One of the standard procedures in the hydrological analysis nowadays is the Digital Elevation Models

One of the standard procedures in the hydrological analysis nowadays is the Digital Elevation Models. From the result of DEMs, you may extract topographic parameters, such as drainage networks, slope, and basins, which are necessary for hydrological studies that are usually used in the simulation of hydrology. Hydraulic and hydrological models are dependent in the elevation model for accuracy of result. Due to the rapid evolution in the past decades, DEMs increases its accuracy. Satellite sensors in the visible, infrared and microwave ranges can be used to monitor rivers and to delineate flood zones, yet this method can only be used over the large rivers or areas that have been covered with flood in order to detect changes at the pixel level. Like all datasets and databases, DEMs have errors which are produced form the topographic parameters. From the existing DEMs, it is relevant to improve its accuracy of the drainage networks and other topographic parameters that have been extracted. There’s another type of geospatial information that is available for collection of data in collaboration with OpenStreetMap (OSM). Volunteer citizens have great contribution in creating vector data, using various data of available feature types, such as rivers, streets, buildings, or points of interest, that is represented by points, lines, and relations.