Identificación de espacios inundables mediante evaluación multicriterio y sistemas de información geográfica en la cuenca del Río Chone, provincia Manabí.

Abstract

This research work deals with the multi-criteria evaluation and geographic information systems for the identification of floodplains in the Chone river basin, Manabí province, in which zones susceptible to flooding are established. This study was carried out using geotechnologies, the ArcGIS 10.4.2 program was used as the main tools for the processing and analysis of the information; as well as the official cartography. The methodology began with the selection of the variables considering all the aspects that can be related to the physical environment, their importance in the development of the phenomenon and the availability of official digital cartographic information (shapefile) for the study area. The variables chosen were: slope of the terrain, permeability, geoform, size of the materials with which the index maps were elaborated under the Universal Transverse Mercartor projection (UTM), georeferenced to the WGS84 datum for zone 17S, then for the superposition of variables, a relative weight was assigned to each variable indicator in order to obtain the weighted specific susceptibility map.Both the variables and the indicators were assigned relative values ​​according to their importance using the additive compensatory technique which is based on the Method of Analytical Hierarchies of Multicriteria Evaluation, this method proposes the use of a contrast matrix between pairs, where the number of rows and columns will be determined by the variables or indicators to be weighted; which will be compared to define if one has greater weight than the other (aij), and then proceed to determine the eigenvector which is the main vector establishing the weights (wj) and the eigenvalue that creates a quantitative measure of the correspondence of the value judgments between pairs of variables or indicators. The susceptibility maps were obtained from the previous reclassification of the indicators. At the end of the previous stage, the final susceptibility map was created once the relative weights had been assigned according to expert judgment, a modified algorithm was designed.