Geomatic techniques to analyze the loss of urban wetlands in Bogotá. What role do illegal settlements play?Técnicas de análisis geomático en la pérdida de humedales urbanos de Bogotá. ¿Qué rol juegan los asentamientos ilegales?

Abstract

© 2022, Revista de Geografia Norte Grande. All rights reserved.Urban wetlands are supplied by the rainwater system and store large amounts of water for their vegetation and hydromorphic soils, while contributing to the regulation of flows in cities, however, they have been affected by urbanization processes. As is the case of the Bogotá wetlands, which are invaded by illegal settlements affecting environmental preservation areas, so studies are required to analyze: urban growth, and the trend of rainfall. The urbanization analysis techniques are calculated from the Normalized Built Difference Index (NDBI), which integrates the combination of satellite images for its de-termination. The rainwater trend is analyzed from the IDF curves (intensity-duration-fre-quency). The results show that the wetlands are invaded on average by 7.5% in the city. With regard to the intensity of rainwater, it is mainly concentrated in the eastern hills of Bogotá and due to the effects of runoff, the flow of water runs from east to west, reaching the main wetlands and lakes. Then the information is validated with the calculation of the Normalized Difference Water Index (NDWI), which shows high concentrations of humidity in the western part of the city.