• Title/Summary/Keyword: Creek

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Difference of Suaeda japonica Populations from two Different Habitats in Sorae, Incheon, Korea (인천 소래 간석지내 두개의 칠면초 ( Suadeda japonica ) 개체군간의 차이에 관하여)

  • Lee, Kun-Seop;Oh, Kye-Chil
    • The Korean Journal of Ecology
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    • v.12 no.3
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    • pp.133-144
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    • 1989
  • The morphology and flowering time of two Suaeda japonica populations from different habitats, the creek and the bank of the mudflat in Sorae, were surveyed. And standard transplantation and reciprocal transplantation were carried out to determine whether their characteristics were genetically fixed or not. Also soil sample of these habitats were analyzed. The amounts of loss on ignition, maximum field capacity, total nitrogen, exchangeable calcium and potassium, and soluble phosphorus were found to be significantly different between two habitats. Leaf thickness, leaf width, leaf length, stem height number of branches, and number of seeds were significantly different between plants of two populations. And flowering times of two populations did not overlap. According to the results of transplantation, leaf width, leaf thickness, and flowering times were the same as those at their original habitat. But the stem lenght, leaf lenght, number of branches and unmber of seeds were not. Therefore, the differences in the leaf length, leaf thickness, and flowering time seemed to bo genetically fixed. It were suggested that the creek bank populations of Suaeda japoinica were to be considered as different ecotypes.

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IMPROVING HABITAT OF FORMOSAN LANDLOCKED SALMON BY DAM REMOVAL

  • Yeh, Chao-Hsien;Lien, Hui-Pang
    • Water Engineering Research
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    • v.6 no.4
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    • pp.149-159
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    • 2005
  • With increasing recognition on conservation of endangered species in Taiwan, one of the major conservation projects is the habitat restoration of Formosan Landlocked Salmon which is major threatened by check dams in the channel for their blockading pathway to upstream and causing the problems of population isolation and close-blood mating. By creating an opening in the central dam body appropriately, partial removal dams can provide pathway for the fish for the better upstream channel habitat. Four check dams at Gau-Shan Creek were remodeled between April of 1999 and September of 2002 with information supported from model experiments under certain hydraulic condition of field environment. Based on the follow-up investigation, the channel morphology of observation sections is in stable condition and the total number of Formosan Landlocked Salmon in this creek increased promptly at the reach containing partial-removed dams.

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A Study on the Numerical Modeling for the Floodwave Analysis in a River -Huogi Dam-Break Floods (하천에서의 홍수파해석을 위한 수치모형의 개발-효기댐 파괴에 따른 홍수파 해석을 중심으로)

  • 한건연
    • Water for future
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    • v.20 no.4
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    • pp.285-294
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    • 1987
  • The floodwave analysis for unsteady supercritical flow is performed. The numerical model. based on dynamic wave equation is presented by introducing the general Preissmann scheme and fore-sweep algorithm.The model is applied to Buffalo-Creek floods for proving its validity, and the simulation results have good agreements with those computed by DAMBRK and the observed data. It is also applied to Hyogi dam-break. The outflow hydrograph is derived based on the observed data and the analysis for the floodwave propagation is investigated.

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An Analysis of Runoff Characteristics at Creeks (소하천 유역의 유출변화 특성분석)

  • Jung, Jae-Wook;Yoon, Sei-Eui
    • Journal of the Korean Society of Hazard Mitigation
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    • v.1 no.2 s.2
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    • pp.75-83
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    • 2001
  • In this study, the maintenance problems were investigated through checking the creeks which were improved by close-to-nature river improvement technique. The characteristics of flow were measured at Changsa Creek in Suwon city. The computational results of numerical model with kinematic wave theory was evaluated through observation data about precipitation, velocity, and flow depth. Furthermore, SCS, Clark, and RRL models were compared to the actual observations. As a result, the kinematic wave theory's calculated peak time of discharge concentration occurred little earlier than the actual observation, but the tendency of hydrograph coincided with observation.

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Generating Land Cover Map and Estimating Runoff Curve Numbers Using High Resolution Aerial Orthophotos, Impervious Surface Layers and Feature Analyst (고해상도 수치정사 항공사진, 불투수층 레이어 그리고 Feature Analyst를 이용한 토지피복도 작성과 유출계수 산정)

  • Chung Jin-Won;Cheshire Heather M.;Lee Woo-Kyun
    • Proceedings of the KSRS Conference
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    • 2006.03a
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    • pp.228-231
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    • 2006
  • 유출계수(Runoff Curve Number, CN)란 강수량으로부터 대상유역의 유출량과 우수 잠재능(stormwater potential) 평가에 이용하는 수문학 변수로, 미국 자연자원 보존국(Natural Resources Conservation Service; NRCS)이 제안한 방법이다. 유출계수를 평가하기 위해서는 토지피복, 토양형, 토양 습윤 조건에 대한 정보를 조합하여 분석해야 한다. 본 연구의 목적은 미국 North Carolina의 Raleigh와 Cary시를 관통하는 Walnut Creek 유역 서부지역의 토지 피복도를 제작하여, 이 유역의 유출계수를 산정하는 것이다. 이를 위해서, 첫째 위의 불투수면 레이어와 정사항공사진을 기초자료로, ArcGIS와 Feature Analyst를 이용하여 서부 Walnut Creek 유역의 토지피복도를 제작하였다. 둘째, 제작된 토지 피복도와 본 유역의 수문학적 토양 분류체계도(Hydrologic Soil Group Map)를 중첩하여 이 유역의 유출계수도를 제작하였다.

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Monitoring of Detention Basin after Restoration at Joogyo Creek (주교천 천변저류지의 사후 모니터링)

  • Kim, Ki Heung;Lee, Hyeong Rae;Kim, Cheol Soo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.3
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    • pp.177-194
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    • 2011
  • In order to assess ecologically for the restored detention basin in Joogyo creek, this study carried out a monitoring on the ecosystem of the detention basin. The study site was a small detention basin with an area $6,350m^2$, which had been established in March, 2004. The monitoring started in August and November, 2007. Terrestrial, riparian, and aquatic plants species have increased about 2 times at detention basin compared to that of streamside. Mammals, birds, reptiles, amphibians, aquatic insects and crustaceans were found more in species at detention basin, and especially there were a lot of more fish species. From the results, it seemed that various terrestrial, riparian, and aquatic ecosystem were made in the small detention basin.