http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/59 2026-05-23T10:37:51Z 2026-05-23T10:37:51Z Luong, Tuan Anh Larsson, Rolf http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/267 2011-04-17T03:09:08Z 2008-01-01T00:00:00Z

Stability of spatial interpolation functions in finite element one‐dimensional kinematic wave rainfall‐runoff models Luong, Tuan Anh; Larsson, Rolf This paper analyzes the stability of linear, lumped, quadratic, and cubic spatial interpolation functions in finite element one‐dimensional kinematic wave schemes for simulation of rainfall‐runoff processes. Galerkin’s residual method transforms the kinematic wave partial differential equations into a system of ordinary differential equations. The stability of this system is analyzed using the definition of the norm of vectors and matrices. The stability index, or singularity of the system, is computed by the Singular Value Decomposition algorithm. The oscillation of the solution of the finite element one‐dimensional kinematic wave schemes results both from the sources, and from the multiplication operator of oscillation. The results of computation experiment and analysis show the advantage and disadvantage of different types of spatial interpolation functions when FEM is applied for rainfall‐ runoff modeling by kinematic wave equations. VNU Journal of Science, Earth Sciences. Vol. 24 (2008), No. 2, P. 57‐65

2008-01-01T00:00:00Z Nguyen, Tien Giang Tran, Anh Phuong Tran, Ngoc Anh Nguyen, Thanh Son Nguyen, Truong Khoa http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/266 2011-04-17T03:05:22Z 2008-01-01T00:00:00Z

Using multi‐criteria analysis as a tool to select the feasible measures for sustainable development of brackish water shrimp culture in Quang Tri Province Nguyen, Tien Giang; Tran, Anh Phuong; Tran, Ngoc Anh; Nguyen, Thanh Son; Nguyen, Truong Khoa In recent years, brackish water shrimp culture in Quang Tri Province has developed rapidly. Thanks to this development, lives of many local farmers have been improved, contributing considerably to the poverty alleviation goal. However, together with this positive impact, policymakers and shrimp farmers are facing several issues such as spread of shrimp’s diseases, water pollution and salinity intrusion. For the purpose of sustainable development, it is necessary to search for and implement those measures which can solve effectively these emerging problems. This paper presents the results on the application of a multi‐criteria analysis method to selecting the most feasible measures to these problems. The MCA results suggest the four most feasible measures and pinpoint that the combined option: sedimentation reservoir & reservoir with culture plus improved feeding and water management as the ʺbestʺ option. VNU Journal of Science, Earth Sciences. Vol. 24 (2008), No. 2, P. 66‐78

2008-01-01T00:00:00Z Phung, Dang Hieu http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/265 2011-04-17T03:01:10Z 2008-01-01T00:00:00Z

Numerical study of long wave runup on a conical island Phung, Dang Hieu A numerical model based on the 2D shallow water equations was developed using the Finite Volume Method. The model was applied to the study of long wave propagation and runup on a conical island. The simulated results by the model were compared with published experimental data and analyzed to understand more about the interaction processes between the long waves and conical island in terms of water profile and wave runup height. The results of the study confirmed the effects of edge waves on the runup height at the lee side of the island. VNU Journal of Science, Earth Sciences. Vol. 24 (2008), No. 2, P. 79‐86

2008-01-01T00:00:00Z Nguyen, Manh Khai Pham, Thanh Tuan Nguyen, Cong Vinh Oborn, Ingrid http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/264 2011-04-17T02:58:25Z 2008-01-01T00:00:00Z

Effects of using wastewater as nutrient sources on soil chemical properties in peri‐urban agricultural systems Nguyen, Manh Khai; Pham, Thanh Tuan; Nguyen, Cong Vinh; Oborn, Ingrid Reusing domestic wastewater for irrigation and applying biosolids as a fertiliser in crop production are common practices in peri‐urban areas of Vietnam. This study investigates the effects of using domestic wastewater in field experiments on Fluvisols soils in peri‐urban areas of Hanoi and Nam Dinh cities. We compared long‐term (30‐50 years) wastewater‐irrigated rice‐dominated farming systems. Using wastewater for irrigation significantly affected pH, electrical conductivity (EC), exchangeable K and Na and reverse aqua regia‐digestible (Rev Aq Reg) copper (Cu), lead (Pb) and zinc (Zn) in the investigated areas compared with control plots irrigated using river water. There were no significant effects of wastewater irrigation on the NH4NO3‐extractable fraction of cadmium (Cd) and other trace metals, but the EDTA‐extractable fraction of Cu, Pb and Zn was significantly increased. VNU Journal of Science, Earth Sciences. Vol 24 (2008), No. 2, P. 87‐95

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