José Ramón Hernández Santana

The state of the environment in Mexico

The present work evaluates the state of the environment in Mexico based on indicators of the present status of the country’s natural resource management, social and economical conditions and anthropogenic modifications. The Mexican environment is interpreted as a spatially open system having a historical character that is essentially determined by the continual interaction between nature, society and economy. The landscape approach is followed, considering as units of territorial analysis each one of the 145 biophysical environmental units included in the national physiographic regionalization. The assessment of 16 indicators for each biophysical environmental unit was made considering their regional environmental integrity problems, the degree of disarticulation of their structure and function, and the alteration of their territorial structure, all of which determine whether or not they accomplish their environmental functions and achieve environmental stability. The classification of the state of the environment included 5 categories in 8 combinations represented in the map of the state of the environment in Mexico for the year 2008. The map shows that nearly 47.10% of the country’s surface has an environmental status ranging between unstable and critical, the problematic areas being mostly concentrated in the southeast and center of the national territory.

Evaluación de la expansividad de los suelos en el reparto Hermanos Cruz, Pinar del Río, Cuba: una contribución a la planificación urbana

espanolLos suelos expansivos constituyen un peligro geologico, muchas veces desconocido para la poblacion, que puede afectar a las edificaciones y las infraestructuras. Para evaluar esta problematica del suelo, es necesario conocer algunas de sus propiedades geotecnicas. Generalmente, en las metodologias disenadas para este fin se emplean valores promedios de las propiedades de los suelos, de la formacion geologica o grupo litologico, aspecto que conlleva una gran incertidumbre. Para superar este problema, en la investigacion se propone un procedimiento para la estimacion espacial y modelacion de las principales propiedades del suelo que inciden en la evaluacion de su expansividad. El caso de estudio seleccionado comprende la localidad Hermanos Cruz, perteneciente a la Ciudad de Pinar del Rio en el occidente de Cuba. La investigacion se organizo en las siguientes etapas: evaluacion primaria del potencial de expansion de los suelos, modelacion de propiedades de los suelos utilizando los metodos geoestadisticos en 3D y, finalmente, representacion cartografica del potencial de expansion de los suelos sobre plataforma SIG a profundidades del subsuelo con importancia en la construccion de las cimentaciones superficiales de las obras ingenieriles. La aplicacion de este procedimiento al caso de estudio seleccionado revelo que los suelos del reparto Hermanos Cruz poseen un potencial de expansion bajo a medio y la existencia de sectores aislados con un potencial de expansion medio a alto. EnglishExpansive soils can be categorized as one of the geohazards observed in the urban environment, representing a silent hazard to buildings and infrastructure. To evaluate this problematic soil it is necessary to know some of its geotechnical properties. Generally, the average values of soil properties are used in the methods which characterize the geological formation and the lithological group, which causes a great degree of uncertainty. To overcome this problem, this study proposes a procedure for estimating and modelling the principle soil properties that have an impact on expansive soils. The selected case study is located in the Hermanos Cruz neighbourhood in the city of Pinar del Rio in Cuba. The investigation was organized into the following stages: primary assessment of the potential expansiveness of the soils, modelling of the soil properties utilizing 3D geostatistical methods and finally the cartographic representation of the potential expansiveness of soils on a Geographic Information System (GIS) platform at different depth zones which are of importance in the construction of shallow foundations of engineering works. The application of this methodology in the Hermanos Cruz neighbourhood revealed that its soils possess a potential expansiveness of low to medium, apart from some isolated zones which show a potential expansiveness of medium to high.

Ordenamiento ecológico general del territorio mexicano: enfoque metodológico y principales experiencias

El presente trabajo presenta los resultados del programa de ordenamiento ecológico general del territorio mexicano (caracterización, diagnóstico, pronóstico y formulación del modelo de ocupación sectorial). Para el análisis territorial y la evaluación del estado medioambiental actual, se empleó la regionalización ambiental biofísica de López-Blanco (2008), integrada por 145 regiones. El pronóstico contempló el análisis de conflictos y sinergias intersectoriales, la realización de talleres de consulta y validación, y la construcción de los escenarios contextual (2008) y tendenciales (2012, 2023, 2033). El modelo de ordenamiento ecológico territorial incluyó 5 niveles de atención prioritaria, 80 regiones ecológicas, 34 tipos de actividades rectoras del desarrollo, 10 lineamientos ambientales generales, 44 estrategias ecológicas y 273 acciones de implementación.

Geomorphic compatibility of agricultural land use in the upper basin of the Lerma River, Mexico

Abstract Please click here to download the map associated with this article. A method for assessing land sustainability that has emerged in recent years is the application of quantitative spatial indicators, using simple methodologies, and reliable data to determine and monitor trends, as well as to provide accurate cartographic representations. The present work defines geomorphic compatibility coefficients for agricultural land use in the upper basin of the Lerma River in Mexico. The methodology identifies geomorphic processes and, based on the lithologic susceptibility of the substrate and slopes, assesses their potential intensity. This analysis allows us to determine which areas are incompatible with agricultural land use, as a percentage of the total area of cropland in the zone under study, based on grouping geomorphic processes into different compatibility categories. The resulting coefficients are a valuable aid for land use planning and sustainable regional development, as they make it possible to identify areas in which existing agricultural land use is incompatible with the geomorphic processes active at the site.