• Journal of the Korean Society of Earth Science Education
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• v.7 no.1
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• pp.43-53
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• 2014

The purpose of this study is to analyze the conceptual simulation observed when students are thinking about the causes of the seasonal change, identifying how students come up with the explanation. For this study, a framework for conceptual simulation process and strategy based on literary research was developed and its validity was proved by four experts in the field of science education. The results were as in the following: First, through the process of explaining the causes for seasonal change, students usually base their explanation on perceptual experience learned from model experiments from a science class. Besides, construct of thought experiment using the familiar object or analogize of the familiar perceptual experience. These all contributed to on explanation firmly. Second, errors from mental simulation were found in the statement of initial representation and running imagistic simulation. It happened when statement of initial representation is not in a complete and secure state or when participants think of an inappropriate situation during running imagistic simulation. Third, the study identified that the use of strategies like 'removal' and 'replace' was shown to enhance the effects of conceptual simulation particularly in regard with solar attitude at meridian passage.

• Journal of Korea Water Resources Association
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• v.47 no.3
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• pp.269-283
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• 2014

This study evaluated the environmental impact based on watershed characteristics and climate change using RCP climate change scenarios provided by the Korea Meteorological Administration. Future dam inflow was estimated by the SWAT model. Dam safety evaluation and downstream duration curve analysis was performed using HEC-ResSim model. Trends of water quality was analyzed through seasonal-Kendall Test using existing water quality observation data. Release discharge and tributary runoff derived SWAT and HEC-ResSim models applied to Qual2E and the future change in water quality trends were analyzed. Integrated environmental review watershed following techniques will be able to obtain the river environment management system and environmental issues such as climate change, new guidelines for preemptively response will be provided.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2013.11a
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• pp.32-35
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• 2013

• Journal of the Korean earth science society
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• v.25 no.7
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• pp.615-628
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• 2004

In order to elucidate seasonal sedimentary characteristics and depositional environment after construction of seawall on macrotidal flat, a seasonal observations of surface sediments (total 450) and sedimentation rates on 4 transects have been investigated for 2 years. The eastern area of Iwon tidal flat, has been changed from semi-closed coast to open coast by construction of seawall, shows general seasonal changes similar to characteristics of open coast type, which represented both fining and bad sorted distribution due to deposition of fine sediments under low energy condition in the summer, and relatively coarser and better sorted distribution because of erosion of fine sediments in the winter. In considering angles of transects, distribution patterns of surface sediments, the northern and southern parts of eastern tidal flat are dominantly influenced by wave and tidal effects, respectively. As time goes by, the eastern tidal flat shows coarsening-trend of surface sediments caused by direct effect of tidal current, were and typhoon. Meanwhile the western area of seawall, which has been re-formed by construction seawall, is sheltered from northwesterly seasonal wind. The seasonal change pattern of western area of seawall is slightly different from that of eastern tidal flat. Mean grain size and sorting of surface sediments during spring is finer and worse than those during summer. This seasonal change pattern maybe influenced by topographic effects caused from the construction of seawall. In consideration of all result, the transport of fine sediments in the study area, which is supplied to limited sediments, shows clockwise circulation pattern that fine sediments are transported from the eastern tidal flat to the western area of seawall because of blocking of seawall in the winter and are transported reversed direction the summer. As a result, many changes have been observed in the study area after construction of seawall; however, this change is still in progress and is expected to need continuous monitoring.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.625-638
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• 2013

Recently, the occurrences of droughts have been increased because of global warming and climate change. Water resources that mostly rely on groundwater are particularly vulnerable to the impact of precipitation variation, one of the major elements of climate change, are very sensitive to changes in the seasonal distribution as well as the average annual change in the viewpoint of agricultural activity. In this study, the status of drought for the present and future on Jeju Island which entirely rely on groundwater using SPI and PDSI were analyzed considering regional distribution of crops in terms of land use and fluctuation of water demand. The results showed that the precipitation distribution in Jeju Island is changed in intensity as well as seasonal variation of extreme events and the amount increase of precipitation during the dry season in the spring and fall indicated that agricultural water demand and supply policies would be considered by regional characteristics, especially the western region with largest market garden crops. Regarding the simulated future drought, the drought would be mitigated in the SPI method because of considering total rainfall only excluding intensity variation, while more intensified in the PDSI because it considers the evapotranspiration as well as rainfall as time passed. Moreover, the drought in the northern and western regions is getting worse than in the southern region so that the establishment of regional customized policies for water supply in Jeju Island is needed.

• Journal of Korea Water Resources Association
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• v.42 no.11
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• pp.933-951
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• 2009

Climate change of global warming may affect the water circulation in Korea. Rainfall is occurred with complex of multiple climatic indices. Therefore, the rainfall is one of the most significant index due to climate change in the process of water circulation. In this research, multiple time series data of rainfall events were extracted to represent the rainfall characteristics. In addition, the occurrence of rainfall time series analyzed by annual, seasonal and monthly data. Analysis method used change analysis of mean and standard deviation and trend analysis. Also, changes in rainfall characteristics and the relative error was calculated during the last 10 years for comparison with past data. At the results, significant statistical results weren't showed by randomness of rainfall data. However, amount of rainfall generally increased last 10 years, and number of raining days had trend of decrease. In addition, seasonal and monthly changes in the rainfall characteristics can be found to appear differently.

• Journal of the Korean earth science society
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• v.22 no.4
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• pp.268-277
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• 2001

This study was to investigate the preconception and phases of children's conceptual change about season through an instruction on the concept. Participants in the study were seventy-eight fifth graders in two classrooms of an elementary school located in Incheon city. Children's preconception was examined using a questionnaire, consisted of a drawing and literal explanation. The questionnaire also was used at the midterm-test, post-test, and one-week delayed-test. The results shows several findings as follows: some children (a) change their synthetic conceptions to form another synthetic conceptions through the instruction; (b) exhibit that their conceptions are unstable; and (c) are mainly influenced by distance and heating effect on the seasonal spatial distribution between the Earth and the Sun, and by the Earth's rotation on the seasonal change of constellations in acquiring the scientific concepts.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.5
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• pp.69-80
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• 2018

This study investigated climate change influences over crop water requirement (CWR) and irrigation water requirement (IWR) of the wheat-rice cropping system of Upper Chenab Canal (UCC) command in Punjab Province, Pakistan. PRECIS simulated delta-change climate projections under the A1B scenario were used to project future climate during two-time slices: 2030s (2021-2050) and 2060s (2051-2080) against baseline climatology (1980-2010). CROPWAT model was used to simulate future CWRs and IWRs of the crops. Projections suggested that future climate of the study area would be much hotter than the baseline period with minor rainfall increments. The probable temperature rise increased CWRs and IWRs for both the crops. Wheat CWR was more sensitive to climate-induced temperature variations than rice. However, projected winter/wheat seasonal rainfall increments were satisfactorily higher to compensate for the elevated wheat CWRs; but predicted increments in summer/rice seasonal rainfalls were not enough to complement change rate of the rice CWRs. Thus, predicted wheat IWRs displayed a marginal and rice IWRs displayed a substantial rise. This suggested that future wheat production might withstand the climatic influences by end of the 2030s, but would not sustain the 2060s climatic conditions; whereas, the rice might not be able to bear the future climate-change impacts even by end of the 2030s. In conclusion, the temperature during the winter season and rainfall during the summer season were important climate variables controlling water requirements and crop production in the study area.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.372-372
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• 2021

The agriculture sector plays a vital role in the economy of Pakistan by contributing about 20% of the GDP and 42% of the labor force. Rivers from the top of Himalayas are the major water resources for this agriculture sector. Recent reports have found that Pakistan is one of the most vulnerable country to climate change that can cause water scarcity which is a big challenge to the communities. Previous studies have investigated the impact of climate change on the trend of streamflow, but the understanding of seasonal change in the regional hydrologic regimes remained limited. Therefore, a better understanding of the seasonal hydrologic change will help cope with the future water scarcity issue. In this study, we used the daily stream flow data for four major river basins of Pakistan (Chenab, Indus, Jhelum and Kabul) over 1962 - 2019. Utilizing these daily river discharge data, we calculated the winter-spring center time and the summer-autumn center times. In this study Winter-spring center time (WSCT) is defined as the day of the calendar year during which half of the total six months (Jan-Jun) discharge volume was exceeded. Results show that the four river basins experienced a statistically significant decreasing trend of WSCT, that is the center time keeps coming earlier compared to the past. We further used the Climate Research Unit (CRU) climate data comprising of the average temperature and precipitation for the four basins and found that the increasing average temperature value causes the early melting of the snow covers and glaciers that resulted in the decreasing of 1^st center time value by 4 to 8 days. The findings of this study informs an alarming situation for the agriculture sector specifically.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.4
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• pp.19-27
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• 2002

When we research a landscape or make a Landscape Impact Assessment, we use the image of a specific season like summer or fall. Since there are four distinct seasons, each with a different landscape, researchers need to understand viewers′visual preferences for individual seasonal landscapes. The purpose of this study is to investigate viewers′visual preferences according to seasonal change and the respondent′s age, gender and profession. In this research, the independent variable is season: suing, summer, fall, winter and snowy winter. Three landscape types used in the experiment: forest, street and agriculture. Each landscape type has two sites for reliability. The assessment media for this research are pictures featuring landscapes taken in each of the four seasons. The study used the "paired comparison" method for taking the score of visual preference. The results of this study are as follows: 1. The summer landscape has the highest visual preference score. However, spring and fall landscapes should also be considered for visual landscape evaluation. 2. The visual preference of winter landscape covered with snow is very high, but since snow is temporal and irregular, it is difficult to consider this factor for visual landscape evaluation. 3. The visual preference score of winter is the lowest of four seasons. The attractive factors of spring are flowers, summer is greenery and fall is autumnal tints. But these are not present in winter. 4. The result of visual preferences according to age groups, gender and profession have no serious differences. 5. Visual preference to scenery of 4 seasons by age group was not different from general preference and thus was concluded to have no connection with age. 6. As a result from the research of visual preference to scenery of 4 seasons by sex, women were shown to like snow-scene more than men. This study presents an indication of general preferences of seasonal landscapes. It is expected that more advanced study will proceed after this one.