Application of analytical and digital photogrammetry methods for forecasting Vistula river floods

Modern flood forecasting methods are based on the use of detailed and up-to-date numerical maps and Digital Elevation Models (DEM). The largest Polish River, Vistula, floods its valley almost every year. The existing traditional maps in scale 1:10000 are outdated and not suitable for the purpose of flood forecasting.The described mapping project, initiated in Spring 1999, deals with the elaboration of DEM and numerical maps for the 400 km long stretch of upper and middle Vistula river with required accuracy.Black and white aerial photography of the area has been acquired in two scales: 1:17000 for generation of DEM and numerical maps, and in and in scale 1:25 000 for generation of orthophoto maps in two periods: April and September, when the level of water was at its lowest. Signalized GCP’s have been measured in field with GPS methods. Aerial triangulation has been performed on analytical plotter Planicomp P-l Zeiss. Block adjustment has been done with the use PAT-MR- GPS Inpho and BINGO-F softwares with Sigma naught 6 pm. Numerical topographic maps in scale 1:10 000 have been elaborated according to map standards and recorded in DXF format in MicroStation environment. The same aerial photos in scale 1:17 000 were used for production of DEM with 25 meters grid and with accuracy in elevation mh = +/- 0.5 m.Aerial photographs in scale 1:25 000 have been scanned with pixel size 22.5 pm with compression by JPEG. Digital aerial triangulation has been performed on ImageStation INTERGRAPH with Sigma naught 8 pm. Scanned photos and highly accurate DEM have been used for generation of ortophoto - maps in scale 1:10 000, with pixel size in field 1 x 1 m. Additionally, the enlarged aerial photographs have been used for the elaboration of land cover and land use maps in MicroStation environment. All these digital data will be incorporated into GIS, to be used by flood forecasting specialists in Regional Water Management Office in Warsaw. This project have been accomplished by the Institute of Geodesy and Cartography and PPKG in Warsaw. MSWiA has awarded this project with 2nd price this year.