Sediment Dynamics for a Changing Future (Proceedings of the ICCE symposium held at Warsaw University of Life Sciences - SGGW, Poland, 14–18 June 2010). IAHS Publ. 337, 2010. 308 Integrated runoff-erosion modelling in the Brazilian Water Resources Information System (SNIRH) CELSO A. G. SANTOS, CRISTIANO DAS N. ALMEIDA, AMÍLCAR SOARES JÚNIOR, FRANCISCO A. R. BARBOSA, TIAGO F. SOUZA & PAULA KARENINA DE M. M. FREIRE Department of Civil and Environmental Engineering, Federal University of Paraíba, 58051-900 João Pessoa, Paraíba, Brazil celso@ct.ufpb.br Abstract This paper presents details of how part of the Brazilian Water Resources Information System (SNIRH) was developed. The work was carried out by four research networks made up of several Brazilian universities. One of these networks was responsible for the integration of rainfall–runoff models to the SNIRH. In order to integrate the rainfall–runoff models into the SNIRH, the OpenJUMP software was used as an interface to manage the input data and the simulation results. Among the selected models, there is a distributed runoff–erosion model named Kineros with a new friendly interface, in order to provide more detailed simulations exercises, allowing users to analyse the results easily. The model can import the rainfall data from SNIRH and separately simulate the runoff and erosion processes. Finally, this new tool, which integrates different hydrological models in a single base, can support the decision-making process for water resources in Brazil. Key words SNIRH; runoff-erosion modelling; Kineros; OpenJump INTRODUCTION Brazil has made several advances in the last 10 years regarding water resources planning and management. In terms of hydrological simulations, three distinct phases can be identified: development of models, integration of these models into Decision Support Systems (DSSs), and the coupling of Geographic Information Systems (GISs), as presented by Silva & Santos (2007). Nowadays, according to demands of the Brazilian Water Resources Information System, the new challenge is to consolidate all the available knowledge into a Spatial Decision Support System (SDSS). This paper presents details as to how part of the Brazilian Water Resources Information System (SNIRH) was developed. The work was carried out by four research networks made up of a group of Brazilian universities. One of these, Network 3, was responsible for the integration of rainfall–runoff models in the SNIRH. The selected models must deal with, amongst other issues, prediction of runoff levels and sediment yields, the impacts of changes in land use, and the estimation of water availability in ungauged basins. This paper presents the Kineros runoff-erosion model, which was integrated into the SNIRH using an Open Geographic Information System (OpenGIS). In this way, the whole SNIRH database is available for simulations and the results can, in return, feedback into the SNIRH system, if the Brazilian National Water Agency allows. The system is presented within a new user- friendly interface which displays and plots simulation results, and allows comparison between each simulation using statistical analysis. THE UNDERLYING BASIC SOFTWARE – AN OPENGIS It was decided to adopt a free and open source GIS platform because the Brazilian National Water Resources Policy stated that the code of this software should be accessible to anyone. In this situation, OpenGIS, i.e. an Open Source Free GIS, was selected and OpenJUMP (www.openjump.org ) was chosen as the basic program, which would be integrated with the rainfall–runoff models. This OpenGIS has been developed by the Geography Department of the University of Zurich in Switzerland, and it uses the JUMP core (JUMP, 2003), which was developed by Vivid Solutions © , a Canadian company. Copyright © 2010 IAHS Press