Abstract. The paper addresses the problem of rapid response to flood events, which frequently occur in the territory of the Republic of Kazakhstan. The relevance of the study is determined by the lack of reliable and timely spatial data required for early flood detection and monitoring. The aim of the research is to develop and evaluate a crowdsourcing-based mobile information system for flood monitoring using data from the Global Navigation Satellite System (GNSS). The object of the study is the process of collecting and processing spatial flood data, while the subject of the research focuses on mobile data collection methods based on the citizen sensing concept. The methodology includes the design and development of a mobile application for the Android operating system, integration with the Global Navigation Satellite System Application Programming Interface (GNSS API), and photo documentation using standardized image metadata (Exchangeable Image File Format, EXIF). As a result, an integrated architecture of a flood monitoring information system has been developed. The proposed architecture consists of a mobile application, a server-side module for data storage and processing, and a web-based control panel for emergency management services. The mobile application provides automatic coordinate acquisition with an accuracy of 8–12 m, geotagging of photographic data, and input of contextual information such as water level and terrain type. The results of a local pilot experiment demonstrate that the proposed system is practically applicable for early flood detection and supports timely decision-making and emergency response under the conditions of Kazakhstan.

Keywords: Global Navigation Satellite System, crowdsourcing method, mobile system, citizen sensing, flood monitoring, information system architecture.