índice de Estado Ecosistémico de Barrancas (IEEB); una metodología para evaluar barrancas urbanas

Abstract

The ravines are characteristic geological formations of the city of Puebla and other cities of the Central Highlands of Mexico. Currently, they are suffering degradation processes, that risk their viability. Actions like disposal of solid and liquid pollutants, irregular human settlements, extraction of stone materials, deforestation, invasion of exogenous specimens and overgrazing, among others are common, despite the evidence that has shown that urban ravines provide ecosystem services to the city such as: erosion control and soil formation, flood control, aquifer recharge, refuge and habitat for resident and migratory species, and regulation of the local and global climate, among others. For a city like Puebla, with a lack of wooded spaces and ecological conservation areas, the ravines constitute the few spaces with the potential to contribute to reducing this deficit. Hence, it is necessary to act towards their recovery and conservation. For this reason, it is necessary to generate methodologies that provide information about them. The objective of this work was to develop a methodology for evaluating urban ravines, since it doesn´t exist, that provides information on the ecosystem state in which they are found, as well as testing this methodology in two city ravines. Through qualitative multicriteria techniques, a simplified diagnostic methodology was designed, which makes up the Ravines Ecosystem State Index (RESI), which was applied in the Malinalli and El Conde ravines. The RESI was made up of nine indicators, whose central axis is the evaluation of the woody forest component, as well as other elements typical of the anthropic presence. According to the RESI, the Malinalli ravine presented an excellent ecosystem state, while the El Conde ravine a poor condition, according to a proposed scale of five values. The application of the index allowed observing the independent behavior between the indicators, their ability to describe the conditions of the ravines and their sensitivity to their ecosystem differences. As well as to contrast the conditions of the ravines, as a product of the anthropic activity in the sites.