• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.509-514
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• 2005

Geumgang canal is planned to connect Geumgang lake with Saemangeum reservoir to accelerate desalinization and dillute polluted water in Saemangeum reservoir. The purpose of this study is to evaluate the variations of water quality by divesion of Geumgang lake flow to the Saemangeum reservoir. WASP5 model was used to estimate water quality concentration of Geumgang lake. Model calibration and verification was done for water quality data for 2001 and 2002. As a result of simulating water quality concentration for 4 scenarios, which was considered whether Geumgang canal will be built, there was little influence on water quality in Geumgang lake though Geumgang lake flow diverted to Saemangeum reservoir.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.315-321
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• 2010

Greenhouse soil cultivated with excessive compost and chemical fertilizer has been an issue to deteriorate soil and water quality in the environment. The objective of this study was to evaluate the nutrient outflow by desalting method, flooding soil surface, after vegetable cropping in greenhouse soils. Field experiment from July to September 2008, was conducted to quantify greenhouse locations, i.e. alluvial plain and local valley. The changes of desalinization in both locations were higher as the amounts of irrigated and drained water were increased. Particularly, the ratio of desalinization in alluvial plain was much higher (66.7%) than the one in local valley (45.6%). However, $NH_4$-N contents of local valley soil during the flooding were higher than in those of alluvial plain. This was caused by high total nitrogen and organic matter in local valley soil than those in alluvial plain soil. With comparing to the input and output loads of T-N and T-P in greenhouses with local valley and alluvial plain soils, the output loads of nutrients were larger than the input loads of nutrients. This result showed that the flooding soil surface can be a good treatment to desalinize greenhouse soils. However, this conclusion remained that the flooding water containing high N and P concentrations might cause the secondary effect on the quality of streams and groundwater since excessive nutrient concentrations can be the main cause of eutrophication problem in aquatic environment.

• Korean Journal of Environmental Agriculture
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• v.22 no.2
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• pp.79-86
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• 2003

This research was conducted to present reference data to be used as newly reclaimed tidal land management. We investigated vegetation succession at 4 reclaimed/reclaiming project areas and discussed relationship with soil and vegetation trhrough investigation and analysis soil chemical characteristics at 2 areas. 14 families 58 kinds were investigated. Vegetation were variou at Dea-Ho conservation polt and Seok-Mun National Industrial Area which are maintaining naturally. Vegetation were simple at Hong-Bo and Dongjin and MinKyong river areas which effected sea water. Common species that were investigated at 9 sites were Suaeda asparagoides, Aster tripolium, Phragmites australis, Suaeda maritima, Suaeda japonica, Carex scabrifolis. As soil desalinization progressing, soil classified at first saline-soidc soil, the nest saline soil and then normal soil. Chenopodiaceae revealed at about 30 dS/m of soil ECe and existed to 10 dS/m of soil ECe. At about 20 dS/m of soil ECe. Aster tripolium, Calamagrostis epigeios, and Sonchus brachyotus revealed and then non-halophytes and common plants at inland revealed at low soil ECe of about 10 dS/m. However it was not to progress vegetation sucdession and soil desalinization at the same time, owing to input of seeds or plants ect from out-ecosystem. So for promotion of vegetation at newly reclaimed tidal land, we proposed that it was very effective to plant artificially halophytes or suitable species through soil test.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.406-411
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• 2014

Serious problems in reclaimed land agriculture are high soil salinity and poor vertical drainage, so desalinization in these soils is very difficult. Also, although desalinization is accomplished in reclaimed top soils, before long, soils are resalinized according to capillary rise of salts from the subsurface soils. To resolve these problems, multi-layered soil columns with subsurface layer of macroporous medium utilizing coal bottom ash (CBA) were constructed and the effects of blocked resalinization of these soils were investigated. In this experiment soil samples were collected from Munpo series (coarse-loamy, nonacid, mixed, mesic, typic Fluvaquents). The soil texture was silt loam and the EC was $33.9dS\;m^{-1}$. As for groundwater seawater was used and groundwater level of 1 cm from the bottom was maintained. The overall rate of capillary rise was $2.38cm\;hr^{-1}$ in soil 60 cm column, $0.25cm\;hr^{-1}$ in topsoil (30 cm) + CBA (5 cm) + subsurface soil (10 cm) column and $0.08cm\;hr^{-1}$ in topsoil (30 cm) + CBA (10 cm) + subsurface soil (10 cm) column. In multi-layered soil columns with CBA 20, 30 cm layer, wetting front due to capillary rise could not be seen in top soil layer. After 70 days capillary rise experiment water soluble Na+ accumulated in top soil of soil columns with CBA 20, 30 cm was diminished by 92.8, 96.5% respectively in comparison with Na+ accumulated in top soil of soil 60 cm column because CBA layer cut off capillary rise of salts from the subsurface soil. From these results we could conclude that the macroporous layer utilizing CBA placed at subsurface layer cut off capillary rise of solutes from subsurface soil, resulting in lowered level of salinity in top soil and this method can be more effective in newly reclaimed saline soil.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.2
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• pp.114-118
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• 1990

Water requirement for desalinization was studied in column experiment filled with a tidal saline soil treated with gypsum partially, one half of the gypsum was mixed to the top one tenth and the other half was spread on the surface of the column soil. Different doses of percolates were collected and analysed with sectionalized column soils after the last percolation. Results obtained are as follows ; 1. One point seven(1.7) times of percolate was enough to desaline sodium from the tidal saline soil to bring the activity ratio of $Na/{\sqrt{Ca+Mg)}}$ to 0.10 at which the mean % Na to the sum of cations was $1.64{\pm}0.57$, but for magnessium, twice as much the percalate as the saline soil was still not enough, so that the activity ratios, $(Na+{\sqrt{Mg}})/(K+{\sqrt{Ca}})$ of soil, at different depth were not contract to an equilibrium point. 2. Most free NaCl was washed out into 1.4 times of percolate to the saline soil There after which the leaching of K and Mg became obvious. 3. Iso ha lime curves of sodium were prepared for water requirement to desaline a tidal saline soil to a projected Na concentration and a predetermined soil depth.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.2
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• pp.107-113
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• 1990

In comparision with calcium sulphate, the effect of calcium-carbonate, -silicate and -hydroxide on desalinization of tidal saline soil was investigated in a continuous leaching column experiments after mixing with an equivalent amount of Ca to sodium plus magnessium in the saline soil. One half of liming materials was mixed to the top one-tenth of column soil and the remainder was spread on the surface. Results obtained are as follows ; 1. Gypsum made easy to percolate and desaline (Na) tidal marine soil but accumulated magnessium in subsoil. 2. $Ca(OH)_2$, $CaCO_3$, and $CaSO_3$ precipitated Mg in the soil which limes were mixed, but they washed down magnessium more severely from the immediate bellow the limed soil and less from the subsequent soil layers. This leaching was more severer at the treatment of $Ca(OH)_2$and lowest at the treatment of $CaSiO_3$. 3. The alkalinity of lime in addition to the dissociation of exchangeable Na raised pH of limed leached tidal soil and slowed down the percolation rate which retarded desalining Na from limed saline soils. This effect was most severe in the $Ca(OH)_2$ treated soil. 4. pH of leached soils was correlated possitively with exchangeable Na and negatively with exchangeable Mg giving follwing relationship pH= 7.77+0.489 Na/Mg r = 0.845.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.618-627
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• 2015

Soil salinity is the most critical factor for crop production at reclaimed tidal saline soil. Subsurface drainage system is recognized as a powerful tool for the process of desalinization in saline soil. The objective of this study was to investigate the effects of subsurface drainage systems on soil salinity and corn development at Saemangeum reclaimed tidal saline soil. The field experiments were carried out between 2012 and 2014 at Saemangeum reclaimed tidal land, Buan, Korea. Subsurface drainage was installed with four treatments: 1) drain spacing of 5 m, 2) drain spacing 10 m, 3) double layer with drain spacing 5 m and 10 m, and 4) the control without any treatment. The levels of water table showed shorter periods above 60 cm levels with the deeper installation of subsurface drainage system. Water soluble cations were significantly greater than exchangeable forms and soluble Na contents, especially in surface layer, were greatly reduced with the installation of subsurface drainage system. Subsurface drainage system improved biomass yield of corn and withering rate. Thus, the biomass yield of corn was improved and the shoot growth was more affected by salinity than was the root growth. The efficiency of double layer was not significant compared with the drain spacing of 5 m. The economic return to growers at reclaimed tidal saline soil was the greatest by the subsurface drainage system with 5 m drain spacing. Our results demonstrated that the installation of subsurface drainage system with drain space of 5 m spacing would be a best management practice to control soil salinity and corn development at Saemangeum reclaimed tidal saline soil.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1045-1051
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• 2006

Geumgang canal is planned to connect Geumgang lake with Saemangeum lake to accelerate desalinization and dilute polluted water to improve water quality in Saemangeum lake. The purpose of this study is to evaluate the impact of water quality on Geumgang lake by diversion of its lake flow to Saemangeum lake. WASP5 model was used to estimate water quality of Geumgang lake. Model calibration and verification were done for water quality data for 2001 and 2002. Water quality concentrations in Geumgang lake were simulated for 4 scenarios, which were considered whether the Geumgang canal is built or not. As a result of simulations, there was little impact on water quality in Geumgang lake, though a little of the Geumgang lake flow diverted to Saemangeum lake. As the Geumgang canal is planned to divert the Geumgang water flow which were discharged into the sea through sluice gates when canal is not built, it is thought that there will be little change by diversion of water flow.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.1
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• pp.75-86
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• 2001

North Korea reported that tideland reclamation projects had been successfully constructed and/or under construction during the period of the third development scheme(1987∼1993), which were 28,400ha in 9 project areas: 8 projects along the western coast and one in the eastern coast. In this study eight projects located in western coast were investigated in order to confirm the detail of works, construction stages and difference from our project formulation methods using the topographic maps published in different years and the recent sattelite image data especially Lansat TM and SPOT PN. Intensity-hue-saturation (IHS) method was adopted to merge two sattelite data for the image enhancement of remote sensing. Construction stages of sea-dikes, land consolidation for paddy and salt pan, reservoir for irrigation and desalinization and the present land use were investigated and estimated the acreage of the development areas. The total gross project areas of 38,105 ha: 16,555 ha completed for paddy or salt pan, 16,826 ha under construction, and 4,724 ha under planning were confirmed, although the area of 27,100 ha in 8 projects were reported to be completed or ongoing on the bimonthly journal of N. Korean Trend published in 1994.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.2
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• pp.113-119
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• 2000

An experimental study has been carried out in order to investigate on a particle deposition on a circular cylinder surface. The present study is focused on the particulate fouling occurring in a heat exchanger for a seawater desalinization, in a laminar flow over circular cylindrical tubes. The objective is to investigate how NaCl concentration influences the $SiO2$ particle deposition on the surface of a glass circular cylinder. The NaCl concentration was changed from 0 g/L to 40 g/L. As the experimental results of $SiO2$ particle which is deposited on the glass circular cylinder surface showed, particle deposition rate per unit time increases rapidly with the increase of NaCl concentration between 0 g/L and 15 g/L. After the maximum of particle deposition rate was found at the NaCl concentration of 15 g/L, particle deposition rate remains unchanged or decreases gradually with the NaCl concentration from 15 g/L to 40 g/L. Also the $SiO2$ deposition rate of particles does not have serious variations with the position at present glass surface.