• Parasites, Hosts and Diseases
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• 제57권2호
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• pp.135-144
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• 2019

There have been some reports on schistosomiasis of school children in Sudan's Nile River basin area; however, information about the infection status of Schistosoma species and intestinal helminths among village residents of this area is very limited. Urine and stool samples were collected from the 1,138 residents of the Al Hidaib and Khour Ajwal villages of White Nile State, Sudan in 2014. The prevalence of overall schistosomiasis and intestinal helminthiasis was 36.3% and 7.7%, respectively. Egg positive rates were 35.6% for Schistosoma haematobium, 2.6% for S. mansoni, and 1.4% were mixed. The prevalence of schistosomiasis was significantly higher in men (45.6%) than in women (32.0%), in Khou Ajwal villagers (39.4%) than in Al Hidaib villagers (19.2%), and for age groups ${\leq}15$ years old (51.5%) than for age groups >15 years old (13.2%). The average number of eggs per 10 ml urine (EP10) of S. haematobium infections was 18.9, with 22.2 eggs in men vs 17.0 in women and 20.4 in Khou Ajwal villagers vs 8.1 in Al Hidaib villagers. In addition to S. mansoni eggs, 4 different species of intestinal helminths were found in the stool, including Hymenolepis nana (6.6%) and H. diminuta (1.0%). Collectively, urinary schistosomiasis is still prevalent among village residents in Sudan's White Nile River basin and was especially high in men, children ${\leq}15$ years, and in the village without a clean water system. H. nana was the most frequently detected intestinal helminths in the 2 villages.

• 한국물환경학회지
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• 제36권6호
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• pp.489-499
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• 2020

Effective science-based management of the basin water resources requires an understanding of the characteristics of the streams, such as the baseflow discharge. In this study, the base flow was estimated in the two watersheds with the least artificial factors among the Nakdong River watersheds, as determined using the chemical hydrograph separation technique. The 16-year (2004-2019) discontinuous observed stream flow and electrical conductivity data in the Total Maximum Daily Load (TMDL) monitoring network were extended to continuous daily data using the TANK model and the 7-parameter log-linear model combined with the minimum variance unbiased estimator. The annual base flows at the upper Namgang Dam basin and the upper Nakdong River basin were both analyzed to be about 56% of the total annual flow. The monthly base flow ratio showed a high monthly deviation, as it was found to be higher than 0.9 in the dry season and about 0.46 in the rainy season. This is in line with the prevailing common sense notion that in winter, most of the stream flow is base flow, due to the characteristics of the dry season winter in Korea. It is expected that the chemical-based hydrological separation technique involving TANK and the 7-parameter log-linear models used in this study can help quantify the base flow required for systematic watershed water environment management.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.173-173
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• 2023

The Mekong River Basin (MRB) is a crucial watershed in Asia, impacting over 60 million people across six developing nations. Accurate satellite-based precipitation products (SPPs) are essential for effective hydrological and watershed management in this region. However, the performance of SPPs has been varied and limited. The APHRODITE product, a unique gauge-based dataset for MRB, is widely used but is only available until 2015. In this study, we present a novel framework for correcting SPPs in the MRB by employing a deep learning approach that combines convolutional neural networks and encoder-decoder architecture to address pixel-by-pixel bias and enhance accuracy. The DLF was applied to four widely used SPPs (TRMM, CMORPH, CHIRPS, and PERSIANN-CDR) in MRB. For the original SPPs, the TRMM product outperformed the other SPPs. Results revealed that the DLF effectively bridged the spatial-temporal gap between the SPPs and the gauge-based dataset (APHRODITE). Among the four corrected products, ADJ-TRMM demonstrated the best performance, followed by ADJ-CDR, ADJ-CHIRPS, and ADJ-CMORPH. The DLF offered a robust and adaptable solution for bias correction in the MRB and beyond, capable of detecting intricate patterns and learning from data to make appropriate adjustments. With the discontinuation of the APHRODITE product, DLF represents a promising solution for generating a more current and reliable dataset for MRB research. This research showcased the potential of deep learning-based methods for improving the accuracy of SPPs, particularly in regions like the MRB, where gauge-based datasets are limited or discontinued.

• 한국지형학회지
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• 제18권4호
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• pp.261-270
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• 2011

연구지역인 웅천천 유역은 차령산지의 남서쪽 말단부에 위치하여 황해와 맞닿아 있다. 본 연구는 지형 규모의 연계성 차원에서 차령산지에 발달한 지형선구조 체계가 국지적 시야의 연구지역 지형경관에 나타나는 바를 확인하여 기술·설명하고자 한다. 연구지역에서 확인되는 주요 지형선구조는 NE-SW, NNE-SSW, NNW-SSE, N-S, E-W 등의 방향이며, 그 중 NNE-SSW, NE-SW방향 선구조가 지형경관에 가장 뚜렷하게 반영되어 인식할 수 있다. 주요 산체와 곡지는 NNE-SSW 방향성을 지니며, NE-SW방향의 선구조 곡지는 비교적 규모가 크고, 저기복 구릉, 산록단구, 하안단구, 범람원 등의 다양한 지형요소가 발달하는 곳이 많다. 반면 NNW-SSE, N-S, E-W 방향 선구조 곡지는 대체로 좁고 깊지 않은 곡지로 나타나지만 선구조는 선명하게 유지하고 있다. 또한 연구지역의 선구조 곡지의 규모와 곡지를 흐르는 하천 차수 간에는 상관성이 없다.

• Water Engineering Research
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• 제1권2호
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• pp.129-136
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• 2000

Predicting water levels is a difficult task because a lot of uncertainties are included. Therefore the neural network which is appropriate to such a problem, is introduced. One day ahead forecasting of river stage in the Bocheong River is carried out by using the neural network model. Historical water levels at Snagye gauging point which is located at the downstream of the Bocheong River and average rainfall of the Bocheong River basin are selected as training data sets. With these data sets, the training process has been done by using back propagation algorithm. Then waters levels in 1997 and 1998 are predicted with the trained algorithm. To improve the accuracy, a filtering method is introduced as predicting scheme. It is shown that predicted results are in a good agreement with observed water levels and that a filtering method can overcome the lack of training patterns.

• 한국농촌계획학회:학술대회논문집
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• 한국농촌계획학회 1998년도 정기총회 및 춘계 학술논문발표회
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• pp.25-26
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• 1998

This study was aimed to investigate the land use characteristics between urban and rural river systems. The ecological land unit systems was used to the key method for that objectives and the visual analysis was also used. The results were as followings : The won-sung river was characterized by the formal urban river system of which the headwater was covered with the various man-made constructions. Also the pong-se river showed a little simptoms of the urbanization from the headwater that meant the urgent ecological land use evaluation about that region.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.515-520
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• 2005

The objective of the study is to assess the water quality improvement resulted from the rearrangement of the irrigation water supply systems at Mankyeong River and Ansung Chun basin. There is a mixed type of watershed composed of urban and rural areas in the region. From the water quality analysis, showed high T-N, T-P concentration in Ansung chun and Mankyeong river caused by paddies separated widely around Ansung chun and Mankyeong river and by runoff of the pollution from the Ansung and Jeonju city. but the upstream of the river showed clean water quality, so if we use the upstream water as river maintenance water for water quality improvement, it is expected to be positive effect for rural environmental aspect.

• 환경영향평가
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• 제18권5호
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• pp.271-280
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• 2009

The objective of this study is to develop a reliable flow forecasting model based on neural network algorithm in order to provide flow rate at stream sections without flow measurement in Nakdong river. Stream flow rate measured at 8-days interval by Nakdong river environment research center, daily upper dam discharge and precipitation data connecting upstream stage gauge were used in this development. Back propagation neural network and multi-layer with hidden layer that exists between input and output layer are used in model learning and constructing, respectively. Model calibration and verification is conducted based on observed data from 3 station in Nakdong river.

• 한국제4기학회지
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• 제3권1호
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• pp.87-101
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• 1989

한탄강유역의 발달과정은 3단계로 나누어질 수 있다. 제1단계는 60만년전 한탄강-임진강유역에 현무암이 회복하기 전에 존재하던 고한탄강의 단계를 말한다. 이 시기에 백의리층이 형성되었는데 이 고기하성층은 현재의 한탄강 유로를 따라 현무암아래에 여러 지점에서 확인되고 있다. 제2단계는 유로가 새로이 형성된 현무암대지 위를 흐르면서 수성퇴적층을 형성한 시기이다. 이 시기동안 고인류는 물가 또는 강변대지에 살면서 현재 발견되는 구석기를 남긴 것으로 보인다. 이 시기는 마지막 현무암분출이 있었을 것으로 보이는 30만년전에 시작되었다고 보여진다. 제3단계는 현재의 한탄강이 현무암 대지에서 멀어져 홍수시에도 현무암대지 상면에 퇴적물을 운반하거나 또는 하천에 의한 침식이 끝난 시점에서 시작되는데 현재로서는 정확한 연대추정이 불가능하지만, 이 지역의 기상상태 -서리작용·집중강우등-과 함께 물리적인 침식이 용이한 현무암의 구조로 보아서 여러차례의 기후변동을 겪지 아니하였을 것으로 보고 커다란 하나의 기후변동 사이클이 지난 20만년 전후로 생각된다. 이는 현무암대지상에 넓게 분포하는 적색조의 점토층이 더운 기후에서 퇴적된 것으로 볼 때 중국의 황토퇴적중에 보이는 20만년 전후의 적색띠와도 잘 부합되고 있다. 고인류의 서식 또한 이 적색점토층의 연대범위를 크게 벗어나지는 않을 것이다.

• Parasites, Hosts and Diseases
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• 제46권4호
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• pp.289-291
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• 2008

The Tamjin River which flows from Jangheung-gun via Gangjin-gun to the South Sea was reported to be a highly endemic area of Metagonimus yokogawai infection in 1977 and 1985. However, there were no recent studies demonstrating how much change occurred in the endemicity, in terms of prevalence and worm burden, of metagonimiasis in this river basin. Thus, a small-scale epidemiological survey was carried out on some residents along the Tamjin River basin in order to determine the current status of M. yokogawai infection. A total of 48 fecal samples were collected and examined by the Kato-Katz thick smear and formalin-ether sedimentation techniques. The egg positive rate of all helminths was 50.0%, and that of M. yokogawai was 37.5%, followed by C. sinensis 22.9% and G. seoi 4.2%. To obtain the adult flukes of M. yokogawai, 6 egg positive cases were treated with praziquantel 10 mg/kg in a single dose and purged with magnesium sulfate. A total of 5,225 adult flukes (average 871 specimens per person) of M. yokogawai were collected from their diarrheic stools. Compared with the data reported in 1977 and 1985, the individual worm burdens appeared to have decreased remarkably, although the prevalence did not decrease at all. It is suggested that the endemicity of M. yokogawai infection along the Tamjin River has been reduced. To confirm this suggestion, the status of infection in snail and fish intermediate hosts should be investigated.