• Title/Summary/Keyword: Forest Watershed

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A Study on Change of Suspended Solids by Forest Road Construction(I) -Parallel Watersheds Method- (임도개설(林道開設)에 따른 부유토사량(浮遊土砂量) 변화(變化)(I) -대조유역법(對照流域法)을 중심(中心)으로-)

  • Kim, Kyoung-Jin;Chun, Kun-Woo
    • Journal of Forest and Environmental Science
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    • v.10 no.1
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    • pp.57-65
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    • 1994
  • This study was carried out to clarify the sediment export by measuring suspended solids included in streamflow during the rainy season. The study area is located in Experimental Forests, Kangwon National University, where the forest road is under construction. For this purpose, the forest watershed with construction of forest road was compared with normal forest watershed in amount of rainfall and discharge, suspended solids and discharge, and the amount of rainfall and suspended solids. The results were shown as followings. 1. The relationship of discharge and the amount of rainfall was shown as Table 3 and Fig. 3. The delay time of peak point observed in hydrograph was changed by rainfall intensity and amount of previous rainfall. That is, when there was a rain on 12. Jun(more than 20mm/hour for hours), the peak point began three hours after the rainfall intensity over 20mm/hour, and showed $1514m^3/hour$ in automatic water level recorder. In case of the 8th of Aug.(maximum rainfall intensity: 40mm/hour), the peak point of discharge was $1246m^3/hour$ in the same time with maximum rainfall intensity. And on the 20th of Aug.(the maximum rainfall intensity: 17.2mm/hour), the peak point of discharge was $1245m^3/hour$ two hours after the maximum rainfall intensity. 2. On watershed under forest road construction, the relationship between discharge and suspended solids is that suspended solids was proportionately increased by raising discharge. That is, on the 12th of Jun, the maximum of discharge per hour was $1514m^3/hour$ and 1261mg/l of suspended solids was observed an hour after peak point of discharge. And in case of 8th and 20th Aug., each of peak points is $1246m^3/hour$ and $1245m^3/hour$ by measuring time. The maximums of suspended solids measured within two watersheds were examined in value of 4952mg/l and 472mg/l at the same time. 3. During the rainy season, the concentration of suspended solids was influenced by rainfall intensity and indicated especially curve-regressional increase in case of strong rainfall intensity. In each of watersheds, the maximums of suspended solids were 1261mg/l and 125mg/l, 4952mg/l and 44mg/l, and 472mg/l and 4mg/l by the order of rain(a), (b), and (c). Two watersheds showed a remarkable difference.

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Changes on the Physicochemical Factor of Stream Water by Medium and Small type Fish Farm in Mt. Baegun Area (백운산 지역내 중소형 양어장에 의한 계류수의 이화학적 요인의 변화)

  • Park, Jae-Hyeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.8 no.3
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    • pp.43-52
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    • 2005
  • Evaluations of the fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research influent, effluent water in the fish farm and stream water qualities around Mt. Baegun area were monitored seasonally for six years and the following results were obtained. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. Also, effluent water from the fish farm increase of EC higher than influent and stream water. As a result of regression analyses, pH, EC, DO, water temperature, total amount of cation and anion in influent and effluent water of fish farm show high significance.

Estimation of Nonpoint Pollutant Removal Capacity in the Buffer Strip with AnnAGNPS Model (AnnAGNPS 모형을 이용한 수변구역의 비점오염물질 제거능 산정)

  • Park, Yun Hee;Kim, Tae Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.9 no.5
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    • pp.22-31
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    • 2006
  • AnnAGNPS model would be applied to simulate the pollutant removal capacity with the buffer strip in the Deachung reservoir watershed. In 2002, 2,270 tons of TN and 221 tons of TP were discharged from the nonpoint source pollutants in this watershed. During the rainy season, from June to September, 66.4% of TN and 71.9% of TP resulted from nonpoint source loads. AnnAGNPS model was also used to simulate the nutrients removal capacity from the buffer strip under the condition that the present landuse would be changed to forest. As the result of simulation, the removal rates of nutrients from the buffer strip of Daecheong reservoir watershed are 406 tons of TN, 39 tons of TP, which means reduction rates are TN 17.9%, TP 17.8%, respectively.

Habitat Evaluation of Japanese Black Bear using GIS

  • Masuyama, Tetsuo;Yamamoto, Toshiharu;Hara, Keitarou;Yasuda, Yoshizumi
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1134-1136
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    • 2003
  • In this research, GIS based evaluation methods were applied to habitats of Japanese black bear (Ursus thibetanus japonicus Schlegel) in northern Honshu. The study area was divided into 828 small watershed units , and five GIS indexes, Vegetation Type(V.T.), Extent of Forest Cover (E.F.C.) Slope Incline (S.I), Average Altitude (A.A.) and Road Density(R.D.), were used to evaluate each watershed unit in terms of suitability as black bear habitat. In addition, Interspersion and Juxtaposition spatial indices were calculated for each watershed unit. The results clearly identified the regions with the most suitable habitats, indicating that this methodology is suitable for application to various environmental planning efforts, such as regional development master plans, project-specific environmental impact assessments, species management plans and biodiversity conservation plans.

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Characteristics on Seasonal Variation of Stream Water Quality on Upland Headwater Streams in Forested Catchments (산림유역의 계류수질 현황 및 계절적 변동 특성)

  • Nam, Sooyoun;Lim, Honggeun;Li, Qiwen;Choi, Hyung Tae;Yang, Hyunje;Kim, Jaehoon
    • Journal of Korean Society on Water Environment
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    • v.38 no.5
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    • pp.220-230
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    • 2022
  • Seasonal variability of water quality in the upland headwater streams in ten forested catchments (37.0~209.0 ha) was examined from April to November 2021. Here, seven physicochemical parameters were analyzed including pH, electrical conductivity (EC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (T-N), total phosphorous (T-P), and BOD/TOC. The parameters were compared with those of lowerland rivers as middle and lower reaches within a watershed. The pH showed was low (6.4~6.9) during all the seasons, however, BOD and BOD/TOC in the fall season were 2-fold higher than in the spring and summer seasons. Based on environmental standards, the water quality level revealed that the upland headwater streams maintained the purity and cleanliness of water except for pH in the summer season. BOD/TOC of all the seasons and BOD of the fall season in the upland headwater streams were higher than that in the lowerland rivers, whereas the rest of the physicochemical parameters in the upland headwater streams were lower than that in the lowerland rivers. Additionally, the water quality level maintained the purity and cleanliness of water as "Good" in two reaches. The unique aspects of our study design enabled us to draw inferences about water quality characteristics with temporal and spatial analysis in upland headwater streams. This design will be useful for the long-term strategy of effective water quality management for integrated upland headwater streams and lowerland rivers within a watershed.

Analysis of Forest Structure Using LiDAR Data - A Case Study of Forest in Namchon-Dong, Osan - (LiDAR 데이터를 이용한 산림구조 분석 - 오산시 남촌동의 산림을 대상으로 -)

  • Lee, Dong-Kun;Ryu, Ji-Eun;Kim, Eun-Young;Jeon, Seong-Woo
    • Journal of Environmental Impact Assessment
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    • v.17 no.5
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    • pp.279-288
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    • 2008
  • Vertical forest distribution is one of the important factors to understand various ecological mechanism such as succession, disturbance and environmental effects. LiDAR data provide information, both the horizontal and vertical distribution of forest structure. The laser scanner survey provided a point cloud, in which the x, y, and z coordinates of the points are known. The objectives of this study were 1) to analyze factors of forest structure such as individual tree isolation, tree height, canopy closure and tree density using LiDAR data and 2) to compare the forest structure between outer and interior forest. The paper conducted to extract the individual tree using watershed algorithm and to interpolate using the first return of LiDAR data for yielding digital surface model (DSM). The results of the study show characters of edge such as more isolated individual trees, higher density, lower canopy closure, and lower tree height than those of interior forest. LiDAR data is to be useful for analyzing of forest structure. Further study should be undertaken with species for more accurate results.

A study on mountain village problems for making forest resources - with Kangwon province as the central region - (삼림자원화(森林資源化)를 위한 산촌문제연구(山村問題硏究) -강원도(江原道)를 중심으로-)

  • Kwon, O-Bok;Woo, Jong-Choon
    • Journal of Forest and Environmental Science
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    • v.9 no.1
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    • pp.19-32
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    • 1993
  • Domestic timber comsumption has increased dramatically in the past few decades in this country. In addition, there is increasing demand for recreational opportunities in the forest areas and concern for watershed management and soil conservation. However, it is difficult to satisfy these demands for forest resources because many of woodland owerners who make such demands possible move from mountain villages to modern cities. Therefore, whether or not it is in the public interest to invest in rurbanization is a central policy question. This is a case study which deals with mountain village problems for making forest resources.

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