El presente trabajo analiza las principales tendencias de investigación (temáticas, metodologías utilizadas, países de los autores y de los datos) en economía del agua de riego en los últimos 10 años (2000-2009). Para ello, se ha utilizado una metodología cuantitativa, novedosa en este ámbito, basada en la revisión de una muestra representativa de 332 artículos publicados en las 15 revistas más importantes en este ámbito científico, indexadas en las bases de datos del Institute for Scientific Information (ISI), el Science Citation Index (SCI) y el Social Science Citation Index (SCCI). Los resultados obtenidos confirman: a) el notable crecimiento del número de artículos publicados, sobre todo, en los tres últimos años, b) la elevada colaboración entre los autores para su realización, incluso de diferente procedencia, c) el protagonismo de EEUU, Australia, India y España como países de los primeros autores y de procedencia de los datos, d) la mayor atención prestada a los temas relacionados con el "análisis de proyectos de inversión", la "planificación de la producción" y, especialmente, a las "funciones de producción y la productividad del agua", y e) el predominio de los trabajos empíricos que utilizan técnicas de análisis básicas (análisis de costes, evaluación de inversiones, etc.). | This work analyses the main research trends (subjects, methodology used, countries of the authors and data) in the economics of irrigation water during the last 10 years (2000-2009). For this purpose, a quantitative methodology has been used which is new to this sphere, based on the review of a representative sample of 332 papers published in the 15 most important journals focused on this field of science indexed in the databases of the Institute for Scientific Information (ISI), the Science Citation Index (SCI) and the Social Science Citation Index (SCCI). The results obtained confirm: a) the notable growth in the number of papers published, especially in the last three years, b) the high degree of collaboration between authors, including those of different origin, for their performance c) the prominence of the USA, Australia, India and Spain as the countries of the first authors and origin of the data, d) the greater attention given to subjects related with "investment project analysis", "production planning" and, especially, "production function and productivity of water", and e) the predominance of empirical studies that use basic analysis approaches (cost analysis, investment evaluation, etc.).

Se evalúa cuantitativamente la incidencia de la presencia de gotas de agua sobre la cúpula de un radiómetro termoeléctrico en la radiación medida por el mismo. Se discute la influencia del tamaño de las gotas y del ángulo de incidencia de la radiación, separando los efectos puramente ópticos de los asociados a la respuesta térmica del instrumento. Se determina también la variación de la irradiación medida por el radiómetro con el domo seco o rociado con gotas, analizando asimismo el proceso de estabilización térmica. | The incidence of the presence of drops of water on the dome of a thermoelectric radiometer in the radiation measured by it is quantitatively evaluated. The influence of the size of the droplets, the angle of the incident radiation, is discussed, separating the purely optical effects from those associated with the thermal response of the instrument. The variation of the energy measured by the radiometer with respect to that actually existing during the thermal stabilization process is also determined. | Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES)

For the quantitative evaluation of the impact of mining on a groundwater system, it is necessary to constrain the hydrogeological and mechanical properties. However, the in situ estimation of the mechanical properties of rock such as compressibility and porosity, is often difficult. Additionally, determining the hydraulic properties such as hydraulic conductivity, of rock by conventional methods is often expensive. The response of the groundwater level to external loading such as Earth tides and barometric pressure, couples the hydrogeological and mechanical processes of rocks, thus providing a way to infer these properties in the field. This study compared aquifer parameters inferred from tidal and barometric responses with those inferred from conventional hydraulic tests and rock mechanics tests in three groundwater monitoring wells at a site in China. The results show that the hydraulic conductivity inferred from a tidal response is similar to that of a pumping test. The compressibility values calculated for the three wells are all higher than those determined by experiment, and the porosity values calculated are all lower than those determined by experiment, but the differences between the calculated and experimentally measured values are lower than one order of magnitude. Considering the costs and convenience of the water-level response method, this method is a good choice for obtaining the properties of an aquifer, especially those in areas of tectonic activity and those affected by anthropogenic perturbations.

Groundwater distribution and flow dynamics were studied in a small watershed located in the discontinuous permafrost zone near Umiujaq in Nunavik (Québec), Canada, to assess the seasonal variations and perform a quantitative analysis of the water cycle in a subarctic watershed. Due to the complexity of the subsurface geology within the watershed, an integrated investigation was instrumental to provide a detailed understanding of the hydrogeological context as a basis for the water balance. Based on this water balance, for the two studied hydrological years of 2015 and 2016, the average values are 828 mm for precipitation, 337 mm for evapotranspiration, 46 mm for snow sublimation, 263 mm for runoff, 183 mm for groundwater exchange (losses with other aquifers outside the watershed), and 0 mm for change in water storage. Although these values likely have significant uncertainty and spatial variability, this water balance is shown to be plausible. It was also found that permafrost influences surface water and groundwater interaction, even if located in low-permeability sediments. It is expected that permafrost degradation will likely increase stream baseflow, especially in winter.

Groundwater in mountainous karst regions is vital for regional water budgets and freshwater supply. Owing to increasing water demand and climate change, detailed knowledge of the highly heterogeneous alpine aquifer systems is required. Multi-tracer analyses have been conducted in the steep karstic Wetterstein Mountains, which includes Germany’s highest summit, Zugspitze (2,962 m asl). Results of artificial tracer tests demonstrate well-developed flow paths through the unsaturated zone (up to 1,000 m thickness). Flow paths cross topographic divides and contribute to deep drainage systems underneath alpine valleys. Cross-formational flow has been identified. Quantitative analysis of tailing-dominated breakthrough curves and stable isotopes (¹⁸O) has enabled determination of the mean transit-time distribution. A fast-flow component with transit times between 3 and 13 days was found in karst conduits and open fissures, dependent on flow conditions. An intermediate-flow component, showing mean transit times of about 2.9–4.9 months, was found in well-drained fissures and fractures. A slow-flow component with mean transit times greater than 1 year is attributable to slow flow and low storage in the poorly drained fissures and rock matrix. The conceptual model enables a better understanding of drainage, water resources and vulnerability of the high-alpine karst system.

Faults and fractures are a critical store and pathway for groundwater in Ireland’s limestone bedrock aquifers either directly as conductive structures or indirectly as the locus for the development of karst conduits. From the quantitative analysis of post-Devonian faults and fractures in a range of lithological sequences, this report describes the principal characteristics of Cenozoic strike-slip faults and joints, the youngest and the most intrinsically conductive fractures within Irish bedrock. Analysis of these structures in more than 120 outcrop, quarry, mine and cave locations in a range of bedrock types, provides a basis for: (1) definition of quantitative models for their depth dependency, lithological control, scaling systematics and links to preexisting structure, (2) conceptualisation of their impact on groundwater behaviour, and (3) estimation of groundwater flow parameters. The quantitative models provide constraints on fracture-controlled flow connectivity. Commonly observed decreases in sustainable flows and water strike interceptions with depth are attributed to increasing confinement and decreasing fracture connectivity and dissolution. Faults and joints have quite different end member geometries, with faults having strongly heterogeneous scale-independent properties and joints more often showing scale-dependent stratabound properties. The highest and most sustainable groundwater flows are usually associated with the complexity of structure of Cenozoic faults and of preexisting Carboniferous structures (on which conductive fracturing localises), enhanced by karstification and strongly jointed limestone bedrock particularly in the near-surface. Increased groundwater flow is promoted within bedded, rather than massive (i.e. unbedded), limestone sequences, characterised by bedding-parallel fractures and karst connecting otherwise subvertical fractures and subvertical wells.