A study was conducted to evaluate the feasibility of GIS programming as a potential tool in the automation of image processing obtained by the LANDSAT 8 satellite to estimate evapotranspiration (ET) in crops. The objective was to develop an algorithm in python language implementing the SEBAL model. 35 complex equations were developed, which were automated for the processing of 13 scenes, thus covering the entire vegetative cycle of corn cultivation on the "Rancho Las Mercedes" property. For the validation of the results, the data measured by the INIFAP weather station network was consulted on the dates corresponding to the images. The results obtained show an RMSE ranging from 0.001 for the month of June to 0.013 for the month of April. The instantaneous ET values are between the ranges of 0.01 mm / hr and 0.80 mm / hr. Maps of their spatial distribution were generated, where it can be seen that the lowest ET values, those close to zero, correspond to human settlements and bare soils, while the highest values correspond to sites of vigorous vegetation and bodies of water.

Reference evapotranspiration (ETo), is the most important parameter to estimate water consumption. Nowadays the FAO-56 Penman-Monteith method is the most used in the world to estimate Eto, and recommended as the standard method. The main limitation to use this method is the availability of the requiere weather data. There are step by step calculations to estimate ETo when there is a lack of climate data; with the purpose to estimate the crop water consumption in arid regions, it was evaluated the presicion and aplicability of three equations to estimate this parameter when there is limited climate data. Estimates of Eto were performed for five sites, New Mexico State University main campus and its research centers Leyendecker, Artesia and Fabian Garcia, in new Mexico, USA; as well as the Agriculture and Range Science School of the Juarez University of Durango State in Mexico. The estimates of ETo were done with all required wheater data and with lack of solar radiation and relative humidity data. The presicion of the equations was evaluated by using the relative error and the index of agreement, consiedring as reference the FAO-56 with full weather data.

Water is one of the most important natural resources for all living beings, it is essential for food security and the health of ecosystems. It occupies 75% of the planet's surface, however, only 3% is available to man for consumption. Mexico has 653 aquifers. 39.1% of the total volume of these is concessioned for agricultural irrigation uses. According to studies carried out by the National Water Commission, as of 2018, of the 653 units, 105 aquifers are reported in a state of overexploitation. The objective of this research was to implement the guide for the identification of areas with potential for water recharge, developed by the Tropical Agronomic Center for Research and Teaching of Costa Rica, which proposes the delimitation of potential recharge areas through geospatial information considering the topics of edaphology, geology, land use and vegetation, as well as relief and slopes. The results obtained show that in the Toluca Valley aquifer there are five categories of possibility of water recharge, although the moderate possibility prevails (59.4%), followed by a low possibility of recharge occurrence (21.0%), very low possibility (16.7%), high possibility (1.6%) and very high possibility (1.2%).

El quitosano en perlas y pH ácido (Q) tiene la capacidad de adsorber arsénico (As) del agua. El Q podría adsorber el As que se encuentra en la solución del suelo. El objetivo de esta investigación fue evaluar la capacidad quelatante del Q ajustado a pH ácido y neutro para disminuir concentración de As soluble en dos Fluvisoles. Para llevar a cabo el experimento se acondicionó Q a dos pH (5 y 7) con la adición de ácido sulfúrico y se dejó Q sin tratar para usarlo como testigo. Se ensayaron cuatro tratamientos (suelos sin Q, con Q sin tratar, con Q ajustado a pH 5 y con Q ajustado a pH 7). Cada tratamiento se condujo por cuadruplicado, haciendo un total de 16 unidades experimentales para cada suelo. Cada unidad experimental consistió de 500 g de suelo empaquetado en una bolsa de plástico, a la cual se le añadió un fertilizante fosfatado (200 mg kg‑1) y se llevó a capacidad de campo, dejándola reposar por 48 h. Al cumplirse el tiempo de reposo, se agregaron a cada bolsa 0.063 g de Q del tratamiento correspondiente y su respectiva réplica, dejándolas en incubación durante 48 h a una temperatura de 25 °C. El diseño experimental empleado fue completamente al azar. A los suelos se les determinó el contenido de As soluble mediante una extracción con agua desionizada y lo extractado se midió por el método de espectrofotometría de absorción atómica con generación de hidruros. Los datos se sometieron a un análisis de varianza y una prueba de medias (Tukey, P ≤ 0.05). Los resultados demostraron que el quitosano ajustado con ácido sulfúrico a pH 5, (QpH5) adsorbió la mayor cantidad de As soluble (640%). Lo que representa una alternativa de recuperación de suelos contaminados con As.