## 4 Results and Discussion  
A strategic framework for integrated river basin management applies decision support tools in the form of hydrodynamic modeling, to ensure flood prevention and reduction of flood risk. The qualitative aspect of the input data shows the sensitivity of a given model to changes in the data quality condition. As a Member State of the European Union Slovakia implements directives [64; 65] in its national legislation Act on flood protection [66] (The Act No. 7/2010 on flood protection was updated on 1 January 2018). The adopted legislative framework generates some flexibility for defining the parameters of spatial data quality evaluation. Spatial data providing the basis for modeling of flood incidents are most commonly obtained because of systematic collection based on recommended surveying procedures and methods. The standard of their qualitative level for water management is partly governed by the legislation. The acquisition and portrayal of geodetic data in the Datum of Uniform Trigonometric Cadastral Network and Baltic Vertical Datum--After Adjustment coordinate systems is a mandatory requirement. The purpose and level of detail of the set of spatial information are dependent on the degree of terrain ruggedness. In this study, the detailed surveys for the needs of hydrodynamic modeling were related to the survey of all important objects along the river and in its close surroundings. All information obtained was directly connected to the appropriate river km (r. km), given in the water management map. The achieved quality of geodetic survey and passpertization of all important water management objects appertaining to the watercourse and its surroundings is satisfactory for the given purpose of processing. The presented qualitative analysis of the chosen method of data acquisition, in fact, confirmed the expected result. The presented group of deviations in the real spatial error incurred in determination of each point's position (close to the limit value) relates to the group of points for which the sky was  
Figure 11: Example of hydrodynamic model generated for selected part of Presov city: map showing maximum flow depths for level Q100. partly obscured during measurement, for example by surrounding vegetation (Figure 4). The average spatial error of determination of each point's position was calculated as 0.017 m.  
The result of statistic processing (Figures 5-7) confirmed the expectation that the RTK measurement of the detailed points is not homogeneous in terms of accuracy. The accuracy of determining the spatial position of a point varies over time depending on the satellite distribution. This is quantified by the Position (3D) Dilution of Precision (PDOP), a satellite configuration with a smaller PDOP (2 or 3) results in a more accurate determination of the point spatial position. Accuracy in the position determination may be further reduced by shielding the signal from satellites at points near trees, buildings, or other obstacles that ultimately have a non-random character. The results confirm that regarding the qualitative aspect, it is sufficient to carry out data acquisition of spatial information using GNSS technology using the RTK method for the needs of water management practice. For water management purposes in the Slovak Republic, the satisfactory positional and vertical accuracy of determination of each point's position in space is guaranteed by the SRTPS service. The usability of DMR as a basis for hydrodynamic modeling is indisputable in the next stage of assessment. DMR is an important basis for the entire modeling process. The level of its quality (accuracy of the model) is the key requirement for achieving relevant results comparable with reality. The assessment of the qualitative aspect was based on a set of recommendations arising from the technical standards for assessment of the quality of spatial information. Data integrity, logical continuity, positional, temporal, and thematic accuracy were among the assessed quality indicators.