• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2022년도 학술발표회
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• pp.156-156
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• 2022

Explicitly spatially distributed and reliable data on industrial water demand is very much important for both policy makers and researchers in order to carry a region-specific analysis of water resources management. However, such type of data remains scarce particularly in underdeveloped and developing countries. Current research is limited in using different spatially available socio-economic, climate data and geographical data from different sources in accordance to predict industrial water demand at finer resolution. This study proposes a random forest regression (RFR) model to predict the industrial water demand at 0.50× 0.50 spatial resolution by combining various features extracted from multiple data sources. The dataset used here include National Polar-orbiting Partnership (NPP)/Visible Infrared Imaging Radiometer Suite (VIIRS) night-time light (NTL), Global Power Plant database, AQUASTAT country-wise industrial water use data, Elevation data, Gross Domestic Product (GDP), Road density, Crop land, Population, Precipitation, Temperature, and Aridity. Compared with traditional regression algorithms, RF shows the advantages of high prediction accuracy, not requiring assumptions of a prior probability distribution, and the capacity to analyses variable importance. The final RF model was fitted using the parameter settings of ntree = 300 and mtry = 2. As a result, determinate coefficients value of 0.547 is achieved. The variable importance of the independent variables e.g. night light data, elevation data, GDP and population data used in the training purpose of RF model plays the major role in predicting the industrial water demand.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.414-418
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• 2005

A finite element model is developed for the numerical simulation of bed elevation change in a curved channel. The SU/PG (Streamline-Upwind/Petrov-Galerkin) method is used to solve 2D shallow water equations and the BG (Bubnov-Galerkin) method is used for the Exner equation. For the time derivative terms, the Crank-Nicolson scheme is used. The developed model is a decoupled model in a sense that the bed elevation does not change simultaneously with the flow during the computational time step. The total load formula with is used for the sediment transport model. The slip conditions are described along the lateral boundaries. The effects of gravity force due to geometry change and the secondary flows in a curved channel are considered in the model. For the verification, the model is applied to two laboratory experiments. The first is $140^{\circ}$ bended channel data at Delft Hydraulics Laboratory and the second is $140^{\circ}$ bended channel data at Laboratory of Fluid Mechanics of the Delft University of Technology. The finite element grid is constructed with linear quadrilateral elements. It is found that the computed results are in good agreement with measured data, showing a point bar at the inner bank and a pool at the outer bank.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 1996년도 학술발표회 논문집
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• pp.111-116
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• 1996

• Journal of Environmental Science International
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• 제28권4호
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• pp.423-433
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• 2019

This study was carried out to identify the problems of the underground watersheds on Jeju Island, and to establish the hydraulic groundwater basin to be used as basis for the analysis of the groundwater model. In order to evaluate the adequacy of the groundwater basin on Jeju Island, a correlation analysis between elevation and groundwater level was conducted using data from 125 observation wells. The analysis, conducted with an elevation step of 100 m, exhibited values of R2 in the range 0.1653-0.8011. No clear correlation was observed between elevation and groundwater level. In particular, the eastern and western areas showed an inverse proportionality between elevation and groundwater level. The Kriging technique was used to analyze the underground water level data and to define the equipotential lines for all areas of Jeju Island. Eight groundwater watersheds were delineated by considering the direction of groundwater flow, the positions of the observation wells, and the long and short axes of the watersheds.

• Journal of Pharmaceutical Investigation
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• 제6권2호
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• pp.101-110
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• 1976

1. In the rabbit and the dog, the blood pressure response to water extract and methanol extract obtained from Atractylodes rhizoma alb'a was investigated. 2. Water extract and methanol extract, when administered into the rabbit and the dog by the route of vein, produced fall of the blood pressure. 3. The depressor response of the rabbit to water extract and methanol extract was not affected by $Avicel{\circledR}$, propranolol and atropine. 4. The depressor response by water extract and methanol extract in the rabbit was not affected by guanethidine, but water extract and methanol extract produced elevation of blood pressure in this rabbit. 5. Pretreatment of rabbit with chlorisendamine or phenoxybenzamine weakened the depressor response to water extract and methanol extract, and the both extracts produced secondary elevation of blood pressure in this rabbit. 6. The pressor response of the chlorisondamine-treated rabbit to water extract and methanol extract was not affected by atropine. 7. Water extract decreased the pressor action of tyramine and depressor action of pilocarpine and isoproterenol, but did not affect the blood pressure response of nor einephrine, angiotensin and dimethylpehnyl piperazinium iodide(DMPP).

• Journal of Environmental Impact Assessment
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• 제15권1호
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• pp.53-65
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• 2006

Topographic condition is one of the most important things in farming activities. The topographic condition didn't matter for farming in the past because agricultural products had competitive power in the market. So farmers tried to extend their farms without any concern of topographic condition. We need less labor-consuming farming as industrial structure has been changed and the competitive power of the farming has been getting weak. This study analyzed the fallow potential in agricultural area by topographic condition so that we have got results as follows. Maps of elevation, slope, distance from roads and water resources were made for getting a fallow probability model in farms, and these 4 factors were used as independent variables while a variable on whether it is fallow or not is a dependent variable in logistic regression model. In an analysis of the fallow potential depending on farm land types, the fallow probability in fallow orchard showed the highest value of farm lands, 0.973. Cultivated orchard had 0.730 and upland had 0.616 of the fallow probability. The fields having high fallow potential had high elevation, steep slope, and long distance from water resources and roads. Especially, fields having a probability over 0.99 appeared in orchards, fallow uplands and single cropping uplands, which were recognized to have several disadvantages related to the fallow like as high elevation, steep slope, and long distance from water resources and roads. With the logistic analysis, the suitable farm lands appeared at 16.45m of the mean elevation, 1.89 degree of the mean slope, 39.91m of the average distance from water resources, and 32.39m of the average distance from roads. On the contrary, non-suitable land appeared at 114.7m of the mean elevation, 24.9 degree of the mean slope. The distance from roads was more important variable than the distance from water resources for analyzing suitable farm land.

• Journal of Ecology and Environment
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• 제43권2호
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• pp.271-281
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• 2019

Background: The plant communities within reservoir drawdown zones are ecologically important as they provide a range of ecosystem services such as stabilizing the shoreline, improving water quality, enhancing biodiversity, and mitigating climate change. The aim of the study was therefore to identify the major environmental factors affecting these plant communities within the drawdown zone of the Soyangho Reservoir in South Korea, which experiences a monsoonal climate, and thereafter to (1) elucidate the plant species responses and (2) compare the soil seedbank composition along main environmental gradients. Results: Two main environmental gradients affecting the plant community structure were identified within the drawdown zone; these were a vertical and longitudinal gradient. On the vertical dimension, a hydrological gradient of flood/exposure, the annual-dominated plant community near the water edge changed to a perennial-dominated community at the highest elevation. On the longitudinal dimension from the dam to the upstream, plant species composition changed from an upland forest-edge community to a lowland riverine community, and this was correlated with slope degree, soil particle size, and soil moisture content. Simultaneously, the composition of the soil seedbank was separated along the vertical gradient of the drawdown zone, with mainly annuals near the water edge and some perennials at higher elevations. The species composition similarity between the seedbank and extant vegetation was greater in the annual communities at low elevation than in the perennial communities at higher elevation. Conclusions: The structures of plant community and soil seedbank in the drawdown zone of a monsoonal riverine reservoir were changed first along the vertical and secondly along the longitudinal gradients. The soil seedbank could play an important role on the vegetation regeneration after the disturbances of flood/exposure in the drawdown zone. These results indicate that it is important to understand the vertical and longitudinal environmental gradients affecting shoreline plant community structure and the role of soil seedbanks on the rapid vegetation regeneration for conserving and restoring the drawdown zone of a monsoonal reservoir.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제15권2호
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• pp.221-230
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• 1997

In hydrology analysis, the result of a slope analysis for terrain have an very important effect on water quality and water quantity Recently, a slope analysis tend to use the digital elevation model rater than the traditional map sheet. But a terrain slope analysis by the digital elevation model depends on grid size of the digital elevation model. Hence the effect of a slope analysis by the digital elevation model is a important factor. In this study, therefor, in order to determine a hydrological parameter and a terrain parameter for simulation of the water quality and the hydrological property, we adapted two sample area that are the Nerin stream of the basin of the Soyang lake and a Osip stream of Samchuk, and its individual coverages are $640\;km^2$ and $33\;km^2$. Also to analyze the effect of grid size in the slope of a basin, we apply DEM changing a grid size respectively at intervals of 100 m from 100 m to 1.000m for the Nerin stream basin and at intervals of 10 m from 20 m to 300 m for the Osip stream basin.

• Journal of Korea Water Resources Association
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• 제48권5호
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• pp.379-391
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• 2015

Multi-functional weirs has been installed in four rivers are hydraulic structures across the river. The structures were divided into movable and fixed weirs. Hence, riverbed-level variation and sediment transport can be varied due to water gate operation. In this study, the long-term riverbed-level variation of Geum river basin due to water gate operation of multi-functional weirs was studied. Result of this study shows that the variation of thalweg elevation was greater than the variation of annual average riverbed elevation due to multi-functional weirs construction and water gate operation. Maximum riverbed degradation of thalweg elevation that occurred was 2.79m and riverbed aggradation was 1.90m. Maximum riverbed degradation of the annual average riverbed elevation that occurred was 2.16m and riverbed aggradation was 1.24m. Analysis result of flood stage by the variation of riverbed-level shows that flood stages were increased in majorities area. The maximum increase in the value of flood stage was 2.23m. For this reason, flood stages can be greater than the freeboard of the levees. Therefore, we should consider the water gate operation of multi-functional weirs when planning and managing sediment in the river. We are expecting to use the result of this study in river planning for river management and selecting the river regime.

• Journal of Environmental Impact Assessment
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• 제4권2호
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• pp.39-57
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• 1995

The water quality model SWAT (Soil and Water Assessment Tool) was used in combination with GIS, Arc/Info and GRASS, to evaluate land use impacts in the Delaware River Basin in Pennsylvania. This paper describes application of GIS with the water quality model in the 250 square kilometer Brodhead Creek Watershed. Date used in water quality modeling include 1:250,000 digital elevation models (DEM), soil data, and monitored streamflow and curve numbers, and other input variables.