• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.319-325
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• 2005

Sediments of Mankyung and Dongjin river were examined on the physico-chemical properties and phosphorus fractionations. The content of total-P in sediment of Mankyung river ranged from 290.1 to 405.4 mg/kg (average = 363.4 mg/kg), while that in sediment of Dongjin river ranged from 304.1 to 431.7 mg/kg (average = 353.6 mg/kg). In both rivers, the total-P was highest in June to September. It is presumed that surficial sediment in arable land flowed into the rivers with rainfall-runoff. Phosphorus fractionations in Mankyung and Dongjin river were apatite-P 52.1% and 42.7%, residual-P 27.3% and 34.2%, nonapatite inorganic-P 18.1% and 22.5%, and adsorbed-P 0.6% and 0.6%, respectively. Adsorbed-P in sediment was the most scarcity fraction. It thus appears that adsorbed phosphorus was not effected in aquatic ecosystem. But nonapatite inorganic-P would be highly released under changes of redox condition and pH in aquatic ecosystem.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.439-455
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• 2018

Hanon made in the largest maar crater in Korea, is the only paddy field ecosystem in Jeju Island that has been conducting rice farming, for the past 500 years. Flora surveys were conducted eight times, 2015-2018, to understand floristic characteristics and a restoration plan of the study area. As a result, vascular plants of Hanon paddy fields were listed 225 taxa that consist of 55 families, 151 genera, 194 species, 1 subspecies, 25 varieties, and 4 forms. The taxonomic group including the most species, was Gramineae (36 taxa). The next families were Compositae (29 taxa), Cyperaceae (20), Leguminosae (13), and Polygonaceae (11). Biological type of the Hanon was $Th-R_5-D_4-t$ type. The rare plants revealed 3 taxa; Ottelia alismoides(L.) Pers., Acorus calamus L., Pseudoraphis ukishiba Ohwi. Endemic plant revealed 1 taxon; Saururus chinensis(Lour.) Baill. Forty three taxa were naturalized plants composed of 15 families, 24 genera, 41 species, and 2 varieties. The urbanization index and naturalized index were 13.3% and 16.9%, respectively. The Hanon has high plant diversity, including endemic plant and rare plants, and is the only rice paddy in Jeju Island. So, the Hanon has sufficient values in ecological and socio-cultural aspects, so it should be maintained continuously in the future.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.5
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• pp.21-27
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• 2014

Sediment-laden water is problematic in aquatic ecosystem and for hydraulic structures in a watershed, and agriculture area in a watershed is one of source areas of nonpoint source (NPS), since soil surface typically exposures due to agricultural activities. Especially, severe sediment might flow into stream when agricultural area is located near stream like the Imha-dam watershed. Soil erosion is affected by precipitation, therefore there is a need to consider precipitation characteristics in soil erosion and best management practices (BMPs) simulation. The Web-based Spreadsheet Tool for the Estimation of Pollutant Load (STEPL WEB) allows estimating long-term sediment loads and the impact of best management practices to reduce sediment loads. STEPL WEB and predicted precipitation data by MIROC-ESM model was used to estimate sediment loads and its reduction by filter strip and conversion of agricultural area to forest in the future 30 years. The result indicates that approximately 70 % of agricultural area requires filter strip installation or that approximately 50 % of agricultural area needs to be converted to forest, for 41 % of sediment load reduction.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.441-444
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• 2002

In recent, industrialization increases the level of pollution load in sea areas, and the inflows of pollutants to public sea areas cause sudden and wide-range of influence to the water quality and the ecosystem. To prepare for these kinds of unpredictable water pollution issues, the necessity is emerging to build an automatic water quality monitoring system, which can monitor and alarm the water quality changes of the subject sea areas. For the ongoing installation plan of the automatic water quality monitoring system around the Saemankeum sea area, this report compares and analyzes its installation conditions as well as the physical and chemical characteristics of the in-situ type and the water-sampling type of the automatic water quality monitoring equipments, and subjects to provide elementary data for the system installation in the Saemankeum.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.97-100
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• 2002

So far, the water management have separately been accomplished by water supply, flood control, and environmental river management. In spite of sustainable policy of water resource development, flood & drought damage, poor water accident, and deterioration of river ecosystem have continuously occurred. It means that it is difficult to improve those problems with the present systems and institutions. So, it is time to discuss to change the present water management system of administrative sense into the one classified by the watershed in order to understand problems of water resource in the regional basis. First, a integration of similar branch office in organization and a work specialization should be driven in the government. Second, it is desirable to develop the water resources according to the inherent characteristics of the watershed.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.147-150
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• 2003

According to development and urbanization of country, environment and ecosystem were ignored during the past thirty years. Therefore canal, which had been developed by concrete, is remained as the space where life can not alive any longer. In this study, Environmental friendly canal construction method using porous loess block are investigated. Porous loess blocks are which is developing focused on both scenery and hydraulic safty. Canal using Porous loess blocks can take a vegetation's distribution and improvement of soil properties and hydraulic safty of bank. In this study, The examination of applied canal construction method using porous loess block that is considering vegetation's distribution and properties of material is done to present development of environmental friendly canal construction method.

• Spatial Information Research
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• v.4 no.2
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• pp.107-119
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• 1996

The purpose of this study was to carry out land use suitability analysis of Seoul Metropolitan City based on ecopolis planning concept or environmentally sound and sustainable development. Objectives of the analyses were to save energy by increasing urban density and allocating urban land use types near to public transportation system, to increase food producing capacity by restoring fertile agricultural lands, and to enhance urban ecosystem by expanding and networking parks and green spaces. This study has two phases. First, the land use suitability analyses for commercial, industrial, residential, agricultural, and green spaces were carried out. Second, required urban land use .types were allocated based on ESSD concept. Two alternative land use plans were developed based on two population sizes:existing population of 11million and 4.4million derived by the application of ermergy theory of T. Odum.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.690-694
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• 2005

It is necessary that the construction of submerged breakwater could minimize and compensate the negative effect on the marine environment and ecosystem caused by the Saemangeum reclamation. The important merit of this proposal is that the space between Saemangeum embankment and submerged breakwater is expected to become nursery ground for fish and shellfishes. The purpose of this study was investigated hydraulic characteristic of submerged breakwater to investigate the possibility of mitigation in the fisheries ground by hydraulic experiment.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.170-174
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• 2005

The waste land can be changed to the land that creature can survive by the greening. The studies on the rooftop greening have increased rapidly in number since these studies have made a positive effect on the improvement of the urban ecosystem and the lacking greens environment of the city. However, the majority of research are for rooftop greening system of the public and commercial building. Therefore, the development of easily available rooftop greening system for private residences is required.

• 한국유가공학회:학술대회논문집
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• 2006.06a
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• pp.47-56
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• 2006

The common recognition which the organic product is compared as safe to baby does not mean there is especially plentiful nutrition in organic product. The part mineral content of agricultural products follows in soil quality, therefore plentiful chemical fertilizer-use to change soil quality results in the possibility of the mineral content change. The vitamin, carbohydrate, protein and fatty acid composition does not change largely from original nutrition facts. Rather than, the most advantage of organic product is relieving baby from agricultural chemical harms. It will be a strong desire for consumers to eat safe, believable and healthy food like organic foods. Furthermore, it will be sincerely good to environment and ecosystem.