[Objective] The aim was to explore the measurement methods of drawdown of motor-pumped well in land consolidation. [Method] Based on pumping information, the relation curve of drawdown and pumped volume was drawn and ...[Objective] The aim was to explore the measurement methods of drawdown of motor-pumped well in land consolidation. [Method] Based on pumping information, the relation curve of drawdown and pumped volume was drawn and the empirical formula was concluded, with examples. [Result] The type of drawdown （h） and flow volume （Q） includes linear type, parabolic type, exponential curve and logarithmic curve. Graphical method and calculus of differences are available for determining the type of curve. [Conclusion] The empirical formula based on pumping test reflects relation between drawdown and pumping volume, which is simple and effective.展开更多
In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation an...In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation and maintenance. Many different types of wetland treatment systems have been built during the last 10 years, among which the free water surface wetland has been predominant. Most of the large-scale systems are government projects for improving the water quality of the streams flowing into the estuary dikes and reservoirs. The covering plants used in this system are different in different areas but cattails and reeds or their combinations are common. Constructed wetlands in Korea can be characterized by their shallow depths and short hydraulic residence times. There is no established flow pattern and configuration rules for constructing wetlands, but many efforts have been made with a view to improving their ecological function. Flow control is the most difficult problem in designing a riverbed or riparian wetland. There have been scores of flow rate control devices developed for wetlands, but none of them guarantee wetlands’ safety against flooding. In earlier wetland construction, the building materials were mainly soil. Recently, strong and durable building materials such as rocks, gravel beds, concrete and steel are used at vulnerable places to protect them from erosion. Our investigation indicated that the wetland system would be an appropriate technology because it is not only cheaper to construct, but also requires less maintenance work. However, we suffer from the reduced effectiveness in performance during the winter. We need to evaluate the partial treatment accomplished during 6 to 7 months per year.展开更多
文摘[Objective] The aim was to explore the measurement methods of drawdown of motor-pumped well in land consolidation. [Method] Based on pumping information, the relation curve of drawdown and pumped volume was drawn and the empirical formula was concluded, with examples. [Result] The type of drawdown （h） and flow volume （Q） includes linear type, parabolic type, exponential curve and logarithmic curve. Graphical method and calculus of differences are available for determining the type of curve. [Conclusion] The empirical formula based on pumping test reflects relation between drawdown and pumping volume, which is simple and effective.
文摘In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation and maintenance. Many different types of wetland treatment systems have been built during the last 10 years, among which the free water surface wetland has been predominant. Most of the large-scale systems are government projects for improving the water quality of the streams flowing into the estuary dikes and reservoirs. The covering plants used in this system are different in different areas but cattails and reeds or their combinations are common. Constructed wetlands in Korea can be characterized by their shallow depths and short hydraulic residence times. There is no established flow pattern and configuration rules for constructing wetlands, but many efforts have been made with a view to improving their ecological function. Flow control is the most difficult problem in designing a riverbed or riparian wetland. There have been scores of flow rate control devices developed for wetlands, but none of them guarantee wetlands’ safety against flooding. In earlier wetland construction, the building materials were mainly soil. Recently, strong and durable building materials such as rocks, gravel beds, concrete and steel are used at vulnerable places to protect them from erosion. Our investigation indicated that the wetland system would be an appropriate technology because it is not only cheaper to construct, but also requires less maintenance work. However, we suffer from the reduced effectiveness in performance during the winter. We need to evaluate the partial treatment accomplished during 6 to 7 months per year.
