http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/66 2026-05-17T16:06:02Z 2026-05-17T16:06:02Z Luong, Van Viet et al. http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/9212 2011-05-28T12:00:44Z 2009-01-01T00:00:00Z

Title: A nalyse the fluctuation and water level trend in Saigon- Dong Nai river system Authors: Luong, Van Viet; et al. Abstract: Beside the effect of gravitational forces, the water level in Sai Gon-Dong Nai River System is also affected by non gravitational forces such a wind, air pressure, rainfall and sea level rise. The purpose of this paper is to simulate the water level of these river based on the tidal and non-tidal constituents, from that assess the role of non-tidal constituents to water variation. In this study, the none-tidal data used includes the wind field at surface, sea level pressure and the rainfall in Sai Gon- Dong Nai Basin. With the analyzed data series from 1980 to 2007, the results show that after supplementing the non-tidal elements, the water level simulation quality is increased, the wind and rainfall have an important rote to water level. The results also show that near river mouths, the water level raised 13 cm from 1980-2007 due to the global climate change.

2009-01-01T00:00:00Z Tran, Thi Van Tran, Thi Binh http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/9208 2011-05-28T11:56:24Z 2009-01-01T00:00:00Z

Title: Application of remote sensing for shoreline change detection in Cuu Long estuary Authors: Tran, Thi Van; Tran, Thi Binh Abstract: Coastal zone of Cuu Long estuary is a place through which Mekong River flows into the Eastern Sea with 8 estuaries. is the zone is formed under the influences in the interaction between river and sea. Geologically, coastal zone of Mekong delta is characterised by the predominat of clay and silt formations. These two factors makes the shoreline sensitive to exogenous processes such assedimentation and erosion.. This paper presents an application of satellite remote sensing technology to detect and analyze the spatial changes as well as quantify the shoreline change in Cuu Long estuary. Landsat and Aster satellite images were used with band ratio method for shoreline change detection. The results present shoreline changes maps in three periods: 1989, 2001 and 2004. The outcomes of the case study can be used as an orientation for the sustainab1e integrated management p1an of coastal zones.

2009-01-01T00:00:00Z Tran, Nghi http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/9206 2011-05-28T11:49:47Z 2009-01-01T00:00:00Z

Title: Method of sedimentary basin reconstruction and compilation of lithofacies - paleogeographic maps Authors: Tran, Nghi Abstract: A secondary basin corresponds with a second order depositional cycle, is limited by two erosional surfaces which are also the boundaries of a seismic sequence. In other words, a secondary basin is a component of an overall sedimentary basin. A secondary basin is formed at the same time with a tectonic phase where the three most important factors are faulting, subsidence and uplifting. Basin-forming faults are usually normal faults and are called "syn-depositional fault". The reconstruction of a sedimentary basin, is rather complicated, but it is very necessary for basin analysis, facial analysis and compilation of lithofacies-paleogeographic maps, as the dimensions and thickness of the present secondary basin are not the same as of the primitive basin. To get a true picture of the primitive basin one must carry out the following steps: - Drawing the recontructed geologic sections - Reconstructing the sediment thickness - $$h_1 = h_2\roof t 3 {K.\frac {P_1}{P_2}}$$ where $h_1$ is the primitive thickness $h_2$ is the present thickness K is the shrinkage coefficient (depending on the rock type) - - $P_1$ is the primitive common porosity - $P_2$ is the present common porosity - Reconstructing the integrated geologic-sedimentary sections: - + Width of the basin $$L_1=C.[L_2-\sum_{t=1}^n L_{1i}+\sum_{t=1}^mL_{2i}+\sum_{t=1}^fL_{3i}]$$ where $C$ is a correction coefficient: $C=l.25$ (digenetic stage), 1.55 (catagenetic stage) and 1.9 (metagenetic stage). + Thickness of the basin: $H_1 = ch_2$ - Reconstructing the boundaries of the basin - Reconstructing the isopach map - Compiling the lithofacies-paleogeographic map.

2009-01-01T00:00:00Z Nguyen, Thuy Duong http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/9205 2011-05-28T11:29:08Z 2009-01-01T00:00:00Z

Title: Palynological investigation from a deep core at the coastal area of the Red River Delta, Vietnam Authors: Nguyen, Thuy Duong Abstract: Palyno1ogica1 study in a deep core (69.5 m depth) in the coasta1 area of the Red River De1ta, Vietnam provides evidences on vegetation change in the regiona1 area in about 12000 years before present. This research aims to reconstruct the vegetation deve1opment and paleoenvironmenta1 changes in the Red River Delta, Vietnam during the Holocene. These data show that the region supported a Fagaceae-Coniferous, especially Quercus, Pinus và Castanopsis, similar to contemporary vegetation described in Vietnam and southeast China. Tropica1 broadleaf forest dominated at the time right after 12.000 BP. At the same time, Scyphiphora hydrophyl/aceae is the dominant wood species in the back mangrove forest at the studied area. After this time, the elima te became warmer a1though there were severa1 periods with co1der climate in between.

2009-01-01T00:00:00Z