Photomap producing for wenchuan earthquake disaster emergency

Photomap,as a kind of map that integrates the map with the remote sensing image,has the advantages of both images and Line symbol maps and is the composite of multi-source spatial data.As a formation of map product,image-rich detailed photomap can provide fast and practical geographic information for many industries and communities,and direct its current and potential application in fields such as urban planning,infrastructure construction,disaster prevention and mitigation,environmental protection,agricultural planning,information management and national defense.Therefore,it is essential geospatial information.The Wenchuan photomap productions need to use the photogrammetric information of the earthquake-stricken area and high-resolution satellite remote sensing images.Using the photogrammetry and remote sensing technology,it needs to rapidly produce the orthoimages of the disaster areas,and moderately overlay 1:50000 core elements of the earthquake-stricken area to form sub-county wall photomaps,the region-wide photomaps of 1:25,000-scale and the urban and regional focus photomaps of 1:5000-scale.It can provide geographic information services in a timely manner for post-disaster damage assessment,disaster monitoring and survey,planning,and post-disaster reconstruction work.During the period of disaster emergency,according to the "producing as well as the application" principle,in only a month it has completed the production of 98 county photomaps of the 95 counties of whole coverage,the 2653 photomaps of 1:25,000 scale covering 95 counties and the 2114 photomaps of 1:5000 scale of key areas.They are being provided to the affected areas and government departments,and has played an important role in the analysis of the disaster assessment,planning,and post-disaster reconstruction work.Comparing with traditional types of ordinary maps,thematic maps and the comprehensive maps,photomap has not only the features of the traditional map,using the computer graphics technology,but also a large number of remote sensing image processing technology.It has a new production requirement for the content structure,the means of expression and the production process.