Using earth observation for national high resolution dynamic material stock modelling through time; Assessing sand consumption in Malaysia from 1989 to 2020

Understanding the spatio-temporal dynamics of volumes of construction materials is becoming crucial for environmental sustainability and achieving long-term development goals. This study presents a new methodology for quantifying national-scale material stocks in Malaysia using high-resolution Earth Observation (EO) data. The study includes construction materials; sand, crushed rock / gravel, bricks, tiles, and cement but particular focus is given to sand as it generates the greatest risks to the supply chain, the most significant environmental and social impacts and exhibits the most persistent data gaps. The approach of the study integrates EO-derived building footprint and elevation data with deep learning-based classification of building types and ages. Material Intensity coefficients, adapted from regional literature, are applied to estimate material volumes across ~ 9.1 million buildings. Modelled results have been compared to reported national level data. Results reveal that modern Malaysia’s building stock has consumed approximately 5.8 billion tonnes of construction materials. Modelled sand consumption shows a good correlation to reported production, improving on existing proxies such as cement production, but only when transport and major infrastructure projects are factored in, demonstrating the complexity and requirements for location specific knowledge for building models for construction material use. This methodology offers a scalable, mechanism for capturing often incomplete data for material construction material flows with a high spatial and temporal resolution. This is particularly valuable in regions with a high degree of underreporting in the extraction sectors. It supports evidence-based policymaking for resource governance, circular economy planning, and mitigation of impacts from primary resource consumption.