A conceptual modeling of database using UML-Geoframe to estimate the impact of land use and land cover changes in direct runoff
ISBN 978-85-88783-11-9
Authors
1Schafer, A.; 2Richa, C.
1FEDERAL UNIVERSITY OF PAMPA Email: alexandro.schafer@unipampa.edu.br
2FEDERAL UNIVERSITY OF PAMPA Email: cesarhuegel@live.com
Abstract
Currently one of the main problems related to water resources in developing countries is the impact resulting from the urban development. To minimize these impacts, it is extremely important to understand the consequences of the changes caused by urban development in the hydrological processes of a watershed and the integration of this understanding in planning the development. Monitoring is a key technique in this process Geographic Information Systems (GIS) have been widely used in matters involving monitoring. However, although GIS is a technology able to address problems involving the temporal aspect of the data, the question of how to represent the spatio-temporal dynamics in these systems was ignored until the late 1980s. An important issue in the search for the incorporation of the time variable in GIS is the conceptual modelling of data. As the GIS are not capable of processing information that is beyond the capabilities of representing their data models, geographical representation and data models are critical to improving query processing and analysis of geographic information. This paper presents the development of a conceptual model of a database that allows register and monitoring changes in watersheds over time and verifying the impact of these changes in runoff. The conceptual model was developed using UML-Geoframe modeling techniques. UML-Geoframe diagrams were constructed from the semantic analysis of the variables involved in the issue of runoff in watersheds using the Curve Number method of USDA 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. This conceptual model uses the model of representation of spatial data based on object and permits the representation of past, present and future events. Through the conceptual model proposed, it is possible to store the result of several simulations for a watershed, linking each simulation to a specific event and identifying what 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.
Keywords
CONCEPTUAL MODELING; DATABASE; WATERSHED