• Korean Journal of Ecology and Environment
• /
• v.36 no.3 s.104
• /
• pp.336-343
• /
• 2003

Two types of statistical models, simple and multivariate log linear models, were studied for continuity simulation and trend analysis of water qualities in incoming flows to Lake Paldang. Water quality is a function of one independent variable (flow) in the simple log linear model, and of three different variables (flow, time, and seasonal cycle) in multivariate model. The independent variables act as surrogate variables of water quality in both models. The model coefficients were determined by the monthly data. The water qualities included 5-day Biochemical Oxygen Demand ($BOD_5$), Total Nitrogen (TN), and Total Phosphorus (TP) measured from 1995 to 2000 in the South and the North branches of Han River and the Kyoungan Stream. The results indicated that the multivariate model provided better agreements with field measurements than the simple one in a31 attempted cases. Flow dependency, seasonality, and temporal trends of water quality were tested on the determined coefficients of the multivariate model. The test of flow dependency indicated that BOD concentrations decreased as the water flow increased. In TN and TP concentrations, however, there were no discernible flow effects. From the temporal trend analyses, the following results were obtained: 1) no trends on BOD at all three upstreams, 2) increase on TN at the South Branch and the Kyoungan Stream, 3)decrease on TN at the North Branch,4) no trends on TP at the North and the South Branches and 5) increase on TP at the Kyoungan Stream by 3 to 8% per years. The seasonality test showed that there were significant seasonal variations in all three water qualities at three incoming flows.

• Journal of Korea Water Resources Association
• /
• v.47 no.11
• /
• pp.1017-1026
• /
• 2014

To investigate the effect of upstream dam operation and river water use on the downstream flows, SWAT-K watershed model was applied to the Paldang Dam watershed of the Han River basin. Analysis results from 2001 to 2009 showed that outflows from the multi-purpose dams such as the Soyanggang Dam and Chungju Dam much have a strong influence on the downstream flows during both the low- and high-flow seasons. This resulted an increase of low-flow at the Paldang Dam, the end of Pukhangang, and the Yangpyeong stage station by $100.57m^3/s$, $33.01m^3/s$, and $49.66m^3/s$, respectively. Whereas, the impact of river water use was hardly found in the Pukhangang, and also was not significant in the (Nam)hangang. Therefore, the effect of small dam such as the Hoengseong Dam or river water use would be able be excluded for long-term runoff analysis. But, in the case of the areas with a large amount of water use, a sufficient information such water-intake and water movement also must be taken into account like this study.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2000.11a
• /
• pp.173-174
• /
• 2000

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2000.11a
• /
• pp.171-172
• /
• 2000

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2018.10a
• /
• pp.287-287
• /
• 2018

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2018.10a
• /
• pp.288-288
• /
• 2018

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2019.09a
• /
• pp.98-98
• /
• 2019

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2021.04a
• /
• pp.37-37
• /
• 2021

• Journal of the Korean Association of Geographic Information Studies
• /
• v.18 no.4
• /
• pp.31-42
• /
• 2015

The objective of this study is to estimate the flood flow of inaccessible regions using satellite-derived rainfall and global geographic data. This study focuses on Dongsingun, an area located upstream of the Cheongcheon River in North Korea. The IFAS model was used to estimate flood flow. The model was calibrated in the Gap Stream watershed in South Korea and verified for the Byeongsung Stream watershed in the Nakdong River basin. Satellite-derived rainfalls for North Korea was revised using ground gauge data. Analysis results using CMORPH and GSMaP_NRT showed $4,886m^3/s$ and $5,718m^3/s$ respectively. In future studies, hydrological analysis in unmeasured and inaccessible regions will be carried out by applying more rainfall events.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.27 no.4
• /
• pp.205-227
• /
• 2016

The research analyzed the collaborative research network based on the data of international academic papers in order to understand the structure of production of scientific knowledge by North Korean scientists. According to the analysis results, the subject areas of research were concentrated on basic science fields such as physics, mathematics and chemistry. The main collaborative research collaboration with North Korea is China, and the phenomenon has become stronger since Kim Jong Eun era. Major joint research in physics has moved from Germany to China. Among the research institutions that actively engaged in academic activities, KIM IL SUNG UNIV, ACAD SCI DPRK, KIM CHAEK UNIV TECHNOL, and UNIV SCI among 32 research institutes belonging to North Korean researchers who published international academic papers.