• Title/Summary/Keyword: Coastal Ground Water Discharge

Search Result 14, Processing Time 0.035 seconds

Distribution of Coastal Ground Water Discharge from Surficial Aquifers of Major River Districts (권역별 충적층 지하수의 해안 유출량 분포)

  • Han, Soo Young;Hong, Sung Hun;Park, Namsik
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.1B
    • /
    • pp.1-6
    • /
    • 2006
  • Amount of coastal ground water discharge(CGD) of surficial aquifer via coastlines of Nakdong River watershed, Seomjin River watershed, Youngsan River watershed and Keum River watershed is estimated. Compared to other major hydrological components, such as evapo-transpiration and river discharge, CGD is not so large in the amount. However, it is important since coastal ground water can be developed relatively free of environmental impact on downstream area and since most of coastal areas currently suffers water shortage. Regional groundwater investigation data and assessment based on Darcy's law are used for estimating coastal groundwater discharge. In this work the amount of CGD across the coastlines of the four rivers is estimated as 1.8 billion cubic meter per year and that is about 2.3 percentage of total amount of annual precipitation. Nakdong River watershed is most appropriate region in view of developing groundwater.

Assessment of Coastal Ground Water Discharge for Complex Coastlines (해안선의 형태를 고려한 지하수 해안 유출량 평가 기법)

  • Han, Su-Young;Hong, Sung-Hoon;Park, Nam-Sik
    • Journal of Korea Water Resources Association
    • /
    • v.37 no.11
    • /
    • pp.939-947
    • /
    • 2004
  • Amount of ground water discharging through coastline(CGD) is small compared to the amount of river discharges. However, CGD is important for gound water development in coastal areas and for contamination of coastal waters by nutrients transported by ground water. In the previous study, a method was proposed to estimate CGD from simple data such as ground water levels at observation wells and hydraulic conductivities. In this study, the method is enhanced by taking into account complexity of coastlines. A new method is proposed to estimate average hydraulic gradient, length of coastline, and average thickness of freshwater The new method is verified against numerical solutions. It is shown that the method is able to estimate CGD from complex coastlines more accurately than the previous method.

Search of submarine discharge locations with multi-temporal thermal infrared images and ground radar surveys

  • Onishi K.;Sairaiji M.;Rokugawa S.;Tokunaga T.;Sakuno Y.
    • Proceedings of the KSRS Conference
    • /
    • 2004.10a
    • /
    • pp.685-688
    • /
    • 2004
  • Fresh water discharge from the sea floor strongly affects a coastal ecology and the diffusion of contaminants. Much fresh water discharge has been found in the edge of Kurobe alluvial fan, in which annual rainfall is over 4000mm and there is abundant groundwater. However, it is difficult to find the groundwater discharge, thus the search of possible areas with some remote sensing tools is required. Because the temperature of the discharge point is relatively low compared with the surrounding sea water surfaces, there is a possibility to detect the area as an irregular zone of thermal infrared images. Two anomalous temperature zones, which have no surface streams from rivers, are detected by ASTER thermal-infrared images. One of them was verified as the groundwater discharge point by dives. In addition, the distribution of water table under the land side of the two areas is also detected as irregular zones by a ground-penetrating radar

  • PDF

Resistivity Exploration of Submarine Groundwater Discharge in Busan Area (부산지역의 해저용출수 전기비저항탐사)

  • Park, Jun-Kyu;Kim, Sung-Wook;Lee, Jin-Hyuk;Kim, In-Soo
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2010.03a
    • /
    • pp.711-716
    • /
    • 2010
  • This study selected the promising area of submarine groundwater discharge(SGD) that flows into the sea following unconfined physical aquifer through the electrical resistivity survey of the land and sea. The submarine groundwater discharge(SGD) mostly flows into the sea following fracture zones, and the detection of the fault zone becomes the important guideline of groundwater discharge. Electrical sounding of the land assessed the groundwater flow and integration possibility according to the location of a fault that is a water path between underground reservoir and surface water as well as a rock fracture. In addition, the study conducted sea electrical resistivity to expand the area with high potential and selected the expected water potential groundwater area. The areas of the study were Busan and coastal areas, and for the terrain analysis, the candidates of the ground exploration were selected after analyzing lineaments that is expanded to coast direction.

  • PDF

Evaluation of Discharge Capacity for Gravel mat due to Geosynthetic Using Calibration Chamber Test (모형실험을 통한 토목섬유 적용에 따른 쇄석배수층 통수능 평가)

  • Kim, Jae-Hong;Im, Eun-Sang
    • Journal of the Korean Geosynthetics Society
    • /
    • v.13 no.2
    • /
    • pp.11-20
    • /
    • 2014
  • To create a large-scale complex, it is often the case to perform ground improvement by using vertical drain method after the reclamation of coastal soft ground, for construction period shortening and stable site renovation. During this process, the pore water migrates to the horizontal drainage layer of the ground surface through the vertical drain installed in the soft ground and discharged out to the open. In the past sand was used as the material for the horizontal drainage layer in numerous cases, however recently, due to material shortage and high pricing, the use of crushed stones has increased. To prevent mixing of the materials between the horizontal drainage layer and the upper landfill, geosynthetics (PPMat) are installed. However, the use of geosynthetics results in high additional cost for material purchase and installation, therefore it is necessary to examine the validity of the installation itself. In this study, to verify the necessity, model tests were performed. Results from the model tests indicate that the drainage ability of the horizontal drainage layer is barely affected by the application of geosynthetics.

A Study on Non-point Source Pollutants from Pavement of Coastal Area and Guidance for Selecting BMP (연안지역 포장면 비점오염물질 유출 및 최적관리방안 시설의 선정을 위한 가이던스에 관한 연구)

  • Ko, Woong;Park, Kisoo;Chen, Yaoping;Kim, Youngchul
    • Journal of Wetlands Research
    • /
    • v.15 no.4
    • /
    • pp.543-553
    • /
    • 2013
  • In Korea, there have been many studies and progresses on various types of pilot scale or commercialized field scale Best Management Practices(BMP) during the last 10 years. Runoff characteristics of diffuse pollutants from different land uses are well identified and documented. However, for the coastal area connected directly with shoreline, runoff patterns and management schemes of non-point pollution were not fully studied. Recently, coastal area is emerging as a new development axis especially in west coast side of Korea such as Incheon city and Chungnam province, thus urbanized area rapidly increased but there are no buffer zones and BMP facilities to aim at preventing direct discharge of the first flush into coastal sea and beaches. In this study, parking area in Deacheon harbor, Boryeong City in Chungnam Province was selected and rainfall runoff was monitored for two year period in order to examine run-off features from which proper type of BMP suitable for coastal area is proposed. Coastal area usually has a low ground water level and consists of plain land, so that large scale BMP such as storm water retention pond and wetland requiring great excavation works is not best management plan. In addition, monitoring study shows that storm water from the paved parking area has a high salinity compared with those in storm water from the inland. High salinity is detrimental for the vegetation. Therefore, BMP employing least vegetative cover and also in terms of maintenance is a good option such as infiltration trench and porous pavement.

Assessment of Potential Groundwater Resources for Optimal Management of Coastal Groundwater (해안 지하수 최적관리를 위한 개발가능량 산정 기법)

  • Park, Nam-Sik;Hong, Sung-Hun;Seo, Kyung-Soo
    • Journal of Korea Water Resources Association
    • /
    • v.40 no.8
    • /
    • pp.665-675
    • /
    • 2007
  • An equation is developed to estimate potential groundwater resources available for development. This equation is useful for preliminary planning stages prior to detailed design stages. The equation is a function of major factors such as aquifer characteristics, saltwater intrusion length, coastal groundwater discharge and potential locations of pumping wells. Thus, most important factors are taken into account. The equations are derived using well-known analytical solutions. Thus, the basis is scientifically sound. Use of the equation is quite simple since it is an explicit function of variables. A logical method is proposed to assess a radius of influence of a pumping well considering aquifer characteristics and the pumping rate. Applications to a hypothetical problem and comparison with results from a more rigorous numerical simulation model indicate that results obtained from the proposed equation are conservative.

A Study of Technical Development of Mariculture in the Coastal Water (천해양식어업발달과정에 관한 연구 - 기술개발활동을 중심으로 -)

  • Choi, Jeang-Yoon
    • The Journal of Fisheries Business Administration
    • /
    • v.16 no.1
    • /
    • pp.91-124
    • /
    • 1985
  • Mariculture is contrasted with inland aqua-culturing fisheries. It is defind as the Industry of rearing Aquaorganism in limited coastal area relatively shallow in depth. Then, It's coming into being realization of Mariculture in it is long in history that Mariculture was realized in Korea. But it is from the early part of 1960s, that this industry has normally developed. Owing to 200 miles economy-zone problems of coastal countries, the development of deep sea fishing was limited, so the Korean Government has now appreciated the importance of cultured industries in the field of coastal fisheries. And the Korean Mariculture the output of which was only 18, 000 M/T in '60s attained 540, 000M/T in 1980s, has now occupied its relative importance in Korean Fisheries Industry. So the purpose of this report is to suggest the prospect of technical development of mariculture in the future of Korea, through the analysis of the various problems that affect upon the individual management '||'&'||' fishing ground utilization, along with the appreciation of "how to extend of those technical innovation" and "how the fishermen's technique level is extended at this stage. According to this study, the result is summarized as follows. First, Maricultural technique is classified into 8 sub-techniques as follows, as shown in fig. 1.Fig. 1. The Formation structure of mariculture technique Second, the change of technical method of mariculture in coastal area of Korea has made as 5 stages; 1) Scattering of culturing organism 2) Culturing by putting stone and installing bamboo 3) Culturing by installing rope and seeding 4) Culturing of putting objectives in cages 5) Culturing fish by feed Third, the maricultural fisheries of Korea has about 70 years long in history. It began from 1910s. But at that time there was no special technique in aquaculture and its technique was confined in searching out the object of species. The species was laver, oyster ect.Forth, although realization of mariculture in Korea has been long time, it is of late from 1960s that this has been industrial with normal development, and its technique of mariculture has mainly has developed from 1970s. Its result not only contributed to the high growth in Korean ecconomy along with the well balanced development between industires, but also it played a great role for the resolution of nation's food problem. Especially maricultural production has shown its sustained annual increase of 13.8% during the last 20 years. So the portion of mariculture among total fisheries stucture was extended from 4.1% in the early 1960s to 22.4% in 1980s.Fifth, it could be safely said that such development in maricultural field is resulted from the activity of aquacultural institutes such as Fisheries Reseach '||'&'||' Development production of major kinds such as Oyster, Sea-mustard, and Laver etc. As well as in the innovation of aquaculturing method with synthetic fiber utilization. FRDA has played important role in the efficient propargation of new aquacultural technique.Sixth, as for the change in aquaculture structure and its during period between 1970s and 1980s, the private management participation shown 25% increase from household number of 45, 173 to 56, 268 in total number. And in the respect of the management scale, of their management decreased, while it showed an increase in relative large scale management, the increase over 3 employees compared with other fisheries field between '70s and 80s. This must be an major trait to be recorded, Now the data above mentioned are shown as in table 1 and 2.Table 1. The maricultural fishing ground development situation in 982.Table 2. The mariculture management as seen in the employmnet size in high seasion.Owing to the technical innovation, of the mariculture in coastal area new income of fishermen increased and it also is true that the number of fishermen participating in its industrialization increased. But the problem being from now on is the self-discharge of the destruction fishing ground considered resulted from rapid expansion in aquaculture industry and the preventive system of sentility of fishing ground. sentility of fishing ground.

  • PDF

Temporal and Spatial Fluctuations of Coastal Water Quality and Effect of Small Tide Embankment in the Muan Peninsula of Korea (무안반도 연안수질의 시ㆍ공간적 변동과 소규모 방조제의 영향)

  • Lee Dae-In;Cho Hyeon-Seo;Lee Gyu-Hyung;Lee Moon-Ok
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.6 no.4
    • /
    • pp.24-36
    • /
    • 2003
  • In this study, we estimated the seasonal fluctuations of water quality and effect of small tide embankment in coastal water around the Muan Peninsula, which is located in the northern part of Mokpo city, and layer farming ground is spread around there. Some physical and chemical factors were analyzed to characterize water quality from Jan. to Oct. in 1994. The results were as follows: Dissolved oxygen was slightly under saturation in the almost areas of July, and in some bottom layer at ebb tide of October. Distribution of COD showed high values that over 2㎎/L in October and flood tide of April by the discharge of freshwater and resuspension of benthic sediment, which exceeded water quality criteria II. Maximum values of dissolved inorganic nitrogen ware appeared in surface layer during the flood tide of October, while minimum of that showed in surface layer in April. Concentration of dissolved inorganic phosphorus was higher at July than the others, which ranged from 0.24 to 2.08㎍-at/L. Mostly mean values of N/P ratio were lower than 16, it mean that nitrogen is more limiting nutrient than phosphorus for the growth of phytoplankton. The values of eutrophication index were in the range of 0.07~0.81. However, very high values due to increase of COD were estimated near the tide embankment and southern part in relation to tidal current in October. Water quality around tide embankment was suddenly changed worse within a short period after opening the water gate during the rainfall.

  • PDF

Spatiotemporal Changes of the Sand Barrier using Marine Charts Analysis in the Nakdong River Estuarine (해도분석을 통한 낙동강 하구 사주 면적의 시.공간 변화)

  • Yoo, Chang-Ill;Yoon, Han-Sam;Ryu, Cheong-Ro;Lee, In-Cheol
    • Journal of Ocean Engineering and Technology
    • /
    • v.20 no.6 s.73
    • /
    • pp.54-60
    • /
    • 2006
  • This study discusses characteristic of spatiotemporal changes of the sand barrier in the Nakdong estuarine for the last century, focusing on geomarphologic evolution and mobility of sand barriers in the view of coastal engineering. The Nakdong estuarine, the research subject, has a complexly changing natural environment by interaction between ground and marine elements such as ocean wave, tidal current, sediment, etc. Moreover, recently, unnatural geomorphologic changes (e.g., seaside reclamation, new harbor construction, etc.) has been radically increased in this area with increasing desire for coastal development. Because of this, its sand barrier has developed quite unstable condition. Therefore, to identify the development process of geomorphologic changes in this area, required is a close examination on historical characteristics of spatiotemporal changes of the sand barrier in relation to surrounding seaside reclamation and physical environmental changes. This study, based on the marine charts published in between 1927 and 1995 year, analyzes the length and area of the sand barrier for the last hundred years, and investigates the cause of the changes by looking into the change of water depth for the last two years and doing ocean-physical site observations. In conclusion, the sand barrier of the Nakdong estuarine expands toward the open sea by $7.4{\sim}26m$ in annual average, maintaining a fixed distance of $1,241{\sim}1.279m$, and its area is expected to increase about $2.8km^2$ annually. This is characterized by the wocean wave from the open sea and the discharge of Nakdong River.