A GIS- Based Material Stock-Flow Analysis of Antigua & Barbuda through the lens of the built and socio-economic environment

Abstract

Small island developing states (SIDS) in the Caribbean are centered around a service-based economy, where the built environment (or material stocks) functions as the backbone of their social and economic wellbeing. The sensitivity of island economies to both internal and external shocks and vulnerabilities leads to an important question: Can a small island developing state, such as Antigua and Barbuda be sustainable? In the midst of growing climate threats, SIDS have proven to be highly vulnerable to extreme weather events. As a result, there is an urgency to build resilience amongst these island states, with special focus towards the built environment. This research examines the adoption of a Geographical Information Systems (GIS) based methodological approach in analyzing the trends of material stocks (MS) and flows of critical construction materials (aggregates, timber, concrete, and steel) used in buildings on the island of Antigua & Barbuda (A&B). In a bottom-up stock-driven approach, GIS and census data are incorporated through the use of physical parameters pertaining to the building size, (material intensity, number of floors, and the gross floor area) as a means to conduct a material stock analysis. For 2004 the total MS in buildings was estimated at 4,698 kilotonnes (kt), equivalent to 58.5 tonnes per capita. The main construction material of the MS consisted of non-metallic minerals (2,898 kt), followed by aggregates (1,176 kt), steel (443 kt), and timber (181 kt). The gross addition to stock (GAS) from 2006 to 2017 equaled to 3,480 kt with an average of 348 kt of construction materials added per year. A sea level rise analysis aimed to assess the extent of vulnerability the built environment was exposed to on the island. Under a 2-meter rise scenario an estimated 198 kt of material stock would be exposed, equivalent to 4.2% of the island’s total MS. The tourism industry accounts for 80% of A&B’s GDP and experienced the greatest exposure of 19% of the coastal industry’s MS. This research emphasizes the extent of environmental and economic vulnerability and examines the role between the interrelationship of material stocks-flows-services in A&B, from a socio-economic and ecological perspective. This study makes a contribution by emphasizing the role that material stock accounts can play in understanding island sustainability through the development of disaster management risk information, providing insight to policy makers on resource use dynamics base on spatial analysis and adequate physical infrastructure planning.