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Damage due to climate change is increasing worldwide; in South Korea, the increase in temperature is greater than the average global temperature increase. These changes in temperature have increased the frequency of and damage caused by droughts. To reduce drought damage, the importance of efficient water management policies and evapotranspiration, an index used for water management policies, is increasing. Analyzing the variation in evapotranspiration is relevant to understanding climate change and agricultural water management. Owing to the lack of evapotranspiration data collected using a Lysimeter, evapotranspiration has been estimated using the FAO-56 Penman–Monteith (PM) equation on meteorological datasets as recommended by the United Nations Food and Agriculture Organization. Long-term meteorological data with a maximum of 100 years were collected from 12 sites to estimate evapotranspiration. The objectives of this study were the following: (1) estimate evapotranspiration based on the PM equation, (2) analyze the trends in temperature and evapotranspiration, and (3) evaluate the relationship between temperature and evapotranspiration through correlational analysis. The results improve our understanding of climate change and provide a valuable reference for regional water resource management. We estimated evapotranspiration and analyzed the tendency of temperature and evapotranspiration. As a result, analysis of seasonal ET0 at all stations represented generally increasing trends in spring, summer, and autumn with generally decreasing trends in winter. Results of the seasonal Mann–Kendall test between temperature metrics (maximum, average, minimum) and ET0 showed that the maximum temperature exhibited a distinct increase in spring and winter in some areas. In this study, we determined the strength of the relationship between temperature and ET0 using the Pearson correlation coefficient. The results of evaluating the relationship between each temperature metric and evapotranspiration showed that the maximum temperature had the strongest relationship compared to the average and minimum temperatures.
Min-Gi Jeon; Won-Ho Nam; Young-Sik Mun; Eun-Mi Hong. Climate Change Impacts on Reference Evapotranspiration in South Korea Over the Recent 100 Years (1904–2018). 2021, 1 .
AMA StyleMin-Gi Jeon, Won-Ho Nam, Young-Sik Mun, Eun-Mi Hong. Climate Change Impacts on Reference Evapotranspiration in South Korea Over the Recent 100 Years (1904–2018). . 2021; ():1.
Chicago/Turabian StyleMin-Gi Jeon; Won-Ho Nam; Young-Sik Mun; Eun-Mi Hong. 2021. "Climate Change Impacts on Reference Evapotranspiration in South Korea Over the Recent 100 Years (1904–2018)." , no. : 1.
Weather and hydrological phenomena have been changing due to climate change as evidenced by localized torrential rainfall and precipitation falling by more than 30% compared to the annual average. From 2013 to 2017 the ninety-nine reservoirs reached a water storage rate of 0%, making a secure stable water supply for agriculture uncertain. There is an increased need for information regarding agricultural water management to respond to the changes in the agricultural environment and climate. Therefore, automatic water level measurement facilities have been introduced to determine the real-time reservoir storage capacity and agricultural water supply. According to the Ministry of Agriculture, Food and Rural Affairs' guidelines for the installation and operation of water level measurement instruments, automatic water level facilities are currently installed at 1,734 reservoirs and 1,880 irrigation canals, with water level data generated at 10-minute intervals. The official recognition of hydrological water level data for agricultural reservoirs increased from six in 2016 to forty-nine in 2019. Anomaly detection algorithm methods for data regarding the agricultural reservoir level as well as quality control measures based on agricultural reservoir characteristics are required to minimize data quality degradation and generate reliable hydrological data over time. Though it was practically impossible to analyze the correlation between the water level or run-off and influential factors such as weather and terrain, recently a non-linear hydrological analysis has been possible using models such as Artificial Neural Networks (ANNs). This study aims to present an anomaly detection algorithm for reservoir level data using deep learning based LSTM (Long Short-Term Memory) models, in combination with other neural networks for managing quantitative information of agricultural water supply.
Mi-Hye Yang; Won-Ho Nam; Han-Joong Kim; Taegon Kim; An-Kook Shin; Mun-Sung Kang. Anomaly Detection in Reservoir Water Level Data Using the LSTM Model Based on Deep Learning. Journal of the Korean Society of Hazard Mitigation 2021, 21, 71 -81.
AMA StyleMi-Hye Yang, Won-Ho Nam, Han-Joong Kim, Taegon Kim, An-Kook Shin, Mun-Sung Kang. Anomaly Detection in Reservoir Water Level Data Using the LSTM Model Based on Deep Learning. Journal of the Korean Society of Hazard Mitigation. 2021; 21 (1):71-81.
Chicago/Turabian StyleMi-Hye Yang; Won-Ho Nam; Han-Joong Kim; Taegon Kim; An-Kook Shin; Mun-Sung Kang. 2021. "Anomaly Detection in Reservoir Water Level Data Using the LSTM Model Based on Deep Learning." Journal of the Korean Society of Hazard Mitigation 21, no. 1: 71-81.
Agricultural drought can have long-lasting and harmful impacts on both the agricultural ecosystem and economy. Recently, as climate change has increased global warming, the frequency and intensity of droughts are increasing as weather and environmental factors that directly affect agriculture are rapidly changing. In South Korea, severe droughts have occurred every year for the past seven years. Compared to paddies supplied with water from agricultural reservoirs, upland crops are highly vulnerable to drought due to a lack of irrigation facilities. The consumption requirements for upland crops cannot be satisfied by rainfall alone and require supplementation through irrigation. The amount of upland crop consumption and irrigation water should be calculated not only by the amount of evaporation but also by taking into account the soil moisture movement. Soil moisture is a key variable for defining the agricultural drought index; however, in situ soil moisture observations are unavailable for many areas. Remote sensing techniques can allow surface soil moisture observations at different tempo-spatial resolutions. Soil available water content is an important factor used in evaluating upland drought impacts. It is recognized as a major factor in water resource circulation. This study proposes a practical method to perform drought risk assessments for upland crops based on evaporation and soil moisture by utilizing Famine Early Warning Systems Network evaporation acidity satellite images provided by the United States Geological Survey.
Min-Gi Jeon; Won-Ho Nam; Hee-Jin Lee; Eun-Mi Hong; Seonah Hwang; Seung-Oh Hur. Drought Risk Assessment for Upland Crops using Satellite-derived Evapotranspiration and Soil Available Water Capacity. Journal of the Korean Society of Hazard Mitigation 2021, 21, 25 -33.
AMA StyleMin-Gi Jeon, Won-Ho Nam, Hee-Jin Lee, Eun-Mi Hong, Seonah Hwang, Seung-Oh Hur. Drought Risk Assessment for Upland Crops using Satellite-derived Evapotranspiration and Soil Available Water Capacity. Journal of the Korean Society of Hazard Mitigation. 2021; 21 (1):25-33.
Chicago/Turabian StyleMin-Gi Jeon; Won-Ho Nam; Hee-Jin Lee; Eun-Mi Hong; Seonah Hwang; Seung-Oh Hur. 2021. "Drought Risk Assessment for Upland Crops using Satellite-derived Evapotranspiration and Soil Available Water Capacity." Journal of the Korean Society of Hazard Mitigation 21, no. 1: 25-33.
Drought is a natural disaster affecting agriculture worldwide. Drought mitigation and proactive response require a comprehensive vulnerability mapping approach considering various factors. This study investigates the vulnerability to agricultural drought in South Korea based on exposure, sensitivity, and adaptability. The evaluation of agricultural drought factors yielded 14 items, which are categorized into meteorological, agricultural reservoir, social, and adaptability factors. Each item is assigned a weight using the analytical hierarchy process (AHP). We analyzed vulnerability to drought disaster in agricultural reservoirs, and generated vulnerability maps by applying the vulnerability framework for climate change. The generated map was divided into four categories based on drought vulnerability: A (Very high), B (High), C (Moderate), and D (Low). The weights for the meteorological (0.498), agricultural reservoir (0.286), social (0.166), and adaptability (0.05) factors were obtained using AHP. The rating frequencies were 41.91%, 19.76%, 9.58%, and 5.39% for A, B, C, and D, respectively. The western region is extremely vulnerable to meteorological and agricultural reservoir factors, whereas the eastern region is more vulnerable to adaptability. The results of this study visually represent agricultural drought and can be used for evaluating regional drought vulnerability for assisting preemptive drought responses to identify and support drought-prone areas.
Young-Sik Mun; Won-Ho Nam; Min-Gi Jeon; Na-Kyoung Bang; Taegon Kim. Assessment of Vulnerability to Drought Disaster in Agricultural Reservoirs in South Korea. Atmosphere 2020, 11, 1244 .
AMA StyleYoung-Sik Mun, Won-Ho Nam, Min-Gi Jeon, Na-Kyoung Bang, Taegon Kim. Assessment of Vulnerability to Drought Disaster in Agricultural Reservoirs in South Korea. Atmosphere. 2020; 11 (11):1244.
Chicago/Turabian StyleYoung-Sik Mun; Won-Ho Nam; Min-Gi Jeon; Na-Kyoung Bang; Taegon Kim. 2020. "Assessment of Vulnerability to Drought Disaster in Agricultural Reservoirs in South Korea." Atmosphere 11, no. 11: 1244.
Egypt is a country that is vulnerable to many of the sustainability challenges and climate change effects to which all countries around the world are struggling to respond, and the United Nations is warning that Egypt could run out of the water by the year 2025. Reference evapotranspiration is the first step in estimating crop water requirements and irrigation water management. A better understanding of trends in reference evapotranspiration is crucial for scientific management of water resources in arid and semi-arid regions. The aim of this study is to identify the spatiotemporal of annual and monthly reference evapotranspiration changes in Egypt, as evidenced by spatial distribution and temporal trends. The results showed that significant changes in spatial distribution of reference evapotranspiration have occurred in the last 35 years beginning in the 1980s. The southeastern regions, the older agricultural lands in the Nile Delta and valley, as well as the northwestern regions were most affected regions. However, the western desert showed the lowest impact from climate change. The winter season from November to February showed the lowest impact from climate change, while during the summer season, the highest significant differences occurred, especially from June to October. The last five years (2013–2017) showed a significant decrease from the previous 5 years (2008–2012) but still show a significant increase from previous periods of time (1983–2007). Hence, the western desert is more suitable for agricultural expansion. Furthermore, agricultural and irrigation activities during the summer season have to change respond to the impact of climate change on water resources management.
Ahmed Nagy Yassen; Won-Ho Nam; Eun-Mi Hong. Impact of climate change on reference evapotranspiration in Egypt. CATENA 2020, 194, 104711 .
AMA StyleAhmed Nagy Yassen, Won-Ho Nam, Eun-Mi Hong. Impact of climate change on reference evapotranspiration in Egypt. CATENA. 2020; 194 ():104711.
Chicago/Turabian StyleAhmed Nagy Yassen; Won-Ho Nam; Eun-Mi Hong. 2020. "Impact of climate change on reference evapotranspiration in Egypt." CATENA 194, no. : 104711.
Drought is the meteorological phenomenon with the greatest impact on agriculture. Accordingly, drought forecasting is vital in lessening its associated negative impacts. Utilizing remote exploration in the agricultural sector allows for the collection of large amounts of quantitative data across a wide range of areas. In this study, we confirmed the applicability of drought assessment using the evaporative stress index (ESI) in major East Asian countries. The ESI is an indicator of agricultural drought that describes anomalies in actual/reference evapotranspiration (ET) ratios that are retrieved using remotely sensed inputs of land surface temperature (LST) and leaf area index (LAI). The ESI is available through SERVIR Global, a joint venture between the National Aeronautics and Space Administration (NASA) and the United States Agency for International Development (USAID). This study evaluated the performance of ESI in assessing drought events in South Korea. The evaluation of ESI is possible because of the availability of good statistical data. Comparing drought trends identified by ESI data from this study to actual drought conditions showed similar trends. Additionally, ESI reacted to the drought more quickly and with greater sensitivity than other drought indices. Our results confirmed that the ESI is advantageous for short and medium-term drought assessment compared to vegetation indices alone.
Dong-Hyun Yoon; Won-Ho Nam; Hee-Jin Lee; Eun-Mi Hong; Song Feng; Brian D. Wardlow; Tsegaye Tadesse; Mark D. Svoboda; Michael J. Hayes; Dae-Eui Kim. Agricultural Drought Assessment in East Asia Using Satellite-Based Indices. Remote Sensing 2020, 12, 444 .
AMA StyleDong-Hyun Yoon, Won-Ho Nam, Hee-Jin Lee, Eun-Mi Hong, Song Feng, Brian D. Wardlow, Tsegaye Tadesse, Mark D. Svoboda, Michael J. Hayes, Dae-Eui Kim. Agricultural Drought Assessment in East Asia Using Satellite-Based Indices. Remote Sensing. 2020; 12 (3):444.
Chicago/Turabian StyleDong-Hyun Yoon; Won-Ho Nam; Hee-Jin Lee; Eun-Mi Hong; Song Feng; Brian D. Wardlow; Tsegaye Tadesse; Mark D. Svoboda; Michael J. Hayes; Dae-Eui Kim. 2020. "Agricultural Drought Assessment in East Asia Using Satellite-Based Indices." Remote Sensing 12, no. 3: 444.
Technological and socioeconomic interventions accompanied by climate warming strongly dictate farming practices, lending a direct impact over future irrigation water demand and supply. In this article, two pivotal factors of farming practices and climate change were included to assess their role in the future paddy water management of Korea. Field surveys were conducted across irrigated areas of twelve agricultural reservoirs to distinguish traditional and current paddy farming practices. Projected climate for two future time slices the 2060s (2020 to 2059) and the 2100s (2060 to 2100) under two representative concentration pathway scenarios (4.5 and 8.5) were used for climate change impact assessment. Crop evapotranspiration (ETc), effective rainfall, gross duty of water (GDW) and annual inflow were simulated from 1987 to 2100 under both farming practices. Future climate projections suggested a continuous warming trend accompanied by distinctively negative/positive shifts in central/southern region annual rainfall by the end of the twenty-first century. Annual inflow in the central (southern) region reservoirs exhibited downward (upward) trends during the 2060s and only upward trends during the 2100s, respectively, whereas rice ETc showed upward tendencies regardless of the farming practices. Rice season effective rainfall varied for different reservoirs mostly showing increasing tendencies. The GDW increased implying that projected positive rainfall shifts might not withhold the driving impacts of temperature rise over regional irrigation water demands. Following the traditional farming practices in future would intensify the anticipated rise in irrigation demand and may lead to water shortages given the present storage capacities of agricultural reservoirs.
Gun-Ho Cho; Mirza Junaid Ahmad; Seulgi Lee; Kyung-Sook Choi; Won-Ho Nam; Hyung-Joong Kwon. Influence mechanism of climate change on paddy farming practices and irrigation water demand. Paddy and Water Environment 2019, 17, 359 -371.
AMA StyleGun-Ho Cho, Mirza Junaid Ahmad, Seulgi Lee, Kyung-Sook Choi, Won-Ho Nam, Hyung-Joong Kwon. Influence mechanism of climate change on paddy farming practices and irrigation water demand. Paddy and Water Environment. 2019; 17 (3):359-371.
Chicago/Turabian StyleGun-Ho Cho; Mirza Junaid Ahmad; Seulgi Lee; Kyung-Sook Choi; Won-Ho Nam; Hyung-Joong Kwon. 2019. "Influence mechanism of climate change on paddy farming practices and irrigation water demand." Paddy and Water Environment 17, no. 3: 359-371.
Understanding long-term changes in precipitation and temperature patterns is important in the detection and characterization of climate change, as is understanding the implications of climate change when performing impact assessments. This study uses a statistically robust methodology to quantify long-, medium- and short-term changes for evaluating the degree to which climate change and urbanization have caused temporal changes in precipitation and temperature in South Korea. We sought to identify a fingerprint of changes in precipitation and temperature based on statistically significant differences at multiple-timescales. This study evaluates historical weather data during a 40-year period (1973–2012) and from 54 weather stations. Our results demonstrate that between 1993–2012, minimum and maximum temperature trends in the vicinity of urban and agricultural areas are significantly different from the two previous decades (1973–1992). The results for precipitation amounts show significant differences in urban areas. These results indicate that the climate in urbanized areas has been affected by both the heat island effect and global warming-caused climate change. The increase in the number of rainfall events in agricultural areas is highly significant, although the temporal trends for precipitation amounts showed no significant differences. Overall, the impacts of climate change and urbanization in South Korea have not been continuous over time and have been expressed locally and regionally in terms of precipitation and temperature changes.
Won-Ho Nam; Guillermo A. Baigorria; Eun-Mi Hong; Taegon Kim; Yong-Sang Choi; Song Feng. The fingerprint of climate change and urbanization in South Korea. Atmosphere 2018, 9, 273 .
AMA StyleWon-Ho Nam, Guillermo A. Baigorria, Eun-Mi Hong, Taegon Kim, Yong-Sang Choi, Song Feng. The fingerprint of climate change and urbanization in South Korea. Atmosphere. 2018; 9 (7):273.
Chicago/Turabian StyleWon-Ho Nam; Guillermo A. Baigorria; Eun-Mi Hong; Taegon Kim; Yong-Sang Choi; Song Feng. 2018. "The fingerprint of climate change and urbanization in South Korea." Atmosphere 9, no. 7: 273.
South Korea has experienced severe droughts and water scarcity problems that have influenced agriculture, food prices, and crop production in recent years. Traditionally, climate-based drought indices using point-based meteorological observations have been used to help quantify drought impacts on the vegetation in South Korea. However, these approaches have a limited spatial precision when mapping detailed vegetation stress caused by drought. For these reasons, the development of a drought index that provides detailed spatial-resolution information on drought-affected vegetation conditions is essential to improve the country’s drought monitoring capabilities, which are needed to help develop more effective adaptation and mitigation strategies. The objective of this study was to develop a satellite-based hybrid drought index called the vegetation drought response index for South Korea (VegDRI-SKorea) that could improve the spatial resolution of agricultural drought monitoring on a national scale. The VegDRI-SKorea was developed for South Korea, modifying the original VegDRI methodology (developed for the USA) by tailoring it to the available local data resources. The VegDRI-SKorea utilizes a classification and regression tree (CART) modelling approach that collectively analyses remote-sensing data (e.g. normalized difference vegetation index (NDVI)), climate-based drought indices (e.g. self-calibrated Palmer drought severity index (PDSI) and standardized precipitation index (SPI)), and biophysical variables (e.g. elevation and land cover) that influence the drought-related vegetation stress. This study evaluates the performance of the recently developed VegDRI-SKorea for severe and extreme drought events that occurred in South Korea in 2001, 2008, and 2012. The results demonstrated that the hybrid drought index improved the more spatially detailed drought patterns compared to the station-based drought indices and resulted in a better understanding of drought impacts on the vegetation conditions. The VegDRI-SKorea model is expected to contribute to the monitoring of drought conditions nationally. In addition, it will provide the necessary information on the spatial variations of those conditions to evaluate local and regional drought risk assessment across South Korea and assist local decision-makers in drought risk management.
Won-Ho Nam; Tsegaye Tadesse; Brian Wardlow; Michael J. Hayes; Mark D. Svoboda; Eun-Mi Hong; Yakov A. Pachepsky; Min-Won Jang. Developing the vegetation drought response index for South Korea (VegDRI-SKorea) to assess the vegetation condition during drought events. International Journal of Remote Sensing 2017, 39, 1548 -1574.
AMA StyleWon-Ho Nam, Tsegaye Tadesse, Brian Wardlow, Michael J. Hayes, Mark D. Svoboda, Eun-Mi Hong, Yakov A. Pachepsky, Min-Won Jang. Developing the vegetation drought response index for South Korea (VegDRI-SKorea) to assess the vegetation condition during drought events. International Journal of Remote Sensing. 2017; 39 (5):1548-1574.
Chicago/Turabian StyleWon-Ho Nam; Tsegaye Tadesse; Brian Wardlow; Michael J. Hayes; Mark D. Svoboda; Eun-Mi Hong; Yakov A. Pachepsky; Min-Won Jang. 2017. "Developing the vegetation drought response index for South Korea (VegDRI-SKorea) to assess the vegetation condition during drought events." International Journal of Remote Sensing 39, no. 5: 1548-1574.
Won-Ho Nam; Taegon Kim; Eun-Mi Hong; Jin-Yong Choi; Jin-Taek Kim. A Wireless Sensor Network (WSN) application for irrigation facilities management based on Information and Communication Technologies (ICTs). Computers and Electronics in Agriculture 2017, 143, 185 -192.
AMA StyleWon-Ho Nam, Taegon Kim, Eun-Mi Hong, Jin-Yong Choi, Jin-Taek Kim. A Wireless Sensor Network (WSN) application for irrigation facilities management based on Information and Communication Technologies (ICTs). Computers and Electronics in Agriculture. 2017; 143 ():185-192.
Chicago/Turabian StyleWon-Ho Nam; Taegon Kim; Eun-Mi Hong; Jin-Yong Choi; Jin-Taek Kim. 2017. "A Wireless Sensor Network (WSN) application for irrigation facilities management based on Information and Communication Technologies (ICTs)." Computers and Electronics in Agriculture 143, no. : 185-192.
Reservoirs are principal water resources that supply irrigation water to paddy fields and play an important role in water resources management in South Korea. For optimal irrigation reservoir operation and management, it is necessary to determine the duration of irrigation water shortages. Management of reservoir operation and irrigation scheduling should take into consideration essential variables that include the water supply in a reservoir and the water demand in the associated irrigation district. The agricultural water supply and demand show different patterns based on the variability and uncertainty of meteorological and hydrological phenomena. The duration of excessive water supply can be quantitatively determined through analysis of deviations and changes in the timing of agricultural water supply and demand. In this study, we introduce an approach to assess the vulnerable seasons of paddy irrigation to enable more effective operation and management of reservoirs. The vulnerable seasons were evaluated through comparison of the potential water supply capacity and irrigation water requirements based on water budget analysis via a time series change analysis. We have assessed the changing in the total duration and duration shifts of the vulnerable irrigation seasons for four agricultural reservoirs using past observed data (1981–2010) from meteorological stations maintained by the Korea Meteorological Administration (KMA) and projected climate change scenarios (2011–2100) as depicted by the Representative Concentration Pathways (RCPs) emission scenarios. For irrigation vulnerable seasons under both the RCP 4.5 and RCP 8.5 scenarios, the results showed periods of significant increases in which total vulnerable seasons compared to the historical period; the longest duration of vulnerability occurred during the 2071–2100 period under the RCP 8.5. Identification of the vulnerable seasons for paddy irrigation can be applied in agricultural water management to more effectively manage reservoir operation during irrigation periods with climate changes.
Won-Ho Nam; Taegon Kim; Eun-Mi Hong; Jin-Yong Choi. Regional climate change impacts on Irrigation Vulnerable Season Shifts in Agricultural Water Availability for South Korea. Water 2017, 9, 735 .
AMA StyleWon-Ho Nam, Taegon Kim, Eun-Mi Hong, Jin-Yong Choi. Regional climate change impacts on Irrigation Vulnerable Season Shifts in Agricultural Water Availability for South Korea. Water. 2017; 9 (10):735.
Chicago/Turabian StyleWon-Ho Nam; Taegon Kim; Eun-Mi Hong; Jin-Yong Choi. 2017. "Regional climate change impacts on Irrigation Vulnerable Season Shifts in Agricultural Water Availability for South Korea." Water 9, no. 10: 735.
Knowledge of the microbial quality of irrigation waters is extremely limited. For this reason, the US FDA has promulgated the Produce Rule, mandating the testing of irrigation water sources for many farms. The rule requires the collection and analysis of at least 20 water samples over two to four years to adequately evaluate the quality of water intended for produce irrigation. The objective of this work was to evaluate the effect of interannual weather variability on surface water microbial quality. We used the Soil and Water Assessment Tool model to simulate E. coli concentrations in the Little Cove Creek; this is a perennial creek located in an agricultural watershed in south-eastern Pennsylvania. The model performance was evaluated using the US FDA regulatory microbial water quality metrics of geometric mean (GM) and the statistical threshold value (STV). Using the 90-year time series of weather observations, we simulated and randomly sampled the time series of E. coli concentrations. We found that weather conditions of a specific year may strongly affect the evaluation of microbial quality and that the long-term assessment of microbial water quality may be quite different from the evaluation based on short-term observations. The variations in microbial concentrations and water quality metrics were affected by location, wetness of the hydrological years, and seasonality, with 15.7-70.1% of samples exceeding the regulatory threshold. The results of this work demonstrate the value of using modeling to design and evaluate monitoring protocols to assess the microbial quality of water used for produce irrigation.
Eun-Mi Hong; Daniel Shelton; Yakov A. Pachepsky; Won-Ho Nam; Cary Coppock; Richard Muirhead. Modeling the interannual variability of microbial quality metrics of irrigation water in a Pennsylvania stream. Journal of Environmental Management 2017, 187, 253 -264.
AMA StyleEun-Mi Hong, Daniel Shelton, Yakov A. Pachepsky, Won-Ho Nam, Cary Coppock, Richard Muirhead. Modeling the interannual variability of microbial quality metrics of irrigation water in a Pennsylvania stream. Journal of Environmental Management. 2017; 187 ():253-264.
Chicago/Turabian StyleEun-Mi Hong; Daniel Shelton; Yakov A. Pachepsky; Won-Ho Nam; Cary Coppock; Richard Muirhead. 2017. "Modeling the interannual variability of microbial quality metrics of irrigation water in a Pennsylvania stream." Journal of Environmental Management 187, no. : 253-264.
For agricultural water management to be successfully achieved, flow analysis of irrigation canal network flows is essential to determine the proper distribution of crop water requirements and to contribute to an optimized irrigation operation and water allocation. This study developed a hydraulic analysis model for irrigation canal flow by using the Storm Water Management Model (SWMM) module by adding the network modelling and paddy water balance model. This model was applied to a rice paddy field rehabilitation project area in the Daesan District located in the western part of South Korea. Results obtained from the calibrated simulation model were compared with the actual measurement data from water-level gauges at the irrigation canals. The irrigation hydraulic analysis model for canal network flow indicates the significance of using irrigation management tools in improving the analysis for accurate irrigation scheduling based on its simulation results, such as flow travel time, water level and flow amount. Copyright © 2016 John Wiley & Sons, Ltd.Pour la réalisation réussie de la gestion de l'eau agricole, il est essentiel d'analyser les écoulements dans les canaux d'irrigation, afin d'optimiser le fonctionnement du système d'irrigation et d'améliorer l'allocation de l'eau en fonction de la répartition des cultures. Cette étude a élaboré un modèle d'analyse hydraulique de l'écoulement des canaux d'irrigation en ajoutant la modélisation en réseau et un modèle de bilan hydrique du riz à un module du modèle de gestion des eaux pluviales (SWMM). Ce modèle a été appliqué à une rizière en réhabilitation dans le district de Daesan (ouest de la Corée du Sud). Les résultats obtenus après calibrage du modèle ont été comparés pour validation avec les données de jaugeage dans les canaux d'irrigation. Le modèle d'analyse hydraulique des flux de réseau de canaux d'irrigation montre l'importance d'utiliser des outils de gestion de l'irrigation pour améliorer la planification de l'irrigation en se basant sur des résultats de simulation, tels que le temps de transit, le niveau de l'eau et le flux.
Hae-Do Kim; Jin-Taek Kim; Won-Ho Nam; Sun-Joo Kim; Jin-Yong Choi; Bo-Sung Koh. Irrigation Canal Network Flow Analysis by a Hydraulic Model. Irrigation and Drainage 2016, 65, 57 -65.
AMA StyleHae-Do Kim, Jin-Taek Kim, Won-Ho Nam, Sun-Joo Kim, Jin-Yong Choi, Bo-Sung Koh. Irrigation Canal Network Flow Analysis by a Hydraulic Model. Irrigation and Drainage. 2016; 65 ():57-65.
Chicago/Turabian StyleHae-Do Kim; Jin-Taek Kim; Won-Ho Nam; Sun-Joo Kim; Jin-Yong Choi; Bo-Sung Koh. 2016. "Irrigation Canal Network Flow Analysis by a Hydraulic Model." Irrigation and Drainage 65, no. : 57-65.
Eun-Mi Hong; Won-Ho Nam; Jin-Yong Choi; Yakov Pachepsky. Projected irrigation requirements for upland crops using soil moisture model under climate change in South Korea. Agricultural Water Management 2016, 165, 163 -180.
AMA StyleEun-Mi Hong, Won-Ho Nam, Jin-Yong Choi, Yakov Pachepsky. Projected irrigation requirements for upland crops using soil moisture model under climate change in South Korea. Agricultural Water Management. 2016; 165 ():163-180.
Chicago/Turabian StyleEun-Mi Hong; Won-Ho Nam; Jin-Yong Choi; Yakov Pachepsky. 2016. "Projected irrigation requirements for upland crops using soil moisture model under climate change in South Korea." Agricultural Water Management 165, no. : 163-180.
Agricultural water is delivered by open irrigation canals in system of reservoirs with a widespread distribution in South Korea. Traditional irrigation management problems include water distribution systems with less capacity than the peak demand, irregular delivery rates, and low irrigation efficiency and uniformity. It is necessary to strategically compare the estimated irrigation demands with the actual water supplies for decision making in order to maintain the water supply according to the demand. Accurate measurement and monitoring of water distribution systems is essential in order to solve the problems of water efficiency and availability. Auto water level gauges installed at the head and tail sections of each irrigation canal in the Dongjin River were used to measure the discharge during irrigation periods. In this study, we introduced an approach to assess the water delivery performance indicators of the open irrigation canals, which is essential for identifying the key issues for water management improvement. The irrigation efficiencies according to the water delivery performance indicators were measured with an automatic water gauge in the irrigation canals and were calculated from the spatial and temporal distribution of the water supply for the lack of planning in water delivery. The calculated performance indicators are useful to understand the irrigator behavior and general irrigation trends. Analysis of the results yielded insights into possible improvement methods in order to develop water management policies that enable irrigation planners to improve the temporal uniformity and equity in the water distribution.
Won-Ho Nam; Eun-Mi Hong; Jin-Yong Choi. Assessment of water delivery efficiency in irrigation canals using performance indicators. Irrigation Science 2016, 34, 129 -143.
AMA StyleWon-Ho Nam, Eun-Mi Hong, Jin-Yong Choi. Assessment of water delivery efficiency in irrigation canals using performance indicators. Irrigation Science. 2016; 34 (2):129-143.
Chicago/Turabian StyleWon-Ho Nam; Eun-Mi Hong; Jin-Yong Choi. 2016. "Assessment of water delivery efficiency in irrigation canals using performance indicators." Irrigation Science 34, no. 2: 129-143.
Won-Ho Nam; Guillermo A. Baigorria. Analysing changes to the spatial structures of precipitation and temperature under different ENSO phases in the Southeast and Midwest United States. Meteorological Applications 2015, 22, 797 -805.
AMA StyleWon-Ho Nam, Guillermo A. Baigorria. Analysing changes to the spatial structures of precipitation and temperature under different ENSO phases in the Southeast and Midwest United States. Meteorological Applications. 2015; 22 (4):797-805.
Chicago/Turabian StyleWon-Ho Nam; Guillermo A. Baigorria. 2015. "Analysing changes to the spatial structures of precipitation and temperature under different ENSO phases in the Southeast and Midwest United States." Meteorological Applications 22, no. 4: 797-805.
Eun-Mi Hong; Jin-Yong Choi; Won-Ho Nam; Jin-Taek Kim. Decision Support System for the Real-Time Operation and Management of an Agricultural Water Supply. Irrigation and Drainage 2015, 65, 197 -209.
AMA StyleEun-Mi Hong, Jin-Yong Choi, Won-Ho Nam, Jin-Taek Kim. Decision Support System for the Real-Time Operation and Management of an Agricultural Water Supply. Irrigation and Drainage. 2015; 65 (2):197-209.
Chicago/Turabian StyleEun-Mi Hong; Jin-Yong Choi; Won-Ho Nam; Jin-Taek Kim. 2015. "Decision Support System for the Real-Time Operation and Management of an Agricultural Water Supply." Irrigation and Drainage 65, no. 2: 197-209.
Drought has had large impacts on economies, societies and the environment, and could become even more disruptive given the context of climate change characterized by increasing temperature and more variable and extreme precipitation. Changes in the frequency, duration, and severity of droughts will have enormous impacts on the hydrological cycle, water management and agricultural production. Therefore, one major concern arising from climate change is its potential effects on water resources. Although South Korea has been experiencing serious drought and water scarcity issues in recent years, preparedness for potential changes in the frequency, severity and duration of drought disasters due to climate change effects has received only limited attention. It is important to detect changes in temporal trends of drought at the regional scale. This information will aid understanding the impacts of climate change and its subsequent effects on hydrology and agriculture. In this paper, we have addressed the question of how climate change might influence the impact of drought hazard by estimating the potential changes in temporal trends of drought in South Korea. We have assessed the temporal trends of future drought with drought indices (Standardized Precipitation Index [SPI], Standardized Precipitation Evapotranspiration Index [SPEI], and Self-Calibrating Palmer Drought Severity Index [SC-PDSI]) using past observed data (1981–2010) from 54 meteorological stations maintained by the Korea Meteorological Administration (KMA) and projected climate change scenarios (2011–2100) as depicted by the Representative Concentration Pathways models (RCPs). The drought hazard assessment was quantitatively evaluated by analyzing drought frequency, duration, severity and magnitude using the run theory method based on different timescales of the drought indices. The results demonstrated a significant increase of potential drought impacts in the future. Additionally, significant increases in the drought magnitude and severity were found at different time scales for each drought indicator. The results indicated that the temporal pattern of potential drought progression and recession across South Korea can be used for the development of proactive drought risk management and mitigation strategies.
Won-Ho Nam; Michael J. Hayes; Mark D. Svoboda; Tsegaye Tadesse; Donald A. Wilhite. Drought hazard assessment in the context of climate change for South Korea. Agricultural Water Management 2015, 160, 106 -117.
AMA StyleWon-Ho Nam, Michael J. Hayes, Mark D. Svoboda, Tsegaye Tadesse, Donald A. Wilhite. Drought hazard assessment in the context of climate change for South Korea. Agricultural Water Management. 2015; 160 ():106-117.
Chicago/Turabian StyleWon-Ho Nam; Michael J. Hayes; Mark D. Svoboda; Tsegaye Tadesse; Donald A. Wilhite. 2015. "Drought hazard assessment in the context of climate change for South Korea." Agricultural Water Management 160, no. : 106-117.
Detecting changes in the spatio‐temporal patterns of temperature and precipitation is a prerequisite for developing effective adaptation options and strategies for the future. An effective method for assessing climate change and for providing information to decision makers and stakeholders is needed to implement appropriate adaptation strategies. The objective of this study was to determine whether climate change has caused spatio‐temporal changes in meteorological elements in North Korea. We delineated the spatio‐temporal patterns of temperature and precipitation caused by climate change in specific time periods based on statistically significant differences using a statistically robust method. Historical weather data from 27 meteorological stations over a 30‐year period (1981–2010) were used. The results demonstrated that statistically significant changes occurred over the 30 years. The temporal trends in the maximum and minimum temperatures were highly significantly different in the western agricultural regions and central/southwest urban regions during 1996–2010 compared with 1981–1995. The precipitation amounts were significantly different in the southeast regions (around the coast). The numbers of precipitation events were significantly different for portions of the northern and northeast areas near the mountains. Additionally, statistically significant differences in the spatial structures of the temperature and precipitation were found at different time scales. The significant differences were not uniform in each season/month. Therefore, significant differences occurred in the meteorological elements, and particular locations and urbanized areas were affected by global warming. However, the temporal trends and spatial structures of each meteorological element were not equally modified; the meteorological changes occurred locally as a result of the changing climate.
Won-Ho Nam; Eun-Mi Hong; Guillermo A. Baigorria. How climate change has affected the spatio-temporal patterns of precipitation and temperature at various time scales in North Korea. International Journal of Climatology 2015, 36, 722 -734.
AMA StyleWon-Ho Nam, Eun-Mi Hong, Guillermo A. Baigorria. How climate change has affected the spatio-temporal patterns of precipitation and temperature at various time scales in North Korea. International Journal of Climatology. 2015; 36 (2):722-734.
Chicago/Turabian StyleWon-Ho Nam; Eun-Mi Hong; Guillermo A. Baigorria. 2015. "How climate change has affected the spatio-temporal patterns of precipitation and temperature at various time scales in North Korea." International Journal of Climatology 36, no. 2: 722-734.
Won-Ho Nam; Jin-Yong Choi; Eun-Mi Hong. Irrigation vulnerability assessment on agricultural water supply risk for adaptive management of climate change in South Korea. Agricultural Water Management 2015, 152, 173 -187.
AMA StyleWon-Ho Nam, Jin-Yong Choi, Eun-Mi Hong. Irrigation vulnerability assessment on agricultural water supply risk for adaptive management of climate change in South Korea. Agricultural Water Management. 2015; 152 ():173-187.
Chicago/Turabian StyleWon-Ho Nam; Jin-Yong Choi; Eun-Mi Hong. 2015. "Irrigation vulnerability assessment on agricultural water supply risk for adaptive management of climate change in South Korea." Agricultural Water Management 152, no. : 173-187.