• Journal of The Korean Society of Agricultural Engineers
• /
• v.50 no.3
• /
• pp.31-41
• /
• 2008

There are many agricultural facilities (46.7%) that have been over 30 years in the Republic of Korea (the ratio of reservoirs built before 1945 is 53%, from 1946 to 1971 is 35%). In the case of reservoirs which do most important functions among these facilities, only 3,000 reservoirs are managed by Korea Rural Community & Agriculture Corporation (KRC) and the other 15,000 reservoirs are managed by local authorities (City and Gun). But, 15,000 reservoirs included in City. Gun have been built in more wide area than KRC and the reservoir management system has not been operated well because of shortage of budget and manpower of the local authorities. Particularly, the abnormal weather happened during every summer season recently has ruined a lot of rural community facilities. So flood control function have been more important than irrigation function in agricultural reservoir system and it may be required to introduce new safe, management and maintenance techniques in City Gun reservoirs. So we investigated landscapes and deteriorations of agricultural reservoirs managed by local small governments for revealing not only present usage but also future value. Survey shows that there are no structural managements except typical hydrological reportings and the deterioration of small darn is very serious. There are needs for more systematic management system and equipment methods. Therefore, this study may suggest that reservoir (that takes charge of the greatest deal of weight in all agricultural facilities) must be considered as new concept of the usage and the unification. On the other hand, reservoir must be also developed as amenity resources, natural circumstances and district values.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.56 no.3
• /
• pp.65-74
• /
• 2014

Water footprint is defined as the total volume of direct and indirect water used to produce a good and service by consumer or producer, and measured at the point of production based on virtual water concept. The green and blue water footprint refers to the volume of the rainwater and the irrigation water consumed, respectively. Crop water footprint is expected to be used as the basic data for agricultural water resources policies at production, consumption and trade aspect. Thus, it is necessary to estimate suitable green and blue water footprint for South Korea. The objective of this paper is to quantify the green and blue water footprint and usage of upland crops during the period 2001-2010. To estimate the water footprint, 43 upland crop production quantity and harvested area data were collected for 10 years and FAO Penman-Monteith equation was adopted for calculating crop water requirement. As the results, the water footprint of cereals, vegetables, fruits and oil crops accounted for 1,994, 165, 605, and 4,226 $m^3/ton$, respectively. The usage of water footprint for crop production has been estimated at 3,499 (green water) and 216 (blue water) $Mm^3/yr$ on average showing a tendency to decrease. Fruits and vegetables have the largest share in the green water usage, consuming about 1,200 and 1,060 $Mm^3/yr$ which are about 65 % of gross usage. The results of this study are expected to be understood by the agricultural water footprint as well as by the total water footprint from both a production and consumption perspective in Korea.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1999.06a
• /
• pp.137-159
• /
• 1999

Over the last three decades, Korean farming system has been directed to maximum agricultural production and to increase farmer's income through adoption of high-yielding crop varieties and high input of agrochemicals . These farming practices have resulted in problems of water-quality deterioration, soil degradation , and food safety. At present, over 40 million tones of animal waste are bing produced annually, which amounts to disposing the waste at the annual rate of 20 tones per ha in the total area of farming land in Korea. Nearly a half of total available water resources is used as irrigation water predominantly for rice paddy field. Thus, non-point source contamination of the water resources has been linked to agriculture across the nation. However, the extent to which agriculture contributes to the water quality is not fully known. Recently, Korean government provided various institutional measures to reduce the negative impacts of agricultural practices on the environ ental quality, and the Agricultural Environment Act was also passed by the legislature in 1998 and became effective January 1999. This Act does not cover the broad spectrum of the sustainable agriculture ; thus, the limited incentives within this Act are arguably ineffective to control the non-point source pollution. Recently new bulk blending of fertilizers(BB fertilizer) are bing produced (100, 000 tones in 1998) with Government subsidies. The BB fertilizers are to balance N-P-K ratio in the soils . Although the use of the BB fertilizers are encouraged with Government subsidies, non-point source pollution is still serious and will become worse. Precision farming is regarded as a new means for sustainable agriculture. It is a new technology that modifies the existing techniques and incorporates new one such as GIS, GPS , differential applicator to produce a new set of tools for the farmer to use. Precision farming, however, has constraints for individual farming practices. For exam le , farm size or parcel unit of each farmer is too small to adopt the precision agriculture on farmhouse-hold bases and farmer's ability to adopt the new technology is limited. However, it would be appropriate to establish local or regional cooperatives to operate such a precision farming system. It is recommended that Government provide sufficient incentives to help establish local and/or regional cooperatives.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.19 no.1
• /
• pp.1-11
• /
• 2016

Currently, urban green space is disappearing due to urbanization, industrialization and various environmental problems including the disruption of the ecology in urban areas. To solve such problems and increase urban green area, roof greening has been suggested as an alternative. Through observing the responses of three plant species (Mukdenia rossii, Dianthus chinensis, and Pachysandra terminalis) plantrd on the soil mixed with Geohumus, this study investigated the effect of Gehumus on soil water content and plant survival. Soil water content of the rooftop soils has been increased when mixed with Geohumus. The responses were proportional to the amount of Geohumus in the mixture. Geohumus exerted a stronger influence on raising soil moisture content for soil A which had lower water-holding capacity. The stress responses of the plants varied in relation to the amount of Geohumus and soil moisture content. The stress response was lowest for Dianthus chinensis and increased in the order of Mukdenia rossii and Pachysandra terminalis. With the highest plant stress, Pachysandra terminalis showed the lowest survival rate among the three species. Without irrigation, the plants survived only for six weeks on green roofs. The survival rate differed depending on the amount of Geohumus mixed. The results of the experiment showed, with some exceptions, that Geohumus helped to improve soil water content, reduce plant stress, and extend plant survival period.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.12 no.3
• /
• pp.2029-2034
• /
• 1970

This research was attempted to study on the effects of desalinization by the depth and interval of open conduit in Kang-Hwa polder where is located at the Kil-sang Myun, Kang-Hwa Gun, Kyung-gi Do, and it has been continued for the three years from 1967 to 1969. The results obtained are as follows; 1. The depths of saline expulsion by supplying of irrigation water are approximately 30cm to 50cm under the ground surface, but saline expulsion is hardly done in case of the depth which is deeper than the above mentioned, because the moisture and saline content hardly change in such a condition. 2. The speed of vertical percolation gradually decreases below the 30cm depth, but it is noticed that there is a tendency to make the percolation of the horizental direction from its layer in Kang-Hwa reclaimed tidal land. 3. Comparing experimental treatments-varing depths and intervals of open conduits, the interval of open conduit has a more effect upon the promotion of desalinization and increasing of the rice yields than the depth of it. Therefore, according to the results of experimental data, the optimum depth of open conduit is about 0.9m, the effective interval of it is about 18m. 4. Considering the loss of arable area by the layout of open conduit, the reasonable interval of it could extend to 36m.

• KCID journal
• /
• v.18 no.2
• /
• pp.87-100
• /
• 2011

This study is to delineate the watershed hydrological parameters such as area, slope, rain gauge weight, NRCS-CN and time of concentration (Tc) by using the Geographic Information Sytem (GIS) technique, and estimation of design flood for an ungauged watershed. Especially, we attempted to determine the Tc of ungauged watershed and develop simple program using the cell-based algorithm to calculates upstream or downstream flow time along a flow path for each cell. For a $19km^2$ watershed of tributary of Nakdong river (Seupmoon), the parameters including flow direction, flow accumulation, watershed boundary, stream network and Tc map were extracted from 30m Agreeburn DEM (Digital Elevation Model) and landcover map. And NRCS-CN was extracted from 30m landcover map and soil map. Design rainfall estimation for two rainfall gauge which are Sunsan and Jangcheon using FARD2006 that developed by National Institute for Disaster Prevention (NIDP). Using the parameters as input data of HEC-l model, the design flood was estimated by applying Clark unit hydrograph method. The results showed that the design flood of 50 year frequency of this study was $8m^3/sec$ less than that of the previous fundamental plan in 1994. The value difference came from the different application of watershed parameter, different rainfall distribution (Huff quartile vs. Mononobe) and critical durations. We could infer that the GIS-based parameter preparation is more reasonable than the previous hand-made extraction of watershed parameters.

• Journal of Korean Neurosurgical Society
• /
• v.58 no.6
• /
• pp.547-549
• /
• 2015

Acute subdural hematoma (SDH) of arterial origin is rare, especially SDH associated with an arteriovenous malformation (AVM) is extremely rare. The authors report a case of acute spontaneous SDH due to rupture of a tiny cortical AVM. A 51-year-old male presented with sudden onset headache and mentality deterioration without a history of trauma. Brain CT revealed a large volume acute SDH compressing the right cerebral hemisphere with subfalcine and tentorial herniation. Emergency decompressive craniectomy was performed to remove the hematoma and during surgery a small (5 mm sized) conglomerated aciniform mass with two surrounding enlarged vessels was identified on the parietal cortex. After warm saline irrigation of the mass, active bleeding developed from a one of the vessel. The bleeding was stopped by coagulation and the vessels were removed. Histopathological examination confirmed the lesion as an AVM. We concluded that a small cortical AVM existed at this area, and that the cortical AVM had caused the acute SDH. Follow up conventional angiography confirmed the absence of remnant AVM or any other vascular abnormality. This report demonstrates rupture of a cortical AVM is worth considering when a patient presents with non-traumatic SDH without intracerebral hemorrhage or subarachnoid hemorrhage.

• Korean Journal of Agricultural Science
• /
• v.32 no.2
• /
• pp.107-126
• /
• 2005

The most limited production resource in Korea is land. During the period from 1995 to 2002, annual farm land area of 17,600ha have been converted to urban and industrial land. The self-sufficiency rate of rice, Korean staple food, is expected to be decreased from 97.5% in 2003 to 60-70% in 2020. Under such conditions, this study is aimed at first identifying multi-functional benefits of the reclamation projects such as agricultural production, industrial water supply, urban land supply, transportation effects, sightseeing effects and environmental values with and without the projects. To carry out the objectives, three existing tideland reclamation projects such as Daeho, Kumgang and Yongsangang irrigation project stage II were evaluated and Saemangeum tideland reclamation project which was jointly revaluated by environmental NGO and Govn't appointed specialists in 2000 was reviewed. According to this study results, tide land reclamation projects were showed financially and economically feasible and environmentally sustainable. The joint cost like estuary dam should be allocated based on the multi-functional benefits of the projects. To allocate the joint cost, legal and institutional improvement should adapt the joint cost allocation method as the specific cost-remaining benefit method. Korea has more than 402,000 ha of tidal flat of which 76,396ha have been reclaimed in 2003. To meet food security and to cope with shortage of land, phil-environmental reclamation projects should be continuously implemented and necessary tidal flats for protecting environmental ecosystem should be remained according to the detail survey results of reclaimable resources.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.4
• /
• pp.1693-1705
• /
• 2013

To restore old aqueduct in Korea which is a irrigation bridge to supply water in paddy field area, it is needed to estimate approximate costs of restoration because the basic design for estimation of construction costs is often ruled out in current system. In this paper, estimating models of construction costs were developed on the basis of performance data for restoration of RC aqueduct bridges since 2003. The regression analysis (RA) model and case-based reasoning (CBR) model for the estimation of construction costs were developed respectively. Error rate of simple RA model was lower than that of multiple RA model. CBR model using genetic algorithm (GA) has been applied in the estimation of construction costs. In the model three factors like attribute weight, attribute deviation and rank of case similarity were optimized. Especially, error rate of estimated construction costs decreased since limit ranges of the attribute weights were applied. The results showed that error rates between RA model and CBR models were inconsiderable statistically. It is expected that the proposed estimating method of approximate costs of aqueduct restoration will be utilized to support quick decision making in phased rehabilitation project.

• Archives of Plastic Surgery
• /
• v.38 no.1
• /
• pp.89-92
• /
• 2011

Purpose: Electrical burn of scalp is uncommon. Much more, chronically exposed dura in unstable burn scar is quite exceptional. Hence, we report a case of chronically exposed dura following electrical burn. Methods: A 63-year-old man presented with an about 40 years history of an ulcerative lesion arising from electrical burn scar with 'squeeze like sensation' around wound. Wound was about $6{\times}8$ cm. Area in the center was $3{\times}3$ cm nonviable dura without sequestrum. Tangential excision with an intraoperative neurosurgical consultation and transposition flap under general anesthesia was done. Intraoperative biopsy was done. The wound was diagnosed as chronic osteomyelitis, not Marjolin ulcer. Flap was taken successfully. But after 5 days, infectious discharge had been appeared during 2 weeks, despite irrigation and drainage. As flap was re-evaluated, we could see remnant necrotic dura. After that, latissimus dorsi muscle free flap with meshed split thickness skin graft was transferred without excision of necrotic dura. Results: Flap was taken successfully. Follow-up at 10 weeks has been uneventful, with good and stable coverage of the wound. Conclusion: It is true that complete excision of devitalized tissue with sagittal sinus obliteration is prerequisite to flap taken. But necrotic dura was tangentially excised instead of total dura excision, because, posterior two-thirds of the sagittal sinus was involved underneath. Muscle is rich in blood vessels and decrease the recipient-site bacterial count effectively. In this case, muscle flap with skin graft without total dura excision is an alternative treatment.