• Journal of The Geomorphological Association of Korea
• /
• v.19 no.4
• /
• pp.97-108
• /
• 2012

There exist plenty of geomorphological resources in Haean Basin, Yonghwasan Mt., and Gandong Basin in Eastern DMZ area in Gangwon Province which can be used as geotourism resources. Meticulous strategies are necessary to improve the geotourism bases in such a mountainous region. Potential geosites including Yongneup and Simjeog wetlands are nearby, so it is necessary to include these geosites when planning geotourism courses. The values of these sites coinciding with the goal of geopark are as follows: this region shows contrasting landforms derived from distinctive rocks such as gneiss and biotite granite, and there are many landforms derived from differential weathering of granite too. They can be used to explain the developmental history of numerous basin structures in entire Korean peninsula.

• Korean journal of applied entomology
• /
• v.46 no.1 s.145
• /
• pp.27-35
• /
• 2007

Seasonal occurrences of tobacco cutworm, Spodoptera litura and beet armyworm, Spodoptera exigua were observed using sex pheromone traps at different locations and climatic regions in Yeongnam district. In Gyeongnam province, S. litura male adults kept occur from mid or late March to mid or late November Whereas in Gyeongbuk province, S. litura occurred from mid or late April to early or mid November with exception at Uljin where it was late May to late October. According to the climatic regions, the peak occurrence of S. litura was middle September at the southern coast region, late August at the inland and the basin region, middle August at the inland mountainous region, and early September at the eastern middle coast region. The occurrence rate of S. litura was the highest at Jinju with 20.0% and the lowest at Changyeong with 8.6% in Cyeongnam province, while it was the highest at Sungju with 3.3% and the lowest at Uljin with 0.8% in Gyeongbuk province. In accordance with the climatic regions, the occurrence rate of S. litura was the highest at the inland region with 43.7%, and followed by the southern coast region (36.3%), the basin region (8.4%) and the inland mountainous region (7.0%), and was the lowest at the eastern middle coast legion with 4.6%. On the other hand, S. exigua occurred from early March to middle November with the exception of the eastern middle coast region including Pohang, Yeongdeog and U]ien in Cyeongbuk province where it occurred from mfd April to middle November. The peak occurrence of s. exigua was early August at the inland region, the basin region and the inland mountainous region, and was late of August at the southern coast region and the eastern middle coast region. The occurrence of S. exigua was the highest at Changyeong with 1.6% and the lowest at Busan with 0.4% in Gyeongnam province, while it was the highest at Sungju with 37.2% and the lowest at Uljin with 2.7% in Gyeongbuk province. The climatic regional occurrence rate of S. exigua was the highest at the basin region with 54.3%, and followed by the inland mountainous region (29.9%), the eastern middle coast region (9.3%) and the inland (3.9%), and was the lowest at the southern coast region with 2.6%. As a whole, S. litura occurred more in Gyeongnam province than Cyeongbuk province, while S. exigua occurred more in Gyeongbuk province than Gyeongnam province. According to the regions grouped by climatic differences, the occurrence of S. litura and S. exigua was the highest at the inland region in Gyeongnam province and at the basin region in Gyeongbuk province. The total number of S. litura captured by sex pheromone trap was 2.4 times higher than that of S. exigua. However, the first occurring time and the peak occurrence of S. exigua were slightly earlier than those of S. litura.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.178-182
• /
• 2007

In this study, we evaluated current raingauge network of Soyanggang dam region applying spatial-correlation analysis and Entropy theory to recommend an optimized raingauge network. In the process of analysis, correlation distance of raingauge stations is estimated and evaluated via spatial-correlation method and entropy method. From this correlation distances, respective influencing radii of each dataset and each methods is assessed. The result of correlation and entropy analysis has estimated correlation distance of 25.546km and influence radius of 7.206km, deducing a decrease of network density from $224.53km^2$ to $122.47km^2$ which satisfy the recommended minimum densities of $250km^2$ in mountainous regions(WMO, 1994) and an increase of basin coverage from 59.3% to 86.8%. As for the elevation analysis the relative evaluation ratio increased from 0.59(current) to 0.92(optimized) resulting an obvious improvement.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.6 no.3
• /
• pp.164-169
• /
• 2004

A spatial interpolation scheme incorporating local geographic potential for cold air accumulation (TOPSIM) was used to test the feasibility of operational frost warning in Chatancheon basin in Yeoncheon County, where the introduction of new crops including temperate zone fruits is planned. Air temperature from April to June 2003 was measured at one-minute intervals at four locations within the basin. Cold-air accumulation potentials (CAP) at 4 sites were calculated for 3 different catchment scales: a rectangular area of 65 x 55 km which covers the whole county, the KOWACO (Korea Water Corporation) hydrologic unit which includes all 4 sites, and the sub-basins delineated by a stream network analysis of the digital elevation model. Daily minimum temperatures at 4 sites were calculated by interpolating the perfect prognosis (i.e., synoptic observations at KMA Dongducheon station) based on TOPSIM with 3 different CAPs. Mean error, mean absolute error, and root mean square error were calculated for 45 days with no precipitation to test the model performance. For the 3 flat locations, little difference was detected in model performance among 3 catchment areas, but the best performance was found with the CAPs calculated for sub-basins at one site (Oksan) on complex terrain. When TOPSIM loaded with sub-basin CAPs was applied to Oksan to predict frost events during the fruit flowering period in 2004, the goodness of fit was sufficient for making an operational frost warning system for mountainous areas.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.247-247
• /
• 2015

Global Climate Model (GCM) is too coarse to apply at a basin scale. The spatial downcsaling is needed to used to permit the assessment of the hydrological changes of a basin. Furthermore, temporal downscaling is required to obtain hourly precipitation to analyze a small or medium basin because only few or several hours are used to determine the peak flows after it rains. In the current study, the spariotemporal distribution of downscaled hourly precipitation for RCP4.5 and RCP8.5 scenarios over South Korea is presented as well as its implications over hydrologica responses. Mean hourly precipitation significantly increases over the southern part of South Korea, especially during the morning time, and its increase becomes lower at later times of day in the RCP8.5 scenario. However, this increase cannot be propagated to the mainland due to the mountainous areas in the southern part of the country. Furthermore, the hydrological responses employing a distributed rainfall-runoff model show that there is a significant increase in the peak flow for the RCP8.5 scenario with a slight decrease for the RCP4.5 scenario. The current study concludes that the employed temporal downscaling method is suitable for obtaining the hourly precipitation data from daily GCM scenarios. In addition, the rainfall runoff simulation through the downscaled hourly precipitation is useful for investigating variations in the hydrological responses as related to future scenarios.

• Geophysics and Geophysical Exploration
• /
• v.20 no.2
• /
• pp.88-95
• /
• 2017

Chogye basin, which is surrounded by country rock, has a closed-basin form. In such a basin, incident seismic energy can form multiply reflected waves, thus causing energy concentration to occur at this closed-basin area. Microtremor measurement survey was performed at the Chogye basin, which is located in Chogye-myeon and Jeokjungmyeon, Hapcheon-gun, Gyeongsangnam-do, Republic of Korea. Microtremor data were transformed into the frequency domain, and then the horizontal-to-vertical spectral ratios (HVSR) were calculated. Fundamental resonance frequencies were estimated from the HVSR results for every observation point. Using the empirical relationship between site period and thickness for sediment sites in Korea known from the previous study, the distribution of sediment thickness of the Chogye basin was estimated from the fundamental resonance frequencies. Being compared with the mountainous rim with steep slope, the measurement points inside the basin have low values of the fundamental resonance frequency with the minimum of 1.03 Hz, which corresponds to the thickness of sedimentary layer with the maximum depth of about 100 m. A three-dimensional basin model was constructed for bedrock topography of the Chogye basin by an interpolation of basin depths estimated at each measurement site.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.32 no.3
• /
• pp.56-66
• /
• 1990

To investigate the status of irrigation water use and the degree of repeated use of irrigation water, observations for water balance analysis were made during the irrigation periods in 1986 and 1987 crop year. The total area of studied site is 1,441 ha. The site is a major portion of Jedaecheon basin which is located in Bubuk-myeon, Miryang-gun, Gyeongnam Province. The studied area was subdivided into six small blocks. The water balance analysis for these subdivided blocks were carried out considering characteristics of each block. Obtained results are as follow: 1.In mountainous sloppy paddy area(less than 7% slope), the surface inflow was 5A mm/day in average that is one third of the surface inflow into plain paddy area ; 16.7 mm/day. 2.The surface inflows at the vegetative stage and the ripening stage were 15.5 mm/day and 10.4 mm/day, respectively. Those figures were larger than the actual consumptive use at respective same stages ; 13.3 mm/day and 9.2 mm/day, respectively. Whereas, the surface inflow at generative stage was 12.5 mm/day which was less than 14.0 mm/day ; the actual consumptive use. 3.The range of the variation of water storage term was 1 mm/day. This means that there were no change in depth of ponded water on paddy fields. The relationship between the variation of water storage(AS) and the variation of ground water table(H) could be expressed as follow: : AS=0.14H+0.26 4.The ground water inflow: into the transition region ; paddy fields which are located continuously from the mountainous area to the plain area, was larger than the out flow from this region, in general. Rowever, in the plain region where the ground water utilization was predominant, the ground water outflow from this region was larger than inflow: to this region. The relationship between the ground water flow(G2- G1) and the consumptive use in large paddy area(D1-D2) could be expressed as follow: (G2-G1) =0.95(D1-D2) -3.79

• Journal of the Korean Geographical Society
• /
• v.49 no.6
• /
• pp.795-811
• /
• 2014

Stream piracy is one of the dynamic geomorphic processes in the mountainous area. If many stream piracies were concentrated in a certain region, the concentrated distribution of those might reflects the geological structure and tectonic movements of that region. In this study, the stream piracies identified in the lower areas between the Chiri and the Deokyoo mountainous areas were analyzed in relation with the tectonic line from Kwangju to Pohang and the so-called Hansan Mountains. The stream piracy at the Subunchi occurred between the lower-altitude, higher-gradient upper reach of the Seomjin-River flowing on the lower-level basin and the higher-altitude, lower-gradient upper reach of the Geum-River flowing on the higher-level basin. The geomorphic evidences concerning the stream piracy and the human responses to the headward erosion might be found in the vicinity of stream piracy site. Together with the Deunbongsaem(the source fountain of Geum-River), the Subunchi at which the geomorphic processes of stream piracy could be identified in a small area will be a good site for the geography education as well as the geo-tourism.

• The Journal of Engineering Geology
• /
• v.27 no.4
• /
• pp.393-403
• /
• 2017

Mountain disasters in Korea have caused massive social and economic damage. During the period 2005-2014 there has been an annual average of 7 deaths and disaster recovery costs of 79.8 billion won in the country's 4393 ha of mountainous areas. The primary mountain disasters are landslides on mountain slopes, and secondary debris flows can spread along mountain streams, damaging facilities and settlements in lower areas. Typhoons and local rainfall can cause such disasters, while anthropogenic factors include development that damages the mountainous terrain. The study area was divided into three basins. For each basin, a debris flow vulnerability assessment method was proposed considering FLO-2D analysis results and the local topography, geology, and forestation. To establish an in situ investigation, analysis, and evaluation plan for potential mountain disasters, we selected mountain basins that are potentially vulnerable to mountain disasters through analysis of their mountain slopes and streams. This work suggests the establishment of a comprehensive plan for disaster prevention based on a mountain basin feature.

• Journal of Korean Society of Forest Science
• /
• v.103 no.1
• /
• pp.98-104
• /
• 2014

This study aims to predict the amount of soil loss from Mt. Palgong's small basin, by using influence factors derived from related models, including RUSLE and MUSLE models, and verify the validity of the model through a comparative analysis of the predicted values and measured values, and the results are as follows: The amount of soil loss were greatly affected by LS factor. In comparison with the measured value of the amount of total soil loss, the predicted values by the two models (RUSLE and MUSLE), appeared to be higher than those of the measured soil loss. Predicted values by RUSLE were closer to values of measured soil loss than those of MUSLE. However, coefficient of variation of MUSLE were lower, but two model's coefficient of variation in similar partial patterns in the prediction of soil loss. RUSLE and MUSLE, prediction soil loss models, proved to be appropriate for use in small mountainous basin. To improve accuracy of prediction of soil loss models, more effort should be directed to collect more data on rainfall-runoff interaction and continuous studies to find more detailed influence factors to be used in soil loss model such as RUSLE and MUSLE.