North Han River Research Articles

남북공유하천 북한강의 물이용 문제점 및 수리권 추정 (I) -임남댐 유역변경에 의한 하류 영향 분석

북한강 수계의 경우 북한이 임남댐을 개발하여 유역변경식으로 물을 이용하고 있어 하류지역에서 여러 가지 문제가 나타나고 있다. 따라서 남 북한이 공유하천을 효과적으로 관리하기 위해서는 수량이나 수질 등 다양한 분야에서의 협력이 절실히 요구되고 있다. 그러나 남 북공유하천에서 상 하류국가간 물이용의 공평성을 실현하기 위한 노력은 매우 미흡한 실정이다. 본 논문에서는 남북공유하천의 공평한 물이용의 판단기준이 되는 수리권을 검토하기 위해 북한의 임남댐에 의한 영향을 주요 분야별로 심도 있게 분석하였다. 분석결과, 한강유역의 용수공급은 1978년을 이수안전도 평가를 위한 기준갈수년으로 할 경우 임남댐으로 인해 379백만<TEX>$m^3$</TEX>/년의 공급부족이 발생하는 것으로 나타났다. 아울러 한강 수계의 발전용댐도 유입량 감소로 인하여 연간발전량이 234GWh/년 감소하게 되었고, 수질은 북한강 삼봉리 지점 기준 BOD 약 0.065 ppm 증가하는 것으로 분석되었다. 결과적으로 남북공유하천에서 북한의 절대영토주권주의에 입각한 불공평한 수자원 이용은 하류국가인 남한에 직 간접적으로 상당한 영향을 미치고 있음을 확인하였다. Imnam Dam construction and inter-basin water transfer use by North Korea have caused several problems including water resources management aspects in the downstream reach of North Han River. Therefore, cooperative works between North and South Korea are required to make a reasonable management situation of the shared river for water quantity and quality. However, efforts by the North and the South has done not enough to achieve equitable water use in the shared river. This study analyzes main impacts caused by Imnam Dam in key sectors for reviewing water use right regarded as the most important decision-making criterion in international rivers. As the results, water deficit by Imnam Dam is calculated at 379 million <TEX>$m^3$</TEX>/year when river drought year for water assessment is set in 1978 in the Han River basin. Additionally hydropower production is decreased by 234 GWh/year in exclusive hydropower generation dams. In respective of water quality, BOD concentration is increased by 0.065 ppm at Sambongli in North Han River. Finally it is identified that unequitable water use based on the absolute territorial sovereignty by North Korea in North Han River has directly and indirectly affected severe impacts to South Korea as the downstream user.

남북공유하천 북한강의 물이용 문제점 및 수리권 추정 (II) -하류유역 수리권 추정

There are not many practical measures to solve a water conflict, when a hydromorphologically asymmetric situation in international rivers exists whereby downstream users may not affect upstream users but upstream users do cause downstream impacts. In taking advantage of this merit, North Korea has built Imnam Dam in upstream of North Han River and uses water for trans-basin hydropower generation. As an impact of this dam South Korean' area as a downstream user has been suffered from water deficit and dry river. It is very critical for South Korea to solve a key problem such as water allocation for water supply and river maintenance. Therefore, this study is aim to suggest alternatives for equitable water allocation in consideration of special circumstances between the South and the North. For this, reviewing the allocation methods of water rights is carried using lessons obtained from international river cases. The results show that the minimum desired streamflow is calculated at 7.3 ; water budget analysis by the equitable distribution of streamflows at the border line of the North Han River, the difference in water supply deficiency is at 3.7 before and after Imnam Dam; in the determined distribution method, the difference in water deficiency is at 11.38 . These results show that South Korea should be secured 11.38 from North Korean's Imnam Dam in respective of water use right and sound river maintenance.

강원도 지역의 PRISM를 이용한 강우의 공간분포 해석

본 연구에서는 강원도의 지역인자를 이용하여 지점 강우량과 면적 강우량의 관계를 파악하였다. 강원도는 면적의 대부분이 산지로 형성된 산악지형이며 태백산맥 동쪽 (영동지방)은 경사가 급하여 해안평야의 발달이 취약하고, 태백산맥 서쪽 (영서지방)은 경사가 완만하여 남 북한강의 대하천이 발달하고 곳곳에 산지가 분포되어 있는 복잡한 지형이다. 강원도 지역의 확률강우량 공간분포를 산정하기 위하여 강원도 인근의 기상관측소 66개소의 자료를 이용하였으며, 강우의 공간분포를 분석하기위하여 PRISM을 적용하였다. 적용결과를 도시한 결과 지형 조건 (고도 및 경사)과 지역적인 조건(영동 및 영서지방, 북한강 지역 및 남한강 지역)에 따라 적정하게 분포된 것으로 나타났으며, 교차검증을 통한 분석결과 RRBIAS 및 RRMSE가 모두 0.1 이하의 낮은 값을 나타내어 PRISM 분석이 적정하게 수행되었음을 알 수 있었다. 따라서 본 연구에서 적용한 PRISM 모형이 강원도 내 확률강우량의 공간분포를 예측하는데 유용한 것으로 판단된다. In this study, the regional factors in Gangwondo were used to analysis the relationship between point precipitation and areal precipitation. The most province area in Gangwondo is consist of mountainous terrain. At the east part of the Taebaek Mountains, the slope is very steep and the coastal plains don't exist. At the west part of the Taebaek Mountains, the slope is mild, there are many rivers, such as South Han-river and North Han-river, and the regions are very complex terrain. The data of 66 stations in Gangwondo and the PRISM (Parameter-elevation Regression on Indepedent Slope Model) were used to estimate the spatial distribution of precipitation. According to the topographic conditions, such as elevation and slope, and the regional conditions, such as Youngdong and Youngseo, the spatial distribution of precipitation is well shown. At the results of cross-validation, the RRBIAS and the RRMSE are under 0.1 and therefore the analysis of the PRISM are well conducted. Consequently the PRISM in this study is a appropriate method to estimate the spatial distribution of precipitation in Gangwondo.

Optically stimulated luminescence and radiocarbon dating of samples from two Palaeolithic sites (Hahwagye-ri and Hwadae-ri) in the middle part of Korean Peninsula

OSL dating on sedimentary quartz grains from two archaeological sites in Korea, called Hahwagye-ri and Hwadae-ri, was undertaken to aid archaeological interpretation for the migratory routes of the Upper Palaeolithic and Mesolithic people in Korea. The Hahwagye-ri site is located on a river terrace of the North Han river at Kangwon prefecture and the Hwadae-ri is located on a river terrace of the Imjin river at Gyeonggi prefecture, both in the central region of Korean Peninsula. From the results of excavation conducted for recent two years, archaeologists strongly suggest that these areas would be an ideal camping place with relatively long-term residence for the Palaeolithic and/or Mesolithic foragers to get food resources by means of collecting, fishing and hunting. In order to check the quartz OSL results on the sediments at those excavation sites, radiocarbon dating was also carried out on a small series of finely layered charcoal samples. The OSL ages obtained showed a good stratigraphic correlation and were found to be in satisfactory agreement with those of the radiocarbon dating, implying that the incomplete bleaching of quartz grains, which is usually observed from fluvially deposited sediments, is not significant for these samples. These consistent ages also suggest that the quartz OSL dating can provide reliable age estimates in case that there are not enough materials suitable for other conventional tools for dating archaeologically important sediment layers. The resultant ages may provide important and useful chronological information for the Upper Palaeolithic and Mesolithic culture in Korean.

Temporal Analysis of Trends in Dissolved Organic Matter in Han River Water

This study used the extensive monitoring datasets of the Korea Ministry of Environment to examine trends in dissolved organic carbon (DOC) in Han River raw water. To estimate the organic contents of water, we adopted allied parameters such as biochemical oxygen demand (BOD) and chemical oxygen demand (COD) as substitutes for DOC. Spatial and temporal analyses were performed on monthly BOD and COD data from 36 monitoring stations (14 for Main Han River, 7 for North Han River and 15 for South Han River) measured from 1989 to 2007. The results of trend analysis indicated that, on the whole, water quality according to BOD showed a downward trend at more than 67% of monitoring stations (9 for Main Han River, 6 for North Han River and 9 for South Han River). However, the water quality of COD showed an upward trend at more than 78% of monitoring stations (8 for Main Han River, 7 for North Han River and 13 for South Han River). The upward trend of COD contrary to the BOD trend indicates that there has been an increase in recalcitrant organic matter in Han River water that is not detectable by means of BOD.

Uranium isotopes as a tracer of sources of dissolved solutes in the Han River, South Korea

The uranium (U) content and 234U/ 238U activity ratio were determined for water samples collected from Korea's Han River in spring, summer, and winter 2006 to provide data that might constrain the origin of U isotope fractionation in river water and the link between U isotope systematics in river waters and the lithological nature of the corresponding bedrock. The large difference in the major dissolved loads between the two major branches of the Han River, the North Han River (NHR) and South Han River (SHR), is reflected in the contrasting U content and 234U/ 238U activity ratio between the tributaries: low U content (0.08–0.75 nM; average, 0.34 nM) and small 234U/ 238U activity ratio (1.03–1.22; average, 1.09) in the NHR; and high U content (0.65–1.98 nM; average, 1.44 nM) and large 234U/ 238U activity ratio (1.05–1.45; average, 1.24) in the SHR. The large spatial differences in U content and 234U/ 238U activity ratio are closely related to both lithological differences between the two tributaries and groundwater input. The low U content and small 234U/ 238U activity ratio in the NHR arise mainly from a combination of surface and meteoric weathering of the dominant silicate rocks in this branch and congruent dissolution of already weathered (secular equilibrium) materials. In contrast, the high U content and large 234U/ 238U activity ratio in the SHR are ascribed to the dissolution of carbonates and black shales along with significant inputs of deep groundwater.

Tracing the sources of nitrate in the Han River watershed in Korea, using δ15N-NO 3− and δ18O-NO 3− values

The dissolved nitrate concentrations and their nitrogen and oxygen isotopic ratios were analyzed in seasonal samples from Korea's Han River to ascertain the seasonal and spatial variations of dissolved nitrate and its possible sources. Nitrate concentrations in the South Han River (SHR) were much higher than those in the North Han River (NHR), probably because of the more extensive distribution of agricultural fields, residential areas and animal farms in the SHR drainage basin. The nitrogen isotopic composition of dissolved nitrate indicates that nitrate-nitrogen (NO 3 −-N) is derived mainly from atmospheric deposition and/or soil organic matter in the NHR but comes principally from manure or sewage, with only a minor contribution from atmospheric deposition or soil organic matter, in the SHR. The oxygen isotopic compositions of dissolved nitrate suggest that most atmospheric nitrate undergoes microbial nitrification before entering the river.

Chemical weathering of carbonates and silicates in the Han River basin, South Korea

A detailed investigation of the fluvial geochemistry of the Han River system allows to estimate the rates of chemical weathering and the consumption of CO 2. The Han River drains approximately 26,000 km 2 and is the largest river system in South Korea in terms of both water discharge and total river length. It consists of two major tributaries: the North Han River (NHR) and the South Han River (SHR). Distinct differences in basin lithology (silicate vs. carbonate) between the NHR and SHR provide a good natural laboratory in which to examine weathering processes and the influence of basin geology on water quality. The concentrations of major elements and the Sr isotopic compositions were obtained from 58 samples collected in both summer and winter along the Han River system in both 2000 and 2006. The concentrations of dissolved loads differed considerably between the NHR and SHR; compared with the SHR, the NHR had much lower total dissolved solids (TDS), Sr, and major ion concentrations but a higher Si concentration and 87Sr/ 86Sr ratio. A forward model showed that the dissolved loads in the NHR came primarily from silicate weathering (55 ± 11%), with a relatively small portion from carbonates (30 ± 14%), whereas the main contribution to the dissolved loads in the SHR was carbonate weathering (82 ± 3%), with only 11 ± 4% from silicates. These results are consistent with the different lithologies of the two drainage basins: silicate rocks in the NHR versus carbonate rocks in the SHR. Sulfuric acid derived from sulfide dissolution in coal-containing sedimentary strata has played an important role in carbonate weathering in the SHR basin, unlike in the NHR basin. The silicate weathering rate (SWR) was similar between the NHR and SHR basins, but the rate of CO 2 consumption in the SHR basin was lower than in the NHR basin due to an important role of sulfuric acid derived from pyrite oxidation.

Hydrogeochemical and isotopic investigations of the Han River basin, South Korea

Summary The Han River, the largest river in South Korea draining approximately 26,000 km 2 , comprises two major tributaries: the North and the South Han Rivers. Seasonal and spatial variations in the major ion chemistry and isotope compositions of the Han River were monitored for one year at 14–23 locations, covering about 80% of the entire drainage basin. Compared to the South Han River (SHR), the North Han River (NHR) was much lower in total dissolved solids (TDS), Sr, and major ion concentrations, but higher in Si concentration, δ 34 S SO 4 values, and 87 Sr/ 86 Sr ratios. These observations suggest strong influence of prevailing rock types in the drainage basins on the chemical and isotopic compositions of the river waters. These are silicate rocks in the NHR basin and carbonate rocks in the SHR basin. The headwaters of the NHR basin, where several flood control dams have been constructed, show enrichment in deuterium and oxygen-18, indicating evaporative loss. The δ 34 S SO 4 data suggest dissolved sulfates in the NHR and SHR are mostly derived from atmospheric deposition, and variable mixtures of atmospheric deposition and sulfide oxidation, respectively. The 87 Sr/ 86 Sr ratios are much higher in the NHR (0.71793–0.72722) than in the SHR (0.71495–0.71785) with one exception, indicating weathering of Precambrian and Mesozoic granitic rocks and marine carbonates, respectively.

Longitudinal Distribution of Benthic Macroinverterbrate in Five Consecutive Lakes Located in the North Han River System

Longitudinal Distribution of Benthic Macroinverterbrate in Five Consecutive Lakes Located in the North Han River System

Determining the seasonality of groundwater recharge using water isotopes: a case study from the upper North Han River basin, Korea

The stable isotopes of oxygen and hydrogen were used to determine the seasonal contributions of precipitation to groundwater recharge at a forested catchment area in the upper North Han River basin, Korea. A comparison of the stable isotopic signatures of groundwater and precipitation indicates that the precipitations which occurred during both the dry and rainy seasons are the important source of groundwater recharge in this region. A stable isotopic signature shown in the stream waters at the upstream reaches is similar to that of groundwaters, indicating that stream waters are mostly fed by groundwater discharge. Reservoir waters in the downstream flood control dams have lower deuterium excess values or d-values compared with those of the upstream waters, indicating a secondary evaporative enrichment. These results can provide a basis for the effective management of groundwater and stream water resources in the North Han River basin.

Factors controlling carbon isotope ratios of dissolved inorganic carbon in two major tributaries of the Han River, Korea

AbstractUnderstanding the carbon cycle of the Han River system in Korea is of prime interest in managing and preserving this valuable water resource for more than 20 million residents in the area. As a part of a comprehensive carbon cycling study for the Han River system, this report focuses on the carbon isotope compositions of dissolved inorganic carbon (DIC) in its two major tributaries, the North and the South Han Rivers. The major difference in carbonate chemistry of the tributaries originates primarily from the lithology of the catchment areas. The South Han River, draining a carbonate‐dominant terrain, has much higher alkalinities and DIC concentrations, whereas the lower concentrations in the North Han River indicate little influence of carbonate weathering. Likewise, δ13CDIC values in the South Han River indicate that the DIC input from the carbonate rocks is important in controlling carbon isotope ratios of DIC. For the North Han River, the oxidation of organic material influences the amount of riverine DIC and δ13CDIC values to a greater extent. Overall, remarkable seasonal and spatial variations of river chemistry and carbon isotope compositions of DIC reflect the variability in geo‐hydrologic characteristics, in the water regime, and in metabolic activities in the river water and/or the drainage areas. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Seasonal and spatial variations of rare earth elements in rainwaters, river waters and total suspended particles in air in South Korea

In order to investigate the seasonal and spatial variations of rare earth element (REE) concentrations in natural waters in the central part of South Korea, rain and river waters were collected during 2003–2004. Total suspended particles (TSP) in air were also sampled to investigate the effect of the Asian dust (the Yellow sand) on the chemistry of rainwaters. All samples showed that the absolute concentrations of the light REEs (LREEs) were higher than those of the heavy REEs (HREEs). The post-Archean Australian shale (PAAS)-normalized REE patterns indicate that the REEs in TSP and rainwaters were affected by Asian dust and anthropogenic contaminant, whereas those of river waters were mainly controlled by the geology of their drainage basin and seasonal changes in water regime. The calculated fluxes and yields of total REEs (REEs plus Y) in the South Han River were much greater than those in the North Han River due to the more widespread distribution of sedimentary rocks in the drainage area and more efficient chemical weathering.

Shared Vision 모형을 이용한 용수수급의 안정성 분석

최근 들어 지구온난화와 기상조건의 변화로 기후의 변동폭이 증가하면서 극심한 가물이 자주 발생하고 있다. 또한 기 개발된 용수원의 수질 오염, 물 분배에 관한 상류지역의 반대 및 지방자치단체간의 수리권 문제 등도 상류지역으로부터의 맑은 수자원 확보를 필요하게 만드는 요인이다. 따라서 이에 대한 용수공급 관리 방안의 필요성에 대한 인식이 부각되고 있으며, 수도권의 용수수요 변화에 대한 북한강 유역 댐의 용수공급 능력에 대한 적절한 검토가 필요한 실정이다. 본 연구에서는 북한강 유역 댐의 용수공급 가능성을 파악하고 적절한 용수 공급방안을 제시하기 위하여 shared vision 모형인 스텔라 소프트웨어를 이용한 모의 운영시스템을 개발하였다. 또한 이 모형에서는 수위에 따른 평균의 최소, 중간, 최대의 조건으로 3가지 Rule을 정하여 저수지의 운영곡선의 변화와 발전방류에 따른 안전 공급율 변화를 분석하였다. Recently, the extreme drought is often occurred due to the global warming and the serious weather changes. Also, the problems of the water pollution In the developed areas, the oppositions from people in the upper stream area and water concession from the local governments affect the national request to get more clean water resources in upper stream of the undeveloped areas. It also brings on the necessity of recognition for water supply managements. Therefore, as the water demand is rapidly changes in the metropolitan areas, the capability of water supply from the north Han river basin dams should be appropriately investigated. In this study, we developed a simulation system using STELLA (equation omitted) software environment, a shared vision model, to analyze the possibility of the stable water supply from north Han river basin dams. Also, three different rules are applied on this model by dividing the water level to minimum(Rule 1), medium(Rule 2) and maximum(Rule 3). Using the rules, the safety yield changes are analyzed for dam rule curve of the reservoir and hydropower release.

Evaluation of nitrate contamination sources of unconfined groundwater in the North Han River basin of Korea using nitrogen isotope ratios

To evaluate the nitrate contamination sources of unconfined groundwater in the North Han River basin (127°45′E, 37°55′N), groundwater samples were collected monthly for three years (1997–1999) from 20 wells, and analyzed for the concentration (n=599) and δ15N (n=96) of NO3−N. Frequency distribution of NO3−N concentration showed that 43.9% of samples exceeded the national standard for drinking water (10 mg NO3−N L−1). During dry season between October and March, only 36.1% of a total of 296 samples had NO3−N concentration above 10 mg L−1. However, 51.5% of a total of 303 samples exceeded the standard level during wet season between April and September. Concentrations of nitrate increased with direction of groundwater flow. Wells located in vicinity of livestock feedlots showed consistently high nitrate concentration irrespective of precipitation pattern. The δ15N signatures of NO3− showed that in general, both15N-depleted source (e.g., chemical fertilizer) and15N-enriched source (e.g., compost and manure) impacted groundwater quality concurrently. The δ15N ranges of groundwater NO3− were +1.5–+12.9‰ in dry season and +3.2–+9.9‰ in wet season. These δ15N data suggested that the effects of compost and/or manure on nitrate concentration were apparent in dry season. A positive correlation (r2=0.32) between N concentration and δ15N of NO3− in dry season also suggested that nitrate concentration increased with increasing loading of nitrate from compost and/or manure wastewater. On the other hand, the relatively narrow range of δ15N and high nitrate concentration in wet season suggested that increased flush of nitrate derived from mixed sources such as fertilizer, compost, and manure during storm event resulted in high nitrate concentration. In this area, neither high δ15N values nor a negative correlation between δ15N and N concentration of NO3−, indicating denitrification was observed because of the coarse textured soil matrix. Therefore, reduction of nitrogen inputs through curtailment of fertilizer and compost application rates and appropriate treatment of livestock manure are the most effective and practical ways to prevent groundwater contamination.

A study on the river bed and hydraulic characteristic changes by flood wave

This study is to predict the river bed and characteristics changes by flood wave using numerical and physical model when Jara island’s land-use area changes in North Han river.

Urea decomposition associated with the activity of microorganisms in surface waters of the North Han River, Korea

Urea decomposition associated with the activity of microorganisms in surface waters of the North Han River, Korea