Evaluating the effectiveness of the stock utilization of transport infrastructure In Vietnam

10 Nguyen Thi Cuc EVALUATING THE EFFECTIVENESS OF THE STOCK UTILIZATION OF TRANSPORT INFRASTRUCTURE IN VIETNAM ĐÁNH GIÁ SỰ HIỆU QUẢ CỦA VIỆC SỬ DỤNG VẬT LIỆU XÂY DỰNG TÍCH LŨY TRONG CƠ SỞ HẠ TẦNG GIAO THÔNG VIỆT NAM Nguyen Thi Cuc University of Science and Technology – The University of Danang; cucnguyen@dut.udn.vn Abstract - Vietnam’s good performing economy is characterized by the rehabilitation and modernization of transport infrastructure. The large scale of construction activities for expansion and maintenance of the road network has required huge amounts of construction materials and posed environmental problems. In the attempt to support the development of sustainable transport in Vietnam, this study investigates the material stocks of road network and subsequently evaluates the effectiveness of stock utilization regarding its provided services. Based on the statistical data of sixty-one provinces/cities in 2014, the results show that, (1) nearly 2800 million tons of construction materials was stocked in the road infrastructure in Vietnam in 2014, (2) when evaluating the effectiveness of transportation infrastructure’s stock utilization basing on the relation between traffic flows and road stock, the urban areas, especially municipalities experienced the high value of service effectiveness indicators. The outcomes of this research are intended to assist the future development strategies, particularly the Green Growth Strategy in Vietnam. Tóm tắt - Sự mở rộng và nâng cấp hệ thống giao thông đóng vai trò quan trọng trong việc giúp nền kinh tế Việt Nam có những bước phát triển vượt bậc. Sự mở rộng về quy mô của hoạt động trong xây dựng và bảo dưỡng mạng lưới giao thông đã gây ra những vấn đề về môi trường cần được quan tâm. Với nỗ lực nhằm hướng tới sự phát triển giao thông vận tải bền vững, nghiên cứu này tập trung vào sự tiêu thụ và tích lũy vật liệu xây dựng trong mạng lưới đường bộ. Kết quả tính toán dựa vào số liệu của sáu mươi mốt địa phương vào năm 2014 như sau: (1) Lượng vật liệu tích lũy trong hệ thống đường bộ ở Việt Nam năm 2014 là xấp xỉ 2800 triệu tấn, (2) Khi đánh giá sự hiệu quả của việc sử dụng vật liệu xây dựng trong cơ sở hạ tầng giao thông Việt Nam dựa vào lưu lượng giao thông, các khu đô thị, đặc biệt là các thành phố trực thuộc Trung ương thể hiện tính hiệu quả cao. Kết quả nghiên cứu giúp các nhà quản lý hoạch định được các chính sách cho chiến lược phát triển Tăng trưởng Xanh của Việt Nam. Key words - Material stock analysis; construction materials; waste management; infrastructure Từ khóa - Phân tích tích lũy vật liệu; vật liệu xây dựng; quản lý chất thải; cơ sở hạ tầng 1. Introduction It is the ultimate goal of every economy to reach a certain degree of development and so for the last decade, global efforts to improve the low-income economies have results in unprecedented growth of economies. Tantamount to the growth of economies is rapid withdrawal and utilization of the materials and energy from the environment. While these resources provide the basic needs of the socio-economic system, the extraction, processing and utilization bring disturbance to the natural ecosystem affecting biodiversity, displacement, and wastes discharged to the environmental system. Anthropogenic material stocks require huge raw materials and energy to form and provide services to society. In 2015, a “Sustainable consumption and production” (SCP) has been recognized as one of the Sustainable Development Goals [1], patening the increasing environmental awareness of all countries, developed and developing alike, who are striving to promote the framework of actions and policies for a more efficient use of materials, a lower resource consumption and for decreasing environmental pressures. As can be seen from developed countries such as European countries and Japan, there are many policies toward more sustainable and efficient patterns of resources consumption and stock accumulation [2]. However, unlike its counterparts, the developing countries are still moving their first steps into the field of sustainable development goals. Demands on infrastructure and related services increase as people expect a higher quality of life and public services. There are many indicators for measuring services from transport by many kinds of perspectives and among them; some are taken into consideration from monetary perspectives. For transport services, passenger and goods flows, which are absolutely traffic data, are simply used as good indicators that show transportation service that the transport sector provides. For measuring the effectiveness of utilization of infrastructure, Santosa et al. [3] defined based on the ratio between output and outcome. Accepting stock existence as outcome of material accumulation, passenger flows, and goods flows are taken as the output of services. Currently, researchers paid more attentions to material consumption and environment problems of infrastructure construction. Hashimoto et al. [4] clarified the relationship between stock and flow for two stock types namely non- potential wastes and secondary resources. Tanikawa et al. [5] analyzed material accumulation over time in urban metabolism using four-dimensional geographic information system data. For the material stock studies related to infrastructure in Vietnam, Fishman et al. [6] are the only obvious studies that attempted to trace material stock accumulation by applying top-down method. This allows for analyzing the change of flow intensity, building time series material stock and even modeling the volume of future material. However, due to requiring a large amount of information and statistics regarding historical flows, its application on the global scale, especially in developing countries, is more difficult. That is a reason ISSN 1859-1531 - TẠP CHÍ KHOA HỌC VÀ CÔNG NGHỆ ĐẠI HỌC ĐÀ NẴNG, SỐ 5(126).2018, Quyển 2 11 why the measurement of stock quantities in these countries often relies on the second method namely bottom-up approach. Being one of large absorption sources of materials and energy, together with building stocks, transportation infrastructure’ stocks provide important services to society in Vietnam. The development of Vietnam’s transportation infrastructure, particularly roads, has contributed significantly to the economic growth and to regional development. The transport system in Vietnam relies highly on road transport that handles significant percentage of the country’s passenger movement and freight movement. In the recognition of its importance, transport sector investment of Vietnam has been focused on the road network development. Construction of such great amount of roadway network may cause increased resource consumption and associated environmental problems such as resource depletion. Indeed, since the consumed construction materials such as gravel, sand, and limestone for building and maintaining the road systems rely on the domestic production that is extracting from natural sources, the increasing consumption of these minerals obviously has affected the natural environment. Therefore, seeking the effective way to utilize infrastructure stock, reduce the material consumption and associated environmental impacts is very important to help policy- makers to formulate policies to realize the sustainable development. In this view thereof, this study of material stock accounts is conducted. Passenger flows and goods flows are taken as service indicators of traffic and used in finding the effectiveness of transport stock utilization. 2. Data and Methodology 2.1. Material Flow and Stock Accounts Figure 1. The system boundary of EW flows and stocks (being adapted from Eurostat, 2001) [8] This study is based on the Material Flow Analysis (MFA) approach, allowing account the volume of materials during their transitions into and out of the defined systems regarding time and space. Eurostat, the statistics division of the European Commission, has created the framework namely Economy-wide MFA (EW-MFA) [7] for either regional or national boundary. Not only introducing standardized systems of method to account material flows, EW-MFA also provides concepts regarding abbreviations, indicators and terminology in Material flows and stocks field. Figure 1 shows the key indicators using in this study as well as the relations between them. In which: (a) Material stock (MS): This indicator refers to the sum of materials in society in a given year. It is defined as the composition of all physical goods as well as amassed goods that are in wait to be used. Due to focus only on transportation infrastructure and construction minerals, this study considers only the in-used stocks of such type of infrastructure. In other words, those unused roads and railroads that have not yet been demolished will not be taken into account. (b) Domestic Material Consumption (DMC): This is classified as consumption indicator, referring to the total quantity of material input which is directly used by a national economy in a given year. (c) Gross Additions to Stock (GAS): This indicator refers to the additional annual stock to the human society in a given year. In the case of construction materials, there is usually partly amount of DMC becoming GAS with some below assumptions: - DMC is comprised of both raw, semi-manufactures, processed materials and final products. Therefore, only a certain percentage of this input flow is used on purpose. - This certain percentage does not become stocked without splitting for other types of consumption. - Since our scope is the category of construction mineral forming in used stocks, the materials that become waste during construction of those stocks will not take part in this study. (d) Removal from Stock (RS): This is an outflow indicator. It is defined as the stock that has been demolished and removed from the society. (e) Net Additions to Stock (NAS): It is classified as balancing indicator and is equivalent to the amount of GAS and demolished stocks in a given year. 2.2. Bottom-up Approach to Measure Material Stock of Roads Figure 2. Flowchart for the Estimation of the Material Stock of Roadways 12 Nguyen Thi Cuc The bottom-up approach is applied to estimate Material stocks of Roads. For the estimation of non-metallic materials stocked in road networks in Vietnam, we have applied the bottom-up approach (Eq.1). In this way, we estimate materials stocked in four different road types regarding pavement including asphalt, stone, mixed stone and soil, soil roads. Figure 2 illustrates the flow diagram for the calculation of the stock per material utilized in the road system. MS𝑖,𝑗 (𝑡) = A𝑗(𝑡) × I𝑖,𝑗 (Eq. 1) Where: A𝑗(𝑡) is the total area of specific road category j at year t. I𝑖,𝑗 (𝑡) is the material intensity of material i in specific road category j. 2.3. Data Sources 2.3.1. The regional length of roads To quantify in physical terms of road infrastructure, this study uses data regarding the total lengths of roadways derived from reliable national data sources (General Statistical Office) for the year 2014, at provincial level. 2.3.2. Material Intensity This is the important indicator affecting material stock accumulation. The material intensities for the above- mention road categories are estimated based on the Standard Specifications for Construction which is provided by Vietnamese Ministry of Construction in 2007 [9]. Due to the lack of reliable material intensity data for the previous years of 2007, it is assumed there is no change of this data over the studied period. It meant that material intensity data in 2007 is applied to calculate material stock of roads in Vietnam for the year 2014. Table 1. Material Intensities of Roadways in Vietnam No. P a v in g t y p e Material intensity (kg/𝒎 𝟐) for roads in Vietnam Surface layer Base layer S to n e S a n d A sp h a l t S to n e S a n d C em en t 1 Asphalt 210 5 1,530 97 2 Stone 330 40 1,800 3 Mixed stone and soil 215 74 2,070 4 Soil 1,680 3. Results and Discussions In-use stocks of construction materials in roads are estimated for the year 2014 at the regional level for 61 Vietnamese provinces/cities. This study does not consider Tay Ninh and Binh Duong provinces due to lack of data. In 2014, the total material stock accumulation in roads in Vietnam was 2,827 Million tons (Mt). Figure 3a presents material stocks in 2014 at the provincial level. The significant amount of material stocks of the year are concentrated in the provinces/cities that are socio- economic zones and included high densities of industrial zones, big airports or seaports. a) Material Stock of Roads in 2014 b) Service Effectiveness Indicator (SEI) For Goods Flow, national average SEI = 20 tkm/ton For Passenger Flow, national average SEI = 42 pkm/ton Figure 3. a) Material Stock of Road in provinces in 2014; b) Service Effectiveness Indicator (SEI) for Goods Flow and Passenger Flow ISSN 1859-1531 - TẠP CHÍ KHOA HỌC VÀ CÔNG NGHỆ ĐẠI HỌC ĐÀ NẴNG, SỐ 5(126).2018, Quyển 2 13 The Service Effectiveness Indicator offers some interesting facts to be observed. Although accumulating higher material stocks of roads, most of provinces/cities in Northern Midlands and Mountain Areas, Central Highlands and Mekong River Delta experienced the low Service Effectiveness for goods flows and passenger flows (Figure 3b). Considering the municipalities including Ha Noi, Hai Phong, Da Nang, Ho Chi Minh City, Can Tho, it is found that those provinces/cities had high effective levels of stock utilization. The huge traffic volume regarding passenger and domestic cargo transport reflects the more effective utilization of roads in such areas. Nevertheless, the lifespan of road stocks would be reduced due to the high carriage, leading to the need of building new roads for the replacement. Apparently, not only the huge amount of construction cost but future raw material consumption, energy and water usage will be consumed for the process of maintaining and building new roads. The importance of long-lifespan infrastructure stocks in developing sustainability has already been mentioned in some literature [10, 11]. Therefore, although getting high SEI regarding material usage perspective, those municipalities have faced challenges regarding traffic congestion and decrease of road stock quality. The authorities should accordingly consider suppressing traffic flows to other sub-transport sector for slowing down the deterioration process so that the service lifetimes of existing road stocks would be prolonged. 4. Conclusion This study has assessed the material stocks related to construction of the Vietnam road infrastructure for year 2014. Planning to become a fully industrialized country by 2020, Vietnam has experienced a sharp increase in construction activities since the beginning of the XXI century. This has led to a rapid growth of extraction and consumption of construction minerals, as well as an increase in road material stock. Despite the very limited data available at a regional level, we have been able to show the difference of stocks as well as their service effectiveness in the provinces of Vietnam, which is useful to tailor future local environmental policies. An efficient transport infrastructure is indispensable to foster socio-economic development. Nevertheless, the ever increasing extraction and consumption of construction materials poses serious environmental threats. The government of Vietnam needs to take strong action to make sure that its construction minerals which are supplied through a sustainable chain will limit environmental impacts. Acknowledgement This research was financially supported by the Environment Research and Technology Development Fund of the Ministry of Environment, Japan. The authors gratefully appreciate the fund support that made it possible to complete this study. REFERENCES [1] L. Akenji, M. 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