A Conceptual Modeling of spatio-temporal database to Estimate Runoff Changes in Urbanized Watersheds

Abstract. This paper presents the development of a conceptual model of a database that allows the monitoring of changes in watersheds over time and verifies the impact of these changes on runoff. The conceptual model was developed using ER modeling techniques. ER diagrams were constructed from the semantic analysis of the variables involved in the issue of runoff in watersheds using the Curve Number method of Natural Resource Conservation Service. The conceptual model was developed based on the concepts of states and events, and the use of time as a basis for organizing spatial data allowed to record the time and place of any changes. The model of representation of spatial data based on object was employed. Through the proposed conceptual model, it is possible to store the results of several simulations for a watershed, linking each simulation to a specific event and identifying which scenario is valid at the time. Thus, it is possible to identify quantitative changes related to runoff over time and relate them to the events that caused them and the entities involved in such events. The conceptual model supports the existence of alternate realities, allowing the simulation and comparison of past and future scenarios.