• 제목/요약/키워드: River Sand

검색결과 702건 처리시간 0.034초

금강하구 표층퇴적물의 지화학적 특성에 관한 연구 (Geochemical Characteristics of Surface Sediments in the Keum River Estuary Adjacent to Coastal Area)

  • 서만석;박영석
    • 수산해양교육연구
    • /
    • 제19권1호
    • /
    • pp.1-7
    • /
    • 2007
  • The purpose of this study was to investigate geochemical characteristics of surface sediments in the Keum river estuary adjacent to coastal area. For this study we collected the 21 surface sediments samples. Mean size of surface samples was $3.24{\sim}6.65{\phi}$ on inner estuary and was $2.15{\sim}3.42{\phi}$ on outside estuary. Surface samples were composed of silt on inner estuary and were composed of sand which was more larger than $4{\phi}$ on outside estuary. Most major elements except CaO, $Na_2O$ showed good relationships between variation of contents and grain size. Contents of $Al_2O_3$, $Fe_2O_3$, MgO, $K_2O$, $TiO_2$, $P_2O_5$ and $M_nO$ were increased predominately owing to the variation of mean size of surface samples. Contents of Co, Cr, Cu, Li, Sr, Zn, La, Ce, Pb, Rb, Nd have a good relationships with grain size but Ba, Th, Sm have not. All of major and minor elements contents except $K_2O$ and Ba were less than world mean contents of shallow surface sediments but apprehend a high pollution possibility on silt sediments in the estuaries.

한강하류지형면의 분류와 지형발달에 대한 연구 (양수리에서 능곡까지)

  • 박노식
    • 동굴
    • /
    • 제68호
    • /
    • pp.23-73
    • /
    • 2005
  • Purpose of study; The purpose of this study is specifically classified as two parts. The one is to attempt the chronological annals of Quaternary topographic surface through the study over the formation process of alluvial surfaces in our country, setting forth the alluvial surfaces lower-parts of Han River area, as the basic deposit, and comparing it to the marginal landform surfaces. The other is to attempt the classification of micro morphology based on the and condition premising the land use as a link for the regional development in the lower-parts of Han river area. Reasons why selected the Lower-parts of Han river area as study objects: 1. The change of river course in this area is very serve both in vertical and horizontal sides. With a situation it is very easy to know about the old geography related to the formation process of topography. 2. The component materials of gravel, sand, silt and clay are deposited in this area. Making it the available data, it is possible to consider about not oかy the formation process of topography but alsoon the development history to some extent. 3. The earthen vessel, a fossil shell fish, bone, cnarcoal and sea-weed are included in the alluvial deposition in this area. These can be also valuable data related to the chronological annals. 4. The bottom set conglometate beds is also included in the alluvial deposits. This can be also valuable data related to the research of geomorphological development. 5. Around of this area the medium landform surface, lower landform surface, pediment and basin, are existed, and these enable the comparison between the erosion surfaces and the alluvial surfaces. Approach : 1. Referring to the change of river beds, I have calculated the vertical and horizontal differences comparing the topographic map published in 1916 with that published in 1966 and through the field work 2. In classifying the landform, I have applied the method of micro morphological classification in accordance with the synthetic index based upon the land conditions, and furthermore used the classification method comparing the topographic map published in 1916 and in that of 1966. 3. I have accorded this classification with the classification by mapping through appliying the method of classification in the development history for the field work making the component materials as the available data. 4. I have used the component materials, which were picked up form the outcrop of 10 places and bored at 5 places, as the available data. 5. I have referred to Hydrological survey data of the ministry of Construction (since 1916) on the overflow of Han-river, and used geologic map of Seoul metropolitan area. Survey Data, and general map published in 1916 by the Japanese Army Survbey Dept., and map published in 1966 by the Construction Research Laboratory and ROK Army Survey Dept., respectively. Conclusion: 1. Classification of Morphology: I have added the historical consideration for development, making the component materials and fossil as the data, to the typical consideration in accordance with the map of summit level, reliefe and slope distribution. In connection with the erosion surface, I have divided into three classification such as high, medium and low-,level landform surfaces which were classified as high and low level landform surfaces in past. furthermore I have divided the low level landform surface two parts, namely upper-parts(200-300m) and bellow-parts(${\pm}100m$). Accordingly, we can recognize the three-parts of erosion surface including the medium level landform surface (500-600m) in this area. (see table 22). In condition with the alluvial surfaces I have classified as two landform surfaces (old and new) which was regarded as one face in past. Meamwhile, under the premise of land use, the synthetic, micro morphological classification based upon the land condition is as per the draw No. 19-1. This is the quite new method of classification which was at first attempted in this country. 2. I have learned that the change of river was most severe at seeing the river meandering rate from Dangjung-ni to Nanjido. As you seee the table and the vertical and horizontal change of river beds is justly proportionable to the river meandering rate. 3. It can be learned at seeing the analysis of component materials of alluvial deposits that the component from each other by areas, however, in the deposits relationship upper stream, and between upper parts and below parts I couldn't always find out the regular ones. 4. Having earthern vessel, shell bone, fossil charcoal and and seaweeds includen in the component materials such as gravel, clay, sand and silt in Dukso and Songpa deposits area. I have become to attempt the compilation of chronicle as yon see in the table 22. 5. In according to hearing of basemen excavation, the bottom set conglomerate beds of Dukso beds of Dukso-beds is 7m and Songpa-beds is 10m. In according to information of dredger it is approx. 20m in the down stream. 6. Making these two beds as the standard beds, I have compared it to other beds. 7 The coarse sand beds which is covering the clay-beds of Dukso-beds and Nanjidobeds is shown the existence of so-called erosion period which formed the gap among the alluvial deposits of stratum. The former has been proved by the sorting, bedding and roundness which was supplied by the main stream and later by the branch stream, respectively. 8. If the clay-beds of Dukeo-bed and Songpa-bed is called as being transgressive overlap, by the Eustatic movement after glacial age, the bottom set conglomerate beds shall be called as being regressive overlap at the holocene. This has the closest relationship with the basin formation movement of Seoul besides the Eustatic movement. 9. The silt-beds which is the main component of deposits of flood plain, is regarded as being deposited at the Holocene in the comb ceramic and plain pottery ages. This has the closest relationship with the change of river course and river beds.

하천 퇴적물 내 중금속 오염도 평가에 관한 연구 (낙동강 수계 표층 퇴적물을 대상으로) (Contamination Assessment of Heavy Metals in River Sediments (For the Surface Sediments from Nakdong River))

  • 김신;안정민;정강영;이권철;권헌각;신동석;양득석
    • 한국물환경학회지
    • /
    • 제33권4호
    • /
    • pp.460-473
    • /
    • 2017
  • In order to certificate the contamination assessment of heavy metals in surface sediments from the Nakdong river. Surface sediments were collected of 24 sampling sites (main 14st., tributary 10st.) and analyzed for grain size heavy metals contents. Study area mainly composed of sand (avg. 94.1%) and mean grain size was $1.46{\Phi}$ on average. Heavy metals contents (avg. Al: 12.5%, Zn; 74.4, Cr: 45.3, Li: 26.0, Pb: 17.1, Ni: 10.5, Cu: 7.8, Cd: 0.22 mg/kg) were relatively high contents in the composed of fine sediments. In addition, the results of pearson's correlation coefficient showed that most heavy metals and grain size (silt and clay) were highly correlated. The contents of Zn (6st.) and Ni (1st.) evaluated as moderately polluted, Zn (6st.) evaluated as LEL when compared with sediment quality standard of USEPA and Ontario sediment quality guidelines. Most heavy metals contents were I levels that dose not affected the benthos when compared with sediment pollution evaluation standard of NIER. The results of EX, EF, Igeo and CF showed the contents of Zn, Pb and Cd exceed the background contents and distributing of anthropogenic pollution and evaluated as moderately polluted level. And Nm-08 were relatively high level of contamination in the study area. However as results of PLI (less than 1), all sampling sites were evaluated unpolluted level.

하천 복원을 위한 과거 및 현재 자료 기반의 하천지형학적 특성 분석: 미호천과 내성천을 중심으로 (Analysis on Fluvial Geomorphological Characteristics based on Past and Present Data for River Restoration: An Application to the Miho River and the Naesung River)

  • 이찬주;김지성;김규호;신형섭
    • 한국수자원학회논문집
    • /
    • 제48권3호
    • /
    • pp.169-183
    • /
    • 2015
  • 하천 복원을 위한 기초 작업으로서 자연 상태에 가까운 하천의 지형학적 특성을 파악하기 위해 과거 및 현재 자료를 이용하여 하천지형학적 분석을 실시하였다. 대상 하천은 미호천과 내성천이다. 분석에 포함된 지형학적 변수는 하곡변수인 곡저폭, 하도 형상변수인 사행도, 강턱하폭, 하도경사, 구성재료 변수인 하상재료, 지배 변수인 강턱유량, 비유수력이며, 지배적인 프로세스가 함께 고려되었다. 분석 결과 두 하천은 비슷한 유역면적을 갖는 모래하천이지만, 곡저폭, 하도 형상변수, 종단적 위치에 따른 지배적인 프로세스 등에서 차이가 있는 것으로 나타났다. 또한 지형학적 변수들 사이의 상호 관계를 분석하였다. 그 결과 강턱하폭은 강턱유량에 비례하여 증가하였고, 그 경향성은 기존의 연구 결과와 대체로 일치하고 있다. 강턱유량과 하도경사를 분석한 결과 미호천은 사행하천과 망상하천의 특성을 나타내고 있는 반면, 내성천은 대부분의 구간에서 망상하천에 해당하는 것으로 나타났다. 하도경사와 하폭수심비 관계를 이용하여 지배적인 프로세스를 분석한 결과 미호천은 사구-연흔의 특성을 나타내고 있으나 내성천은 하류에서는 망상하천 특성이 지배적인 반면, 상류에서는 여울-소 내지는 평하상 특성이 지배적인 것으로 나타났다. 과거 자료를 이용한 분석 결과는 정비된 하천의 자료를 이용한 분석 결과에 비해 합리적인 것으로 나타났다.

섬진강 중류 (곡성-순창) 구간의 하천지형 변화 연구 (Temporal Change of Fluvial Geomorphology in the Middle Reaches of the Sumjin River, Korea)

  • 남욱현;양동윤;김주용;김진관
    • 한국제4기학회지
    • /
    • 제16권1호
    • /
    • pp.17-27
    • /
    • 2002
  • 순창에서 대강, 곡성에 이르는 섬진강 본류에서 건설부 (1978)가 설정한 199∼145번 횡단측선에서 측량을 실시하고, 이를 1978년과 1989년에 건설부에서 조사한 횡단측선과 비교하여 시간에 따르는 하상지형의 변화를 고찰하였다 그 결과, 본 연구지역은 전체적으로 하방침식이 우세한 환경이며, 일부 구간에서는 측방침식과 함께 최심선이 제방측으로 이동하는 경향을 나타내는 것으로 나타났다. 이렇게 침식이 우세하게 나타나는 원인으로서 다음 두가지를 들 수 있다. 첫 번째로 유속이 증가하였다는 점이다. 습지 파괴, 구하도 파괴, 인공제방 축조 등 인간간섭에 의하여 하도폭이 축소·고정되었으며 하도가 직강화되었으며, 이에 따라 유속이 크게 증가하였다. 유속 증가는 하상 퇴적물에 자갈 및 극조립∼조립질 모래가 우세하게 분포하고 있다는 사실에서도 확인할 수 있다. 두 번째로, 1980~1990년대에 본 연구구간과 연구구간의 하류측에서 집중적으로 골재채취가 이루어졌다는 점이다. 이러한 원인으로 인하여 본 연구구간은 침식이 우세하게 나타나게 되는데, 특히 188∼187번 측선의 우안 일대와 155번 측선의 좌안 일대에서 인공제방 하부의 침식이 크게 진행되고 있으며 최심선도 제방쪽으로 이동하고 있는 양상이 관찰되어, 홍수시에 제방이 파괴되는 파제의 위험성이 큰 것으로 사료된다.

  • PDF

한강 하구 습지복원을 위한 장항습지의 사주 지형변화 및 식생정착 (Topographical change of sandbar and vegetation settlement in Jang-Hang wetlands for Han River Estuary Wetlands Restoration)

  • 안홍규;김시내;정상준;이동준;이삼희
    • 한국습지학회지
    • /
    • 제14권2호
    • /
    • pp.277-288
    • /
    • 2012
  • 기수역은 하천의 종횡단 방향으로 수질 하안 저질 재료 및 미지형이 변화하는 환경변화가 매우 큰 공간으로 이러한 환경의 질적 차이에 의하여 생물 서식처가 달라지는 특수한 공간이다. 본 연구는 신곡 수중보의 건설과 수중보 하류의 과도한 준설 등이 수리적인 여건 변화를 제공하였고 이로 인하여 사주 변화가 급격히 진행된 한강의 장항습지를 대상으로 하구습지의 공간적 변화 추이와 장항습지의 물리 생태적 특성을 분석하여 사주부 식생의 정착과 확장과정을 규명하였다. 그 결과 장항습지의 사주면적은 1985년과 비교하여 2006년도에는 6배정도로 습지가 확장되었고, 갈대군락은 점차 감소하는 반면 선버들 군락은 증가하였다. 또한 토층분석 결과 장항습지는 하천의 영향을 받아 형성되었으며, 습지의 중류역에서부터 목본류가 정착하여 상하류로 확산된 것으로 분석되었다.

자연지리 답사를 통한 지역화 교육 프로그램의 개발과 운영 - 미호천 유역 하천지형을 사례로 - (Development and Operation of Region-Focused Program by Field Survey of Physical Geography with the Case Study on Miho River Basin, Central Korea)

  • 이민부;김정혁;최훈
    • 한국지형학회지
    • /
    • 제21권4호
    • /
    • pp.53-67
    • /
    • 2014
  • 본 연구의 목적은 초 중 고 대학생을 대상으로 지역화 교육 답사 프로그램을 개발하고 운영하여 삶의 터전에 대한 올바른 이해를 도모하고 일상생활이 이루어지는 장소에 나타나는 지형들을 지리적 방식에서 바라 볼 수 있도록 안내하는데 있다. 이를 위해 금강 중류에서 합류하는 가장 큰 지류인 미호천 인근에 자연지리 학습장을 개발하고 초 중 고 대학생을 대상으로 총 4차례에 걸쳐 자연지리 답사를 진행하였다. 본 연구지역은 충청북도에서 가장 규모가 큰 충적평야 지대로 미호천 하도, 습지 및 하중도, 자연제방 등의 하천 지형 사례가 다양하게 분포하고, 특히 개발에 의한 변화 과정을 쉽게 확인할 수 있어 지형과 인간생활과의 관계를 올바르게 이해하는데 효과적으로 활용될 수 있다. 자연지리 답사를 운영하는데 있어 답사 집단에 따른 성취 기준은 각각 다르게 적용하였지만, 일상생활이 이루어지는 장소의 자연적 기반인 지형에 의미를 부여하고, 지형과 삶의 관계를 이해하며 해석하려는 태도를 기르는 궁극적인 목적은 모든 집단에게 동일하게 적용하였다.

영산강 부유하중의 시계열적 입도 특성 변화: 승촌보, 죽산보를 중심으로 (Time-series Changes in Particle Size Characteristics of Suspended Sediment at the Seungchon and the Juksan Weir in the Yeongsan River)

  • 임영신;김진관
    • 한국지형학회지
    • /
    • 제26권4호
    • /
    • pp.1-20
    • /
    • 2019
  • In order to establish appropriate policy to control sediment-associated problems, it is necessary to identify the physical characteristics of the reservoir sediments in particulate form in the Yeongsan River. Two time-integrated suspended sediment samplers were installed at Seungchon and Juksan weir on the upper and middle Yeongsan River in July 2012. Reservoir sediment samples were obtained at monthly intervals until October 2014. During the monitoring period, a total of 38 sediment samples were obtained and analyzed. Seasonal trends of suspended sedimentation rates and grain size distributions were examined based on variations in precipitation and discharge fluctuations. Moreover, stream flow characteristics, which has a great influence on the physical characteristics of the river sediment, was analyzed using flow duration curve for the period 2003-2019 at Naju gauging station. Sedimentation rates during summer, when heavy rainfall was concentrated due to the monsoonal front and typhoon, were very high, indicating the positive relationship between sediment concentration and discharge. Particle size analysis of the collected sediment showed that coarse silt and very fine sand-sized sediment dominated most of the Seungchon weir sediment. On the other hand, medium silt-sized sediment dominated the downstream Juksan weir except for a few summer samples. These results implied that the physical characteristics of the suspended sediment are determined not only due to flow fluctuations, but also with regard to the antecedent rainfall conditions, hillslope-channel connectivity, and the supply of materials from various contributing regions. This information about flow characteristics and temporal variations in reservoir sediment can be used for safe management of the weir and discussing the issues on the dismantling of the weirs.

식물추출액을 이용한 지반 고결제 개발 (Development of Soil Binder Using Plant Extracts)

  • 박성식;최선규;남인현
    • 한국지반공학회논문집
    • /
    • 제28권3호
    • /
    • pp.67-75
    • /
    • 2012
  • 본 연구에서는 식물추출액을 이용하여 모래 입자 사이에 친환경적으로 탄산칼슘을 석출시켜 모래 고결을 유발하고자 하였다. 식물추출액에는 고결유발 미생물(예: $Sporosarcina$ $pasteurii$)과 같이 요소를 탄산이온과 암모늄이온으로 분해하는 우레아제 성분이 포함되어 있다. 분해된 탄산이온과 용액 속에 녹아 있는 칼슘이온이 결합하여 탄산칼슘을 석출시키는 원리를 이용하여 모래의 고결을 유도하였다. 깨끗한 낙동강모래에 식물추출액과 요소 그리고 칼슘원(염화칼슘 또는 수산화칼슘)을 혼합한 용액을 섞어서 비빈 다음 다짐방법으로 공시체를 제작하였다. 요소의 농도를 세 종류로 달리하였으며, 제작된 공시체를 실내($18^{\circ}C$)에서 3일 동안 양생시킨 다음 일축압축시험과 SEM 및 XRD분석을 실시하여 사질토의 고결 정도를 연구하였다. 칼슘원에 관계없이 요소의 농도가 높을수록 탄산칼슘이 더 많이 침전되어 일축압축강도는 식물추출액을 사용하지 않은 경우보다 최대 10배까지 증가하는 경향을 보였다. 염화칼슘을 사용한 공시체가 수산화칼슘을 사용한 경우보다 더 높은 강도를 나타내었다.

사질토 지반에서 말뚝의 수평거동 (Lateral Behavior of Sin811e and Group Piles in Sand)

  • 김영수;김병탁
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 1999년도 가을 학술발표회 논문집
    • /
    • pp.3-44
    • /
    • 1999
  • This paper discusses the lateral behavior of single and group piles in homogeneous and non-homogeneous(two layered) soil. In the single pile, the model tests were conducted to investigate the effects on ratio of lower layer height to embedded pile length, ratio of soil modules of upper layer to lower layer, boundary rendition of pile head and tip, embedded pile length, pile construction condition, ground condition with saturate and moisture state in Nak-Dong river sand. Also, in the group pile, the model tests were to investigate the effects on spacing-to-diameter ratio of pile, pile array, ratio of pile spacing, boundary condition of pile head and tip, eccentric load and ground condition. The maximum bending moment and deflection induced in active piles were found to be highly dependent on the relative density, pile construction condition, boundary condition of pile head and tip. Based on the results obtained, it was found that the decrease of lateral bearing capacity in saturated sand was in the range of 31% - 53% as compared with the case of dry sand. Also, in the group pile, a spacing-to-diameter of 6.0 seems to be large enough to eliminate the group effect for the case of relative density of 61.8%, and 32.8%, and then each pile in such a case behaves essentially the same as a single pile. In this study, the program is developed by using the modified Chang method which used p - y method and the exact solution of governing equation of pile and it can be used to calculate the deflection, bending moment and soil reaction with FDM in non-homogeneous soil. In comparing the modified Chang method with field test results, the predict results shows better agreement with measured results in field tests.

  • PDF