Geoscience Reference
In-Depth Information
Model Generalization of the Hydrography
Network in the CARGEN Project
Savino Sandro, Rumor Massimo, Canton Fabio, Langiù Giovanni,
Reineri Marco
University of Padua, Department of Information Engineering
via Gradenigo 6/B 35131 Padua, Italy
sandro.savino@dei.unipd.it
Abstract
This paper will present a complete process for the generalization of a
hydrography network. The process was developed in the Italian CARGEN
project, that aims at the generalization of geodatabase data from 1:5000 to
1:25000 scale. The model generalization process relies on the data enrich-
ment of the input model that allowed to re-classify the data according to
the output model and to drive the selection assessing the importance of
each river. The information gathered is the river width, the Strahler order,
the flow direction, the longest path to the furthermost source, the length,
the number of branches uphill and the density. The paper will describe
how the width of each river was measured, how the classification of the
rivers was harmonized, how the flow direction was calculated from the z
coordinates, the reconstruction of the river courses and the algorithm for
the selection of the rivers both on length and density thresholds.
1- Background and objectives
In 2006 the Department of Information Engineering together with the local
government Regione Veneto started a research project to investigate the
problem of cartographic generalization. This project, called CARGEN
(CARtographic GENeralization), enjoyed the collaboration of the Italian
NMA, the IGMI (Istituto Geografico Militare Italiano). The aim of the
CARGEN project is to develop algorithms for the cartographic generaliza-
tion of the IGMI geodatabase DB25 in 1:25000 scale starting from the
regional geodatabase GeoDBR in 1:5000 scale.
