Análisis probabilístico de la variabilidad espacio-temporal del humedal pugllohuma utilizando imágenes radar de apertura sintética de la misión sentinel – 1

Abstract

The study of environmentally sensitive areas and their ecosystem services has become a priority worldwide, especially in public institutions’ objectives that administer natural resources. The Pugllohuma wetland was chosen as the area of interest because it is in the Mica Quito-Sur system, which is one of the four water collection systems used in Quito’s drinking water network, and the conservation status of the wetland influences the hydrological cycle of the water that reaches Quito. It is located within the Antisana Sustainable Water Conservation Area in the Jatunhuayco River’s micro-basin, north of the La Mica system. The wetland and its surroundings had been commonly studied using optical remote sensor. However, the use of optical sensors is limited when cloud cover is greater than 60%. For this reason, in the last 5 years, there has been an increase in the search for techniques that allow permanent monitoring of this area. Therefore, the current research work used radar images to detect changes in the wetland’s water regime from 2017 to 2019 and the radar image classification process was accelerated by means of decision trees to perform supervised classifications. Thereby, the building of supervised classification models evidenced that Pugllohuma wetland’s space-time changes are governed by the day of the year, terrain elevation, atmospheric temperature, and precipitation. Also, the supervised classification results indicated that the wetland’s water table had a temporal distribution of a seasonal nature. So, the soil drought season takes place in January, February, and March, whereas high water tables were more frequent from June to September, and from November to December. Because of that, the area of interest showed its seasonal changes around the following distribution of the soil classes which were considered in the present work: 170 ha of dry soil, 17 ha of moist soil, and 7 ha of soil near saturation.