• Journal of Ecology and Environment
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• 제30권2호
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• pp.171-177
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• 2007

Korean rivers and their surrounding environments have been used excessively for rice production in the past and more recently for construction of urban areas to accomodate the rapidly increasing population. Affected Korean rivers experience dramatic fluctuations in their water levels and have faster currents compared with those in other countries. In order to restore more natural conditions in rivers experiencing such conditions, we employed a partial restoration method, which is designed to achieve physical and biological stability simultaneously. Concrete blocks were introduced to increase the river's physical stability during floods, and terra cottem, a soil enhancer, was used to reduce water loss due to intense heat. These interventions increased the river's ability to hold water and thereby promoted plant growth. This restoration method increased vegetation coverage and species diversity in treated areas, and changed the species composition in treated areas to more closely approximate that of the control site. These results suggest that this method is effective in restoring damaged habitats to more natural conditions.

• International Journal of Contents
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• 제13권4호
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• pp.23-28
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• 2017

Of the total economic loss caused by disasters, 40% are due to floods and floods have a severe impact on human health and life. So, it is important to monitor the water level of a river and to issue a flood warning during unfavorable circumstances. In this paper, we propose a modified error function to improve a hydrological modeling using a multi-layer perceptron (MLP) neural network. When MLP's are trained to minimize the conventional mean-squared error function, the prediction performance is poor because MLP's are highly tunned to training data. Our goal is achieved by preventing overspecialization to training data, which is the main reason for performance degradation for rare or test data. Based on the modified error function, an MLP is trained to predict the water level with rainfall data at upper reaches. Through simulations to predict the water level of Nakdong River near a UNESCO World Heritage Site "Hahoe Village," we verified that the prediction performance of MLP with the modified error function is superior to that with the conventional mean-squared error function, especially maximum error of 40.85cm vs. 55.51cm.

• 한국물환경학회지
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• 제27권5호
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• pp.587-596
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• 2011

The interest in hydrological modeling has increased significantly recently due to the necessity of watershed management, specifically in regards to lumped models, which are being prosperously utilized because of their relatively uncomplicated algorithms which require less simulation time. However, lumped models require empirical coefficients for hydrological analyses, which do not take into consideration the heterogeneity of site-specific characteristics. To overcome such obstacles, a distributed model was offered as an alternative and the number of researches related to watershed management and distributed models has been steadily increasing in the recent years. Thus, in this study, the feasibility of a grid-based rainfall-runoff model was reviewed using the flood runoff process in the Han River basin, including the ChungjuDam, HoengseongDam and SoyangDam watersheds. Hydrological parameters based on GIS/RS were extracted from basic GIS data such as DEM, land cover, soil map and rainfall depth. The accuracy of the runoff analysis for the model application was evaluated using EFF, NRMSE and QER. The calculation results showed that there was a good agreement with the observed data. Besides the ungauged spatial characteristics in the SoyangDam watershed, EFF showed a good result of 0.859.

• 인간식물환경학회지
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• 제24권6호
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• pp.551-561
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• 2021

Background and objective: Vietnam is prioritizing agricultural production for food export capacity in all national policies. As a result, for three decades, its agriculture has been making quite many remarkable achievements. Methods: The most successful one is that the nation has become one of the world's leading rice exporters and ensures its national food security. Through these endeavors, the Mekong River Delta (MRD), in particular, has emerged as a key region in ensuring national food security and rice export. Results: The new era can now see Vietnamese agriculture turning to place special emphasis on commodity quality and the improvement of the living environment. This is evidenced, for example, by the phenomenon that the MRD, as a rice basket of the whole country, is making moves back to nature-based agriculture with attempts to restore the natural ecology, including preserving and restoring local traditional rice seeds, adopting natural farming practices and minimizing the use of chemical fertilizers and pesticides. Conclusion: The case studies of nature-based farming practices in the MRD indicate that, while the national agriculture is generally developing large-scale production, the small-scale farming in the region, integrated with tourist and educational activities on-site, is meeting the demands of a highly potential domestic niche market. Moreover, this model appears to be a sustainable farming approach that defines itself as a working green livelihood for the region.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.118-118
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• 2020

This study investigates the change of flow characteristics over 10 Asian river basins in the past 30 years (1976-2005). The variation is estimated from The Soil and Water Assessment Tool (SWAT) model outputs based on reanalysis data which was bias-corrected for Asian monsoon reagion. The model was firstly calibrated and validated using observed data for daily streamflow. Four statistical criteria were applied to evaluate the model performance, including Coefficient of determination (R2), Nash - Sutcliffe model efficiency coeffi cient (NSE), Root mean square error-observations standard deviation ratio (RSR), and Percentage Bias (PBIAS). Then parameters of the model were applied for the historical period 1976-2005. The estimates show a temporal non-considerable increasing rate of daily streamflow in most of the basins over the past 30 years. The difference of monthly discharge becomes more significant during the months in the wet season (June to September) in all basins. The seasonal runoff shows significant difference in Summer and Autumn, when the rainfall intensity is higher. The line showing averaged runoff/rainfall ratio in all basins is sharp, presenting high variation of seasonal runoff/rainfall ratio from season to season.

• 한국조경학회지
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• 제33권6호
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• pp.22-39
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• 2006

This paper is the study on the activity of citizen participation in the movement of Million Amenity Park's creation which was proposed by citizen participation for large scale's flat park within city. This park was proposed by the Busan Green Plan, commission study in 1999. The location of Park site was finally proposed at Dunchi-do, Bonglim-dong, Gangseo-gu, Busan and neighbor areas. The area of park site is approximately 500ha included the surface area of West-Nakdong River. Citizen's organization for Million Amenity Park which has 3,500 members, was established in 2001 in order to compose Million Amenity Park The development processes of this study were found to have quickening period, germination period, the 1st growing period, and the 2nd growing period, and then the results of this activity was also arranged by the researcher of this study. The movement for this park was found to have a positive activity for participating and understanding all the citizens during 7 years. And then the activities for this park were as follows: every information, fund-raising campaign, organization, purchase of park site, contribution of purchasing park site to Busan city. The results of this study, through the movement of citizen's participation such as this park movement were 1) respectively found to have the settlement in the movement of NGO, 2) the possibility of large scale's park fostering by public and civil partnership, and 3) the model presentation of frontier park in the citizen participation's types which will be able to introduce the development of city.

• 한국구조물진단유지관리공학회 논문집
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• 제19권1호
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• pp.109-119
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• 2015

최근 수십년간의 산업발달 및 인구증가에 따라 산업폐수 및 각종 비점오염원의 유입으로 수질오염이 심각한 실정이다. 이에 대해 국내 및 국외에서 이에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 유기물질의 분해효과가 있는 유용미생물과 포러스콘크리트를 이용하여 하천 현장에 설치하여 구조적 성능평가와 장기간 수질정화능력을 평가하였다. 구조적 성능평가 결과, 시험체의 공극률은 15%가 적절하다고 판단되며, 또한 수질정화성능 검토 결과 각항목에 대한 제거율은 SS 34.1%, BOD 14.6%, COD 34.9%, T-N 11.4%, T-P 12.6%를 나타냈다. 따라서 유용미생물을 이용한 포러스콘크리트의 현장적용시 수질을 정화시키는데 효과적이라고 판단된다.

• 환경영향평가
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• 제21권2호
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• pp.229-238
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• 2012

This research was to examine the physiochemical factors and the attached diatoms of ecological wetland in Paju from August 2010 to May 2011. As a result of physicohemical water quality assessment, the water temperature did not fluctuate much due to ample riparian vegetation and aquatic plants growing at the site. Due to the effect of Han River Estuary, site 4, 5 and 6 had high electricity conductivity. The BOD concentration was high at site 2, 3, and 4 caused by decrease in water quantity and inflow of polluted water. At all sites, T-N and T-P concentrations ranged from eutrophic to hypertrophic status. At the downstream, the T-N and T-P concentrations decreased by inhabiting aquatic plant. Total of 98 taxa of attached diatoms were found. As for dominant taxa, Achnanthes convergens, A. minutissima, Gomphonema gracile, G. parvulum, Melosira varians, Navicula seminulum, N. minima, N. pseudolanceolata, Nitzschia amphibia, N. palea, Surirella minuta and Synedra ulna var. fragilariodes appeared. The result of biological assessment of water quality rated the sites B(suboptimal)~D(poor) during seasons of low water temperature, Fall and Winter, with DAIpo ranging 24.1~68.2 and TDI of 48.4~85.6. During Spring and Summer, all sites were rated D(poor) with DAIpo lower than or equal to 40, and TDI above or equal to 70. The biological assessment of water quality at the research site showed inferior TDI result compared to that of DAIpo.

• 한국환경복원기술학회지
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• 제23권4호
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• pp.97-110
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• 2020

This study conducted observations at 72 traffic lights and road signs in Sejong-si, Korea from March to June 2019 in order to analyze nest-site, nest-site characteristics and feeding behavior in Tree sparrow (Passeer montanus) in urban. Feeding behavior during breeding season in 2019 was investigated at 10 Town representing traffic facilities installed on the road located in the center of the city and 10 Riverside Geumgang river's riverside road. We fitted both general linear model and regression model to our field data and estimated the spatial variation of initial date of the first feeding (i.e., being date of breeding) and the total number of caterpillar fed by parents per hour. Our results showed that the frequency of nest building on artificial structures, such as traffic lights, was about 26% higher and about 8 days earlier in the riverside. In particular, the first feeding was significantly faster when the nearest distance between nest to green field as foraging site was shorter whereas there was no significant effect of the number of nest within 50 meters on the first feeding. Number of caterpillars fed by parents was higher in the Riverside than in the Urban, and especially the number in the second brood was sharply decreased in the Urban. As we estimated average amount of caterpillars per hour to 446 traffic safety facilities in Sejong-si, it was estimated that Tree sparrows fed 18,742.8 caterpillars per hour during the breeding season. In this study, we showed that characteristics of nests built in artificial structures and feeding behavior in order to analyze effects of environmental condition in urban on life-history traits during the breeding season. Finally, we discussed the conservation of birds in urban and pest control effects.

• 헤리티지:역사와 과학
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• 제47권4호
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• pp.120-135
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• 2014

최근의 백제사찰 재조사에서 기존 가람의 양식과는 다른 가람배치 양상이 확인되면서 금강사지의 가람에 대하여 다시금 조사의 필요성을 가지게 한다. 본 연구는 GPR탐사법을 이용하여 금강사지의 잔존 유구 및 사역전체의 건물배치 양상을 확인하고자 하였으며, GIS기술을 이용하여 항공사진을 분석하고 수치지형도를 활용한 토양유실량(RUSLE)을 분석하여 금강사지의 입지와 지형변화를 파악하고자 하였다. GPR탐사 결과, 사역의 북편과 서편에서 기 발굴조사에서 미처 확인되지 않았던 건물지가 추가로 확인되어 사역의 범위는 추정 가람보다 더 넓었을 것으로 보인다. 또한 금강사지는 하안 단구면에 위치하고 있고 토양유실량이 매우 적은 안정된 지형장에 위치하며 자연발생적인 배수체계를 기반으로 하는 최적의 입지를 보이고 있음을 알 수 있었다.