• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.14 no.4
• /
• pp.859-866
• /
• 1994

It is difficult to make an exact estimate of the peak discharge or the runoff depth of flood and establish the proper measure for the flood protection since the water stage or discharge has been nearly measured at most medium or small river basins. The objective of this study is to estimate parameters of the discrete, linear, input-output model for medium or small river basin. The On-Cheon River basin in Pusan was selected for the study area. The runoff data used in the study has been observed since June 1993, and the effective rainfall was determined using the storage function method. The parameter sets of the discrete, linear, input-output model were estimated using the least squares method and the correlation function method, respectively. The calculated hydrographs by the discrete, linear, input-output model regenerated the observed outflow hydrographs well, and also the simulated flood hydrograph was comparable to the observed one. Therefore, it is believed that the discrete, linear, input-output model is simpler than other runoff analysis methods, and can be applied to a medium or small river basin.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.6 no.6
• /
• pp.56-71
• /
• 2003

Waste landfills have been the center of environmental problems and they must be restored due to environmental pollution, disgusting landscape, and cost of management. It is suggested that they be recycled urban space as cities expand. Specially, nonsanitary waste landfills which have no pollution prevention facilities cause serious problems. Restoring the landfills as parks and golf courses, so on makes more benefits because of cheap use land, closeness to urban area, flat topography applicable to parks and golf courses, and high land values after restoration and the changes to local recreation sites. Restoration of waste landfills is a complex, costly, and interdisciplinary work. But, the waste landfill is a manmade ecosystem. Control, restoration and postmanagement of waste landfills are very important problems. The role of vegetation prevents soil erosion, reduces soil water storage, and obstructs leachate seepage. Early restoration makes derelict lands into man park artificially geared to soil, vegetation, landforms and hydrology. But, Ideal restoration is to make stable ecosystem nature-friendly and compatible with surrounding landscape without more management. Landscape is structured hierarchically with patches and stands as small components and forms forest as large components. Therefore, landscape formation of the waste landfills needs much restoration process. There are many ecological restoration techniques for the waste landfills. Those are divided into artificial and natural methods. The artificial method is anthropogenic plantings while the natural method is to trigger and use succession processes. The most important thing in the restoration of waste landfills is to consider the final restoration objectives of each waste landfill. According to these objectives, the depth of covering layer, planting degree, and structural design should be determined. The effective restoration methods should be selected of artificial and natural options.

• Journal of Families and Better Life
• /
• v.28 no.6
• /
• pp.81-94
• /
• 2010

This qualitative research was designed to explore the use of housing among Korean Chinese people in Harbin, China. Focusing on the use which based on the epistemology of housing adjustment, this was particularly designed to examine its cultural assimilation and acculturation on the way of life course, it employed the in-depth interview on the oral history of 5 interviewees in their 60s and 70s, individualized interviews were conducted from May 28 to 31 in 2010. Key findings were summarized as follows; 1. The free market reform in China resulted in privatization that allowed respondents to become homeowners, and the ownership was viewed as part of family asset centered upon a sense of solidarity. 2. Although homeowners in multi-story houses were responsible to decorate interior spaces, the common features in using interior spaces were found: entrance had no thresholds; kitchen was small, lack of storage cabinets, tile-flooring; washers were installed inside bathroom; and newly built apartment didn't have proper space to store Korean fermented foods. It was observed that housing adaptation outweighed housing adjustment. Those who used to live in Chinese houses with indoor-wearing-shoes or Russian houses with indoor-wearing-slippers were receptive to the use of dining table and bed, and the community heating system discouraged the use of individual electric water heater because of high electricity cost. 3. In daily life, eating habit wasn't much changed to the Chinese style, meals were shared, dish sterilizer was popular, and Kimchi fridge wasn't used. Because of the influence of the Chinese culture, such Korean traditions as ancestral rites and bedroom allocation tradition faded away, but traditional family values remained unchanged. In conclusion, Korean Chinese people experience normative housing deficits and adaptation selectively incurred. It's implied that residential design meets the needs resulting from the dual culture in terms of cultural assimilation and acculturation.

• Journal of Soil and Groundwater Environment
• /
• v.22 no.6
• /
• pp.94-103
• /
• 2017

Surface soil is one of the most important resources that have many functions for human needs such as conservation of water resource, purification of contaminated materials, and productivity of food or energy. However, the surface soil is a limited resource that cannot be recovered readily for a long time once it is lost by erosion. In Korea, the Ministry of Environment enacted the notification on the investigation of surface soil erosion and corresponding countermeasures. As the results, database of soil quality assess criteria (biomass, groundwater recharge, habitat, carbon storage, buffer, and soil loss) was established, and the web-based system that can evaluate surface soil conditions was developed. However, non-experts have difficulties in using the system because the system requires in-depth knowledge about soil qualities. In this study, the Web Geographic Information System (GIS) watershed-based surface soil information system was developed to improve usability of the system and accessibility of soil quaility database. The system provides the current condition of surface soil characteristics and GIS-based soil data at selected locations. The users are able to download soil quality data in different districts, watersheds, and special regions allocated by TauDEM module. The system developed in this study would valuable surface soil information for studies of soil quality and its environmental effects, and thereby contributing to establishing more appropriate and robust soil conservation laws.

• Korean Journal of Ecology and Environment
• /
• v.35 no.1 s.97
• /
• pp.28-35
• /
• 2002

The effect of physical parameters on water quality was analyzed using monitoring data of 193 agricultural reservoirs. The retention time of reservoirs ($t_d$) ranged between 10 and 140 days, and the ratio of drainage area (DA) to reservoir surface area (SA) was between 10 and 120. Both ratios of DA/SA and total area (TA)/ reservoir storage (ST) in Korean agricultural reservoirs were relatively greater than those in natural lakes in other countries. As retention time was plotted against DA/SA ratio, it was shorter in Korean reservoirs than natural lakes. The semi-logarithmic relationship between TA/SA and t>$t_d$ was $t_d\;=\;42.21(TA/ST)^{-1}$ (n = 50, $R^2\;=\;0.89$). While areal loading of total phosphorus (TP) was below $4\;gTP{\cdot}m^{-2}{\cdot}yr^{-1}$ in general, it exceeded $10\;gTP{\cdot}m^{-2}{\cdot}yr^{-1}$ in reservoirs where DA/SA ratio was greater than 100, which implies that areal loading of TP increases as DA/SA ratio increases. Chl-a concentration was positively related with the mean depth of reservoir, implying the higher Chl-a concentration with deeper the mean depth. Therefore, the deeper reservoir might be advantageous in water quality management perspective if other morphological conditions are similar. The empirical regression equation using physical parameters was also suggested in the estimation of TP concentration in the reservoirs. Combined information presented in this paper might be applicable to the water quality management in agricultural reservoirs.

• Korean Journal of Soil Science and Fertilizer
• /
• v.35 no.1
• /
• pp.1-11
• /
• 2002

Root distribution was monitored in the root zone of corn fields on several soil series in central Illinois during three growing seasons in order to find the effect of soil series and tillage system on root growth. A minirhizotron technique was used to videotape each soil profile in weekly intervals to a depth of 75 cm under conventional tillage (CT) and no tillage (NT) systems of cultivation. Root distribution near soil surface generally increased during the early stages of the growing season, but declined as surface soil moisture was depleted in late summer. Even though root distribution was not significantly different between soil series in this experiment. differences in root distribution between soil series were associated with the increases in root-available water storage capacity. Root population in the top 30 cm of NT plots. where increased water infiltration rates and saturated flow of soil moisture into the subsoil, was generally higher than that of CT plots in Illinois corn fields. Foots appeared in the deeper layers later in the growing season, with root penetration into subsoil layers occurring as much as 2-3 weeks earlier on the NT plots than in CT plots. In conclusion, root distribution was significantly affected by the tillage systems, but not different by soil series.

• Journal of Korea Water Resources Association
• /
• v.56 no.10
• /
• pp.655-665
• /
• 2023

In this study, unit hydrographs are calculated when precipitations of 10 scales instantaneously occurs in a virtual watershed with a constant slope and roughness. Then, the relationship between the peak flow rate and the peak occurrence time of the unit hydrograph was calculated for the precipitation scale, respectively. At this time, the virtual watershed simplified with a rhombic shape, a constant slope, and a flow condition with a certain roughness was applied instead of a natural watershed in order to understand the effect the precipitation scale has on the peak value of the unit hydrograph. And it was assumed that the precipitation in the basin was effective rainfall and the runoff was direct runoff, and the runoff flowed in a straight, uniform flow from the drop point to the outlet. The relationship between the peak flow and the peak occurrence time of the unit hydrograph was calculated in the case of 10 types of precipitation scales of 10 mm, 40 mm, 90 mm, 160 mm, 250 mm, 360 mm, 640 mm, 1,000 mm, 1,210 mm, and 1,690 mm of effective precipitation. A noteworthy achievement of this study is that, even without the storage effect of the watershed, as the scale of precipitation increases, the depth of runoff increases, so the flow rate in the watershed increases and the distance per unit time increases, so the peak flow rate increases and the peak occurrence time increases. This is a nonlinear characteristic of watershed runoff.

• Economic and Environmental Geology
• /
• v.51 no.1
• /
• pp.67-76
• /
• 2018

This study reviews three eco-friendly energy towns with hybrid thermal energy supply systems and borehole thermal energy storage (BTES) in Canada and Denmark. The district heating and cooling systems were designed by using multi-source energy for the higher efficiency and reliability as well as environment. ADEU (Alexandra District Energy Utility) located at the developing area in the city of Richmond, Canada was designed to supply district energy with the installation of 726 borehole heat exchangers (BHEs) and a backup boiler using natural gas. DLSC (Drake Landing Solar Community) located in the town of Okotoks, Canada is a district system to store solar thermal energy underground during the summer season by seasonal BTES with 144 BHEs. Brædstrup Solpark district heating system located in Denmark has been conducted energy supply from multiple energy sources of solar thermal, heat pump, boiler plants and seasonal BTES with 48 BHEs. These systems are designed based on social and economic benefits as well as nature-friendly living space according to the city based energy perspective. Each system has the energy center which distribute the stored thermal energy to each house for heating during the winter season. The BHE depth and ground thermal storage volume are designed by the heating and cooling load as well as the condition of ground water flow and thermophysical properties of the ground. These systems have been proved the reliance and economic benefits by providing consistent energy supply with competitive energy price for many years. In addition, the several expansions of the service area in ADEU and Brædstrup Solpark have been processed based on energy supply master plan. In order to implement this kind of project in our country, the regulation and policy support of government or related federal organization are required. As well as the government have to make a energy management agency associated with long-term supply energy plan.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.4 s.50
• /
• pp.1-13
• /
• 2006

Soil and rock dynamic properties such as shear wave velocity $(V_s)$, compressional wave velocity $(V_p)$ and corresponding Poisson's ratio (v) are very important geotechnical parameters in predicting deformational behavior of structures as well as practicing seismic design and performance evaluation. In an effort to measure the parameter efficiently and accurately, various bore-hole seismic testing techniques have been, thus, developed and used during past several decades. In this study, cross-hole seismic testing technique which is known as the most reliable seismic method was adopted for obtaining geotechnical dynamic properties. To perform successfully the cross-hole test for rock as well as soil layers regardless of the ground water level, spring-loaded source which impact laterally a subsurface ground in vertical bore-hole was developed and applied at three study areas, which contain four sites composed of two existing port sites and two new LNG storage facility sites. The geotechnical dynamic properties such as $V_s,\;V_p$ and v with depth from the soil surface to the engineering and seismic bedrock were efficiently determined from the laterally impacted cross-hole seismic tests at study sites, and were provided as the fundamental parameters for the seismic performance evaluation of the existing ports and the seismic design of the LNG storage facilities.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2005.09a
• /
• pp.155-175
• /
• 2005

Soil and rock dynamic properties such as shear wave velocity (VS), compressional wave velocity (VP) and corresponding Poisson's ratio ( v ) are very important geotechnical parameters in predicting deformational behavior of structures as well as practicing seismic design and performance evaluation. In an effort to measure the parameter efficiently and accurately, various bore-hole seismic testing techniques have been, thus, developed and used during past several decades. In this study, cross-hole seismic testing technique which is known as the most reliable seismic method was adopted for obtaining geotechnical dynamic properties. To perform successfully the cross-hole test for rock as well as soil layers regardless of the ground water level, spring-loaded source which impact laterally a subsurface ground in vertical bore-hole was developed and applied at three study areas, which contain four sites composed of two existing port sites and two new LNG storage facility sites. The geotechnical dynamic properties such as VS, VP and v with depth were efficiently determined from the laterally impacted cross-hole seismic tests at study sites, and were provided as the fundamental parameters for the seismic performance evaluation of the existing ports and the seismic design of the LNG storage facilities.