Urban Crowd Density Prediction Based on Multi-relational Graph

Urban crowd density prediction, which predicts the future crowd density in different areas based on the historical data, is playing an increasingly significant role in epidemic prevention and traffic optimization. Most existing methods model the spatial information through a single relationship, i.e., distance, and extract the temporal information only by short time sequences, which limits the model to fully capture the spatiotemporal information. Therefore, in this paper, we propose a Multi-relational Graph Convolutional Gate Recurrent Unit (MGC-GRU) model to represent the spatiotemporal information more comprehensively for better urban crowd density prediction. Specifically, we first construct a multi-relation urban area graph to enrich the spatial relationship between areas. Then a graph representation module based on a multi-relational graph convolution network is proposed to represent spatial information of the area, in which aggregator distinguishes the information of different relationships and propagator equips the self-attention mechanism to refine the representation. Afterwards, we further construct a fine-grained sequence prediction module to enhance the temporal dependency by modeling time sequences in different granularity, i.e., daily and hourly. Finally, extensive experiments on a real-world dataset demonstrate the superior performance of MGC-GRU on urban crowd density prediction task.