On the basis of Digital Elevation Model （DEM） data, watershed delineation and spatial topological relationship were proposed by the Digital Elevation Drainage Network Model （DEDNM） for the area upstream of the Han...On the basis of Digital Elevation Model （DEM） data, watershed delineation and spatial topological relationship were proposed by the Digital Elevation Drainage Network Model （DEDNM） for the area upstream of the Hanzhong Hydrological Station in the Hanjiang River in China. Then, the Muskingum-Cunge method considering lateral flow into the river was applied to flood routing on the platform of digital basin derived from DEDNM. Because of considering lateral flow into the river, the Muskingum-Cunge method performs better than the Muskingum method in terms of the Nash-Sutcliffe model efficiency coefficient and the relative error of flood discharge peak value. With a routing-after-superposition algorithm, the Muskingum-Cunge method performs better than the Muskingum method in terms of the Nash-Sutcliffe model efficiency coefficient and the relative error of flood discharge peak value. As a result, the digital basin coupled with the Muskingum-Cunge method provides a better platform for water resources management and flood control.展开更多
The operational function of the trunk limbs (thoracic appendages), of Daphnia, P3 and P4, is a long-term disputed definition between “solid walls”, sieving filters. Sieving is unlikely process for routine particle c...The operational function of the trunk limbs (thoracic appendages), of Daphnia, P3 and P4, is a long-term disputed definition between “solid walls”, sieving filters. Sieving is unlikely process for routine particle collection, particle capture is not a simple mechanical process and not by sieving alone. Analysis promotion supported by direct observational examination of the in-vivo cinematographic slow-motion film and magnified solid photos of tethered Daphnia by high-speed camera (250 frames per second) resulted in a definite interpretation presented in this paper. The Daphnia’s feeding mechanism achieves particles abstraction not by sieving. The existence of two internal alternate water flow routs was indicated: Lateral and Median. These micro flow structures are suggested as vulnerability reduction.展开更多
Efficiency in solving the Saint-Venant equations for watershed rainfall-runoff routing is important in flood hydrology. This paper presents a high-efficiency numerical solution of one-dimensional dynamic wave equation...Efficiency in solving the Saint-Venant equations for watershed rainfall-runoff routing is important in flood hydrology. This paper presents a high-efficiency numerical solution of one-dimensional dynamic wave equations(HEDWE) for watershed rainfall-runoff routing, in which the full momentum equation is written as a quadratic equation with only one unknown variable Q, water depth is derived from the continuity equation using the two-step predictorcorrector method, and the discrete scheme is the explicit upwind scheme. The results of numerical tests showed the HEDWE approach has several major advantages. 1) It is a stable numerical method, even for an initially dry area. 2) Its computational efficiency is higher than 4.76E+05 times/s. 3) It can be used for overland flow, river flow, and combinations thereof. The primary disadvantages of the HEDWE approach are its unsuitability for rapidly varying flow, such as dam-break floods.展开更多
This study proposes the use of a novel integrated framework for 2D en route airspace sub-sectorization.The integrated framework combines the multi-commodity flow optimization approach,complex network cluster-ing appro...This study proposes the use of a novel integrated framework for 2D en route airspace sub-sectorization.The integrated framework combines the multi-commodity flow optimization approach,complex network cluster-ing approach,and Minimum Bounding Geometry(MBG)-coupled Rule-based Approach for boundary design.A decomposition-based discrete particle swarm optimization(DPSO)is used to solve the clustering problem.The output of the flow optimization is used as a guiding standard for the DPSO.Experimentations were performed using the Indian airspace sector to validate the framework and DPSO was run for different maximum number of generations(maxgen).The findings reveal that the multi-commodity flow approach captures system-wide flow operations.Clustering results corresponding to maxgen=100 and maxgen=150 perform best in terms of equitable and balanced distribution of cluster size and traffic load.The MBG-coupled Rule-based Approach leads to com-pact and convex sub-sector boundary design.Major implications of this research include dynamic adaptability of the integrated framework,increased sensitivity of sector design to network evolution,and a computationally tractable framework.The higher controllability of the proposed framework also offers an increased acceptance among practitioners.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No :40171016) and the National KeyBasic Research Programof China (Grant No :2006CB400502) .
文摘On the basis of Digital Elevation Model （DEM） data, watershed delineation and spatial topological relationship were proposed by the Digital Elevation Drainage Network Model （DEDNM） for the area upstream of the Hanzhong Hydrological Station in the Hanjiang River in China. Then, the Muskingum-Cunge method considering lateral flow into the river was applied to flood routing on the platform of digital basin derived from DEDNM. Because of considering lateral flow into the river, the Muskingum-Cunge method performs better than the Muskingum method in terms of the Nash-Sutcliffe model efficiency coefficient and the relative error of flood discharge peak value. With a routing-after-superposition algorithm, the Muskingum-Cunge method performs better than the Muskingum method in terms of the Nash-Sutcliffe model efficiency coefficient and the relative error of flood discharge peak value. As a result, the digital basin coupled with the Muskingum-Cunge method provides a better platform for water resources management and flood control.
文摘The operational function of the trunk limbs (thoracic appendages), of Daphnia, P3 and P4, is a long-term disputed definition between “solid walls”, sieving filters. Sieving is unlikely process for routine particle collection, particle capture is not a simple mechanical process and not by sieving alone. Analysis promotion supported by direct observational examination of the in-vivo cinematographic slow-motion film and magnified solid photos of tethered Daphnia by high-speed camera (250 frames per second) resulted in a definite interpretation presented in this paper. The Daphnia’s feeding mechanism achieves particles abstraction not by sieving. The existence of two internal alternate water flow routs was indicated: Lateral and Median. These micro flow structures are suggested as vulnerability reduction.
基金funded by the National Natural Science Foundation of China (Grant No. 41501046)the Innovation Program of Guangdong Province, China (Grant No. 2016-14)
文摘Efficiency in solving the Saint-Venant equations for watershed rainfall-runoff routing is important in flood hydrology. This paper presents a high-efficiency numerical solution of one-dimensional dynamic wave equations(HEDWE) for watershed rainfall-runoff routing, in which the full momentum equation is written as a quadratic equation with only one unknown variable Q, water depth is derived from the continuity equation using the two-step predictorcorrector method, and the discrete scheme is the explicit upwind scheme. The results of numerical tests showed the HEDWE approach has several major advantages. 1) It is a stable numerical method, even for an initially dry area. 2) Its computational efficiency is higher than 4.76E+05 times/s. 3) It can be used for overland flow, river flow, and combinations thereof. The primary disadvantages of the HEDWE approach are its unsuitability for rapidly varying flow, such as dam-break floods.
基金PMRF PM/MHRD-20-16823.03 for the financial support。
文摘This study proposes the use of a novel integrated framework for 2D en route airspace sub-sectorization.The integrated framework combines the multi-commodity flow optimization approach,complex network cluster-ing approach,and Minimum Bounding Geometry(MBG)-coupled Rule-based Approach for boundary design.A decomposition-based discrete particle swarm optimization(DPSO)is used to solve the clustering problem.The output of the flow optimization is used as a guiding standard for the DPSO.Experimentations were performed using the Indian airspace sector to validate the framework and DPSO was run for different maximum number of generations(maxgen).The findings reveal that the multi-commodity flow approach captures system-wide flow operations.Clustering results corresponding to maxgen=100 and maxgen=150 perform best in terms of equitable and balanced distribution of cluster size and traffic load.The MBG-coupled Rule-based Approach leads to com-pact and convex sub-sector boundary design.Major implications of this research include dynamic adaptability of the integrated framework,increased sensitivity of sector design to network evolution,and a computationally tractable framework.The higher controllability of the proposed framework also offers an increased acceptance among practitioners.
