• Title/Summary/Keyword: Water circulation index

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Effective Drought Prediction Based on Machine Learning (머신러닝 기반 효과적인 가뭄예측)

  • Kim, Kyosik;Yoo, Jae Hwan;Kim, Byunghyun;Han, Kun-Yeun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.326-326
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    • 2021
  • 장기간에 걸쳐 넓은 지역에 대해 발생하는 가뭄을 예측하기위해 많은 학자들의 기술적, 학술적 시도가 있어왔다. 본 연구에서는 복잡한 시계열을 가진 가뭄을 전망하는 방법 중 시나리오에 기반을 둔 가뭄전망 방법과 실시간으로 가뭄을 예측하는 비시나리오 기반의 방법 등을 이용하여 미래 가뭄전망을 실시했다. 시나리오에 기반을 둔 가뭄전망 방법으로는, 3개월 GCM(General Circulation Model) 예측 결과를 바탕으로 2009년도 PDSI(Palmer Drought Severity Index) 가뭄지수를 산정하여 가뭄심도에 대한 단기예측을 실시하였다. 또, 통계학적 방법과 물리적 모델(Physical model)에 기반을 둔 확정론적 수치해석 방법을 이용하여 비시나리오 기반 가뭄을 예측했다. 기존 가뭄을 통계학적 방법으로 예측하기 위해서 시도된 대표적인 방법으로 ARIMA(Autoregressive Integrated Moving Average) 모델의 예측에 대한 한계를 극복하기위해 서포트 벡터 회귀(support vector regression, SVR)와 웨이블릿(wavelet neural network) 신경망을 이용해 SPI를 측정하였다. 최적모델구조는 RMSE(root mean square error), MAE(mean absolute error) 및 R(correlation Coefficient)를 통해 선정하였고, 1-6개월의 선행예보 시간을 갖고 가뭄을 전망하였다. 그리고 SPI를 이용하여, 마코프 연쇄(Markov chain) 및 대수선형모델(log-linear model)을 적용하여 SPI기반 가뭄예측의 정확도를 검증하였으며, 터키의 아나톨리아(Anatolia) 지역을 대상으로 뉴로퍼지모델(Neuro-Fuzzy)을 적용하여 1964-2006년 기간의 월평균 강수량과 SPI를 바탕으로 가뭄을 예측하였다. 가뭄 빈도와 패턴이 불규칙적으로 변하며 지역별 강수량의 양극화가 심화됨에 따라 가뭄예측의 정확도를 높여야 하는 요구가 커지고 있다. 본 연구에서는 복잡하고 비선형성으로 이루어진 가뭄 패턴을 기상학적 가뭄의 정도를 나타내는 표준강수증발지수(SPEI, Standardized Precipitation Evapotranspiration Index)인 월SPEI와 일SPEI를 기계학습모델에 적용하여 예측개선 모형을 개발하고자 한다.

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Comparative Review of Domestic & USA's Site Design Certification Index and Criteria for Sustainability - Focusing on Water & Soil+Vegetation Index - (국내외 외부공간의 지속가능성 인증지표 및 기준의 비교검토 - 물과 토양 및 식생 평가항목을 중심으로 -)

  • Chun, Seung-Hoon;Chae, Soo-Kwon
    • Journal of Environmental Impact Assessment
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    • v.29 no.6
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    • pp.430-440
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    • 2020
  • The application contents, process, and its limitations are discussed for the setting of Korean legal guides & criteria for water cycle and ecological condition in development project of land use by thorough comparison and examination of prerequisites and credits of water cycle and soil+vegetation by USA's SITES (Sustainable Sites Initiative). In the case of SITES, due to the implementation procedure operated as a non-governmental independent assessment system by Green Business Certification, Inc, the natural condition of water cycle and soil-vegetation items-the key element of ecosystem services can be quantitatively assessed, well along with its legal and institutional guidelines and regulations. On the other hand, in the case of Korea, as a part of the national certification procedure for green building, the ecological area ratio system still have very limited role as an only amenity resource in the creation of artificial green spaces and insufficiency of management system for rain water. In conclusion, it was understood as an urgent situation in necessary for prompt establishment of site's sustainability certification system at the national level, based on management of water circulation and natural soil & vegetation in developed area with consideration of various land uses and types of development projects.

Complementary measures for Environmental Performance Evaluation Index of External Space of Green Standard for Energy and Environmental Design for Apartment Complex - Focused on the Respect of Response to Climate Change - (공동주택 녹색건축인증기준의 외부공간 환경성능 평가지표 보완방안 - 기후변화 대응 측면을 중심으로 -)

  • Ye, Tae-Gon;Kim, Kwang-Hyun;Kwon, Young-Sang
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.1
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    • pp.3-14
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    • 2018
  • An apartment complex is a building use with great potential to contribute to solving problems related to urban ecological environment and climate change. The first goal of this study is to grasp the current situation of application and limitations of the ecological area rate, which is a representative evaluation index used to evaluate the environmental performance of the external space of an apartment complex in Green Standard for Energy and Environmental Design (G-SEED). The second goal is to propose a prototype of the evaluation index for evaluating greenhouse gas (GHG) reduction performance in order to supplement the evaluation index for the environmental performance of the external space in terms of response to climate change. We analyzed 43 cases of apartment complexes certified according to G-SEED, which was enforced since July 1, 2010, and found application characteristics of each space type and the limitations of ecological area rate. We analyzed overseas green building certification systems such as LEED and BREEAM that derived implications for supplementing the limitations of ecological area rate, which is focused on the evaluation of soil and water circulation function, and set up a development direction of complementary measures. Through analysis of previous studies, relevant regulations and standards, and technical documents of the manufacturer, the heat island mitigation performance of the pavement and roof surfaces of the apartment complex and the carbon uptake performance of the trees in the apartment complex was selected as parameters to yield the GHG reduction performance of the external space of the apartment complex. Finally, a quantitative evaluation method for each parameter and a prototype of the evaluation index for the GHG reduction performance were proposed. As a result of applying the prototype to an apartment complex case, the possibility of adoption and applicability as an evaluation index of G-SEED were proved.

The Antiulcer Effects of Alove vera on the Stomach ulcer Induced by Stress in rats (흰쥐의 스트레스성 위궤양에 대한 Alove vera의 항궤양작용)

  • 박은지;이용욱
    • Journal of Food Hygiene and Safety
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    • v.9 no.3
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    • pp.175-184
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    • 1994
  • This was performed to investigate the antiulcer effects of Aloe vera on the stomach ulcer induced by restraint and water-immersion stress in rats. For this experiment, 60 male Sprague-Dawley strain were used. The experimental groups were divided into five: a control(CA) and 4 aloe treatment groups. Each dose of aloe was 50 mg/kg BW(AA), 100mg/kg BW(AB), 200 mg/kg BW(AC), and 400 mg/kg BW(AD). The rats were allocated to each group by 12 and observed for 4 weeks. The results are as following. 1. The stomach surface pH in each group showed no significant difference, byt the values of aloe treatment groups were higher than the value of the control group. 2. The gastric wall mucus was significantly increased in all aloe treatment groups(p<0.05) compared with the control group. Especially in AC and AD group the differences were higher(p<0.01). 3. At shear rate rate 11.25, 45.0, 90.0, 225.0 sec-1, whole blood viscosity and plasma viscosity were measured. Most of the values of aloe treatment groups were significantly low compared with those of the control group(P<0.05). 4. The ulcer index of aloe treatment groups were significantly low campared with control group(p<0.05). Especially in AC and AD group the differences were more significant(p<0.01). 5. Less severe ulcers were observed in AA and AB group than in the control group. Tissues of AC and AD group had only slight ulcers and necrosis of tissue was not observed in these groups. Especially in AD group, there was more mucus than other groups and it seemed that alove vera stimulated the epithelial regeneration. From the results of this study, it can be concluded that the oral administration of Alove vera results in protection of stomach ulcer by stimulating the secretion of gastric mucus and the circulation of blood.

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A Study on derivation of drought severity-duration-frequency curve through a non-stationary frequency analysis (비정상성 가뭄빈도 해석 기법에 따른 가뭄 심도-지속기간-재현기간 곡선 유도에 관한 연구)

  • Jeong, Minsu;Park, Seo-Yeon;Jang, Ho-Won;Lee, Joo-Heon
    • Journal of Korea Water Resources Association
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    • v.53 no.2
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    • pp.107-119
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    • 2020
  • This study analyzed past drought characteristics based on the observed rainfall data and performed a long-term outlook for future extreme droughts using Representative Concentration Pathways 8.5 (RCP 8.5) climate change scenarios. Standardized Precipitation Index (SPI) used duration of 1, 3, 6, 9 and 12 months, a meteorological drought index, was applied for quantitative drought analysis. A single long-term time series was constructed by combining daily rainfall observation data and RCP scenario. The constructed data was used as SPI input factors for each different duration. For the analysis of meteorological drought observed relatively long-term since 1954 in Korea, 12 rainfall stations were selected and applied 10 general circulation models (GCM) at the same point. In order to analyze drought characteristics according to climate change, trend analysis and clustering were performed. For non-stationary frequency analysis using sampling technique, we adopted the technique DEMC that combines Bayesian-based differential evolution ("DE") and Markov chain Monte Carlo ("MCMC"). A non-stationary drought frequency analysis was used to derive Severity-Duration-Frequency (SDF) curves for the 12 locations. A quantitative outlook for future droughts was carried out by deriving SDF curves with long-term hydrologic data assuming non-stationarity, and by quantitatively identifying potential drought risks. As a result of performing cluster analysis to identify the spatial characteristics, it was analyzed that there is a high risk of drought in the future in Jeonju, Gwangju, Yeosun, Mokpo, and Chupyeongryeong except Jeju corresponding to Zone 1-2, 2, and 3-2. They could be efficiently utilized in future drought management policies.

Estimation of Potential Evapotranspiration using LAI (LAI를 고려한 잠재증발산량 추정)

  • Kim, Joo-Hun;Kim, Kyung-Tak
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.4
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    • pp.1-13
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    • 2005
  • In the process of a hydrology circulation, evapotranspiration is considered a very important factor to build a plan for the development of water resources and to operate water resources system. This study purposes to estimate daily potential evapotranspiration quantity in consideration of energy factors of the surface by using spatial information such as Landsat TM (ETM+) data, DEM and Landcover. Kyounan-cheon, Han River is selected as a target area, and landcover is divided by vegetation and non-vegetation covered area. Penman-Monteith equation which considers leaf-area index is used to estimate potential evapotranspiration quantity of vegetation covered area. The combination method (energy burget and aerodynamic method) is used in non-vegetation covered area. Among the input data for estimating potential evapotranspiration, NDVI, SR and Albedo is formed by Landsat, TM and ETM+ from 1986 through 2002. ground heat flux is estimated by using NDVI distribution map, LAI distribution map is drawn by using SR distribution map. The result of estimation shows that the average potential evapotranspiration in the whole basin is about 1.8-3.2mm/day per each cell. THe results of estimating potential evapotranspiration quantity by each landcover are as follows; water surface 3.6-4.9mm/day, city 1.4-3.1mm/day, bareland 1.4-3.5mm/day, grassland 1.7-3.7mm/day, forest 1.7-3.0mm/day and farmland 1.8-3.6mm/day. The potential evapotranspiration quantity is underestimated in comparison with observed evaporation data by evaporation pan, but it is considered that it has physical propriety.

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A Study on the Concept of the Right and the Left in Oriental Medicine (한의학(韓醫學)의 좌우이론(左右理論)에 관(關)한 고찰(考察))

  • Park Seung-Mi;Park Hi-Joon;Lee Hyang-Sook;Son Yang-Sun;Lim Sa-Bi-Na;Lee Hye-Jung
    • Korean Journal of Acupuncture
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    • v.18 no.1
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    • pp.81-94
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    • 2001
  • We could summerize the concept of the right and left mentioned in Nai-Gyung and some literature of oriental medicine as follow At first the right and left is a directional right and left which implys left-liver-right-lung(左肝右肺), left-yang-right-eum(左陽右陰), secondly it is also the road of eumyang which implys man-left-woman-right(男左女右), left-blood-right-ki(左血右氣), left-sinsu-right-myungmon(左腎水右命門), and left-right of pulse. left-liver-right-lung(左肝右肺), left-yang-right-eum(左陽右陰) and man-left-woman-right(男左女右) are expressions of the movement of yang which is a core of chang, at the same time, left-blood-right-ki(左血右氣), left-sinsu-right-myungmon(左腎水右命門), and left-right of pulse are expressions of the eum in response to the movement of yang. (go up and down of water and fire) Finally, both a directional right and left and a road of eumyang mean a road of going up and down of eumyang so, this is very important index in circulation and keeping ballance of eumyang (ki-Hyul:氣血) in the human body therefore, we can treat a disease with acupuncture in the use of this charater, for example when a disease occurs in the left side, we can treat it with acupuncture in the right side, the same applys to right.

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Uncertainty of Simulated Paddy Rice Yield using LARS-WG Derived Climate Data in the Geumho River Basin, Korea (LARS-WG 기후자료를 이용한 금호강 유역 모의발생 벼 생산량의 불확실성)

  • Nkomozepi, Temba D.;Chung, Sang-Ok
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.4
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    • pp.55-63
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    • 2013
  • This study investigates the trends and uncertainty of the impacts of climate change on paddy rice production in the Geumho river basin. The Long Ashton Research Station stochastic Weather Generator (LARS-WG) was used to derive future climate data for the Geumho river basin from 15 General Circulation models (GCMs) for 3 Special Report on Emissions Scenarios (SRES) (A2, A1B and B1) included in the Intergovernmental Panel on Climate Change (IPCC) 4th assessment report. The Food and Agricultural Organization (FAO) AquaCrop, a water-driven crop model, was statistically calibrated for the 1982 to 2010 climate. The index of agreement (IoA), prediction efficiency ($R^2$), percent bias (PBIAS), root mean square error (RMSE) and a visual technique were used to evaluate the adjusted AquaCrop simulated yield values. The adjusted simulated yields showed RMSE, NSE, IoA and PBIAS of 0.40, 0.26, 0.76 and 0.59 respectively. The 5, 9 and 15 year central moving averages showed $R^2$ of 0.78, 0.90 and 0.96 respectively after adjustment. AquaCrop was run for the 2020s (2011-2030), 2050s (2046-2065) and 2090s (2080-2099). Climate change projections for Geumho river basin generally indicate a hotter and wetter future climate with maximum increase in the annual temperature of $4.5^{\circ}C$ in the 2090s A1B, as well as maximum increase in the rainfall of 45 % in the 2090s A2. The means (and ranges) of paddy rice yields are projected to increase by 21 % (17-25 %), 34 % (27-42 %) and 43 % (31-54 %) for the 2020s, 2050s and 2090s, respectively. The A1B shows the largest rice yield uncertainty in all time slices with standard deviation of 0.148, 0.189 and $0.173t{\cdot}ha^{-1}$ for the 2020s, 2050s and 2090s, respectively.

Application of Artificial Neural Network Ensemble Model Considering Long-term Climate Variability: Case Study of Dam Inflow Forecasting in Han-River Basin (장기 기후 변동성을 고려한 인공신경망 앙상블 모형 적용: 한강 유역 댐 유입량 예측을 중심으로)

  • Kim, Taereem;Joo, Kyungwon;Cho, Wanhee;Heo, Jun-Haeng
    • Journal of Wetlands Research
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    • v.21 no.spc
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    • pp.61-68
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    • 2019
  • Recently, climate indices represented by quantifying atmospheric-ocean circulation patterns have been widely used to predict hydrologic variables for considering long-term climate variability. Hydrologic forecasting models based on artificial neural networks have been developed to provide accurate and stable forecasting performance. Forecasts of hydrologic variables considering climate variability can be effectively used for long-term management of water resources and environmental preservation. Therefore, identifying significant indicators for hydrologic variables and applying forecasting models still remains as a challenge. In this study, we selected representative climate indices that have significant relationships with dam inflow time series in the Han-River basin, South Korea for applying the dam inflow forecasting model. For this purpose, the ensemble empirical mode decomposition(EEMD) method was used to identify a significance between dam inflow and climate indices and an artificial neural network(ANN) ensemble model was applied to overcome the limitation of a single ANN model. As a result, the forecasting performances showed that the mean correlation coefficient of the five dams in the training period is 0.88, and the test period is 0.68. It can be expected to come out various applications using the relationship between hydrologic variables and climate variability in South Korea.

A Study on the Criteria for Demarcating Ecological Types of Urban Areas by the Affection of Ecosystems - Case Study in Gangdong-Gu, Seoul - (시가화지역 생태적 유형구분을 위한 관련지표 특성 연구 - 서울시 강동구를 사례로 -)

  • Hong, Suk-Hwan;Lee, Kyong-Jae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.36 no.2
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    • pp.24-31
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    • 2008
  • Studies for demarcation of urban areas by ecological type have been developed, but the demarcation of urban areas by ecological perception is thus far dependent on artificial land use. Therefore, the purpose of this study is to find factors that account for the urban area ecosystems by surveying a variety of ecosystem factors. By land use type, the urban area of Gangdong District, Seoul was defined. Then ecological factors in each polygon were surveyed. Ecological factors are associated with energy use(building coverage ratio, floor area ratio and ground temperature), water circulation(biotope area factors and impermeable pave ratio) and biological diversity(bird appearance index and green area ratio). The correlation between each factor was analyzed. The results indicate that urban ground temperature is divided into three groups(high, middle and low) by the biotope area factor. The bird population is divided into two groups(abundant and scarce) by the green area ratio. Therefore, demarcating the urban areas by ecological type is applicable to the biotope area factor and green area ratio.