Estimating Potential Evapotranspiration by Missing Temperature Data Reconstruction

This work studies the statistical characteristics of potential evapotranspiration calculations and their relevance within the water balance used to determine water availability in hydrological basins. The purpose of this study was as follows: first, to apply a missing data reconstruction scheme in weather stations of the Rio Queretaro basin; second, to reduce the generated uncertainty of temperature data: mean, minimum, and maximum values in the evapotranspiration calculation which has a paramount importance in the manner of obtaining the water balance at any hydrological basin. The reconstruction of missing data was carried out in three steps: (1) application of a 4-parameter sinusoidal type regression to temperature data, (2) linear regression to residuals to obtain a regional behavior, and (3) estimation of missing temperature values for a certain year and during a certain season within the basin under study; estimated and observed temperature values were compared. Finally, using the obtained temperature values, the methods of Hamon, Papadakis, Blaney and Criddle, Thornthwaite, and Hargreaves were employed to calculate potential evapotranspiration that was compared to the real observed values in weather stations. With the results obtained from the application of this procedure, the surface water balance was corrected for the case study

Plataforma de adquisición y monitoreo para el estudio de las condiciones ambientales externas y de confort en casas prototipo para la validación de un control térmico por medio de un sistema de muro verde y aislante térmico

En la actualidad un tema que ha cobrado gran importancia es el de las fachadas verdes dado que su principal aplicación es para mejorar el confort en las viviendas y el ahorro de energía, debido a que estos se encuentran directamente relacionados con el nivel de vida que se presenta en una casa habitación; aunque existen muchos factores que influyen en la calidad de la vivienda, se considera uno de los más importantes al material con la que ésta construida, porque de este dependen las condiciones ambientales que se generan dentro de la vivienda y que definen la calidad de la vivienda. En este proyecto se implementó un sistema que permite adquirir los diferentes datos de confort obtenidos en un par de casetas experimentales para comparar el efecto que se tiene al colocar un recubrimiento vegetal en la fachada sur a una caseta con respecto a otra a la que no se le colocó. El sistema es capaz de adquirir y transmitir de manera inalámbrica las señales de los sensores de temperatura, humedad y flujo de calor que fueron colocados en ambas casetas. Finalmente, los datos recibidos se procesan en una aplicación desarrollada en MATLAB para analizar y mostrar los datos de cada caseta.Palabra(s) Clave(s): aplicaciones de comunicación inalámbrica, aplicaciones de MATLAB, confort en viviendas, fachadas verdes

The V471A polymorphism in autophagy-related gene ATG7 modifies age at onset specifically in Italian Huntington disease patients

The cause of Huntington disease (HD) is a polyglutamine repeat expansion of more than 36 units in the huntingtin protein, which is inversely correlated with the age at onset of the disease. However, additional genetic factors are believed to modify the course and the age at onset of HD. Recently, we identified the V471A polymorphism in the autophagy-related gene ATG7, a key component of the autophagy pathway that plays an important role in HD pathogenesis, to be associated with the age at onset in a large group of European Huntington disease patients. To confirm this association in a second independent patient cohort, we analysed the ATG7 V471A polymorphism in additional 1,464 European HD patients of the “REGISTRY” cohort from the European Huntington Disease Network (EHDN). In the entire REGISTRY cohort we could not confirm a modifying effect of the ATG7 V471A polymorphism. However, analysing a modifying effect of ATG7 in these REGISTRY patients and in patients of our previous HD cohort according to their ethnic origin, we identified a significant effect of the ATG7 V471A polymorphism on the HD age at onset only in the Italian population (327 patients). In these Italian patients, the polymorphism is associated with a 6-years earlier disease onset and thus seems to have an aggravating effect. We could specify the role of ATG7 as a genetic modifier for HD particularly in the Italian population. This result affirms the modifying influence of the autophagic pathway on the course of HD, but also suggests population-specific modifying mechanisms in HD pathogenesis

Habilidad de estimación de los métodos de evapotranspiración para una zona semiárida del centro de México

In arid and semiarid areas, the evapotranspiration process constitutes a major loss of water to the atmosphere, prompting the need for a better understanding and quantification of this phenomenon, especially in semiarid environments where water resources are scarce. There are many available methods to estimate evapotranspiration, however, their performance in specific environments must be evaluated before making a selection. A weather station was used to collect data from a semiarid zone of Central Mexico with the purpose to evaluate eight different methods for daily, weekly and monthly periods of observation. The estimated results were compared with measured data from an ET gage company, as this device has been calibrated and proven to be closely associated to reference evapotranspiration data. The mean absolute error, root mean squared error, regression line intercept and slope, as well as determination coefficient R2, were obtained to statistically evaluate the performance of evaluated methods. A poor performance for all time scales was found for the Oudin, McGuinness, Jensen and Haise, and Romanenko methods, with high values of mean absolute error and root mean squared error. Low values of the intercept, slope and R2 parameters were also obtained for such methods, making them not suitable and consequently not suited for the study area. On the other hand, the Penman-Monteith and Penman methods, showed the best performance in different time scales. Similar results have been fund by other authors, supporting Penman-Monteith as a method of reference. A multiple regression equation to predict reference from climatic variables was also obtained with R2= 0.8, 0.82 and 0.91 for daily, weekly and monthly scales, respectively, indicating the possibility of using regression models for semiarid conditions.En zonas áridas y semiáridas, el proceso de evapotranspiración constituye una gran pérdida de agua hacia la atmósfera, por lo que existe una necesidad por entender y cuantificar este proceso, especialmente en los ambientes semiáridos donde los recursos hídricos son escasos. Muchos métodos para estimar la evapotranspiración están disponibles; sin embargo, su desempeño bajo un ambiente específico tiene que ser evaluado antes de realizar una selección. Se utilizó una estación metereológica para tomar datos de una zona semiárida del centro de México, con el propósito de evaluar ocho diferentes métodos a una escala de observación diaria, semanal y mensual. Los resultados estimados se compararon con datos medidos de un ET gage company, ya que este instrumento ha sido calibrado y probado de estar estrechamente asociado a los datos de evapotranspiración de referencia. El error absoluto medio, el error de la media cuadrática, la intercepción y pendiente de la regresión lineal y el coeficiente de determinación R2, fueron obtenidos para evaluar estadísticamente el desempeño de los métodos evaluados. Se encontró un bajo desempeño para todas las escalas de tiempo de los métodos Oudin, McGuinness, Jensen y Haise, y Romanenko, con altos valores de error absoluto medio y error de la media cuadrática. Parámetros de valores bajos de intercepción, pendiente y R2; fueron obtenidos también para estos métodos, haciéndolos impropios y por lo tanto no recomendables para el área de estudio. Por otra parte, los métodos Penman-Monteith y Penman, mostraron el mejor desempeño a diferentes escalas de tiempo. Resultados similares se han encontrado por otros autores, apoyando el método de referencia de Penman-Monteith. Se obtuvo una ecuación de regresión múltiple para predecir la evapotranspiración de referencia derivada de las variables climáticas, con valores de R2= 0.8, 0.82 y 0.91 para escalas diarias, semanales y mensuales, respectivamente, indicando la posibilidad de usar modelos de regresión para condiciones semiáridas

Análisis y simulación del modelo físico de un invernadero bajo condiciones climáticas de la región central de México

The use of greenhouses for vegetable production has expanded rapidly in recent years in México. The most important aspect for the success of these agro-businesses is the improvement of production efficiency, higher quality and productivity, which are related to specific climatic conditions of each region. The present study introduces the analysis and simulation of a mathematical model of greenhouse climate. The model is formulated on basic principles of mass and energy transfer processes, and simulates the greenhouse air, soil, roof and crop temperatures, as well as relative humidity. The dynamic simulation of the mathematical model was made using the SIMULINK tool of MATLAB software. The simulation results were calibrated and validated with the measured data collected in a 1000 m2 experimental greenhouse developed at the University of Querétaro. The results from the validation were prediction equations for the roof temperature (R2=0.855), inner air temperature (R2=0.964), crop temperature (R2=0.835), soil temperature (R2=0.714) and relative humidity (R2=0.960). The magnitude of the coefficients indicates that the model can be used to predict the greenhouse climate with a high level of confidence, and it is a tool for supporting the analysis of the necessary conditions for greenhouse vegetable production under climatic conditions of the Central Region of MéxicoEl uso de invernaderos para la producción de hortalizas ha crecido en México rápidamente en los últimos años. Lo más importante para el éxito de estos agronegocios es incrementar la eficiencia de la producción, lograr mayor calidad y alta productividad, lo cual está relacionado con las condiciones climáticas específicas de cada región. En este estudio se presenta el análisis y simulación de un modelo matemático del clima en un invernadero. El modelo está formulado con base en los principales procesos de transferencia de masa y energía, y simula las temperaturas del aire, suelo, cubierta, cultivo, y humedad relativa del invernadero. La simulación dinámica del modelo matemático se hizo con la herramienta SIMULINK del software MATLAB. Los resultados de la simulación se calibraron y validaron con los datos medidos en un invernadero experimental de 1000 m2 desarrollado en la Universidad Autónoma de Querétaro. Los resultados de la validación fueron ecuaciones de predicción: para la temperatura de la cubierta (R2=0.855), temperatura del aire interno (R2=0.964), temperatura del cultivo (R2=0.835), temperatura del suelo (R2=0.714) y humedad relativa (R2=0.960). La magnitud de los coeficientes indica que el modelo puede usarse para la predicción del clima en el invernadero con un buen nivel de confianza y es una herramienta de apoyo para el análisis de las condiciones necesarias para la producción de hortalizas en invernaderos bajo las condiciones climáticas de la región central de Méxic

Estimating Potential Evapotranspiration by Missing Temperature Data Reconstruction

This work studies the statistical characteristics of potential evapotranspiration calculations and their relevance within the water balance used to determine water availability in hydrological basins. The purpose of this study was as follows: first, to apply a missing data reconstruction scheme in weather stations of the Rio Queretaro basin; second, to reduce the generated uncertainty of temperature data: mean, minimum, and maximum values in the evapotranspiration calculation which has a paramount importance in the manner of obtaining the water balance at any hydrological basin. The reconstruction of missing data was carried out in three steps: (1) application of a 4-parameter sinusoidal type regression to temperature data, (2) linear regression to residuals to obtain a regional behavior, and (3) estimation of missing temperature values for a certain year and during a certain season within the basin under study; estimated and observed temperature values were compared. Finally, using the obtained temperature values, the methods of Hamon, Papadakis, Blaney and Criddle, Thornthwaite, and Hargreaves were employed to calculate potential evapotranspiration that was compared to the real observed values in weather stations. With the results obtained from the application of this procedure, the surface water balance was corrected for the case study

The rainfall-runoff-erosion relationship in hillsides and microwatersheds

The rainfall-runoff-erosion process was evaluated for runoff plots with different management practices for row and cover crops, as well as for a hillside parcel with corn crops in andosol soil. The study was carried out in 2007 in the Villa Victoria watershed, in the Mexico Cutzamala System. During the study period, 168 rainy events were registered, only 14 of which generated surface runoff and soil erosion. The results showed that in land with a 30 percent slope, the average efficiency of runoff and soil erosion control was 40% for row crops in contour strips and 62% for cover crops. In these soils, erosion was highly correlated with runoff, effective rainfall, peak runoff, rainfall intensity and antecedent soil moisture; surface flow (runoff) was related with peak runoff and rainfall intensity, and; peak flow was highly correlated with rainfall intensity. Though 37% of the total runoff occurred in June and July, total soil loss from erosion was 68%. It is during this period that the land is worked and the crop canopy coverage is between 45 to 85%. The minimum requirements for the rainfall-runoff-soil erosion process to occur were rainfall depth of 4.2 mm, rainfall intensity of 8.69 mm/h and an antecedent soil moisture near field capacity (around 53% humidity)