Comision Nacional Del Agua Research Articles

CARACTERIZACIÓN DEL VIENTO EN VILLAHERMOSA, TABASCO EN EL PERÍODO 2008-2018

El presente trabajo se enfoca en la caracterización de los vientos que cruzan la ciudad de Villahermosa, Tabasco, mediante el análisis de rosas de vientos en el período de estudio 2008-2018. Se analizaron las gráficas anuales y trimestrales de los datos obtenidos de la Comisión Nacional del Agua. Los resultados muestran que la dirección dominante de los vientos es del Este, lo cual se asocia al Jet de bajo nivel presente a lo largo del año. Los vientos secundarios son asociados a los diferentes fenómenos que predominan en el Golfo de México como es el caso de los Vientos Alisios y Nortes en invierno, mientras que, para el verano, los componentes se asocian a fenómenos de las Ondas del Este. Por otro lado, el estudio muestra que la actividad de El Niño-Oscilación del Sur puede influir en la presencia de otros componentes.

La relación entre las arribadas de la tortuga golfina (Lepidochelys olivacea) y el ambiente físico en La Escobilla, Oaxaca, México durante 2005

Background. Sea turtles of the genus Lepidochelys exhibit a complex and synchronous mass-nesting behavior termed “arribada.” Goals . This paper analyzes the local physical environment during the arribada events that occurred in 2005 at La Escobilla, Oaxaca, Mexico. Methods. Daily night patrols were conducted from May to November 2005, along the nesting zone. Daily records for air temperature and rainfall were obtained from the automatic weather station by the Comision Nacional del Agua. Sea surface temperature and salinity fields were obtained from the Hybrid Coordinate Ocean Model (HYCOM), and surface ocean currents were obtained from the Asia-Pacific Data Research Center. Results . The analyses showed five arribada events during the period. A common feature was the presence of eddies and strong currents at the beginning of each arribada. A correlation of statistical significance was observed between the abundance of the arribada and the current speed (R = 0.93, R2 = 0.86, p = 0.04). The correlation with salinity showed values of R = 0.55, R2 = 0.31, p = 0.32, whereas correlation with rainfall was R = 0.53, R2 = 0.28, p = 0.14. A weak correlation was observed with air temperature (R = 0.35, R2 = 0.12, p = 0.59) and with sea surface temperature (R = 0.23, R2 = 0.05, p = 0.66). Conclusions. Although sea turtles are strong swimmers, the proximity to favorable oceanic currents generated by eddies might be related to the beginning of the arribada, considering that this current might provide energy savings and accumulate chemical compounds and food in the water column.

Análisis crítico de las campañas de comunicación para fomentar la “cultura del agua” en México

Se analizaron las campañas publicitarias efectuadas por la Comisión Nacional del Agua con el objetivo de fomentar la cultura del agua en la población, y se identificaron algunos factores que explican su limitado impacto en la modificación de hábitos en su consumo. Se concluye que es necesario considerar procesos de aprendizaje formativo y participativo como parte de dichas campañas para que sean más eficaces.

Adaptation and Sizing of Solar Water Heaters in Desert Areas: For Residential and Hotels.

Use of flat plate collectors is significantly limited in desert areas, which presents the contrast of low temperatures in winter close to 0°C, and high temperatures in summer above 40°C. Mexicali, Baja California has a good availability of solar radiation, 5.72kWh/m2/day, but it has a semidesert climate. Suppliers of these technologies do not include these zones as target markets, and therefore the performance of these systems in extreme climates is not very known, and so do regard the problems for the installation and design drawbacks. The present work shows the technical-economic evaluation about the performance of flat plate collectors for water heating, an outlook of economic and environmental benefits, considering its potential to be use in residential and hotel sectors in Mexicali, Baja California. The analysis was performed with data from a field monitored system during one year, to observe and record information of relevant variables for the performance of solar heater, such as ambient temperature, wind speed and solar radiation, which were obtained from weather stations located in Calexico, California, USA, and Comision Nacional del Agua in Mexicali, Mexico. Also, temperatures in the collector's fluid and in the storage tank were measured and recorded at 5minutes intervals using a data acquisition system. This information allowed to predict the system's performance for a greater capacity throughout a year, relating the most relevant system variables. The solar heater showed a good performance in winter, keeping an average of 40°C in the storage tank and in summer a minimum temperature of 60°C and maximum up to 85°C. From the above, an economic analysis was generated considering the current market potential in residential and hotel sectors in Mexicali, which translates into savings of 33%, at least in conventional energy consumption and estimated payback in four years for the Hotel's case. Energy savings for residential case is about 80% and the investment return is approximately 5 years, because in desert areas the greater demand of hot water occurs in winter. In conclusion, solar water heater performance is adequate for residential and hotel applications in desert areas and its hot water production is enough for remunerable use of solar collectors under specific and well defined scenarios.

Redesign and Modernization of the Mexican Water Quality Monitoring Network

ABSTRACT Mexico is a large developing country, much of which is arid and semiarid. With a population of more than 81 million, Mexico is confronted with growing water scarcity and serious pollution of much of its surface water The National Water Commission (Comision Nacional del Agua—CNA) has embarked on a major program of modernization of water management. The water quality program, now consisting of 564 surface water stations (plus 239 groundwater stations), has no strategic design, has major data gaps, is not representative of important areas, is often unreliable, does not contain data for many current issues such as organic contaminants, and suffers from out-of-date or lack of facilities. Because the existing network is not representative of the range of issues for which data are needed, network redesign began from first principles rather than as an optimization of the existing network. The new program is built around client needs, and uses four components—a primary network of some 200 stations that are designed to characterize important water bodies over the long term; a flexible secondary network that focuses on effluent regulatory issues; surveys and special studies for river basin planning and issue-specijic purposes; and a mobile emergency capability. Modernization of the water quality program also includes parallel activities focusing on training, institutional, and legal issues.