Abstract:
Objectives Natural disasters in China are characterized by many kinds, wide distribution, high frequency, and high intensity, which often cause huge losses. Therefore, effective prevention of disasters, timely understanding of disaster information, and scientific reduction of disaster losses are of great significance to the safety of people’s lives and property. In the process of disaster prevention and control, emergency survey and mapping support mainly play an indispensable role through provide geographic information rapid mapping service. Emergency disaster rapid mapping is highly time-sensitive and generally requires services to be provided within a few hours or less, but conventional mapping methods are difficult to meet demand (1-2 days or even longer). Our purpose is to improve the efficiency of emergency mapping and to provide support for the rapidly emergency mapping service in different stages, including emergency rescue, disaster assessment, post-disaster reconstruction, etc.
Methods To solve the problem of randomness and efficiency of emergency mapping, three technologies were introduced: The knowledge decomposition and matching of rapid mapping for an emergency, the rapid and dynamic integration of emergency thematic data, and the adaptive fast mapping of multi-factor triggered mapping rules. The first technology decomposed knowledge of rapid mapping for an emergency to the symbol, label, rule of mapping, decoration and so on, and further subdivided them. So as to form the building blocks of cartography knowledge and provide components for building the cartography with specific needs, and to realize multiple associations and integrated storage of emergency data and mapping knowledge. The second technology integrated the natural language processing and word segmentation technology with the spatial information in the disaster information and proposed the spatial matching method of place names and addresses based on the statistical model, which realized the rapid integration of disaster information.The third technology took emergencies as the first driving mapping factor and map elements as the second mapping factor. By the spiraling means, it automatically determined the elements of map such as the location, range, map type, layout size, scale, projection, data source type, symbol and annotation, map conflict processing, and decorations step by step, to realize the automation of emergency map process.
Results With the support of the first two technologies, we constructed an integrated emergency mapping database, which includes various multi-level scale basic geographic information data, disaster data, emergency thematic data, symbols, mapping rules, and the strategy. Based on the integrated emergency mapping database and adaptive fast mapping technology of multi-factor trigger rules, the research and development of geographic information emergency rapid mapping system was completed, which could realize fast, flexible, automatic map production to meet the demands of rapid mapping of basic geographic information and emergency thematic information.
Conclusions The key technology and system of emergency rapid mapping achieve the goal of efficient mapping, which reduces the mapping time of a single emergency map to 10-15 minutes. It has been applied in the emergency support of mountain landslide in the Maoxian County, Jiuzhaigou earthquake, mountain landslide in the Milin Section of the Yarlung Zangbo River, and other emergencies, provided standardized and efficient cartographic services for disaster prevention and mitigation.