Data collected from the Baidu Migration Platform

The data come from the Baidu Migration Platform (https://qianxi.baidu.com), a platform for public use and access to big data. The dataset has been processed to remove all direct identifiers (e.g., names, addresses, IP addresses) and indirect identifiers (e.g., specific dates and locations have been aggregated to municipal-level or wider scales). No personal or group-level identities can be inferred from the data, which meets the requirements of the CC BY 4.0 license. This study does not involve human subjects or identifiable data, and all data usage complies with the platform's terms of service and relevant legal regulations.