applied to Moving and Stationary Target Acquisition and Recognition (MSTAR) images. The ATR accuracies were evaluated by using the template matching and Adaboost algorithms. Experimental results on the depression angle showed that the target identification rate of the two algorithms decreased by more than 30% from the depression angle of $45^{\circ}$ to $30^{\circ}$. The accuracy of template matching was about 75.88% while Adaboost showed better results with an accuracy of about 86.80%. In the case of partial occlusion, the accuracy of template matching decreased significantly even in the slight occlusion (from 95.77% under no occlusion to 52.69% under 10% occlusion). The Adaboost algorithm showed better performance with an accuracy of 85.16% in no occlusion condition and 68.48% in 10% occlusion condition. Even in the 50% occlusion condition, the Adaboost provided an accuracy of 52.48%, which was much higher than the template matching (less than 30% under 50% occlusion).

Global Rice Production, Consumption and Trade: Trends and Future Directions

  • Bhandari, Humnath
    • Proceedings of the Korean Society of Crop Science Conference
    • /
    • 2019.09a
    • /
    • pp.5-5
    • /
    • 2019
  • The objectives of this paper are (i) to analyze past trends and future directions of rice production, consumption and trade across the world and (ii) to discuss emerging challenges and future directions in the global rice industry. Rice is a staple food of over half of the world's 7.7 billion people. It is an important economic, social, political, and cultural commodity in most Asian countries. Rice is the $1^{st}$ most widely consumed, $2^{nd}$ largely produced, and $3^{rd}$ most widely grown food crop in the world. It was cultivated by 144 million farms in over 100 countries with harvested area of over 163 million ha producing about 745 million tons paddy in 2018. About 90% of the total rice is produced in Asia. China and India, the biggest rice producers, account for over half of the world's rice production. Between 1960 and 2018, world rice production increased over threefold from 221 to 745 million tons (2.1% per year) due to area expansion from 120 to 163 million ha (0.5% per year) and paddy yield increase from 1.8 to 4.6 t/ha (1.6% per year). The Green Revolution led massive increase in rice production prevented famines, provided food for millions of people, reduced poverty and hunger, and improved livelihoods of millions of Asians. The future increase in rice production must come from yield increase as the scope for area expansion is limited. Rice is the most widely consumed food crop. The world's average per capita milled rice consumption is 64 kilograms providing 19% of daily calories. Asia accounted for 84% of global consumption followed by Africa (7%), South America (3%), and the Middle East (2%). Asia's per capita rice consumption is 100 kilograms per year providing 28% of daily calories. The global and Asian per capita consumption increased from the 1960s to the 1990s but stable afterward. The per capita rice consumption is expected to decline in Asia but increase outside Asia especially in Africa in the future. The total milled rice consumption was about 490 million tons in 2018 and projected to reach 550 million tons by 2030 and 590 million tons by 2040. Rice is thinly traded in international market because it is a highly protected commodity. Only about 9% of the total production is traded in global rice market. However, the volume of global rice trade has increased over six-fold from 7.5 to 46.5 million tons between the 1960s and 2018. A relatively small number of exporting countries interact with a large number of importing countries. The top five rice exporting countries are India, Thailand, Vietnam, Pakistan, and China accounting for 74% of the global rice export. The top five rice importing countries are China, Philippines, Nigeria, European Union and Saudi Arabia accounting for 26% of the global rice import. Within rice varieties, Japonica rice accounts for the highest share of the global rice trade (about 12%) followed by Basmati rice (about 10%). The high concentration of exports to a few countries makes international rice market vulnerable to supply disruptions in exporting countries, leading to higher world prices of rice. The export price of Thai 5% broken rice increased from 198 US$/ton in 2000 to 421 US$/ton in 2018. The volumes of trade and rice prices in the global market are expected to increase in the future. The major future challenges of the rice industry are increasing demand due to population growth, rising demand in Africa, economic growth and diet diversification, competition for natural resources (land and water), labor scarcity, climate change and natural hazards, poverty and inequality, hunger and malnutrition, urbanization, low income in rice farming, yield saturation, aging of farmers, feminization of agriculture, health and environmental concerns, improving value chains, and shifting donor priorities away from agriculture. At the same time, new opportunities are available due to access to new technologies, increased investment by the private sector, and increased global partnership. More investment in rice research and development is needed to develop and disseminate innovative technologies and practices to overcome problems and ensure food and nutrition security of the future population.

  • PDF

A Study on the Reinforcement Effect Analysis of Aging Reservoir using Grout Material recycled Power Plant Byproduct (발전부산물을 재활용한 그라우트재의 노후 저수지 보강효과 분석에 관한 연구)

  • Seo, Se-Gwan;An, Jong-Hwan;Cho, Dae-sung
    • Journal of the Korean Geosynthetics Society
    • /
    • v.20 no.2
    • /
    • pp.23-33
    • /
    • 2021
  • In Korea, many reservoirs have been built for the purpose of solving the food shortage problem and supplying agricultural water. However, the current 75.6% of the reservoirs are in serious aged as more than 50 years have passed since the year of construction. In the case of such an aging reservoir, the stability due to scour and erosion inside the reservoir is very reduced, and if concentrated rainfall due to recent abnormal weather occurs, the aging reservoir may collapse, leading to a lot of damage to property and human life. Accordingly, each agency that manages aging reservoirs uses Ordinary Portland Cement (OPC) as an injection material and applies the grouting method. However, in the case of OPC, it may deteriorate over time and water leakage may occur again. And there are environmental problems such as consumption of natural resources and generation of greenhouse gases. So, there is a need to develop new materials and methods that can replace the OPC. In this study, an laboratory test and analysis were performed on the grout material developed to induce a curing reaction similar to that of OPC by recycling power plant byproduct. In addition, test in the field such as electric resistivity survey, Standard Penetration Test (SPT), and field permeability test were performed to analyzed to reinforcement effect and determine the possibility of using instead of OPC. As a results of the test, in the case of recycled power plant byproduct, the compressive strength was 2.9 to 3.2 times and the deformation modulus was 2.3 to 3.3 times higher, indicating that it is excellent in strength and can be used instead of OPC. And it was analyzed that the N value of the reservoir was increased by 1~2, and the coefficient of permeability (k) decreased to the level of 8.9~42.5%. showing sufficient reinforcing effect in terms of order.

Storyboard of Immortal Land in Gugok-Wonlim - A Special Reference to Goisan - (구곡원림(九曲園林)에서 찾는 신선경(神仙境)의 경관 스토리보드 - 괴산 갈은구곡(葛隱九曲)을 대상으로 -)

  • Rho, Jae-Hyun;Park, Joo-Sung;Sim, Woo-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.29 no.1
    • /
    • pp.90-104
    • /
    • 2011
  • This study identified the scenic characteristics in Gugok and symbolism reflected in titles of the scenery of the season in Gugok from a perspective of Sundoism concentrated on Galeun Gugok in Goisan which is influenced most greatly by Sundoism hermit ideas in Korea, along with Seonyudong-Gugok. In addition, it suggested a measure for arrangement and narrative Storyboard of Galeun Gugok structure corresponding with promotion and propagation of Gugok cultural scenes and educational goals. According to analysis and interpretation of the various Gugoks forming Galeun Gugok in terms of their titles, names engraved in surrounding elements and the coherent symbolic meanings of its scenery and place through comparison with secenery of near Seonyudong-Gugok, the result shows that Galeun Gugok comprises wishes for eternal life in the forms of Taoist hermit-related scenery of the season within the range of stream and old stories based on environmental affordance. In figurative way, it ultimately presents the Wonyung(圓融) idea which seeks a harmonious combination of God and humankind. In particular, consciousness of longevity without problems is deeply inherent in the background of eternalness of plants, divinity of animals and natural homeostasis. Also, 9 Gok Seongukam set up at visual terminal reflect noticeably that a game Go is the amusement of the immortals, which describe 9 ranks of GO figuratively. Galeun Gugok is formed in a unity structure, which is hermit-oriented Sundoism and motif, such as longevity and immortality, divinity and enjoyment of Sundoism hermit rather than used as a method to achieve taste for the arts or ethics. Given the fact, it presents eternal longevity and atmosphere of seclusion in very strong way. Development of spatial Storyboard structure based on this is interpreted as 'Entering the world of hermits(Introduction)'-'Looking the world(Development)'-'Living with hermits(Turn)'-'Becoming hermit(Conclusion).' Finally, the scenery image of Galeun Gugok presented in surface structure is based on beauty of the immortal land scenery as well as beauty of pre-achieved space in Gugokdongcheon and arranged the vertical narrative structure as divine space of 9 ranks of GO. Taking those into account, scenery story board of Galeun Gugok was suggested in accordance with a theme of 6 cuts; Gnagsun(降仙)-Sungyeong(仙境)- Sunyak(仙藥)-Sunhak(仙鶴)-Sunyu(仙遊)-Eunsun(隱仙). It is obvious that hermit which live an eternal life as a representative of Sundoism, should be the main motif of scenery planning in a filed of modem landscaping. Therefore, the most valuable component in designing Korean landscape must be the homeostasis of surrounding landscape which supports the characteristics of invariability and divinity of nature.

A Study on the Level of Citizen Participation in Smart City Project (스마트도시사업 단계별 시민참여 수준 진단에 관한 연구)

  • PARK, Ji-Ho;PARK, Joung-Woo;NAM, Kwang-Woo
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.24 no.2
    • /
    • pp.12-28
    • /
    • 2021
  • Based on the global smart city promotion trend, in 2018, the "Fourth Industrial Revolution Committee" selected "sustainability" and "people-centered" as keywords in relation to the direction of domestic smart city policy. Accordingly, the Living Lab program, which is an active citizen-centered innovation methodology, is applied to each stage of the domestic smart city construction project. Through the Living Lab program, and in collaboration with the public and experts, the smart city discovers local issues as it focuses on citizens, devises solutions to sustainable urban problems, and formulates a regional development plan that reflects the needs of citizens. However, compared to citizen participation in urban regeneration projects that have been operated for a relatively long time, participation in smart city projects was found to significantly differ in level and sustainability. Therefore, this study conducted a comparative analysis of the characteristics of citizen participation at each stage of an urban regeneration project and, based on Arnstein's "Participation Ladder" model, examined the level of citizen participation activities in the Living Lab program carried out in a smart city commercial area from 2018 to 2019. The results indicated that citizen participation activities in the Living Lab conducted in the smart city project had a great influence on selecting smart city services, which fit the needs of local residents, and on determining the technological level of services appropriate to the region based on a relatively high level of authority, such as selection of smart city services or composition of solutions. However, most of the citizen participation activities were halted after the project's completion due to the one-off recruitment of citizen participation groups for the smart city construction project only. On the other hand, citizens' participation activities in the field of urban regeneration were focused on local communities, and continuous operation and management measures were being drawn from the project planning stage to the operation stage after the project was completed. This study presented a plan to revitalize citizen participation for the realization of a more sustainable smart city through a comparison of the characteristics and an examination of the level of citizen participation in such urban regeneration and smart city projects.

A Study on the Structural Reinforcement of the Modified Caisson Floating Dock (개조된 케이슨 플로팅 도크의 구조 보강에 대한 연구)

  • Kim, Hong-Jo;Seo, Kwang-Cheol;Park, Joo-Shin
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.27 no.1
    • /
    • pp.172-178
    • /
    • 2021
  • In the ship repair market, interest in maintenance and repair is steadily increasing due to the reinforcement of prevention of environmental pollution caused by ships and the reinforcement of safety standards for ship structures. By reflecting this effect, the number of requests for repairs by foreign shipping companies increases to repair shipbuilders in the Southwest Sea. However, because most of the repair shipbuilders in the southwestern area are small and medium-sized companies, it is difficult to lead to the integrated synergy effect of the repair shipbuilding companies. Moreover, the infrastructure is not integrated; hence, using the infrastructure jointly is a challenge, which acts as an obstacle to the activation of the repair shipbuilding industry. Floating docks are indispensable to operating the repair shipbuilding business; in addition, most of them are operated through renovation/repair after importing aging caisson docks from overseas. However, their service life is more than 30 years; additionally, there is no structure inspection standard. Therefore, it is vulnerable to the safety field. In this study, the finite element analysis program of ANSYS was used to evaluate the structural safety of the modified caisson dock and obtain additional structural reinforcement schemes to solve the derived problems. For the floating docks, there are classification regulations; however, concerning structural strength, the regulations are insufficient, and the applicability is inferior. These insufficient evaluation areas were supplemented through a detailed structural FE-analysis. The reinforcement plan was decided by reinforcing the pontoon deck and reinforcement of the side tank, considering the characteristics of the repair shipyard condition. The final plan was selected to reinforce the side wing tank through the structural analysis of the decision; in addition, the actual structure was fabricated to reflect the reinforcement plan. Our results can be used as reference data for improving the structural strength of similar facilities; we believe that the optimal solution can be found quickly if this method is used during renovation/repair.