• Journal of Environmental Science International
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• v.20 no.12
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• pp.1635-1646
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• 2011

This April 5th dam and Hwanggang dam, which are located in Imjin river, North Korea, become the main causes of water shortages and damages in Imjin river downstream. April 5th dam is assumed a small or medium-sized dam, its total storage volume reaches about 88 million $m^3$. And Hwanggang dam, multi-purposed dam of total storage volume approximately 0.3 billion $m^3$ to 0.4 billion $m^3$ is used as source of residental or industrial water in Gaeseong Industrial Complex. North Korea, which has April 5th dam and Hwanggang dam in Imjin river, manages water of approximately 0.39 billion $m^3$ to 0.49 billion $m^3$ directly. As water is storaged or discharged through dam, it causes a severe damage to areas in Yeoncheon-gun and Paju city, South Korea. Therefore, this study intends to analyze and estimate runoff through dam construction by using hydrological observation data and artificial data such as service water supply and agricultural water in Imjin river, water shortage and damage correctly.

• Journal of Korean Society on Water Environment
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• v.37 no.2
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• pp.75-91
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• 2021

Ocean dumping manure was prohibited in Korea until the end of 2012. Undumped manure was treated by resourcification, purification, and public process in a facility. But poor storage of untreated manure and overproduced compost can pollute river water. In this study, linear regression, Mann-Kendall, Seasonal Mann-Kendall, LOWESS trend, and Spearman's correlation analysis were conducted for investigating the changes in the water quality of Bukhan and Imjin river before and after the prohibition of ocean dumping. In 2017, the Imjin Riv er basin had more than 5.7 times liv estock breeding heads than the Bukhan Riv er basin and more than 3.5 times livestock manure. The areas of land, farmland, and nutrient balance were also higher in the Imjin River basin. Since the two basins have different environments, it is expected that the characteristics of changes in water quality due to the increase in livestock manure generation and treatment methods will be different when comparing the water quality trends before and after the ban. The result of the trend analysis revealed a decrease in EC before the ban but an increase afterward. T-N and BOD of Imjin river increased slightly before the ban but demonstrated great enhancement thereafter. Other sites and T-P exhibited no trend. The correlation analysis result showed that the increase in the number of livestock rearing was correlated with the increase in T-P of Bukhan River and BOD of Imjin River. The increase in livestock manure production was not correlated with the Imjin River basin, while a correlation was observed with the Bukhan River with an increase in T-N and EC and the decrease in T-P.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.132-137
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• 2018

Compared with general rivers, fluctuations of the water level and the river bed are severe in the tidal river. In hydro-dynamic aspect, such fluctuation gives different river-bed data to us according to observing period. The time-dependent river-bed data and pre-estimation of the Manning's roughness coefficient which is the key factor of numerical modelling induces uncertainty of evaluating the design flood level. Thus it is necessary to pay more attention to calculate the flood level at tidal rivers than at general rivers. In this study, downstream of the Imjin River where is affected by tide of the West Sea selected as a study site. From the numerical modelling, it was shown that the unsteady simulation gave considerable mitigation of the water level from the starting point to 15 km upstream compared to the steady simulation. Either making a detention pond or optional dredging was not effective to mitigate the flood level at Gugok - Majung region where is located in the downstream of the Imjin River. Therefore, a more sophisticated approach is required to evaluate the design flood level estimation before constructive measures adopted in general rivers when establishing the flood control plan in a tidal river.

• Journal of the Korean Society of Safety
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• v.25 no.3
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• pp.40-44
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• 2010

North Korea's discharge of water from a dam into the Imjin River that flows through the inter-Korean border swept away a riverside camping site early Sunday morning, killing six people. This tragic incident might have been prevented if the North had given prior notice of the release from its Hwanggang Dam to the South. Investigations are under way to determine the reasons behind the unexpected act. This incident was a man-made disaster not least death of six people. A water level monitoring system(WLMS) of the Imjin River was installed the bridge of Pilseung that operate three public institutions. The WLMS of the A institution set up warning siren and broadcasting as the water level has been rising the bridge of Pilseung in the Imjin River. But the A institution's system was already out of side before discharged of water a dam into the Imjin River and the operators were culpable negligence. The B institution's office employee on charges of negligence that might have contributed to the tragedy and one of the A institution's employees ignored 26 warning messages on the WLMS. This tragic incident was a man-made disaster not least death of six people and might have been prevented if the WLMS was normally operated and the system operators must be worked a tight.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.738-739
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• 2015

The main objective of this study, "Spatial Downscaling of Precipitation from GCMs for Assessing Climate Change over Han River and Imjin River Watersheds", is to carry out over Han River and Imjin River watersheds. To this end, a statistical regression method with MOS (Model Output Statistics) corrections at every downscaling step was developed and applied for downscaling the spatially-coarse Global Climate Model Projections (GCMPs) from CCSM3 and CSIRO with respect to precipitation into 0.1 degree (about 11 km) spatial grid over study regions. The spatially archived hydro-climate data sets such as Willmott, GsMap and APHRODITE datasets were used for MOS corrections by means of monthly climatology between observations and downscaled values. Precipitation values downscaled in this study were validated against ground observations and then future climate simulation results on precipitation were evaluated for the projections.

• Journal of Korea Water Resources Association
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• v.50 no.9
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• pp.617-625
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• 2017

In this study, it was examined that a methodology for evaluating the design flood level reasonably at Imjin River estuary affected by the tide periodically. First of all, the change of the flood level was observed by performing unsteady simulation which can take into account the characteristics of the tidal rivers. And the variations of the flood level was analyzed by change of the Manning's roughness coefficient which is sensitive to the water level calculation. The results were compared with the design flood level at Imjin River estuary announced in the 2011 Imjin River Basic Plan Report. For reference, the design flood level reported in 2011 has been calculated by using a section of a huge riverbed dredging section as input data. From the simulation results, it was found that the flood level evaluated by this study was able to satisfy the freeboard of the levee without the riverbed dredging when the roughness coefficient was assigned to the same value as that of the Han river estuary in the calculation of the flood level, and the unsteady flow simulation was carried out to reflect on the tidal river.

• Journal of environmental and Sanitary engineering
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• v.10 no.1
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• pp.66-75
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• 1995

This survey is executed about the water quality and improvement measure of Imjin- river. The results are summarized as follows; 1 ) Ammonia nitrogen concentration in tap water was two times higher than drinking water standard. 2) The concentration of BOD in textile wastewater was 235ppm which is higher than wastewater distribution standard and leather wastewater showed high nitrogen concentration. 3) Water quality of the Imjin- river upstream was not in problem but that of Shin- stream showed somewhat high concentration in BOD, COD, and ammonia nitrogen. Especially the detected Cynide compound on the lower of Shin- stream implied seriously polluted condition. 4) The heavy metal in soil of the river bed was not detected but iron, zinc was detected to high concentration. 5) It Is urgently suggested to build more municipal sewage and sanitary treatment plants, and run dredging and river bed rearrangement project. 6) The Construction of the wastewater treatment complexes of relevant industries shall be propelled as soon as possible.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.439-439
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• 2015

The temporal and spatial relationship of the weather elements such as rainfall and temperature is closely linked to the streamflow simulation, especially, to the flood forecasting problems. For the study area, Imjin river basin, which has the specific characteristics in geography with river cross operation between North and South Korea, the meteorological information in the northern area is totally deficiency, lead to the inaccuracy of streamflow estimation. In the paper, this problem is solved by using the combination of global (such as soil moisture content, land use) and local hydrologic components data such as weather data (precipitation, evapotranspiration, humidity, etc.) for the model-driven runoff (surface flow, lateral flow and groundwater flow) data in each subbasin. To compute the streamflow in Imjin river basin, this study is applied the hydrologic model SURR (Sejong Univ. Rainfall-Runoff) which is the continuous rainfall-runoff model used physical foundations, originally based on Storage Function Model (SFM) to simulate the intercourse of the soil properties, weather factors and flow value. The result indicates the spatial variation in the runoff response of the different subbasins influenced by the input data. The dependancy of runoff simulation accuracy depending on the qualities of input data and model parameters is suggested in this study. The southern region with the dense of gauges and the adequate data shows the good results of the simulated discharge. Eventually, the application of SURR model in Imjin riverbasin gives the accurate consequence in simulation, and become the subsequent runoff for prediction in the future process.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.57-66
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• 2012

This study was conducted to investigate the reproductive ecology of the Korean Mandarin Fish, Siniperca scherzeri in Seomjin River and Imjin River from April to October 2008. After have investigating the relationship between standard length (SL) and Gonadosomatic index (GSI) of Siniperca scherzeri, we can conclude that the body length of maturation was over 200mm SL in case of females and over 180mm SL in males. The GSI of the females that were from Seomjin river was the highest in April (7.43%), and gradually decreased after May (5.55%) and June (3.58%). The GSI was decreased sharply in August and indicated the lowest value in September (0.44%). The GSI of the females that were from Imjin river showed similar tendency of females' GSI from Seomjin river. The GSI of males from Imjin river was totally higher than that of females, it was 5.96% in April, and 8.03% in May. It was lowered in early June, and late June, it indicated 2.12%. In September, it was the lowest value (0.20%), and increased after October (0.54%). The result of histological study of ovary presented similar result of the study of GSI in Seomjin river and Imjin river. The ratio that fishes constitute in stomach contents of Siniperca scherzeri was 92% in Seomjin river and 90% in Imjin river. Digestion of food organisms and the ratio of unidentifiable fishes in stomach contents was fairly high, and it was 50% in Seomjin river and 72.2% in Imjin river. In the period of study, eating ratio was very low 38.3% (36 ind.) in Seomjin river and 21.8 (53 ind.) in Imjin river.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.454-458
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• 1999

This study is to analyze the causes of flood damage in Imjin river basin inAugust , 1999. and to propose the measure to reudce such flood damage. The northern part of Kyonggin Province in the basin was severely damaged by flood due to the heavy rainfall for 4 days from 31 July to 3 August, whioch was recordedas 1,032mm. The heavy rainfall worth recording was one of main cuasese of such damage, but unsuitable river improvement and basin management were also important causes. The flood proptection works such as flood control reservoir and riverlevee were not contructed or sufficient in spite of the unflavorable geographical conditions of Imjin reiver. In case of irrigatiion faciliteis, 43 pumping stations in 3 FIAs were severely damaged due to inundation of the pump and switch boxes. The protection works for pump room should be improved to reduce the damage due to inundation.