Journal of Water Resources Science and Technology No.34
Create date: 08/26/16

WATER RESOURCES SCIENCE AND TECHNOLOGY JOURNAL
No 34 (Aug/2016)

No

Article

Author

Summary

I

SCIENCE TECHNOLOGY

 

 

1

MỘT SỐ VẤN ĐỀ VỀ SẢN XUẤT LÚA VỤ THU ĐÔNG
Ở ĐỒNG BẰNG SÔNG CỬU LONG

 

Hoat, Nguyen Van

Tuan, Hoang Quoc

Thang, Tang Duc

Hai, Nguyen Thanh

Giap, Pham Van

Trung, Vu Quang

Rice is most popular in the Mekong delta in term of agriculture, and Autumn-Winter rice crop is more and more planted. There are some problems (disadvantages) that affects seriously on this agricultural production, in which change of water source is considered as the most important thing. This paper presents some issues about mentioned

Key worlds: Autumn-Winter crop, crop patern, The Mekong Delta, dry season, flood season, economic analysis.

2

TÍNH TOÁN TIÊU NĂNG DÒNG MẶT SAU BẬC THỤT CÓ MŨI HẤT CONG VÀ GÓC HẤT LỚN

Huy, Nguyen Quoc

Nghi, Le Van

Surface flow energy dissipation with indented step structure have many advantages: efficiency of energy dissipation  is comparable with the bottom flow case (reaches 65%), but the backyard length is shorter than times, and the bottom velocity is low so the backyard thickness is small, then it does not need the backyard if the structure lyes on the rock background. [1.5]. The successive forms of surface, surface – bottom flow with small angle indented step has been comprehensively studied  [1,2,9]. However, it is very rarely applied in Vietnam becaus of it’s status of unstable and long spread wave in the downstream [2].

This article is presented the energy dissipation calculation method of hopper flow, the expansion case of the mixed surface-bottom hydraulic jump with the advantages of surface energy dissipation: stability in the large changes of downstream water level and cutting down the wave in downstream by the formation of “3 reels, 1 wave” in high indented and curved step structures, which has large angle of diffusion, bringing effectiveness of economy and  techniques.

Key words:high indented step structure, surface hydraulic jump, surface-bottom mixed hydraulic jump; hydraulic jump; successive energy dissipation

3

TÍNH TOÁN NHU CẦU NƯỚC VÀ ĐÁNH GIÁ KHẢ NĂNG NGUỒN NƯỚC PHỤC VỤ NỐI MẠNG CHUYỂN NƯỚC LƯU VỰC TỈNH NINH THUẬN

Vuong, Nguyen Dinh

Hoa, Nguyen Xuan

With the mainly river systems is Cái Phan Rang river and many large and small rivers, streams covers in Ninh Thuan province. Arcoding to the calculations to surface water, the volume of potential water in the province is very limited and depends heavily about additional water resources from neighboring provinces (additional water enters from the neighboring provinces were about 500 mil m3/year). While, the province's economy is on track to development and expansion, the industrial park has been invested to build so demand for water is increasing. It is necessary to calculate the water demand and potential water resources of Ninh Thuan province in future in oder to propose proper solutions for water transfering in connecting network of irrigation systems to service of economic development as well as local society.

Key words: Water demand, potention of water, water transfer in irrigation systems, drought, Ninh Thuan

4

ĐÁNH GIÁ HIỆN TRẠNG VỀ SỰ ỔN ĐỊNH VÀ HIỆU QUẢ CỦA CÁC GIẢI PHÁP, CÔNG NGHỆ BẢO VỆ BỜ SÔNG, BỜ BIỂN Ở VIỆT NAM

Cuong, Ho Viet

Quynh, Nguyen Ngoc

 Hieu, Buy Huy

Vietnamis a country which has a vast of river systems and coastlines stretching along 29 provinces and cities. So there are a huge of regulated flow works and bank protection works have been developed with both structural and category diversity. The technology application for flow regulation and bank protection aims to eliminate negative impacts caused by river and sea motivation. This paper presents some results of a study on the appropriateness and effectiveness of the solutions, technologies for bank reinforcement and coastal protection in Vietnam basing on the analysis of survey data.

Key words: works and protection, bank reirforcement and coastal protection

5

GIẢI PHÁP KHỐNG CHẾ ỨNG SUẤT NHIỆT CỦA BÊ TÔNG ĐẦM LĂN – TRƯỜNG HỢP ÁP DỤNG CHO ĐẬP THỦY ĐIỆN TRUNG SƠN

Viet, Nguyen Minh

 

With the results of research solutions to thermal stress control for typical areas in Vietnam, in this paper conducted calculations apply for Trung Son RCCD and recommendations reduces initial concrete temperature from 21oC down 20oC, increase in replacement levels of mineral admixtures in concrete from 70% up 72,5% to ensure cracking on both the upstream and downstream faces of roller compacted concrete dam.

Keywords: Roller Compacted Concrete, Mineral Admixtures, Thermal Stress, Trung Son Dam

6

MỘT SỐ VẤN ĐỀ VỀ DÒNG CHẢY LŨ Ở ĐỒNG BẰNG SÔNG CỬU LONG NHÌN TỪ TRẬN LŨ LỚN NĂM 2011

Thang, Tang Duc

Hai, Nguyen Thanh

Trung, Vu Quang

Giap, Pham Van

Hoat, Nguyen Van

The 2011 flood is big in the Mekong delta, which occured in situation of great change in infrastruture (roads, dykes,...) in whole delta. Many questions about rationality of infastructure in the delta are still not given. Also, flood analysis on hydrodynamic characteristic has been not done in detail. This paper will present some results related with issues above mentioned.

Key words: flood, roads, dykes, discharge, water level, rationality.

7

ĐẶC TRƯNG HÌNH DẠNG CỦA DÒNG CHẢY PHỄU SAU BẬC THỤT CÓ GÓC HẤT LỚN

Huy, Nguyen Quoc

Nghi, Le Van

The hopper flow is the successive form of torrent – smooth flow right behind the high indented and curved step structures, which has large angle of diffusion (a/P>0,2; angle> 250). This is the expansion case of the mixed surface-bottom hydraulic jump, multi-vortices, with of high energy dissipation capacity, and destructive the wave in downstream by the formation of “3 reels, 1 wave” right behind the indented steps. The bottom velocity is small.

In hydraulics, the identification of shape characteristic of hydraulic jump and successive forms in order to design the energy dissipation components is very important for determining the dimension of vortices  in hopper hydraulic jump. The article is presented the shape feature, focuses of the hight of reel flow and length of vortices zone No 2&3 from the  experimental data on physical model.

Key words: physical model; high indented step structure; surface hydraulic jump; surface-bottom mixed hydraulic jump; hydraulic jump; successive energy dissipation.

8

SỬ DỤNG PHỤ GIA HỖN HỢP - MỘT TRONG NHỮNG GIẢI PHÁP LÀM GIẢM NHIỆT KHI THI CÔNG ĐẬP BÊ TÔNG ĐẦM LĂN

Viet, Nguyen Minh

 

RCC in the construction of gravity dams has been proved to be more effective than in traditional concrete dams as well as earth dams for three reasons including: time saving, low cost and cost effective for temproraty works serving the construction diversion. However, there are also dissadvantages namely horizontal leaks in layered  concrete and cracked concrete due to the accumulation of heat of hydration of concrete in the dam body. The article presents a solution to lower the heat during the construction of RCC i.e. using additive mixture.

Key words: Roller Copacted Concrete, hydrated temperature

9

NÂNG CAO HIỆU QUẢ QUẢN LÝ RỪNG NGẬP MẶN Ở HUYỆN HẬU LỘC, TỈNH THANH HÓA     

 

Ngan, Nguyen Thi Mai

Hang, Nguyen Thi Minh

Hau Loc district being a coastal plain of Thanh Hoa province has a relatively long coastline of about 39km, so mangroves particularly play an important role in creating a green wall for protecting dikes and habitants in coastal areas. Therefore, there is a need to take measures to maintain and develop the mangrove ecosystems. One of these solutions is the introduction of management practices in line with the natural conditions, the economy and society of the region. Currently, the mangroves in Hau Loc district is managed under three main methods that are the state administration, the community-based management and household management. Each management practice has its own advantages and disadvantages, among which methods of community-based management is the most effective one in the management and development of the mangroves. The paper also proposes a planning solution which is environmentally friendly for aquaculture zones. In the future there should be effective coordination measures between this method, overcoming the disadvantages existed in each method in order to manage mangrove forests in a sustainable way in Hau Loc district.

Keywords: Mangrove, methods of management, community-based management

10

BÀN VỀ KẾT CẤU TẦNG LỌC VÀ GIẢI PHÁP CẢI TIẾN KẾT CẤU TẦNG LỌC TRONG SỬA CHỮA ĐẬP ĐẤT VỪA VÀ NHỎ

Van, Pham Dinh

Nguyen, Tran Van

In respect of design, repair, and upgrade earth dams affected by seepage issues, engineers often chose seepage prevention approaches (e.g. grout diaphrams, upstream inclining impervious blankets) instead of selecting seepage control approaches. Seepage control is understood as techniques that do not allow internal erosion in the dam body, but they help to lower the phreatic line for greater downstream slope stability and limit the leakage discharge in the permitted range. In order to control the seepage, it is necessary to design leakage water collecting and filtering structures (referred to as a filtering structure) and they should be reasonably arranged in the dam body and foundation with proper technical specifications. This paper provides analyses and remarks in design and execution of filtering structures in Vietnam as well as introduces a new type of filtering structure that is appropriate for repairing and seepage controlling in existing small earth dams.

Keywords:Filter and drainage structures; Seepage control; Earth dams

 

TECHNOLOGY TRANSFER

 

 

11

THIẾT BỊ VỚT RÁC TỰ ĐỘNG DI CHUYỂN, GIẢI PHÁP CÔNG NGHỆ MỚI XỬ LÝ VẤN ĐỀ BÈO RÁC CHO CỬA LẤY NƯỚC CÁC TRẠM BƠM LỚN

 

Que, Nguyen Huu

Tuan, Dinh Anh

Luong, Ngo Duc

Tan, Doan Minh

According to statistics, there are currently over 400 large-scale and middle-scale pumping stations in Vietnam. Pumping station systems play a crucial role in securing water supply and drainage in agriculture, industry and social life as well as preventing floods and protecting infrastructures. However, in the recent years water hyacinths have enormously affected the efficiency and safety of those systems, and water hyacinth harvester machineries have become essential and prioritized in large-scale pumping stations. Therefore, researching on the implementation of the Automatic Waste Harvester machinery for water-intake front gates at large-scale pumping stations has a significant economic, technological and social impact. The report summarizes the key findings and applications of the research on the mentioned topic conducted by the author group. 

Key words: Automatic Waste Harvester machinery, pumping stations

 

Science and technology information and activities

 

 

 

MỘT SỐ GIẢI PHÁP NÂNG CẤP CỬA VAN TỰ ĐỘNG THỦY LỰC ĐỂ TRANH THỦ LẤY NƯỚC NGỌT VÀ ĐIỀU TIẾT NƯỚC Ở KHU VỰC ĐBSCL

 

Hien, Thai Quoc

Hung, Le Dinh

 

 

 

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