OR/18/068 Project approach

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Bide, T P, Brown, T J, Petavratzi, E, and Mankelow, J M. 2018. Vietnam – Hanoi city material flows. Nottingham, UK, British geological Survey. (OR/18/068).

The project scope[edit]

The questions outlined in Objectives of the research project are the starting point of this project. In order to develop a methodology that can provide sufficient answers, additional clarifications to these questions have to be given. This can be achieved by following a method developed by the EU H2020 MICA project on the ‘Integration of data, methods and expert knowledge to inform mineral intelligence’ (Van der Voet, 2017[1]).

Questions 1 and 2 are assessed individually and flowsheets are produced that provide a pathway to reaching a valuable answer. An overview of the key system components and the boundaries of the analysis is provided in Figure 1.

Figure 1    Overview of system components and boundaries.

Question 1: What are the construction material requirements in Hanoi to meet the predicted urban expansion?

The first step in this method requires the translation of the principal question into a series of refined questions. To do so the boundary conditions of Question 1 are first identified.

Table 1    Boundary conditions of Question 1.
Boundary category Boundary condition
Commodities Construction materials
Process chain (activity) Mining and quarrying; material/product manufacture
Impacts Economic
Spatial (activity) City level (Hanoi)
Spatial (impact) The spatial impacts of the urban expansion in Hanoi and the demand for materials may be at city, regional and national level
Temporal (activity) Future — investigating future urban development impacts
Temporal (impact) Future
Flows and stocks Import, export, production, consumption

When assessing the information given by the initial principal question, it becomes clear that uncertainties about the commodities to be included in the analysis and the time horizon to be considered exist. In addition, the question asks for an assessment of construction materials supply and demand and an investigation of the urban growth foreseen for Hanoi. Question 1 can be broken down into sub questions that frame the scope of this project better and enable the development of a methodological approach. The suggested sub-questions are:

1.1 What construction materials are used in Hanoi and in what applications? Of these, what are the commodities included in this research and what are the construction projects considered in the analysis?
1.2 What are the historic trends of construction materials use in Hanoi?
1.3 What urban expansion is foreseen in Hanoi? Are there any forecasts for the urban growth in Hanoi?
1.4 What is the time horizon considered in this project?

Sub-questions 1.1 and 1.2 require an assessment of the availability of data on construction materials at city, regional and national level and an investigation of the construction material consumption trends in Hanoi. Answers to sub-questions 1.1 and 1.2 can be provided by exploring the national statistics on construction minerals.

Sub-question 1.3 requires the assessment of relevant information and data related to urban planning. As a starting point, answers to this question can be provided by desk-based research. Depending however on data availability, stakeholder engagement with urban planners in Vietnam and researchers in Vietnam involved in this subject can provide additional insight.

Sub-question 1.4 requires determining the time horizon of the analysis. This is driven initially by data availability.

There are different ways to answer Question 1 depending primarily on data availability. The flowsheets in Figure 2, Figure 3 and Figure 5 summarise three approaches that provide in detail the data (squares) and methods (yellow circles or mathematical symbols) that are required to reach an answer. These are:

  • Top-down approach to quantifying supply and demand (Figure 2).

This includes the calculation of future supply (left hand side) based on mineral production trends and population growth trends and forecasts. The calculation of future demand (right hand side), projects apparent consumption figures based on forecasted population growth. The top-down approach is based solely on material flows and population statistics and does not take into account urban growth plans, building stock information etc. In that sense, it is much more ‘simplistic’ than the other two approaches presented below.

Figure 2    Schematic diagram explaining the steps involved in the top-down future supply and demand balance calculation.
  • Bottom-up approach to quantifying supply and demand (Figure 3).

Using this approach, the future supply calculation is the same as for the top-down approach in that it is based on mineral production data and projections of population growth. The future demand calculation quantifies material demand in new building stock and it requires information related to building types in Vietnam - building compositions and building floor area information from urban planning documents. This is a much more detailed approach to quantifying material requirements for new construction. It requires access to data that are not readily available for Hanoi, for example the material composition of average buildings in Vietnam, as well as extensive knowledge of how urban planning will evolve in the city of Hanoi, not just in terms of land use (where some data is available), but also with regards to changes in building and construction.

Figure 3    Schematic diagram explaining the steps involved in the bottom-up future supply and demand calculation.
  • Dynamic material flow analysis (MFA) of construction minerals in Hanoi

The dynamic material flow analysis comprises the best approach to obtain an answer to Question 1, as it allows for detailed quantification of the flows and stocks of construction materials in Hanoi. The simplified system describing the construction minerals cycle in Figure 4 presents some of the key flows and stocks available that require quantification to develop a material flow analysis. One of the first steps to be completed for developing a dynamic MFA model is the development of a system describing the Hanoi construction minerals cycle in detail. This requires in depth understanding of the construction sector in Vietnam as well as engagement with stakeholders from Hanoi, ranging from representatives of the construction and extraction industries to urban planners and policymakers. A dynamic model has the time dimension embedded in the analysis. It is possible therefore to evaluate how material flows and stocks change over time, both in past, present but also for predicting future material supply and demand (Figure 5). The dynamic MFA approach is much more detailed and data intensive than either of the top- down or bottom-up approaches, but at the same time it allows better forecast predictions to be made and supply disruption issues to be identified for the city of Hanoi; thus facilitating better informed interventions tailored to resolving specific supply disruption issues. The model could assist the Vietnamese government and Hanoi local authorities to make informed decisions about urban development without material related constraints and also to respond to potential challenges by having access to good supportive information.

Figure 4    Simplified system of the construction minerals cycle.
Figure 5    Schematic diagram explaining the steps involved in using dynamic material flow analysis to forecast future demand of construction materials in Hanoi.

Question 2: What are the implications of the future material demand requirements?

This follows from Question 1 and asks to identify the implications (if any) associated with future material demand. The implications may vary widely, for example, an increase in demand may lead to environmental impacts and health and safety issues due to intensive mining activities, or illegal mining and trade of construction minerals. Supply disruption due to constrained access to raw materials may result in increased prices for materials, a slowdown of construction projects and urban development, and an overall reduction of economic growth.

The boundary conditions of Question 2 are the same as Question 1. Answers to this question can be provided through two different routes:

  • Qualitative assessment of the overall impacts of future material demand through desk based research and stakeholder engagement.
  • Quantitative assessment of selected impacts attempting to develop an additional ‘layer’ in the material flow model. This will require extensive data gathering through engagement with Vietnam stakeholders, i.e. those listed in Appendix 2 - Organisations that may have data for materials flow analysis.

This report only represents a preliminary study of the material status in the city of Hanoi. It provides a top-down quantification of supply and demand and a qualitative assessment of the potential implications associated with growing material demand. A detailed investigation of data availability and gaps has been undertaken to support the present assessment and inform the future steps of this project.

References[edit]

  1. VAN DER VOET, E, PETAVRATZI, E, VAN OERS, L, and GUNN, G. 2017. Integrating data, methods and expert knowledge to inform mineral intelligence. http://www.mica-project.eu/wp-content/uploads/2016/03/D3.4_D4.4_Integrating-data-methods-and-expert-knowledge-to-inform-mineral-intelligence.pdf