• The Journal of Engineering Geology
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• v.13 no.1
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• pp.83-105
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• 2003

Geochemical studies on the alluvial aquifer system near the Nakdong River were carried out for the basic investigation of the estimation of artificial recharge for the river bank filtration. In-situ data do not show any distinct difference between the pumping well and river. Most of waters belong to $_3$ and Ca-$SO_4$ types and show high Mn concentration. In the borehole installed with Multi-Ca-HCOPacker (MP) system, Na, Ca, Mg, $HCO_3$ contents of the groundwater are increased with depth increasing. Cl and $SO_4$ contents of the groundwater show the lowest values at the bottom level (18m depth) and Mn content is very high at the middle level (13.5 m depth) of MP system. There is no distinct difference in the ${\delta}^{18}O$ and D values and tritium content between MP, borehole and surface water samples. The sulfur isotope data indicate that the possible sulfur source is dissolution of sulfate mineral from sedimentary rock. Strontium isotope ratio shows a little differences between the pumping well and observation borehole samples. Nitrogen isotope data indicate that the nitrogen of water samples is originated from fertilizer or organic materials.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.2
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• pp.55-66
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• 1988

This study was conducted to investigate the various engineering properties and correlationshops among the soil constants of alluvial clayey deposits distributed in the bay of Asan and their results are summarized as follows : 1. Grain size distribution of soil was consisted of 12 % of clay, 46-73 % of silt, 2-23 % of sand, and as for the consistency characteristics, 26-36 % of liquid limit, 18-21 % of plastic limit and 6-16 % of plastic index, and so the soil belonging to as a lower plastic nonorganic clay, it's specific gravity was 2,66-2.70, and the location on the plastic chart was approximately above the A-line. Z The natural moisture content and unit weight were 30-43 % and 1.76-1.87 g I cm$_3$, respectively, and according to increment of natural moisture content, the unit weight was decreased, and the initial void ratio and degree of saturation were shown of 0,87-1119 and 92- 100 %, most of saturated. 3. Cone resistance value which was shown 2.4 - 6.5 kg / $cm^2$ was a little lower and it was increased with the depth of layer and shown the formular $q_c=0.7_z+1.32$. 4. Unconfined compression strength was about 0.18-0.43kg /$cm^2$, cu, 0.1-0.22kg / $\psi$, $2-6^{\circ}$ under uu-test condition of triaxial, and CCU, 0.08-0.3 kg/cm , $\psi$, $12-18^{\circ}$ under the condition of cu-test. 5. Pre-consolidation load of characteristics of consolidation was 0.4-0.8 kg / $cm^2$, compression index, about 0.17-0.33. 6. Liquid limit and plastic index were incresased with the increment of clay content but most of alluvial clay was appeared as a normal through non-activity clay soil shown more natural moisture content than liquid limit, and their relationship as follows : LL=0.38( cy+54.8), PI=0.836(LL -17.8), PI =0.468(LL -0.48) 7. The initial void ratio presented correlationship of positive among clay content, natural moisture content and liquid limit, and that of reverse with unit weight, and their results as follws : $e_o=0.024(w_n+0.2)$, $e_o=e_o=0.0003c_y+0.0005 LL+0.0151 W_n+\frac{3.58}{r-t}-1.52$ 8. It was shown that the compression index has correlationship of postive among the clay content, liquid limit, plastic index, natural moisture content and initial void ratio, and their relationships as follows ; $c_c=0.44(e_o-0.47)$, $c_c=0.001$

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.389-395
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• 1996

This survey was conducted to investigate the factors affecting the chemical components of groundwater in the plastic house area cultivated with horticulture crops. The data were evaluated with depth of groundwater, topography and years of cultivation as major factors. $NO_3-N$ content of groundwater was higher at waterside(Alluvial plain) than Inland plain(Alluvial plain), local valley & fan or mountain foot area, and also was detected the highest concentration in 6-10m depth well. The contents of $NO_3-N$ and $SO_4{^{2-}}$ in groundwater were increased with cultivation years. The ionic composition (${\sum}A/{\sum}C$ : ratio between total equivalant of anions and cations) of groundwater decreased with depth and was higher at waterside(alluvial plain) than other topography. The $NO_3-N$ content was negatively correlated with pH whereas it was positively correlated with $SO_4{^{2-}}$, $Cl^-$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$.

• Economic and Environmental Geology
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• v.40 no.1 s.182
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• pp.29-45
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• 2007

Biogeochemical characteristics involving redox processes in groundwater from a riverine alluvial aquifer was investigated using multi-level monitoring wells (up to 30m in depth). Anaerobic conditions were predominant and high Fe ($14{\sim}37mg/L$) and Mn ($1{\sim}4mg/L$) concentrations were observed at 10 to 20 m in depth. Below 20 m depth, dissolved sulfide was detected. Presumably, these high Fe and Mn concentrations were derived from the reduction of Fe- and Mn-oxides because dissolved oxygen and nitrate were nearly absent and Fe and Mn contents were considerable in the sediments. The depth range of high Mn concentration is wider than that of high Fe concentration. Dissolved organics may be derived from the upper layers. Sulfate reduction is more active than Fe and Mn reduction below 20 m in depth. Disparity of calculated redox potential from the various redox couples indicates that redox states are in disequilibrium condition in groundwater. Carbonate minerals such as siderite and rhodochrosite may control the dissolved concentrations of Fe(II) and Mn(II), and iron sulfide minerals control for Fe(II) where sulfide is detected because these minerals are near saturation from the calculation of solubility equilibria.

• Journal of Soil and Groundwater Environment
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• v.12 no.6
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• pp.17-25
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• 2007

Convergent flow tracer test for 2 m (IW-1 well) and 5 m (IW-2 well) of test scale was conducted at the alluvial aquifer with high permeability and storativity. Pumping rate for convergent flow tracer test were $2,500m^3/day$, and the chloride tracer of 5 kg was instantaneously injected into IW-1 and IW-2 wells. Differences of first arrival time and peak concentration were analyzed by using the concentration breakthrough curves of chloride. Recovered chloride mass were analyzed by recovered cumulative mass curves. And, increment and decrement for chloride concentration were analyzed through chloride concentration versus recovered cumulative mass ratio graphs. Also, increment and decrement ratios of chloride concentration were estimated through linear regression analyses for increment and decrement intervals of chloride concentration. Longitudinal dispersivities were estimated by quot;Converging Radial Flow With Instantaneous Injectionquot; method using CATTI code. Longitudinal dispersivities estimated by CATTI code were 0.4152 m between pumping well and IW-1 well, and 3.2665 m between pumping well and IW-2 well. Longitudinal dispersivity was increased according to far distance from the pumping well. The longitudinal dispersivity according to distance were estimated as 0.21 between pumping well and IW-1 well, and 0.65 between pumping well and IW-2 well.

• Journal of the Korean Geographical Society
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• v.29 no.3
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• pp.253-265
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• 1994

The hydraulic-geometrica1 relations between the riverbed slope and water discharge and other hydraulic variables in some selected alluvial rivels in Korea have been investigated. The rivers from which the data relevant to this study were collected are mainly the first tributaries, considered to be mostly in the equilibrium state, of the 10 major rivers in Korea. The investigating methods adopted in this study are similar to the one suggested by Leopold and Maddock and the one suggested by Garde. All of 18 rivers their drainage areas of which range between 100-2,000 $\textrm{km}^2$ were considered and the changes in riverbed slope, drainage area, bed material size along the downstream river distance were measured. It is found in this study that the change in the riverbed slope, S, along the downstream can be expressed in terms of the coefficient, $\beta$, expressing the change in the drainage area along the downstream and the drainage area, A, by an empirical relation as 0.0063 0.0063 S = $S_{ 0}$ $A_{0}$$^{-------- +0.51}$A-$^{-------- -0.51}$. $\beta$ $\beta$ According to this relation, the riverbed slope of the river reaches investigated in this study appear to be proportional to the -0.6th power of the drainage area. This result is consistent with the previous ones obtained by Hack.k.

• Journal of the Korean Geographical Society
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• v.46 no.4
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• pp.396-412
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• 2011

Multi-proxy analysis was used to produce a high-resolution paleoclimatic record from a thick section of the Holocene alluvial fan deposit in Gatap-ri, Buyeo. According to ${\delta}^{13}C$ analyses, five minor climate fluctuations can be determined. From the stage I to stage VI, climate changes are as follows: cool-dry, warm-humid, cool-dry, warm humid, drier than stage IV, and finally more humid environment than stage V. According to magnetic susceptibility records, four different stages can be identified, among which stage ii shows the highest susceptibility. Stage-i deposit is derived from sediments of back marsh-type wetland. Stage-ii and stage-iii deposits, however, show higher magnetic susceptibility because magnetite-enriched soil from weathered upland was transported to the area to form an alluvial fan deposits. Stage-iv deposit is comparable to the modern plow horizon.

• Economic and Environmental Geology
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• v.41 no.6
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• pp.673-683
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• 2008

As-rich alluvial groundwaters occurring in the agricultural area of Mankyeong River watershed were geochemically studied. 15 out of 29 investigated wells (52%) showed As levels exceeding the WHO drinking water standard ($10{\mu}g/L$). Their chemistry is characterized by low Eh levels, low $NO_3$ and $SO_4$ concentrations, and high pH, alkalinity, Fe, $NH_4$, and $PO_4$ levels. This suggests that arsenic is enriched by the reductive dissolution of As-bearing Fe-/Mn-(hydro)oxides, the commonest process in Bangladesh and West Bengal of India, of which groundwaters are severely contaminated by As. It was also revealed that As concentrations in the area are strongly regulated by the presence of agrochemicals such as $NO_3$ and $SO_4$.

• Journal of the Korean Geographical Society
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• v.51 no.5
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• pp.651-665
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• 2016

This paper tried to delimitate the location and scope of Nokdundo located in the Dumangang estuary. In 18th century, Nokdundo was an alluvial island formed by several tributaries divided from the mainstream of Dumangang. In the mid-19th century, Nokdundo was connected to the Russian territory because some tributaries were blocked by sediment flows. In many maps published in the Joseon Dynasty, the location and size of Nokdundo had not been depicted consistently with each other nor been described correctly. Because of the recurrent extinction-generating phenomena of waterways of the Dumangang due to sedimentation process, the location and scope of Nokdundo can be delimitated differently according to the era. According to the distance information of the records published in the 19th and 20th century, the scope of Nokdundo can be extended widely to the Maritime Province of Siberia. So, the author have set the Sodumangang(Karasik River) as the northern boundary of Nokdundo. The Karasik River is called Sodumangang by the Koreans living in the Maritime Province. As a tributary of the Dumangang, Sodumangang flows into the Posyet Bay. Nokdundo was an island separated from the Korean peninsula and the Maritime Province by the Dumangang and the Sodumangang respectively. Tributaries of the Dumangang have formed many alluvial islands at the mouth of Dumangang where the Dumangang meets with the East Sea. So, the possibility that Nokdundo was consisted of several islands can not be excluded.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.127-135
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• 2017

In this study, a cold well and a warm one with the distance of 100 m were installed in the alluvial aquifer. Groundwater used as the heat and the cold source of heat pump was designed to flow into the warm and the cold well with a diameter of 200 mm. In order to increase the heat and cold storage in aquifer, six auxiliary wells with the diameter of 50 mm and the depth of 30 m were installed at an interval of 5 m from the main well. Also, heat pump 50 RT, the thermal tank $40m^3$, and a remote control and monitoring system were installed in three single-span greenhouses ($2,100m^2$) for growing tomato in Buyeo, Chungcheongnam-do. According to the aquifer heat storage test which had been conducted from Aug. 31 to Sep. 22, 2016, warm water of $850m^3$ was found to flow into warm well. The temperature of the injected water was $30^{\circ}C$ (intake temperature : $15^{\circ}C$), and the heat of 12.8 Gcal was stored. The greenhouse heating test in winter had been conducted from Nov. 21, 2016 to Apr. 30, 2017. On Nov. 21, 2016 when heating greenhouse started, the aquifer temperature of the warm well was $18.5^{\circ}C$. The COP for heating with water source at $18.5^{\circ}C$ was 3.8. The intake water temperature of warm well was gradually lowered to the temperature of $15^{\circ}C$ on Jan. 2, 2017 and the heat pump COP was measured to be 3.2 at that time. As a result, the heat pump COP was improved by 18 %. and retrieval heat was 8 Gcal, the retrieval rate of heat stored in aquifer was estimated at 63 %.