Chapter 2, Conceptual Framework

D. R. Maidment
David G. Tarboton, Utah State University


When contemplating the development of a hydrologic information system (HIS), it is appropriate to define the role that this system is intended to play. One useful approach has been established by the geographic information system (GIS) community. Tomlinson (2003, p.3) states that “a GIS stores spatial data with logically‐linked attribute information in a GIS storage database where analytical functions are controlled interactively by a human operator to generate the needed information products.” This definition implies that all the information has been harvested and stored in a local database and is then available for analysis and interpretation. However, unlike GIS where the data are static and change little through time, a hydrologic information system is representing phenomena that are inherently dynamic and vary greatly through time, so some broader context for accessing information is needed.