• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.3
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• pp.101-108
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• 2015

The purpose of this study was to evaluate the safety of the small reservoir, which is distributed in a rural area, based on systemic reliability. It has been estimated that safety of respective reservoir the calculation of failure probability for individual reservoirs can evaluate the safety of the reservoir of the study area. The change of safety for watershed could be figured out as that result. Probability of failure was increased from $3.90{\times}10^{-5}$ to $1.35{\times}10^{-4}$ in Naesu-inpyung reservoir, from $1.33{\times}10^{-5}$ to $4.77{\times}10^{-5}$ in Buyeon reservoir and from $4.24{\times}10^{-5}$ to $2.55{\times}10^{-2}$ in Dalakmal respectively. From the results, the collapse of the upper stream reservoir was analyzed qualitatively that may affect the safety of the reservoir on the downstream area.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.2
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• pp.45-52
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• 2011

This study is to develop a Priority Decision System for Redevelopment (PDSR) which is able to decide the priority for redevelopment of agricultural reservoirs. The major scopes of this research are to make the related GIS data like hydrologic unit map and other thematic maps to determine the suggested priority index (PI), and to develop the PDSR handling the GIS data and calculating weighing factors for the PI. In order to make the weighing factor decision module, the AHP technique was adopted. The result of the weighing factor calculation was showed PC (Possibility Criteria) and RC (Restriction Criteria) were 76% and 24% respectively. Which means that most of the specialist selected PC category prior to RC because of whom to mostly of major technique. So, in order to make more objective result, the selection of specialists is important like environmental activists or local residents and so on. The product from this research can provide more scientific support to decide the priority decision.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.4
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• pp.83-93
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• 2013

Annual average precipitation of Korea is 1,277 mm and around 2/3 of annual precipitation and 74 % of available water resources occurred during monsoon period. In recent years, many agricultural reservoirs have been heightened to increase flood control capacity, reduce flooding damage at downstream areas, and provide sustainable environmental flow during drought period. Thus in this study, the flood control effects of heightening of reservoir banks were simulated with HEC-ResSim and HEC-RAS models. These modes were applied to Bonghak reservoir and it was found that flood control effects were 3~4.5 % with 7 -m heightening. Also, with proper operation (1 m lower of full water level) of reservoir right before the monsoon period, flooding at downstream could be prevented even with design storm of 80 -year recurrence interval. As shown in this study, heightening of agricultural reservoir provides positive effects in flood control and flood damage reduction.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.4
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• pp.1-12
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• 2021

Agricultural drought is a natural phenomenon that is not easy to observe and predict and is difficult to quantify. In South Korea, the amount of agricultural water used is large and the types of use are varied, so even if an agricultural drought occurs due to insufficient precipitation, the drought actually felt in the irrigated area is it can be temporally and spatially different. In order to interpret the general drought in the past, drought disasters were evaluated using single indicators such as drought damage area, precipitation shortage status, and drought index, and a comprehensive drought management system is needed through drought diagnosis survey. Therefore, we intend to conduct research on agricultural drought assessment and diagnosis using re-evaluation of agricultural facilities and irrigation water supply network due to changes in various conditions such as climate change, irrigation canal network, and evaluation of water supply capacity of agricultural facilities. In this study, agricultural drought diagnosis was conducted on two agricultural reservoirs located in Sangju, Gyeongsangbuk-do, with structural or non-structural evaluations to increase spatiotemporal water supply and efficiency in terms of water shortages. The results of the agricultural drought diagnosis evaluation can be used to identify irrigated areas and canal network vulnerable to drought and to prioritize drought response.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.4
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• pp.1-12
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• 2020

The extreme 2017 spring drought affected a large portion of South Korea in the Southern Gyeonggi-do and Chungcheongnam-do districts. This drought event was one of the climatologically driest spring seasons over the 1961-2016 period of record. It was characterized by exceptionally low reservoir water levels, with the average water level being 36% lower over most of western South Korea. In this study, we consider drought response methods to alleviate the shortage of agricultural water in times of drought. It could be to store water from a stream into a reservoir. There is a cyclical method for reusing water supplied from a reservoir into streams through drainage. We intended to present a decision-making plan for water supply based on the calculation of the quantity of water supply and leakage. We compared the rainfall-runoff equation with the TANK model, which is a long-term run-off model. Estimations of reservoir inflow during non-irrigation seasons applied to the Madun, Daesa, and Pungjeon reservoirs. We applied the run-off flow to the last 30 years of rainfall data to estimate reservoir storage. We calculated the available water in the river during the non-irrigation season. The daily average inflow from 2003 to 2018 was calculated from October to April. Simulation results show that an average of 67,000 tons of water is obtained during the non-irrigation season. The report shows that about 53,000 tons of water are available except during the winter season from December to February. The Madun Reservoir began in early October with a 10 percent storage rate. In the starting ratio, a simulated rate of 4 K, 6 K, and 8 K tons is predicted to be 44%, 50%, and 60%. We can estimate the amount of water needed and the timing of water pump operations during the non-irrigation season that focuses on fresh water reservoirs and improve decision making for efficient water supplies.

• Journal of Soil and Groundwater Environment
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• v.27 no.5
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• pp.1-9
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• 2022

A correlation analysis was performed to investigate differences in the response of surface water and groundwater to drought using the Standardized Precipitation Index (SPI). Water level data of 20 agricultural reservoirs, 4 dams, 2 rivers, and 8 groundwater observation wells were used for the analysis. SPI was calculated using precipitation data measured at a nearby meteorological station. The water storage of reservoirs and dams decreased significantly as they responded sensitively to the drought from 2014 to 2016, showing high correlation with SPI of the relatively long accumulation period (AP). The responses of rivers varied greatly depending on the presence of an upstream dam. The water level in rivers connected to an upstream dam was predominantly influenced by the dam discharge, resulting in very weak correlation with SPI. On the contrary, the rivers without dam exhibited a sharp water level rise in response to precipitation, showing higher correlation with SPI of a short-term AP. Unlike dams and reservoirs, the responses of groundwater levels to precipitation were very short-lived, and they did not show high correlation with SPI during the long-term drought. In drought years, the rise of groundwater level in the rainy season was small, and the lowered water level in the dry season did not proceed any further and was maintained at almost the same as that of other normal years. Conclusively, it is confirmed that groundwater is likely to persist longer than surface water even in the long-term drought years.

• Korean Journal of Remote Sensing
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• v.38 no.5_3
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• pp.925-938
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• 2022

Agricultural reservoirs are an important water resource nationwide and vulnerable to abnormal climate effects such as drought caused by climate change. Therefore, it is required enhanced management for appropriate operation. Although water-level tracking is necessary through continuous monitoring, it is challenging to measure and observe on-site due to practical problems. This study presents an objective comparison between multiple AI models for water-body extraction using radar images that have the advantages of wide coverage, and frequent revisit time. The proposed methods in this study used Sentinel-1 Synthetic Aperture Radar (SAR) images, and unlike common methods of water extraction based on optical images, they are suitable for long-term monitoring because they are less affected by the weather conditions. We built four AI models such as Support Vector Machine (SVM), Random Forest (RF), Artificial Neural Network (ANN), and Automated Machine Learning (AutoML) using drone images, sentinel-1 SAR and DSM data. There are total of 22 reservoirs of less than 1 million tons for the study, including small and medium-sized reservoirs with an effective storage capacity of less than 300,000 tons. 45 images from 22 reservoirs were used for model training and verification, and the results show that the AutoML model was 0.01 to 0.03 better in the water Intersection over Union (IoU) than the other three models, with Accuracy=0.92 and mIoU=0.81 in a test. As the result, AutoML performed as well as the classical machine learning methods and it is expected that the applicability of the water-body extraction technique by AutoML to monitor reservoirs automatically.

• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1135-1144
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• 2023

Many agricultural reservoirs in South Korea, constructed before 1970, have become aging facilities. The majority of small-scale reservoirs lack measurement systems to ascertain basic specifications and water levels, classifying them as unmeasured reservoirs. Furthermore, continuous sedimentation within the reservoirs and industrial development-induced water quality deterioration lead to reduced water supply capacity and changes in reservoir morphology. This study utilized Light Detection And Ranging (LiDAR) sensors, which provide elevation information and allow for the characterization of surface features, to construct high-resolution Digital Surface Model (DSM) and Digital Elevation Model (DEM) data of reservoir facilities. Additionally, bathymetric measurements based on multibeam echosounders were conducted to propose an updated approach for determining reservoir capacity. Drone-based LiDAR was employed to generate DSM and DEM data with a spatial resolution of 50 cm, enabling the display of elevations of hydraulic structures, such as embankments, spillways, and intake channels. Furthermore, using drone-based hyperspectral imagery, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) were calculated to detect water bodies and verify differences from existing reservoir boundaries. The constructed high-resolution DEM data were integrated with bathymetric measurements to create underwater contour maps, which were used to generate a Triangulated Irregular Network (TIN). The TIN was utilized to calculate the inundation area and volume of the reservoir, yielding results highly consistent with basic specifications. Considering areas that were not surveyed due to underwater vegetation, it is anticipated that this data will be valuable for future updates of reservoir capacity information.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.163-168
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• 2016

For the quality increase of agricultural and aquatic products, it is necessary to the efficient management system of integrated control and accurate data for improving the water quality of reservoirs. This may be using the USN save time and money. In this paper, the water surface robot was designed and manufactured for measuring and announcing the environment informations, and it's network was constructed. The robot had more excellent durability and was more inexpensive than previous model. The network was designed considering connection with ZigBee, TRS, Wi-Fi or LTE network. Also the exploration function of the robot was confirmed by the simulation and the user interface was programmed.

• KCID journal
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• v.19 no.1
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• pp.30-39
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• 2012

In recent years, there have been a lot of severe flood and drought disasters and the rural environment have been worsened due to rapid industrialization and urbanization in the river basins of Korea. To prevent such disasters and to improve environment in the era of climate change, Korean Government carried out 110 projects to heighten irrigation dam in the rural area. The study has been carried out to evaluate the heightening work of the irrigation dam for the supply of reserved water and to derive optimal scheme to allocate the water resource for irrigation, domestic demand and environmental conservation as well as to contribute for the rural development in sustainable way. The study is focused on the Seoam Irrigation Dam which has been constructed in 2005 to be connected with the new Gami Reservoir which has been constructed since 2010. In addition, it was studied the contribution effect of the reservoirs for the adjacent comprehensive rural development projects which have been executed by local government. In the study, the principles and visions of sustainable development which have been derived by International Commission on Irrigation and Drainage is applied to estimate the sustainability of the irrigation dams in line with the adjacent comprehensive rural development projects. The project is estimated that the water resource in the reservoirs shall be used integratedly in cooperation with various stakeholders not only to conserve water environment but also to increase productivity of agricultural goods and ecological tour in the rural area.