Environmental Effects of Aquifer Overexploitation: A Case Study in the Highlands of Mexico

There are several environmental processes occurring under aquifer overexploitation conditions. These processes include groundwater table decline, subsidence, attenuation and drying of springs, decrease of river flow, and increased pollution vulnerability, among others processes. Some of these effects have been observed on the Upper Basin of the Lerma River. The Lerma River begins in the SE of the Valley of Toluca at 2,600 m asl, in the wetland known as Lagoons of Almoloya del Rı´o. This wetland is made up of a group of lagoons, which are an important aquatic system from an environmental point of view. The water inflow of this wetland is a discharge of springs, which occur between the fractured volcanic material of the mountain range and granular volcanic– continental deposits of the Valley of Toluca aquifer. The intensive exploitation of the Valley of Toluca aquifer to supply urban and industrial wáter to Mexico City and Toluca began in 1950 and is responsable for a steady decline of piezometric levels of 1–3.5 m/yr. Other effects of this exploitation—the drying of the wetland, the decrease of river flow and the land subsidence— caused serious ecological and social impacts. The authorities declared this aquifer as overexploited in order to reduce the exploitation and preserve the availability of wáter resources in this important región

Abastecimiento de agua potable para pequeñas comunidades rurales por medio de un sistema de colección de lluvia-planta potabilizadora

In this paper is showed the design of a system of drinking water supply for small rural communities trough rainfall collection-treatment plant. The design of the developed treatment plant considers a consumption of 60 1/h/d. In this work the following characteristics have been retained as the representatives for a rural comunity: £ 200 inhabitants; lack of potable water and electrical energy; to count on the possibility of supplying themselves of surface water under specific topographical conditions that they diminish the requirements of energy in the purification process. The rainwater harvesting represents a frequent scene in Latin America, and the proposed process of purification considers devices of low cost and easily operation.In this paper is showed the design of a system of drinking water supply for small rural communities trough rainfall collection-treatment plant. The design of the developed treatment plant considers a consumption of 60 1/h/d. In this work the following characteristics have been retained as the representatives for a rural comunity: ≤ 200 inhabitants; lack of potable water and electrical energy; to count on the possibility of supplying themselves of surface water under specific topographical conditions that they diminish the requirements of energy in the purification process. The rainwater harvesting represents a frequent scene in Latin America, and the proposed process of purification considers devices of low cost and easily operation

Usos sociales del agua y medio ambiente en la cuenca internacional del río Colorado

en este artículo se analiza cómo se relaciona la trasfor-mación de los usos sociales del agua con los cambios en lasformas de establecer el vínculo hombre-naturaleza. Se hanmodificado los conceptos y las ideas sobre qué debe hacersecon los recursos naturales, por lo que la forma de aprove-charlos, discutir y hacer propuestas sobre ellos cambia, alenfrentarse a los problemas de manera diferente. Esto seilustra con la corriente internacional del río Colorado, quecon frecuencia se ve como uno de los cuerpos de agua quemayores conflictos ha generado en el sigloxxy que, paraalgunos, puede ser uno de los puntos más importantes deestrés hídrico en los años siguientes

Territorial approach to increased energy consumption of water extraction from depletion of a Highlands Mexican aquifer

This work proposes a method to estimate increased energy consumption of pumping caused by a drawdown of groundwater level and the equivalent energy consumption of the motor-pump system in an aquifer under intensive exploitation. This method has been applied to the Valley of Toluca aquifer, located in the Mexican highlands, whose intensive exploitation is reflected in a decline in the groundwater level of between 0.10 and 1.6 m/year. Results provide a summary of energy consumption and a map of energy consumption isopleths showing the areas that are most susceptible to increases in energy consumption due to pumping. The proposed method can be used to estimate the effect of the intensive exploitation of the Valley of Toluca aquifer on the energy consumption of groundwater extraction. Finding reveals that, for the year 2006, groundwater extraction in the urban zone required 2.39 times more energy than the conditions observed 38 years earlier. In monetary terms, this reflects an increase of USD$ 3 million annually, according to 2005 energy production costs

Estimación de pérdidas económicas directas provocadas por inundación. Aplicación de las curvas inundación-daños en países en desarrollo

Las inundaciones son los desastres causados por fenómenos naturales que más daños provocan a diferentes sectores, como son los de la vivienda, comercial, agrícola, turístico e industrial. Este último es un sector que sufre importantes daños, pero que no ha sido estudiado ya que se le consideraba como poco vulnerable y con capacidad de adaptación ante desastres naturales. La implementación de una metodología para calcular los daños directos tangibles en función de la altura de lámina de agua alcanzada vs daños económicos, permite tener estimaciones de las pérdidas económicas causadas por inundaciones. Este trabajo muestra el estado del arte e identifica las investigaciones referentes al cálculo de daños provocados por inundación y su aplicación en países en desarrollo como lo es México.Universidad Autónoma del Estado de Méxic

Sistemas de información geográfica (SIG) como herramienta en la estimación de la demanda de agua para uso urbano

de información geográfica. Este método proporciona una mayor precisión en la estimación de la superficie que abarca las zonas de suministro de agua potable pero, sobre todo, certidumbre en la cantidad de agua demandada debido al detalle que ofrece la información usada: las Áreas Geo-Estadísticas Básicas (AGEB).Para el año de estudio 2005, una comparación entre las estimaciones de la demanda de agua realizadas por el organismo operador del agua en Toluca, México y el presente método utilizando las AGEB‟s concluyeron que problemas como una distribución inadecuada del agua puede ser resuelta por medio de este método utilizando representaciones espaciales de la demanda proyectada. Además el monitoreo sobre el gasto de agua proyectada y suministrada permitirá un análisis sobre la dotación requerida por tipo de consumo y su reducción dentro del marco de cultura de ahorro de agua

Definition of critical hydrodynamic conditions for sediment motion initiation using optical technique

Sediment motion initiation experiments were performed in a glass rectangular channel, with a loose bed in the central part. The main goal is to obtain the critical hydrodynamic characteristics that causes sediment bed motion initiation, for different cohesionless sediment grain sizes. The optical technique of Particle Tracking Velocimetry (PTV) was used in order to determine the critical velocity profiles for sediment initiation of motion. Between the parameters that define this critical velocity profile is the one known as bed rugosity which represents the height of asperities in the bed. For conditions near bed motion initiation experimental velocity profiles were obtained and they allowed us also to define fluctuating velocities u´, v´ and a value of bed rugosity ks related to a representative grain size of the bed. It was shown that obtained critical velocity profiles are in good agreement with other works in the scientific literature provided an appropriate definition of bed rugosity is made.Universidad Autónoma del Estado de Méxic

Identificación de áreas críticas de erosión en el Curso Alto del Río Lerma

El Curso Alto del Río Lerma (carl) tiene una extensión de 2 117.9 km2, presenta en su parte alta, el Volcán Nevado de Toluca, elevaciones de 4 560 msnm y en su parte baja la presa José Antonio Alzate una elevación de 2 569 msnm. La abrupta topografía, las altas precipitaciones y la intervención humana (tala de bosques y prácticas agrícolas inadecuadas), presentes en la cuenca, generan anualmente una importante pérdida de suelo. En este trabajo se identifican las áreas del carl que producen mayor pérdida de suelo. Se hizo un esfuerzo para identificar los municipios más afectados con el fin de instarles a tomar medidas preventivas. Estos municipios corresponden a Santiago Tianguistenco, Lerma y Ocoyoacac que juntos representan 60% de las zonas con grado de erosión extrema. En índices de erosión alta a los anteriores se le suman Otzolotepec, Temoaya, Xalatlaco, Toluca en las faldas del Nevado y Zinacantepec

Socio-Ecological Regionalization of the Urban Sub-Basins in Mexic

Mexico is a diverse country in terms of culture and natural environments. For this reason, the delimitation of homogeneous basins with similar environmental, social, and economic attributes is important in order to facilitate the elaboration of high-impact regional development strategies. However, this represents an ongoing challenge due to the complexity of the interactions that occur within socio-ecological systems at a regional scale. In the present study, the main objective was to identify the interrelationships among different aspects of the socio-ecological system located within basins, with the goal of utilizing this information to promote the region-specific sustainable development of an Integrated Water Resources Management (IWRM). Therefore, in this study, environmental, social, economic, and institutional variables, relevant to water management and with thecapacitytobeexpressedspatially,wereutilizedtoidentifyregionswithsimilarcharacteristicsand to regionalize the urban sub-basins of Mexico based on a principal component analysis (PCA) and the k-medoids clustering algorithm. The identification of the most adequate number of regions at the national level was determined by the silhouette method. As a result, five distinct regions for Mexico were generated, which forms the first step in the design of integrated water resources management strategies for these regions.Universidad Autónoma del Estado de MéxicoConsejo Nacional de Ciencia y Tecnología (CONACyT-México