Se llevó a cabo un estudio de los usos predominantes de la tierra y la calidad del agua en la cuenca del Río Gama, localizada al suroeste del centro de Brasilia, capital de Brasil. Se escogieron seis estaciones de muestreo distribuidas en dos puntos para los tres usos predominantes de la tierra (bosque conservado, urbano y agrícola) y se tomó una muestra por mes durante cuatro meses, dos meses en la época lluviosa y dos meses en la época seca. Se proponen algunas acciones necesarias para el manejo sostenible de la cuenca del Río Gama. | A study was conducted of water quality in the predominant land uses of the Gama River watershed, located to the southwest of the center of Brasilia, capital of Brazil. Six sampling stations distributed in two points were selected for each of the three predominant land uses (conserved forest, urban, and agricultural areas). One sample per month was taken over four months: two in the rainy season and two in the dry season. Several recommendations are made regarding actions for the sustainable management of the Gama River watershed. | Tesis (Mag.Sc) - CATIE, Turrialba (Costa Rica), 2003

Para el mejor aprovechamiento del agua de riego es necesario que los agricultores dispongan de nuevas tecnologías, por esta razón se realizó un estudio de los parámetros técnicos indispensables para formular una propuesta técnica de sistemas de riego adecuados para el Campo Académico Docente Experimental La Tola (CADET) de la facultad de Ciencias Agrícolas de la Universidad Central del Ecuador. Los resultados determinaron que: En el CADET se utiliza los sistemas de riego por tendido y por surcos, los cuales tienen una baja eficiencia de aplicación, y por lo tanto hay limitaciones de agua, especialmente en la época seca de riego. La información conseguida se elevó a un Sistema de Información Geográfica obteniendo: un mapa detallado de la profundidad efectiva del CADET, y un mapa de la clasificación de los suelos de acuerdo a la pendiente; con los mapas mencionados se realizó una zonificación de la hacienda delimitando 11 zonas aptas para el riego que cubren una área de 63. 06 ha, a cada zona se la dividió en lotes uniformes de acuerdo a la profundidad del suelo y la pendiente. Entre los resultados también se encuentra los parámetros técnicos para el riego como: almacenamiento de agua disponible en el suelo (9.44 %), velocidad de infiltración básica (15.25 mm/hr), datos climáticos, intervalos entre riegos (2 a 8 días), eficiencia de conducción de los canales presentes en el CADET (73.84 %). Después del análisis de toda la información se recomienda para las zonas 2, 3, 4, 5, 6, 7, 8 y 9, en los cuales se hacen cultivos anuales y se maneja potreros la implantación de un sistema de riego por aspersión; en tanto que para las zonas de prácticas docentes el sistema óptimo recomendado será el riego localizado | For a better use of the irrigation water, the farmers need to have new technologies. For this reason a study was carried out on the technical parameters required to formulate a technical proposal of an irrigation system for the “Campo Académico Docente Experimental La Tola (CADET) of the Facultad de Ciencias Agrícolas of the Universidad Central of Ecuador. The results determined that: The irrigation systems currently used at CADET are by furrows and by flooding, which are low efficiency as a consequence there are limitations of water, especially in the dry season. The gotten information was loaded into a Geographic Information system obtaining: a detailed mapof the effective depth of CADET’s soil, and a map of soil classification according to the slop were obtained. Using these maps, the farm zonification was carried out, identifying 11 zones apt to irrigation, covering an area of 63.06 ha. Each zone was subdivided in uniform lots according to the soil depth and slop. Among the results, the irrigation technical parameters were also identified, such as: storage of soil available water (9.44 %), basic water infiltration velocity (15.25 mm/hr), climatic data, irrigation intervals (2 to 8 days), water conduction efficiency of the channels available at CADET (73,84 %). Based on the results, the recommendations are: for zones 2, 3, 4, 5, 6, 7, 8 and 9, where annual cultivations are had and is managed pastures, a sprinkler irrigation system is recommended and for the zones dedicated to teaching practices a localized irrigation system is recommended.

Se llevó a cabo un estudio de los usos predominantes de la tierra y la calidad del agua en la cuenca del Río Gama, localizada al suroeste del centro de Brasilia, capital de Brasil. Se escogieron seis estaciones de muestreo distribuidas en dos puntos para los tres usos predominantes de la tierra (bosque conservado, urbano y agrícola) y se tomó una muestra por mes durante cuatro meses, dos meses en la época lluviosa y dos meses en la época seca. Se proponen algunas acciones necesarias para el manejo sostenible de la cuenca del Río Gama. | A study was conducted of water quality in the predominant land uses of the Gama River watershed, located to the southwest of the center of Brasilia, capital of Brazil. Six sampling stations distributed in two points were selected for each of the three predominant land uses (conserved forest, urban, and agricultural areas). One sample per month was taken over four months: two in the rainy season and two in the dry season. Several recommendations are made regarding actions for the sustainable management of the Gama River watershed.

The hydrodynamic processes and impacts exerted by river–groundwater transformation need to be studied at regional and catchment scale, especially with respect to diverse geology and lithology. This work adopted an integrated method to study four typical modes (characterized primarily by lithology, flow subsystems, and gaining/losing river status) and the associated hydrodynamic processes and ecological impacts in the southern part of Junggar Basin, China. River–groundwater transformation occurs one to four times along the basin route. For mode classification, such transformation occurs: once or twice, controlled by lithological factors (mode 1); twice, impacted by geomorphic features and lithological structures (mode 2); and three or four times, controlled by both geological and lithological structures (modes 3 and 4). Results also suggest: (1) there exist local and regional groundwater flow subsystems at ~400 m depth, which form a multistage nested groundwater flow system. The groundwater flow velocities are 0.1–1.0 and <0.1 m/day for each of two subsystems; (2) the primary groundwater hydro-chemical type takes on apparent horizontal and vertical zoning characteristics, and the TDS of the groundwater evidently increases along the direction of groundwater flow, driven by hydrodynamic processes; (3) the streams, wetland and terminal lakes are the end-points of the local and regional groundwater flow systems. This work indicates that not only are groundwater and river water derived from the same source, but also hydrodynamic and hydro-chemical processes and ecological effects, as a whole in arid areas, are controlled by stream–groundwater transformation.