Caudal ecológico de ciertos ríos que descargan al Golfo de Mexico y al Pacífico Mexicano

Abstract

RESUMENUno de los grandes problemas que enfrenta el manejo del recurso agua en México es el desconocimiento de su variabilidad espacio-temporal. Dicho manejo se ha enfocado en el consumo humano y sus actividades económicas, sin considerar aquel volumen requerido para los ecosistemas y los servicios ambientales que finalmente redundan en la sustentabilidad. Dado lo anterior, las instituciones gubernamentales, académicas y organizaciones de la sociedad civil propusieron una metodología para determinar el caudal ecológico en una serie de cuencas consideradas como futuras reservas de agua, con impacto tanto para la conservación como para su recuperación. Con el empleo de esa metodología, este trabajo tiene como objetivo el estimar al caudal ecológico ordinario estacional (Qecol*) de varios ríos prístinos o con diferentes grados de impacto y con condiciones climáticas distintas, tanto de la vertiente del Golfo de México como del Pacífico mexicano. En las cuencas estudiadas del Golfo de México, se destacaron por su Importancia Ecológica "Muy Alta," con un porcentaje de caudal ecológico (Qecol*): Pánuco (74%), Papaloapan (78%), Grijalva (68%), Palizada (81%), y Candelaria (62%). Por el lado del Pacífico sobresalieron por tener la "Mayor Presión del Uso del Agua" y un porcentaje de caudal ecológico bajo, las cuencas de Culiacán (4%) y Tehuantepec (15%). ABSTRACTOne of the major problems being faced by the management of water resources in Mexico is the lack of knowledge about temporal and space variability. Management has focused on human consumption and its economic activities, without considering the volume required for ecosystems and environmental services that ultimately lead to sustainability. Governmental and academic institutions, as well as civil organizations, have proposed a methodology to determine the environmental flow in a series of basins considered as future water reserves, with impact both for conservation and recovery. With the use of this methodology, the present work aims to estimate the ordinary seasonal environmental flow (Qecol*) of several pristine rivers with different degrees of impact and with different climatic conditions, from both the Gulf of Mexico and the Mexican Pacific. The studied basins of the Gulf of Mexico were noted for their "Very High" ecological importance and environmental flow (Qecol*): Pánuco (74%), Papaloapan (78%), Grijalva (68%), Palizada and Candelaria (62%). On the Pacific side, due to the greater pressure for water use and a lower percentage of Qecol*, the Culiacan (4%) and Tehuantepec (15%) basins stood out. PALABRAS CLAVE caudal ecológico; cuencas; México; recursos hidrológicos; ríos; sustentabilidad ecológico KEYWORDS ecologic sustainability; environmetal flow; Mexico; hydrologic resources; river basins; water level CONTACT Guadalupe de la Lanza Espino gdlle@unam.mx Apartado Postal 70-233, Ciudad de México, México CP 04510

What Do Environmental Flows Mean for Long-term Freshwater Ecosystems’ Protection? Assessment of the Mexican Water Reserves for the Environment Program

“…Eflows from 278 EWR in 10 hydrological regions (HR) were assessed [32][33][34][35][36][37][38][39][40][41]: Lerm Santiago (HR code 12), Río Ameca ( 14 This novel frequency-of-occurrence-based approach for low flows and flood regime eflow components was also chosen because of its potential for managing freshwater and riparian species exposure to each-time-more intensely extreme conditions, and it contributes to addressing the non-stationarity challenge of the flow regime variability by managing resilience within the limits allowed by the biodiversity [11,22,[48][49][50][51][52][53][54]. Another reason for the selection of this method was because, among the desktop-based ones provided by the Mexican Norm, this reaches the highest detail of analysis and, therefore, it has been systematically implemented throughout the country; furthermore, consistency of outcomes has been proved when they were examined against a holistic method [21,[55][56][57][58][59][60][61]. Throughout the article, eflow assessment results from a holistic expert panel for the case of the Usumacinta river are presented to exemplify an evaluation in detail based on the Mexican Standard's Appendix F (Box 1 further in this Section; Boxes 2-4 in Sections 3 and 4).…”

State level water security indices in Mexico

“…There are recent Mexican official data about the environmental flows (E w as % R w ) for some of the 37 hydrological regions (HRs) in the country and their basins, however, which are determined according to Mexican standard NMX-AA-159-SCFI-2012 [30] establishing the environmental flow determination procedure in hydrological basins. These are HR 12 Lerma-Santiago [31], HR 14 Ameca River [32], HR 15 Costa de Jalisco [33], HR 19 Costa Grande Guerrero [34], HR 20 Costa Chica de Guerrero [35], HR 25 San Fernando [36], HR 28 Papaloapan [37], HR 30 Grijalva [38], and the Golfo and Pacífico Rivers [39]. For those regions where such data were not found, an E w value of 30% was assumed, according to official Mexican recommendations [40] and the results from [28].…”

Agua para la vida

“…Considerando la norma mexicana NMX-AA-159-SCFI-2012 (SE, 2012), cuya vigencia se estableció en el propio año (DOF, 2012): "Es la calidad, cantidad y régimen del flujo o variación de los niveles de agua requeridos para mantener los componentes, funciones y procesos de los ecosistemas acuáticos epicontinentales". Aunque los criterios establecidos en la norma han sido aplicados para algunos ríos importantes de acuerdo con su caudal, se han realizado estudios referentes a la misma en varias estaciones hidrométricas por el Instituto Mexicano de Tecnología del Agua (IMTA) y se refiere que integra a valoración social del agua en el ambiente para asegurar su disponibilidad para el consumo y bienestar de comunidades rurales (menores a 2,500 habitantes), el problema del desconocimiento de la variabilidad espaciotemporal de las corrientes de aguas superficial sigue vigente (Zorrilla et al, 2017;de la Lanza et al, 2018;PNUD, 2019).…”