• Journal of Wetlands Research
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• v.14 no.3
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• pp.413-418
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• 2012

In this study, both habitat use analysis by rumen contents of Eurasian river otter (Lutra lutra) were carried out to investigate the preference of habitat environment and diet using their fecal samples. As the target sites, two streams (the Naechon-cheon and the Koonup-cheon) were selected in the upstream of the Hongcheon river, Hongcheon County, Gangwon Province. A total of 478 track samples (e.g., feces, scent and footprint) were found during the survey periods (May to November, 2009 and November, 2010). The dominant points, where the tracks of river otters were observed, were areas with the low depth(0.5-1m) and the slow flow velocity (5m/sec). Also, both rocks and rock-beds were preferred but artificial facilities were avoided. This ecological study of river otters using habitat use analysis and diet analysis by rumen contents will be useful fundamental information to conserve the river otter populations, and to protect their habitats.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.402-406
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• 2015

This study aims at favorable environmental conditions by river otter residing in Hongcheon river ecosystems using spraints along the river. Otter spraints were indicative of habitat use pattern and marking a territory in the areas. Nae-chon and Kuneob-chon river otter spraints were collected totaling 478 with 8 times during 2009-2011, and based on the number river use patterns were analyzed with the technique of index of dispersion. Results with larger than one indicated that river otter habitat use pattern were not random; instead they used preferred areas for habitat use. 'I' values greater than one indicate a clumped distribution and lower than one indicate random distribution. This study also demonstrated that we need a sophiscated linear model that should be developed to identify key habitat elements in river ecosystems.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.591-596
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• 2012

Stream of Hongchon in Gangwon province was well known site for river otter(Lutra lutra) habitat. Because of habitat importance in this region a food analysis was conducted using 478 spraints of the species. A total food was domintnant by fish species occupying 80.5% and the dominant species was Zacco temminckii because of population abundance. Other food items were Amphibians and birds. Summer food was the highest due to its diversity. Gunup and Naechon streams were not different among diversity. Currently the highway construction was underway and we need more information regarding habitat requirement, and management implication for the species in this region.

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.352-360
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• 2005

Acheilognathus signifer is distributed widely in high density in the Naechon-stream. The order of this-stream was 2 ${\sim}$ 4 and the water width is wide but the depth is relatively shallow and the sinuosity is 1.83, which indicates a meandering stream. The water width/stream width ratio is 1.59, which suggests moderate entrenchment. Naechon-stream was classed as B type by Rosgen (1995). The natural habitat of A. signifer is a slow flow velocity pool, like a backwater pool, which is made up of piled up boulders that restricts the flow of water. The stream bed is made up of boulders and sands that enable the spawning host to inhabit. A. signifer selects a microhabitat where the boulders furnish hiding places. The Habitat of A. signifer is strongly affected by the existence or not there of U. douglasiae sinuolatus. After hatching from the mussel, A. signifer inhabits the surface of the water. It then moves to the low layer once it acquires swimming ability. While A. signifer inhabits the river in summer, A. signifer moves to the deeper layers in winter, where there are the refuge like rocks and boulders. In spring A. signifer moves from the deep water to the river line where the mussels reside.

• Journal of Korea Water Resources Association
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• v.52 no.12
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• pp.1057-1066
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• 2019

The storage function method is used as a flood prediction model for four flood control offices in Korea as a method to analyze the actual rainfall-runoff relationship with non-linearity. It is essential to accurately estimate the parameters of the storage function method for accurate runoff analysis. However, the parameters of the storage function method currently in use are estimated by the empirical formula developed by the limited hydrological analysis in 2012; therefore, they are somewhat inaccurate. The kinematic wave method is a method based on physical variables of watershed and channel and is widely used for rainfall-runoff analysis. By adopting the two-term storage function method by the conversion of the kinematic wave method, parameters can be estimated based on physical variables, which can increase the accuracy of runoff calculation. In this research, the reproducibility of the kinematic wave method by the two-term storage function method was investigated. It is very easy to estimate the parameters because equivalent roughness, which is an important physical variable in watershed runoff, can be easily obtained by using land use and land cover, and the physical variable of channel runoff can be easily obtained from the basic river planning report or topographic map. In addition, this research examined the applicability of the two-term storage function method to runoff simulation of Naechon Stream, a tributary of the Hongcheon River in the Han River basin. As a result, it is considered that more accurate runoff calculation results could be obtained than the existing one-term storage function method. It is expected that the utilization of the storage function method can be increased because the parameters can be easily estimated using physical variables even in unmeasured watersheds and channels.