IWRA Proceedings

AbstractThe Salaca River basin locates in North-Easter part of Latvia. The total drainage area of the river basin is 3421 km2 of which the Burtnieks Lake watershed occupies 62%. In Latvia the conceptual model METQ for the simulation of hydrological processes of the different size of river basins has been applied over ten years. The model METQ has many modifications. In this paper the analysis of mathematic modelling results on the basis of the last version METQ2007BDOPT for simulation of daily runoff and water level for the Salaca River basin are presented. In this study the Salaca River basin is divided in six sub-basins. To consider the runoff heterogeneity in runoff processes the sub-basins are divided in hydrological response units characterised by a relative homogeneity with respect to the most important parameters, which includes slope, vegetation and soil characteristics. Input data for the model are daily meteorological data. The model has calibrated and verified from 1961 to 2006. As one of the results the river discharge at eleven points and water level of the lake for the 46-year period has been simulated. To analyses the results of model calibration a statistical criterion R2 and a correlation coefficient r are used. Good coincidence between the observed and simulated daily runoff has obtained. The analysis of optimized parameters of the METQ2007BDOPT shows that the numerical values of the model parameters obtained for each sub-basin have reflected the geomorphologic conditions of studied drainage sub-basins.