• Water for future
• /
• v.14 no.4
• /
• pp.73-81
• /
• 1981

More than 650 numbers of water well ranging in depth from 100M to 200M were installed in South Korean Penninsula during the last decade for the purpose of industrial use and municipal water supply. Those data were compiled and synthesized by writer to determine their hydrogeologic occurences in accordance with their geologic and areal characteristics. Rocks yielding the deep seated ground water beared in the geologic primary and secondary porosities are classified into 6 groups according to their geologic, hydrogeologic, and topographic characteristics, that are: volcanic, sedimentary, meta-sediment and/or schist, andesitic, gneissic, and granitic rocks. The order of ground water productivity of the groups is as written above. Even granitic rocks including porphyries, granite, and intermediate and basic plutonic rocks is considered to be the most poorest ground water yielding group among 6, it's average yield form a single well with average drilling depth of 116M is about 225 cubic meters per day if it's drilling site is properly located. Generally speaking, seizable geologic structures such as fractured, sheared, and faulted zone at the flat surface and valley center yield almost 310% more of deep seated bet rock ground water in comparision with minor structures of joints, bedding planes, and so on that are occured at high land. 50 numbers of water well drilled at crystalline rocks were specially checked and measured it's ground water yie 1ds at each drilled depth to determine each interval's productivity while hammer drilling was going on. The results indicate that the specific capacity and yield of each water well at a depth below 70M to 80M was almost neglegible. It means that optimum well depth of crystalline rocks, except the area having seizable geologic structures, shall be not deeper than 80M.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.2
• /
• pp.1126-1139
• /
• 2014

World is experiencing abnormal weather caused by urbanization and industrialization increasing greenhouse gas and one of these phenomenon domestically happening is flood and drought. The increase of green-house gases is due to urbanization and industrialization acceleration which are causing abnormal climate changes such as the El Nino and a La Nina phenomenon. It is expected that there will be many difficulties in water management, especially considering the topography and seasonal circumstances in Korea. Unlike in the past, a variety of water conservation initiatives have been undertaken like the river-management flow and water capacity expansion projects. To meet the increasing demand for water resources, new environmentally-friendly small and medium-sized dams have been built. Therefore, the development of a new paradigm for water resources management is essential. This study shows that additional security is needed for potential water resources through diversion tunnels and is very important to consider for future water supplies and situations. Using RCP 6.0 and RCP 8.5 in representative concentration pathway climate change scenario, specific hydrologic data of study basin was produced to analyze past observed basin rainfall tendency which showed both scenario 5%~9% range increase in rainfall. Through sensitivity analysis using objective function, population in highest goodness was 1000 and cross rate was 80%. In conclusion, it is expected that the results from this study will help to make long-term and stable water supply plans by using the potential water resource evaluation model which was applied in this study.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.16 no.1
• /
• pp.147-157
• /
• 2013

Rice is a main crop and rice field is the most important farmland in Korea. This study was conducted to propose the methodology assessing impact and vulnerability on rice production by climate change at the regional and national level in Korea. We evaluated a vulnerability of rice paddy according to the outbreak of a main disease and pest of a rice plant. As results, Jeju-do, Gyeongsangnam-do, and Jeollanam-do were more vulnerable area than others. In contrast, the southern central region including Gyeonggi-do was less vulnerable than others. The vulnerable index was significantly higher in 2050s (0.5589) than in present (0.3500). This result showed that the vulnerable to the disease and pest enlarge in the future. The adaptive capacity highly contributed to the vulnerability assessment index. The daily maximum temperature of June and the daily average temperature from May to August also contributed the climate exposure index. The area of occurring sheath blight, rice leaf blast and striped rice borer was related to the system sensitivity index. The ability of water supply (readjustment area of arable land per paddy field area) and rice production technique (rice yield per hectare) were the highly contributed variables to the adaption capacity index.

• Journal of Environmental Science International
• /
• v.30 no.8
• /
• pp.621-628
• /
• 2021

The characteristics of time changes in air temperature, DI (discomfort index) and WBGT (wet-bulb globe temperature) were investigated for inland city (daegu) and coastal city (pohang) of Gyeongbuk Province during the 2018 consecutive heat wave season. The time when the temperature dropped below 33℃ was around 19h in both regions. As such, the two regions were similar with respect to the time up to which the heatwave warning levels continued. However, the discomfort index (DI) was higher than 27 in Pohang. Most people feel unpleasant when an discomfort index of 27 or higher appears. The results indicated that Korea's night-time thermal environment during the summers is particularly poor in the southern coastal areas. WBGT began at 09:00 and lasted until 21:00, with a score of 31 or higher; this score, in principle, corresponded with the duration of outdoor activity in both regions. Therefore, it was found that outdoor work was at a level where all day long had to be stopped in both areas during the heat wave. Although time changes in temperature and WBGT were similar in both regions, Discomfort Index (DI) differed significantly. The difference refers to the fact that Pohang is strongly affected by the high heat capacity effect and the supply of water vapor from the sea.

• Journal of Wetlands Research
• /
• v.3 no.1
• /
• pp.49-59
• /
• 2001

The objective of this study is to provide the results of frequency analysis for Dong-eup reservoir, in which the environmental and ecological roles in addition to the water supply and flood control capacity of the reservoir are increased rapidly. The suggested results are the frequency analysis of annual maximum rainfall data based on eight different rainfall duration data at Masan and Milyang raingauge stations. We also provide the probabilistic inflows from subbasins and evaluate the stage increases of the reservoir. As results, the 24-hour and 100-year return period rainfall is 291.8 mm and consequently inflows are 361.79 cms for Junam, 192.57 for Sannam and 408.28 for Dongpan reservoirs. The 24-hour and 100-year return period reservoir stages are expected as 5.08 m, 5.51 m and 6.89 m depending on the initial reservoir stage. The suggested results of frequency analysis of rainfalls, inflows and reservoir stages in this study will be useful for the scientific and systematic management of the reservoir.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.51 no.5
• /
• pp.35-49
• /
• 2009

This study proposes a method to evaluate agricultural reservoirs drought by modifying SWSI (Surface Water Supply Index). The method was applied to Geum river basin and the results were represented as spatially distributed information. The SWSI evaluates hydrological drought of watershed unit by selectively applying one or all of the components of snowpack, precipitation, streamflow and reservoir storage. South Korea has 22 % of agricultural area, and rice paddy covers 64 % among them. Usually paddy fields scattered along stream are irrigated by so many small agricultural reservoirs. It is difficult to evaluate agriculture drought by the little information and large number of agricultural reservoirs. In this study, seven agricultural reservoirs over 10 million ton storage capacity were selected in Geum river basin, and the SWSI was evaluated for both upstream and downstream of the reservoirs using 16 years data (1991-2006). Using the results, multiple regression analyses with precipitation and reservoir storage as variables were conducted and the equations were applied to other watersheds. The spatial results by applying regression equations showed that the severe and moderate drought conditions of July and September in 1994, June in 1995, and May in 2001 were well expressed by the watershed unit.

• Journal of Korean Society of Rural Planning
• /
• v.22 no.4
• /
• pp.13-24
• /
• 2016

Tourism is often considered as one of the main industries to promote development and modernization in small South Pacific islands countries. In Fiji, this was recognized in the 1960s, and resulted in large-scale resort based tourism development in coastal areas. While tourism has obvious advantages to the economy, a lot of problems such as exclusive foreign control of the main hotels and resorts, considerable overseas leakage of earnings, the limited participation by indigenous resource owners, and localized environmental damages to reefs and mangroves are emerging. For sustainable tourism development, it is needed to set growth objectives and targets for tourism in terms of benefits to Fiji, and to concentrate support on 'Rural Tourism' such as community-based tourism that have lower leakage and put more into local economies. Through case study in this paper, to develop rural tourism at the local level, several recommendations are as follows: 1) to introduce various rural tourism programs such as experiencing Fiji's traditional culture, participating in activities, picking fruits and harvesting agro-products, 2) to enhance aggressive promotion and marketing strategies, 3) to build the capacity of local communities for improving the quality of tourism services, and 4) to provide the infrastructure for tourism business such as road accessing, water supply and disaster prevention.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.39-44
• /
• 2009

Geothermal energy is the heat contained in the earth and its internal fluids. Geothermal energy is stored as sensible or latent heat. Supplied by both internal and external sources, it represents a vast supply which is only started to be tapped for generation of electric power. In general, this is natural dry or wet medium to high enthalpy steam at temperatures above $150^{\circ}C$. For some time, binary systems employing substances with a lower boiling point than water in a secondary circuit have been used to generate vapor for driving turbines at a lower temperature level. The utilization of binary plants and the possibility of production from enhanced geothermal systems can expand its availability on a worldwide basis. The geothermal electricity installed capacity is approaching the 10,000GW threshold. Geothermal energy is not present everywhere, but its baseload capability is a very important factor for its success.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2006.05a
• /
• pp.115-118
• /
• 2006

Nowadays the using of concrete is generalized, and construction material is demanded to be lightweight according to increasing the height and capacity of buildings. Therefore, it needs to develop the products having the great quality and various performance. Extruding concrete panel made of cement, silica source, and fiber, and it is a good lightweight concrete material in durability and thermostable. The silica of important ingredient is natural material with hish SiO2 contents and difficult in supply because of conservation of environment. On the other hand, the stone powder sludge discharged about 20-30% at making process of crushed fine aggregate and it is wasted. The stone powder sludge is valuable instead of silica ole because the stone powder sludge includes water of about 20-60%, SiO2 of about 64% and it has fine particles. This experiment is on the properties of extruding concrete panel using the stone powder sludge use instead of silica. From this experiment, we find that it is possible to replace the silica as stone power sludge up to 50%,

• Journal of The Korean Society of Agricultural Engineers
• /
• v.53 no.2
• /
• pp.9-17
• /
• 2011

Based on the statistical annual report, there are 17,649 reservoirs are operating for the purpose of agricultural water supply in Korea. 58 % of entire agricultural reservoirs had been constructed before 1948 which indicate the termination of required service life and rest of those reservoirs have also exposed to the dam break risk by extreme flood event caused by current ongoing climate change. To prevent damages from dam failure accident of these risky small size dams, it is necessary to evaluate and manage the structural and hydrological safety of the reservoirs. In this study, a simplified evaluation method for hydrologic safety of dam is suggested by using Rational and Creager formula. Hydrologic safety of small scale dams has evaluated by calculating flood discharge capacity of the spillway and compares the results with design frequency of each reservoir. Applicability and stability of suggested simplified method have examined and reviewd by comparing the results from rainfall-runoff modeling with dam break simulation using HEC-HMS. Application results of developed methodology for three sample reservoirs show that simplified assessment method tends to calculate greater inflow to the reservoirs then HEC-HMS model which lead lowered hydrologic safety of reservoirs. Based on the results of application, it is expected that the developed methodology can be adapted as useful tool for small scale reservoir's hydrologic safety evaluation.