• Title/Summary/Keyword: Annual rate of change

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Carbon Uptake and Emissions in Urban Landscape, and the Role of Urban Greenspace for several Cities in Kangwon Province (강원도 일부도시의 경관내 탄소흡수 및 배출과 도시녹지의 역할)

  • 조현길
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.1
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    • pp.39-53
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    • 1999
  • This study quantified carbon uptake and emissions in urban landscape, and the role of urban greenspace in atmospheric carbon reduction for several cities of Chuncheon and Kangleung in Kangwon province. Mean carbon storage by trees and shrubs was 26.0 t (mertric tons)/ha in Chuncheon and 46.7 t/ha in Kangleung for natural lands, and ranged from 4.7 to 6.3 t/ha for urban lands (all land use types except natural and agricultural lands) in both cities. Mean annual carbon uptake by trees and shrubs ranged from 1.60 to 1.71 t/ha/yr for natural lands, and from 0.56 to 0.71 t/ha/yr for urban lands. There was no significant difference (95% confidence level) between the two cities in the carbon storage and annual carbon uptake per ha, except the carbon storage for natural lands. Organic carbon storage in soils (to a depth of 60 cm) of Chuncheon average 24.8 t/ha for urban lands and 31.6 t/ha for natural lands, 1.3 times greater than for urban lands. Annual carbon accumulation in soils was 1.3 t/hr/yr for natural lands of the study cities. Annual per capita carbon emissions from fossil fuel consumption were 1.3 t/yr in Chunceon and 1.8 t/yr in Kangleung. The principal carbon release in urban landscapes was from transport and industry. Total carbon storage by urban greenspace (trees, shrubs, and soils) equaled 66% of total carbon emissions in Chuncheon and 101% in Kangleung. Carbon uptake by urban greenspace annually offset total carbon emissions by approximately 4% in the study cities. Thus, urban greenspace played a partial important role in reducing atmospheric $CO_2$ concentrations. To increase $CO_2$ uptake and storage by urban greenspace, suggested are conservation of natural lands, minimization of hard surfaces and more plantings, selection of tree species with high growth rate, and proper management for longer healthy tree growth.

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Evaluation of water supply capacity using groundwater abstraction contributing to streamflow (하천유량에 기여하는 지하수 양수량의 물공급 능력 평가)

  • Chung, Il-Moon;Kim, Nam Won;Lee, Jeongwoo;Chang, Sun Woo
    • Journal of Korea Water Resources Association
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    • v.50 no.12
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    • pp.889-896
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    • 2017
  • In the present study, an integrated SWAT-MODFLOW model was implemented to analyze the method of supplying groundwater abstraction contributing to Musimcheon stream. Various simulations of supply of groundwater to streamflow with current and maximum groundwater abstraction have been explored for 5 years (2011-2015). In 2015, when the severe drought happened, the monthly discharge change rate due to groundwater supply was ranged from 23% in current abstraction to 68% in maximum abstraction. In terms of annual groundwater recharge, these quantities could be applicable recharges ranged from 75 mm (6.2% of annual mean precipitation) to 290 mm (24% of annual mean precipitation) which could be stable annual supply. Since surface water is vulnerable to drought, the water supply using groundwater could be an effective alternative for stream deficiency.

Prediction of Return Periods of Sewer Flooding Due to Climate Change in Major Cities (기후변화에 따른 주요 도시의 하수도 침수 재현기간 예측)

  • Park, Kyoohong;Yu, Soonyu;Byambadorj, Elbegjargal
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.1
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    • pp.41-49
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    • 2016
  • In this study, rainfall characteristics with stationary and non-stationary perspectives were analyzed using generalized extreme value (GEV) distribution and Gumbel distribution models with rainfall data collected in major cities of Korea to reevaluate the return period of sewer flooding in those cities. As a result, the probable rainfall for GEV and Gumbel distribution in non-stationary state both increased with time(t), compared to the stationary probable rainfall. Considering the reliability of ${\xi}_1$, a variable reflecting the increase of storm events due to climate change, the reliability of the rainfall duration for Seoul, Daegu, and Gwangju in the GEV distribution was over 90%, indicating that the probability of rainfall increase was high. As for the Gumbel distribution, Wonju, Daegu, and Gwangju showed the higher reliability while Daejeon showed the lower reliability than the other cities. In addition, application of the maximum annual rainfall change rate (${\xi}_1{\cdot}t$) to the location parameter made possible the prediction of return period by time, therefore leading to the evaluation of design recurrence interval.

Estimation of Secondary Emissions from Forest Carbon Offset Projects (산림탄소상쇄 사업에 따른 이차적 배출량 산정에 관한 연구)

  • Kim, Young-hwan
    • Journal of Climate Change Research
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    • v.6 no.4
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    • pp.257-265
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    • 2015
  • For estimating a net removal of carbon dioxides from a forest carbon offset project, it is necessary to consider secondary emissions occurred from the use of machineries or vehicles. According to the forest carbon standard in Korea, a default rate (5%) could be applied for estimating secondary emissions of small projects, which provide annual net removals less than or equal to $600tCO_2$, while secondary emissions should be estimated for larger projects with field survey. In this study, we intended to develop a methodology for estimating the secondary emission of a forest carbon project. For this purpose, we analyzed the working process and the carbon emissions of the forest management activities for major tree species in Korea. Based on the developed methodology, we estimated the secondary carbon emission of a reforestation project. The result showed that the secondary carbon emission of a reforestation project was estimated between 0.42% and 1.19 % compared to net removals, that is to say that the current default rate in the forest carbon standard could give an overestimated secondary emission.

Study on the Underground Thermal Environment around Wells for a Design Method of Open-Loop Geothermal System (개방형 지열 시스템 설계법 개발을 위한 관정 주위 지중 온도 환경 검토)

  • Bae, Sangmu;Kim, Hongkyo;Kim, Hyeon-Woo;Nam, Yujin
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.13 no.1
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    • pp.14-20
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    • 2017
  • Groundwater heat pump (GWHP) system can achieve higher performance of the system by utilizing heat source of the annual constant groundwater temperature. The performance of GWHP system depends on the ground thermal environment such as groundwater temperature, groundwater flow rate and hydraulic conductivity. In this study, the geothermal environment was analyzed by using numerical simulation for develop the two-well geothermal system. As the result, this paper shows the change of the groundwater level and underground temperature around wells according to the conditions of flow rate and hydraulic conductivity.

The Impact of Income Inequality on Economic Growth: Empirical Evidence from Vietnam

  • HIEN, Luong Quang
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.2
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    • pp.305-312
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    • 2022
  • Each country's economic progress creates opportunities for its citizens to raise their income. Meanwhile, the country has secured the people's social security policies, particularly the protection of income equality, to promote harmonious and sustained economic development. Vietnam has been located in a dynamic economic development area in Southeast Asia since the 1986 economic reforms, with an annual growth rate of around 7%. Meanwhile, having achieved a middle-income status of roughly 3500 USD per person per year, Vietnam is attempting to maintain income equality and access to welfare systems for its inhabitants. As a result, the primary goal of this study is to use an autoregressive distributed lagged model to investigate the effects of income inequality and other economic factors such as foreign direct investment and trade openness on Vietnam's economic growth from 1992 to 2019. The research focuses attention on literature on income inequality, economic development indicators, and economic development in unique ways in this study. Income inequality slows the rate of change in economic development in the same year, according to our findings. Finally, the study will make policy suggestions to the Vietnamese government.

Evaluation of Percolation Rate of Bedrock Aquifer in Coastal Area (해안지역 암반대수층의 침누수량 평가)

  • Lee, Jeong-Hwan;Jung, Haeryong;Park, Joo-Wan;Yoon, Jeong Hyoun;Cheong, Jae-Yeol;Park, Sun Ju;Jun, Seong-Chun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.14 no.1
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    • pp.21-33
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    • 2016
  • Estimation of groundwater hydrologic cycle pattern is one of the most critical issues in sustainable management of groundwater resources in coastal area. This study estimated groundwater percolation by using the water balance methodology and hydrogeological characteristics of land use and soil. Evapotranspiration was computed by using the Thornthwaite method, and surface runoff was determined by using the SCS-CN technique. Groundwater storage change was obtained as 229 mm/a (17.8% of the average annual rainfall, 1286 mm/a), with 693 mm/a (60.1%) of evapotranspiration and 124 mm/a (9.6%) of surface runoff. Rainfall and groundwater storage change was highly correlated, comparing with the relationships between rainfall and evapotranspiration, and between rainfall and surface runoff. This result indicates that groundwater storage change responds more sensitively to precipitation than evapotranspiration and surface runoff.

Mechanical ventilation in patients with idiopathic pulmonary fibrosis in Korea: a nationwide cohort study

  • Jae Kyeom Sim;Seok Joo Moon;Juwhan Choi;Jee Youn Oh;Young Seok Lee;Kyung Hoon Min;Gyu Young Hur;Sung Yong Lee;Jae Jeong Shim
    • The Korean journal of internal medicine
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    • v.39 no.2
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    • pp.295-305
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    • 2024
  • Background/Aims: The prognosis of patients with idiopathic pulmonary fibrosis (IPF) and respiratory failure requiring mechanical ventilation is poor. Therefore, mechanical ventilation is not recommended. Recently, outcomes of mechanical ventilation, including those for patients with IPF, have improved. The aim of this study was to investigate changes in the use of mechanical ventilation in patients with IPF and their outcomes over time. Methods: This retrospective, observational cohort study used data from the National Health Insurance Service database. Patients diagnosed with IPF between January 2011 and December 2019 who were placed on mechanical ventilation were included. We analyzed changes in the use of mechanical ventilation in patients with IPF and their mortality using the Cochran-Armitage trend test. Results: Between 2011 and 2019, 1,227 patients with IPF were placed on mechanical ventilation. The annual number of patients with IPF with and without mechanical ventilation increased over time. However, the ratio was relatively stable at approximately 3.5%. The overall hospital mortality rate was 69.4%. There was no improvement in annual hospital mortality rate. The overall 30-day mortality rate was 68.7%, which did not change significantly. The overall 90-day mortality rate was 85.3%. The annual 90-day mortality rate was decreased from 90.9% in 2011 to 83.1% in 2019 (p = 0.028). Conclusions: Despite improvements in intensive care and ventilator management, the prognosis of patients with IPF receiving mechanical ventilation has not improved significantly.

Breast Cancer Trend in Iran from 2000 to 2009 and Prediction till 2020 using a Trend Analysis Method

  • Zahmatkesh, Bibihajar;Keramat, Afsaneh;Alavi, Nasrinossadat;Khosravi, Ahmad;Kousha, Ahmad;Motlagh, Ali Ghanbari;Darman, Mahboobeh;Partovipour, Elham;Chaman, Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1493-1498
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    • 2016
  • Background: Breast cancer is the most common cancer in women worldwide with a rising incidence rate in most countries. Considering the increase in life expectancy and change in lifestyle of Iranian women, this study investigated the age-adjusted trend of breast cancer incidence during 2000-2009 and predicted its incidence to 2020. Materials and Methods: The 1997 and 2006 census results were used for the projection of female population by age through the cohort-component method over the studied years. Data from the Iranian cancer registration system were used to calculate the annual incidence rate of breast cancer. The age-adjusted incidence rate was then calculated using the WHO standard population distribution. The five-year-age-specific incidence rates were also obtained for each year and future incidence was determined using the trend analysis method. Annual percentage change (APC) was calculated through the joinpoint regression method. Results: The bias adjusted incidence rate of breast cancer increased from 16.7 per 100,000 women in 2000 to 33.6 per 100,000 women in 2009. The incidence of breast cancer had a growing trend in almost all age groups above 30 years over the studied years. In this period, the age groups of 45-65 years had the highest incidence. Investigation into the joinpoint curve showed that the curve had a steep slope with an APC of 23.4% before the first joinpoint, but became milder after this. From 2005 to 2009, the APC was calculated as 2.7%, through which the incidence of breast cancer in 2020 was predicted as 63.0 per 100,000 women. Conclusions: The age-adjusted incidence rate of breast cancer continues to increas in Iranian women. It is predicted that this trend will continue until 2020. Therefore, it seems necessary to prioritize the prevention, control and care for breast cancer in Iran.

Analysis on Characteristics of Variation in Flood Flow by Changing Order of Probability Weighted Moments (확률가중모멘트의 차수 변화에 따른 홍수량 변동 특성 분석)

  • Maeng, Seung-Jin;Hwang, Ju-Ha
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.5
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    • pp.1009-1019
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    • 2009
  • In this research, various characteristics of South Korea's design flood have been examined by deriving appropriate design flood, using data obtained from careful observation of actual floods occurring in selected main watersheds of the nation. 19 watersheds were selected for research in Korea. The various characteristics of annual rainfall were analyzed by using a moving average method. The frequency analysis was decided to be performed on the annual maximum flood of succeeding one year as a reference year. For the 19 watersheds, tests of basic statistics, independent, homogeneity, and outlier were calculated per period of annual maximum flood series. By performing a test using the LH-moment ratio diagram and the Kolmogorov-Smirnov (K-S) test, among applied distributions of Gumbel (GUM), Generalized Extreme Value (GEV), Generalized Logistic (GLO) and Generalized Pareto (GPA) distribution was found to be adequate compared with other probability distributions. Parameters of GEV distribution were estimated by L, L1, L2, L3 and L4-moment method based on the change in the order of probability weighted moments. Design floods per watershed and the periods of annual maximum flood series were derived by GEV distribution. According to the result of the analysis performed by using variation rate used in this research, it has been concluded that the time for changing the design conditions to ensure the proper hydraulic structure that considers recent climate changes of the nation brought about by global warming should be around the year 2002.