Using Techniques of Mathematical Morphology and Digital Image Processing in Extracting Contours to Determine the Decrease in Reservoir Area of Water Supply for Cities

Due to the representation of the environment, the map must accompany the changes happening in the real world. To detect these changes, it is necessary to keep cartographic products updated.There are many techniques available for this task and the ones performed in this work were combined with the Remote Sensing Digital Image Processing (DPI).. In this work, we used the theory of Mathematical Morphology to extract the contour of a dam in the state of Sao Paulo to demonstrate a decrease in the volume of water and the consequent problem of water in the municipality of Sao Paulo and its surroundings supply. It has been chosen as the features of interest, two sub-images Landsat 8.One image was taken before the drought and the other during a normal rainy season;the dams are located around the city of Sao Paulo - SP - Brazil. The aim of this study was to indicate a more appropriate morphological routine to extract the outline of the calculation aiming dam of the reservoir area at two different times, normal and very dry adverse conditions. The results were interesting and confirmed the potential use of morphological tools in feature extraction that can be used in the process of updating of cartographic products and assisting in planning decision making.