• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.3
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• pp.47-57
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• 2021

Drought monitoring over paddy field area is an important role as the frequency and intensity of drought due to climate change increases. This study analyzed the applicability of drought monitoring on paddy crops using MODIS-based field surveys. As a satellite-based drought index using evapotranspiration for quantitative drought determination, ESI (Evaporative Stress Index), was applied and calculated through the ratio of MODIS- based actual and potential evapotranspiration. For the irrigated areas of Idong, Gosam, Geumgwang, and Madun reservoirs the availability of irrigation water supply, ponding depth, precipitation, paddy growth were investigated for the paddy field within one grid of MODIS. In addition, the percentile-based ESI drought severity was calculated to compare the growth process of paddy and changes in the drought category of ESI. The Idong area was irrigated about a week later than other reservoirs for the period of water supply, transplanting, and water drainage and the ESI drought category tended to be different. The Gosam, Geumgwang, and Madun area expressed moderate drought prior to the farming season, and indicated normal as the water was supplied. During the water drainage, the drought category intensified, indicating that the water available on land was decreasing. These results demonstrated that the MODIS-based ESI could be an effective tool for agricultural drought monitoring over paddy field area.

• Geophysics and Geophysical Exploration
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• v.21 no.4
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• pp.244-254
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• 2018

The first geophysical technique applied to the agricultural sector in Korea was electrical resistivity sounding and conducted in purpose of groundwater exploitation in the 1970s. According to the diversity of agricultural activities since the 1990s, various geophysical methods including electrical resistivity, electromagnetic induction, and self-potential method were applied to several agricultural fields such as soil characterization with saline concentration in vast reclaimed area, delineation of seawater intrusion regions in costal aquifer, safety inspection of embankment dikes with leakage problem, detection of ground subsidence from overpumping and tracing of groundwater aquifer contamination by leachate from livestock mortality burial or waste burial site. This paper introduces representative geophysical techniques that have been utilized in various agricultural fields and suggests several ways to develop the geophysical methods required for the precision agriculture field in the near future based on the past achievements.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.3
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• pp.1-14
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• 2019

North Korea has frequently suffered from extreme agricultural crop droughts, which have led to food shortages, according to the Food and Agriculture Organization (FAO). The increasing frequency of extreme droughts, due to global warming and climate change, has increased the importance of enhancing the national capacity for drought management. Historically, a meteorological drought index based on data collected from weather stations has been widely used. But it has limitations in terms of the distribution of weather stations and the spatial pattern of drought impacts. Satellite-based data can be obtained with the same accuracy and at regular intervals, and is useful for long-term change analysis and environmental monitoring and wide area access in time and space. The Evaporative Stress Index (ESI), a satellite-based drought index using the ratio of potential and actual evaporation, is being used to detect drought response as a index of the droughts occurring rapidly over short periods of time. It is more accurate and provides faster analysis of drought conditions compared to the Standardized Precipitation Index (SPI), and the Palmer Drought Severity Index (PDSI). In this study, we analyze drought events during 2015-2017 in North Korea using the ESI satellite-based drought index to determine drought response by comparing with it with the SPI and SPEI drought indices.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.1
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• pp.39-50
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• 2022

In this study, we suggested the optimal training period for predicting the streamflow using the LSTM (Long Short-Term Memory) model based on the deep learning and CMIP5 (The fifth phase of the Couple Model Intercomparison Project) future climate scenarios. To validate the model performance of LSTM, the Jinan-gun (Seongsan-ri) site was selected in this study. We comfirmed that the LSTM-based streamflow was highly comparable to the measurements during the calibration (2000 to 2002/2014 to 2015) and validation (2003 to 2005/2016 to 2017) periods. Additionally, we compared the LSTM-based streamflow to the SWAT-based output during the calibration (2000~2015) and validation (2016~2019) periods. The results supported that the LSTM model also performed well in simulating streamflow during the long-term period, although small uncertainties exist. Then the SWAT-based daily streamflow was forecasted using the CMIP5 climate scenario forcing data in 2011~2100. We tested and determined the optimal training period for the LSTM model by comparing the LSTM-/SWAT-based streamflow with various scenarios. Note that the SWAT-based streamflow values were assumed as the observation because of no measurements in future (2011~2100). Our results showed that the LSTM-based streamflow was similar to the SWAT-based streamflow when the training data over the 30 years were used. These findings indicated that training periods more than 30 years were required to obtain LSTM-based reliable streamflow forecasts using climate change scenarios.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.1
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• pp.15-26
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• 2023

This study aimed to evaluate the performance of water level classification from CCTV images in agricultural facilities such as reservoirs. Recently, the CCTV system, widely used for facility monitor or disaster detection, can automatically detect and identify people and objects from the images by developing new technologies such as a deep learning system. Accordingly, we applied the ResNet-50 deep learning system based on Convolutional Neural Network and analyzed the water level of the agricultural reservoir from CCTV images obtained from TOMS (Total Operation Management System) of the Korea Rural Community Corporation. As a result, the accuracy of water level detection was improved by excluding night and rainfall CCTV images and applying measures. For example, the error rate significantly decreased from 24.39 % to 1.43 % in the Bakseok reservoir. We believe that the utilization of CCTVs should be further improved when calculating the amount of water supply and establishing a supply plan according to the integrated water management policy.

• The Journal of Fisheries Business Administration
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• v.45 no.1
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• pp.79-93
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• 2014

The Act on Distribution and Price Stabilization of Agricultural and Fisheries Product, which specifies rules and regulations on the trading system of fishery products wholesales markets, has been revised several times, mainly in order to improve the trading system. However, there is still a huge gap between the reality and law when it comes to the trading system of the fishery products wholesale market. This study aims to analyze the problems of the trading system of the fishery products wholesale market and to suggest ways to make improvement. The main problem facing the trading system of the fishery products wholesale market is sales on consignment by intermediate wholesalers, and this paper suggests two alternatives to solve the problem. First, intermediate wholesaler can be converted to market wholesalers, but it also entails other problems. The market wholesaler system has never been successfully adopted in the agricultural and fishery products wholesale market, and it is not clear which system is better between the wholesale market corporation and the market wholesaler system. Second, sales on consignment by intermediate wholesalers can be adopted with a positive view toward it. Negotiation transaction can be carried out for sales on consignment as a transaction method under the current Act on Distribution and Price Stabilization of Agricultural and Fisheries Products. However, since the act cannot provide a solution for listing, it is necessary to introduce Japan's negotiated transaction in advance system as a negotiation transaction method.

• Korean Journal of Agricultural Science
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• v.34 no.2
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• pp.189-200
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• 2007

The purpose of this study is to evaluate the farmland scale improvement project and to present basic data for establishing a long-term improvement scheme of this project. Professional rice cultivators' farming scale after receiving the farmland scale improvement fund has increased compared to the situation before receiving the fund support. The average paddy fields increased by 220% (from 2.75ha to 8.82ha), the average upland increased by 27% (from 0.44ha to 0.56ha), and the average orchard land increased by 44% (from 0.25ha to 0.36ha). The rice production costs per 10a are estimated as 608,678won for below 3ha, 488,721won for 3-6ha, 487,431won for 6~10ha, and 425,313won for over 10ha, which decreased with increasing farming scale. The effects of the farmland scale improvement project on income variation are summarized as follows. 1) Average farm household income for all subjects has increased by 223 % (from 40,517,000won to 90,295,000won). 2) For each category, the results show that average farm household income has increased by 9,766,000won for below 3ha, 35,898,000won for 3~6ha, 42,822,000won for 6~10ha, and 72,697,000won for over 10ha.

• Journal of Korean Society of Rural Planning
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• v.20 no.2
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• pp.81-90
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• 2014

This study was carried out to identify the limitations and problems of organization, as well as present plans to activate the organization through diagnosis on 'My Hometown Keeper' organization that was created for the purpose of growth of agricultural and fishing regions, and environment improvement. Utilizing Weisbord's Six-box Model, an organization diagnosis model useful for diagnosis of 'My Hometown Keeper' organization, 6 areas including organization's objective, structure, relationship, compensation system, leadership, subsidiary device system etc. and 14 survey questions were prepared, and a survey investigation was conducted on the staff at Korea Rural Community Corporation in charge of 'My Hometown Keeper' participating residents and administrative support. Based on the analysis results of survey investigation, the limitations and problems of organization were identified, and as plans to improve these and activate 'My Hometown Keeper' organization, 'Clear establishment of organization's objective and role', 'Preparation of compensation and incentive system', 'Growth of relationship and leadership between constituents' 'Enhancing the utilization of subsidiary device system such as education and information acquisition etc.' etc. were presented.

• Journal of Agricultural Extension & Community Development
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• v.22 no.4
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• pp.423-434
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• 2015

This paper predicts the onion's cultivation areas, yields per unit area, and wholesale prices during ship dates by using wholesale price data from the Korea Agro-Fisheries & Food Trade Corporation, the production data from the Statistics Korea, and the weather data from the Korea Meteorological Administration with an ARDL model. By analyzing the data of wholesale price, rural household income and rural total earnings, onion cultivation areas in 2015 are estimated to be 21,035, 17,774 and 20,557(ha). In addition, onion yields per unit area of South Jeolla Province, North Gyeongsang Province, South Gyeongsang Province, Jeju Island, and the whole country in 2015 are estimated to be 5,980, 6,493, 6,543, 6,614, 6,139 (kg/10a) respectively. By using onion production's predictive value found from onion's cultivation areas and yields per unit area in 2015, the onion's wholesale prices in June are estimated to be 780 won, 1,100 won, and 820 won for each model. Predicted monthly price after the onion's ship dates is analyzed to exceed 1,000 won after August.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.146-152
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• 2015

Heavy metal pollution has been a critical problem in agricultural field near at the abandoned metal mines and chemical amendments are applied for remediation purpose. However, biological activity can be changed depending on chemical amendments affecting crop productivity. Main purpose of this research was to evaluate biological parameters after applying chemical amendments in heavy metal polluted agricultural field. Result showed that soil respiration (SR) and microbial biomass carbon (MBC) were changed after chemical amendments were applied. Among three different amendments, lime stone (LS), steel slag (SS), and acid mine drainage sludge(AMDS), AMDS had an effect to increase SR in paddy soil. Comparing to control ($93.98-170.33mg\;kg^{-1}day^{-1}$), average of 30% increased SR was observed. In terms of MBC, SS had an increased effect in paddy soil. However, no significant difference of SR and MBC was observed in upland soil after chemical amendment application. Overall, SR can be used as an indicator of heavy metal remediation in paddy soil.