• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.57-59
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• 2004

This paper reports the observation of the interferometric synthetic aperture radar (InSAR) phase anomaly on a newly reclaimed mudflat, Hwaong, in west coast of Korea, detected by a series of Radarsat-l SAR data obtained mostly during 2003. The observed phase anomaly could be from subsidence of mud land caused by volumetric contraction of mud in dry season. This process must have been initiated from March 2002 when tidal water supply to this region was permanently blocked by the newly constructed embankment. The maximum subsidence rate measured from InSAR signal is about 3 cm per month. The local heterogeneity of the subsidence rate over the reclaimed mudflat may indicate various mud composition, surface-subsurface hydrological processes, or subsurface information of the mud and basement rock structure. In-situ measurement must follow to support this observation from space.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.4
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• pp.67-73
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• 2009

Chemical properties of soil in the proposed horticultural complexes of Saemangeun reclaimed tideland were studied for sustainable development of the newly reclaimed land resources. The soil texture of Gwanghwal, Gyehwa, Mangyeong and Okgu complex area were sandy loam. The pH and ESP (exchangeable sodium percentage) were 7.42 to 7.82 and 61.05 to 73.62 %, respectively. Compared to general agricultural land in Korea, the soil organic matter and other plant nutrients were low. The concentrations of heavy metals in the soil were found to be acceptable except several sites where they doesn't meet the warning standard of agricultural land contamination. Continuous monitoring and interception of external pollutants are suggested for water-soil-plant system conservation.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.313-318
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• 2014

The remote monitoring system of water salinity was assessed in Wando reclaimed land lake during a farming season in 2009. Increasing of water salinity in this lake used to bring about salt damage on rice plant occasionally. At the early stage of the rice growing period, rice growth was not damaged due to enough rainfall with more than 120 mm from the mid-May to the first ten days of June. Data collection using on-site water salinity measuring sensors every 2 hours and real-time transmission in system were carried out for the experiment. We compared the transmitted values from the sensor system with water sample values collected and analyzed by a local technical office. Salt concentrations measured by sensor in real-time monitoring system were available data. The regression equation between rainfall and water salinity was presented as (water salinity after rainfall) = $0.621{\times}$(water salinity before rainfall)${\times}exp(-0.0139{\times}rainfall)$, ($r^2=0.579$, p<0.01). It is suggested that the system is useful for stable farming in the area where farmer use water in reclaimed lakes as an irrigation source.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.5
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• pp.51-68
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• 2023

Due to the recent integrated water management policy, it is important to identify a reliable supply amount for establishing an agricultural water supply plan. In order to identify the amount of agricultural water supply, it is essential to calculate the discharge by measuring the water level and flow velocity of reservoirs and canal agricultural water, and quality control to ensure reliability must be preceded. Unlike agricultural reservoirs, canal agricultural water are more sensitive to the surrounding environment and reservoir irrigation methods (continuous, intermittent irrigation, etc.), making it difficult to estimate general water level patterns and at the same time a lot of erroneous data. The Korea Rural Community Corporation is applying a filter technique as a quality control method capable of processing large quantities and real-time processing of canal agricultural water level data, and applicability evaluation is needed. In this study, the types of errors generated by the automatic water level measurement system were first determined. In addition, by using the manual quality control data, a technique with high applicability is derived by comparing and analyzing data calibrated with Gaussian, Savitzky-Golay, Hampel, and Median filter techniques, RMSE, and NSE, and the optimal parameters of the technique range was derived. As a result, the applicability of the Median filter was evaluated the highest, and the optimal parameters were derived in the range of 120min to 240min. Through the results of this study, it is judged that it can be used for quantitative evaluation to establish an agricultural water supply plan.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.69-75
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• 2009

Water stress has become a major concern in agriculture. Korea suffers from limited agricultural water supply, and wastewater reuse has been recommended as an alternative solution. A study was performed to examine the effects of microorganism concentration in the ponded-water of a paddy rice field with reclaimed-water irrigation for evaluating the microbial risk to farmers and neighborhood children. Most epidemiological studies were performed based on an upland field, and they may not directly applicable to paddy fields. Beta-Poisson model was used to estimate the microbial risk of pathogen ingestion. Their risk value increased significantly high level after irrigation and precipitation. It implies that agricultural activities such as plowing, and fertilizing, and precipitation need be practiced a few days after irrigation considering health risks. The results about field application of the microbial risk assessment using E. coli showed difference according to monitoring time and treatment plot. Result of the microbial risk assessment showed that risk values of ground-water and reclaimed secondary wastewater irrigation were lower than directly use of wastewater treatment plants' effluent. This paper should be viewed as a first step in the application of quantitative microbial risk assessment of E. coli to wastewater reuse in a paddy rice farming.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.1
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• pp.71-77
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• 2005

Recycling of reclaimed concrete (RC) is very important in the management of construction and demolition wastes. Most of RC is utilized for land-filling after crushing in this country. In this study, a series of elution experiments were conducted to investigate the type and amount of pollutants released from the crushed RC. Most water quality parameters including heavy metals and some organic compounds were below standards for drinking water. Some of heavy metals such as As, Cd, Pb, Hg were detected in 0.5 N H2S04 solution after 24-hour immersing RC, which was conducted for evaluating a long term release effect. The concentration of the heavy metals were higher than the drinking water standards. The results also showed significant adsorption of heavy metals by crushed Re. Potential risks, based on the result of this study were not high in using crushed RC for land-filling. Appropriate management of RC would reduce the risk, for example the separation of hazardous materials from construction wastes. Long term evaluations for the sites of land filled with RC would be required to assess the environmental impacts.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.1
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• pp.75-86
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• 2004

The objective of the research is to develop agricultural resue technologies of reclaiming the effluents from a municipal wastewater treatment plant and reusing for irrigated rice paddies. The Suwon wastewater treatment plant was selected for wastewater reuse tests. The control was the plots with groundwater irrigation (TR＃1), the treatment (TR＃2) using polluted stream water as it was, and three others using wastewater after treatment. Three levels of wastewater treatments were employed： the effluent from the wastewater treatment plant (TR＃3), sand filtering after treatment plant(TR＃4), and ultra-violet treatment after sand filtering (TR＃5). The randomized block method was applied to wastewater application to paddy rice with five treatments and six replica. The effects of various wastewater treatment levels on water quality, paddy soil, crop growth, yields, and the health hazards were investigated. The primary results indicate that cultivating rice with reclaimed wastewater irrigation did not cause a problem to adverse effects on crop growth and yields. Overall, wastewater could be used as a practical alternative measure for reclaimed wastewater irrigation. However, long-term monitoring is recommended on the effects on soil chemical characteristics and its related health concerns.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.238-242
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• 2003

Reclaimed tidal areas for rice cultivation are irrigated with salt mixed water when there is severe drought. Therefore, we identified the critical concentration of saline water for rice growth on a reclaimed saline soil in Korea. The experiment was conducted at the Kyehwado substation of the National Honam Agricultural Experiment Station (NHAES) during 2001-2002. Two experimental fields with 0.1-0.2% for low soil salinity and 0.3-0.4% for medium soil salinity levels were used. The experiment involved four levels of salt solution mixed with sea water (at 0.1, 0.3, 0.5, 0.7%) compared with a control using tap water in a split-plot design with three replicates. Saline solution was applied only two times at seedling stage (10 DAT and 25 DAT) for 5 days. Gyehwabyeo and dongjinbyeo, japonica rice varieties, were used in this experiment. Plant height and number of tillers sharply decreased in the 0.5% saline water in low soil salinity level and 0.1% in medium soil salinity level. For yield components, panicle number per unit area and percentage of ripened grain dramatically decreased in the 0.5% saline water in low soil salinity and 0.1% in medium soil salinity level. But 1,000-grain weight of brown rice decreased sharply in the 0.5% saline water in low soil salinity and 0.3% in medium soil salinity, indicating that this component was not much affected unlike other yield components. Milled rice yield decreased significantly with saline water level in both low and medium soil salinity. In the 0.7% low saline soil, the yield index was only 36% compared with the control. In medium soil salinity, even the control plot showed only 62% yield index compared with the control in the low soil salinity treatment. Results indicated that the critical concentration of saline water for rice growth in terms of economical income of rice production was 0.5% in low soil salinity and tap water in medium soil salinity.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.5
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• pp.83-93
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• 2021

Agricultural reservoirs are important facilities for storing or managing water for the purpose of securing agricultural water, creating and expanding agricultural production bases, and using them to increase agricultural production. In particular, the Korea Rural Community Corporation (KRC) manages agricultural reservoirs scattered across the country, and officially recognizes and distributes hydrological data to increase their public utilization and aims to improve the value of water resources. Data on the water level of agricultural reservoirs are important. However, errors such as missing values and outliners limit utilization of the data in various fields of research and industry. Therefore, water quality data measures should be devised to increase reliability. this study categorized different error types and looked at automatic correction methods to enhance the reliability of the vast hydrological data. In addition, the water level data corrected from errors were compared to the reference hydrologic data through expert judgment in accordance with the quality control procedure, and the most appropriate measures were verified. As KRC manages more agricultural reservoirs than any other institution, the proposed method of efficient and automatic water level data correction in this study is expected to increase the availability and reliability of the hydrological data.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.4
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• pp.127-133
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• 1988

This study was performed to obtain the basic data analyzing salt movement and desalinization effects, and two different desalinization experiments through leaching and rinsing were carried out, using samples of silt loam soil and silty clay loam soil collected in reclaimed tidelands. The relationships between the electrical conductivity of saturation extract and the electrical conductivity at various dilutions, and the correlations between electrical conductivity, total salt concentration, exchangeable sodium percentage and pH during the desalinization of reclaimed tidelands, were analyzed by the statistical method. The results obtained from this study were summarized as follows: 1.The sample soils used in this study were saline-sodic soils in accordance with the USDA classi- fication system of salt affected soils. 2.The electrical conductivity of saturation extract could be estimated conveniently, using the electrical conductivity of extract from various different soil-water suspensions. 3.The total salt concentration could be expressed in the electrical conductivity, but there was a little difference by soil textures. 4.The regression analysis showed that the relationship between the electrical conductivity of saturation extract and the exchangeable sodium percentage during the desalinization of reclaimed lands could be described by a linear regression equation. 5.The value of pH showed a tendency to increase according as the exchangeable sodium percentage decreased during the desalinization of reclaimed tidelands.