• Journal of the Speleological Society of Korea
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• no.67
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• pp.21-34
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• 2005

Jeomal Cave consists of limestone. Soil distribution is very different from mountain area to piedmont area. The Cave developed in a part of the fault valley. The joints controls the low level stream orders in the cave. in this area the geological structure is close relate to the underground water flow. It is certain that the distribution of the clay came from the surface.

• Nutrition Research and Practice
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• v.7 no.1
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• pp.34-42
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• 2013

This study investigated the effects of magnetized water supplementation on blood glucose, DNA damage, antioxidant status, and lipid profiles in streptozotocin (STZ)-induced diabetic rats. There were three groups of 4-week-old male Sprague-Dawley rats used in the study: control group (normal control group without diabetes); diabetes group (STZ-induced diabetes control); and magnetized water group (magnetized water supplemented after the induction of diabetes using STZ). Before initiating the study, diabetes was confirmed by measuring fasting blood glucose (FBS > 200 dl), and the magnetized water group received magnetized water for 8 weeks instead of general water. After 8 weeks, rats were sacrificed to measure the fasting blood glucose, insulin concentration, glycated hemoglobin level, degree of DNA damage, antioxidant status, and lipid profiles. From the fourth week of magnetized water supplementation, blood glucose was decreased in the magnetized water group compared to the diabetes group, and such effect continued to the 8th week. The glycated hemoglobin content in the blood was increased in the diabetes group compared to the control group, but decreased significantly in the magnetized water group. However, decreased plasma insulin level due to induced diabetes was not increased by magnetized water supplementation. Increased blood and liver DNA damages in diabetes rats did significantly decrease after the administration of magnetized water. In addition, antioxidant enzyme activities and plasma lipid profiles were not different among the three groups. In conclusion, the supplementation of magnetized water not only decreased the blood glucose and glycated hemoglobin levels but also reduced blood and liver DNA damages in STZ-induced diabetic rats. From the above results, it is suggested that the long-term intake of the magnetized water over 8 weeks may be beneficial in both prevention and treatment of complications in diabetic patients.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.2
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• pp.22-31
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• 2001

The purpose of this paper is to investigate in resources of natural recreation forest(RNRF) developed both publicly and privately in order to answer the research question: what are the differences in RNRF development between public and private developers. After reviewing the literature, the developer´s decision-making and motivation of investment, and the planning process of natural recreation forest, We constructed the conceptual framework and have formulated the hypothesis of this research. We had obtained data through a questionnaire, which surveyed of 625 visitors at 9 of the 72 natural recreation forests in Korea in 1999, We have analyzed the data using the mean difference test and logistic regression method. We found that 1) the overall quality of resource elements in RNRF has been development excellent except for the sociocultural element of recreational resources, and public recreation forest have been of higher quality than that fo private development, 20 in bivariate analysis, all the variables on quality of RNRF by public developers have turned out to be better than those of private ones, 3) in multivariate analysis, such variable as valley and water, forest and wildness area, wild life, and landscape have been statistically significant at one percent level, 4) the higher the value of valley and water, the higher the probability of public development, while the higher the value of other variables excluding water and valley, the more likelihood the recreational forest is developed by a private developer, and 5) forest and wildness area has been turned out to be the most important independent variable in contributing to the value of dependent variable. The research results suggest that 1) the differences in the quality of resource elements in RNRF developed by public and private body be considered in the planning and design process in order to develop diverse activities to make use of the resource potential, and 2) considering the resource characteristics of private natural recreation forest and the motivation of private developers, private natural recreation forest will possibly be more dynamic and dynamic attractive areas. It is recommended that the difference in the degree of visitor´s satisfaction between public and private development be examined.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.270-274
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• 2015

The complaint was filed for the cold water damage to rice in accordance with the installation of buried drain pipes in the mountainous areas of the valley. Field research was conducted in order to identify and analyze relevance of cold water damage to rice with underground drain pipe installation. In conclusion, water temperature was analyzed by 0.5 to $4.5^{\circ}C$ lower than before the installation of underground drain pipes, so the cold water damage to rice was likely to occur at the rice paddy field using cold water passing through the underground drain pipe. Therefore, the rice harvest was estimated to be impossible without appropriate measures of water temperature rise such as use of small unshaded warming basins, before water is applied to fields.

• Current Photovoltaic Research
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• v.9 no.1
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• pp.17-21
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• 2021

In this study, the effect of water level and temperature on the power generation was investigated in a water tank with an aquavoltaic PV module to perform feasibility research for the development of salt farm aquavoltaic system. The silicon solar cell attached to the bottom of each water tank is a 1-cell mini module, and the underwater effects of the crystal phase (19.0~19.9% of single- & 17.9~19.9% of poly-crystalline) of the PV module were investigated, and power generation characteristics for water level (0~10 cm) and temperature (10~40℃) were analyzed. The deterioration coefficients according to the water level and temperature of each single- and poly-crystalline module were investigated at very similar levels such as, -2.01 %/cm and -2.02 %/cm, -0.50 %/℃ and -0.48 %/℃, respectively. Therefore, in salt farm aquavoltaic system, water levels need to maintain as low as possible, and heat-induced degradation is similar to those shown in general land, and no factors have been found to be affected by the underwater environment depending on the determination.

• Journal of Environmental Science International
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• v.33 no.7
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• pp.463-476
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• 2024

This study examined the effects of riverbed slope and roughness coefficient on flood level and flow velocity. A numerical experiment was conducted by installing HEC-RAS in the valley of a sub-basin in Geochang-gun, Gyeongsangnam-do. For each basin, three slopes of riverbeds (slopes-15.0%, 5.0%, and 1.0%) were chosen with different characteristics, and four coefficients of roughness were applied to each slope to parameterize the flow. Flow velocity and flood level were intensively investigated. It was found that in the cases of 15.0% and 5.0%, where the riverbed slopes are steep, the slope dominates the change in flow velocity and flood level, while in the case of 1%, where the riverbed slope is small, the change in flow velocity and flood level caused by changes in roughness coefficient is insignificant. Usually, the riverbed slope is large in the valley part of the watershed, so in this case, the slope will play a dominant role in the results of flow velocity and flood level when designing water-related structures.

• Environmental Engineering Research
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• v.11 no.4
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• pp.194-200
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• 2006

Recently, the population growth, industrial and agricultural development are rapidly undergoing in the Lower Rio Grande Valley (LRGV) in Texas. The Lower Rio Grande Valley (LRGV) composed of the 4 counties and three of them are interesting for Non-point and point source pollutant modeling: Starr, Cameron, and Hidalgo. Especially, the LRGV is an intensively irrigation region, and Texas A&M University Agriculture Program and the New Mexico State University College of Agriculture applied irrigation district program, projects in GIS and Hydrology based agricultural water management systems and assessment of prioritized protecting stream network, water quality and rehabilitation based on water saving potential in Rio Grande River. In the LRGV region, where point and non-point sources of pollution may be a big concern, because increasing fertilizers and pesticides use and population cause. This project objective seeks to determine the accumulation of non-point and point source and discuss the main impacts of agriculture and environmental concern with water quality related to pesticides, fertilizer, and nutrients within LRGV region. The GIS technique is widely used and developed for the assessment of non-point source pollution in LRGV region. This project shows the losses in $kg/km^2/yr$ of BOD (Biological Oxygen Demand), TN (total Nitrogen) and TP (total phosphorus) in the runoff from the surface of LRGV. Especially, farmers in Cameron County consume a lot of fertilizer and pesticide to improve crop yield net profit. Then, this region can be created as larger nonpoint source area for nutrients and the intensity of runoff by excess irrigation water. And many sediment and used irrigation water with including high nutrients can be discharged into Rio Grade River.

• Journal of Korea Water Resources Association
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• v.37 no.1
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• pp.1-11
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• 2004

The purpose of this study consists in introducing and examining the previous river classification systems applicable to the river improvement technique including geomorphological considerations, and developing a new system using the geomorphological criteria which represent the morphology of rivers. A newly developed system uses the channel reach as a classifying unit which is delineated by upstream and downstream tributaries. It adopts three basic geomorphological criteria for classification: 1) valley-floor width index(VI) reflecting the confinement of the channel in the valley, 2) sinuosity(P) which expresses the channel planform, and 3) bed material($d_{50}$). The system is composed of 24 stream types. Concerning every stream type, valley forms, principal bed forms and fluvial processes with disturbance elements are briefly presented. Finally, the applicability of this system to the Chungmi Stream and the Imjin River data in comparison with that of Rosgen system is examined.

• The Korean Journal of Quaternary Research
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• v.18 no.2 s.23
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• pp.43-46
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• 2004

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.51-67
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• 1996

There are three main rice-growing regions in the United States: the prairie region along the Mississippi River Valley in eastern Arkansas; the Gulf Coast prairie region in southwestern Louisiana and southeastern Texas; and the Central Valley of California. The Central Valley of California is producing about 23% of the US rice(Fig. 1). In California. most of the crop has been produced in the Colusa, Sutter, Butte, Glenn Counties of the Sacramento Valley since 1912, when rice was commercially grown for the first time in the state(Fig. 2). Roughly speaking, the average annual area sown to rice in California is about 300,000 acres to 400,000 acres during the last forty years(Fig. 3). California rice is grown under a Mediterranean climate characterized by warm, dry, clear days, and a long growing season favorable to high photosynthetic rates and high rice yields. The average rice yield per acre is probably higher in California than in any other rice-growing regions of the world(Fig. 4). A dependable supply of irrigation water must be available for a successful rice culture. Most of the irrigation water for California rice comes from the winter rain and snow-fed reservoir of the Sierra Nevada mountain ranges. Less than 10 percent of rice irrigation water is pumped from wells in areas where surface water is not sufficient. It is also essential to have good surface drainage if maximum yields are to be produced. Rice production in California is highly mechanized, requiring only about four hours of labor per acre. Mechanization of rice culture in California includes laser-leveler technology, large tractors, self-propelled combines for harvesting, and aircraft for seeding, pest control, and some fertilization. The principal varieties grown in California are medium-grain japonica types with origins from the cooler rice climates of the northern latitudes (Table 1). Long-grain varieties grown in the American South are not well adapted to California's cooler environment. Nearly all the rice grown recently in California are improved into semidwarf varieties. Choice of variety depends on environment, planting date, quality desired, marketing, and harvesting scheduling. The Rice Experiment Station at Biggs is owned, financed, and administered by the rice industry. The station was established in 1912, as a direct result of the foresight and effort of Charles Edward Chambliss of the United States Department of Agriculture. Now, The station's major effort is the development of improved rice varieties for California.