Translations:Begriffsdefinitionen/5/en

All values necessary for the description of the system elements and their flow relations are summarized under the term system data (arrangement of the system elements, parameters and characteristics). The system loads generate - using the system data - at the respective elements certain system states and resulting reactions. System states describe the momentary conditions within the system and are variable over time. States and reactions are clearly assigned to individual system elements. The terms parameter and characteristic values have different meanings. Characteristics are clearly determinable features of system elements, e.g. the geometry of a pipeline or the dam height of a dam. In the sense of simulation they are considered to be unchangeable, unless they are subject of an investigation. Parameters are also characteristics of system elements, but their unambiguous determination cannot be sufficiently achieved by measurement. These are quantities that can only be measured at points but are related to larger areas (e.g. kf-value of soils) or are representative for a multitude of natural processes, e.g. a retention constant for the description of the effluent concentration from a catchment area. They are subject to calibration and verification. The knowledge of characteristics and parameters is necessary to clearly describe the behavior of the system elements and thus the entire system behavior.