La mayoria de los problemas relacionados con la produccion de cerdas gestantes, criadas en confinamiento, en climas calientes, es debido al estres por las altas temperaturas. El acceso al agua permite que sea alcanzada la sensacion de confort termico; el objetivo principal de este trabajo fue interpretar el comportamiento de las cerdas gestantes en el sistema que utiliza una lamina de agua corriente en los corrales, permitiendo de esta forma el acceso constante al agua como fuente de intercambio termico y confort. Fueron estudiados el efecto de dos tipos de instalaciones para cerdas en gestacion, el primer metodo fue el de piso de concreto, comparado a un segundo que utiliza un canal de agua corriente de 5 cm de profundidad y 1 m de ancho en toda la extension de la nave. Tanto el microclima como la respuesta productiva de las cerdas no tuvieron diferencias significativas, mas la sensacion de confort termico es resaltada debido a un menor numero de animales descartados

Este estudo analisou as variações sazonais e anuais dos fluxos de calor sensível e latente, armazenados pelo dossel vegetativo de floresta tropical úmida, bem como a taxa de infiltração de água no solo em duas parcelas experimentais, uma com exclusáo de chuva e outra submetida às condições reais de precipitação pluvial. Os dados aqui usados foram obtidos do projeto ''Estudo da Seca da Floresta (ESECAFLOR), subprojeto do Experimento de Grande Escala da Biosfera-Atmosfera na Amazônia (LBA), conduzido na reserva florestal de terra firme em Caxiuaná, PA. Os dados de temperatura e umidade relativa do ar foram coletados no perfil da floresta amazônica, em intervalos de 8 m, deSd e a superfície até 32 m, durante o ano de 2008, em intervalos horários, para se determinar os fluxos de calor sensível e latente armazenados nos período chuvoso (fevereiro, março e abril) e menos chuvoso (setembro, outubro e novembro). Os resultados indicaram que o fluxo de calor sensível armazenado no dossel da floresta no ano de 2008, foi 167,93 W m-2 e o fluxo de calor latente armazenado foi de 5184,38 W m-2. A taxa de infiltração de água do solo na floresta foi reduzida drasticamente nos primeiros minutos do início do experimento, independentemente das condições de umidade do solo e, em seguida, ela apresentou comportamento quase constante ao longo do tempo.<br>This study assessed the seasonal and annual variations in both sensible and latent heat storage fluxes in the canopy air-space of tropical rainforest, as well as the infiltration rate in soil in two experimental plots one with exclusion of rainfall and other under actual rainfall. The data used in this study were obtained during the ''Long-term drought impact on water and carbon dioxide fluxes in Amazonian Tropical Rainforest Experiment'' (ESECAFLOR) which is subproject of Large Scale Biosphere Atmosphere Experiment in Amazon forest (LBA), carried out in Caxiuaná National Forest, Pará, Brazil. The air temperature and relative humidity data were collected in a forest profile for each 8 m height layer throughout the 2008 year in order to determine the sensible and latent heat storage fluxes during the rainy season (February, March and April) and less rainy season (September, October and November). The results indicated that sensible heat stored flux in rainforest canopy during the 2008 year was 167.93 W m-2, while the latent heat stored was 5184.38 W m-2. The infiltration rate in the forest was dramatically reduced in the first minutes of the experiment, regardless of soil moisture conditions, and then it presented almost constant behavior throughout the time.

El suelo radiante es un equipamiento presente en invernaderos comerciales y utilizado convencionalmente como método de calefacción. En este trabajo, en cambio, se ha realizado una evaluación experimental de la refrigeración de un invernadero mediante el uso del suelo radiante acoplado a una bomba de calor aire-agua. Se ensayaron dos escenarios durante los veranos de 2005 y 2006: ventilación natural + malla de sombreo (escenario control), y ventilación natural + malla de sombreo + suelo radiante acoplado a una bomba de calor (escenario de refrigeración activa). Se calcularon las diferencias entre la temperatura del aire interior y exterior (salto térmico), y se concluyó que a 0,5 m sobre el suelo, el sistema suelo radiante-bomba de calor redujo esta diferencia 1,1 grados C en 2005 y 0,8 grados C en 2006. Ambos escenarios se compararon con el comportamiento de otros sistemas de refrigeración: se concluyó que el escenario de refrigeración activa obtenía un salto térmico (medido a 0,5 m) más favorable incluso que la nebulización. Se diseñó un modelo basado en las curvas de rendimiento de la bomba de calor para predecir la capacidad refrigerante desarrollada por el sistema suelo radiante-bomba de calor. El consumo energético de la bomba de calor fue 104,8 Wh/m cuadrado/d (de 13:00 a 18:00 h) bajo las condiciones de ensayo. Este sistema parece ser apropiado sólo para refrigerar invernaderos bajo ciertas condiciones, para cultivos de alto valor añadido, cultivos de bajo porte, o cuando el coste de inversión no es un factor limitante ya que éste es aproximadamente 38 Euros/m cuadrado. | This paper describes the experimental cooling of a greenhouse in Madrid (Spain) using a radiant heated floor (RHF) coupled to an air-water heat pump (HP). Two cooling scenarios were studied over the summers of 2005 and 2006: natural ventilation + a shading screen (control system), and natural ventilation + a shading screen + an RHF (concrete) coupled to an air-water heat pump (i.e., in cooling mode; nominal power, 34.1 W/squre m). Using the difference between the outside and inside air temperatures, it was concluded that at 0.5 m above the floor the RHF system reduced the temperature by 1.1 deg C in 2005 and 0.8 deg C in 2006. Both cooling scenarios were compared with other cooling technologies: the use of the natural ventilation + shading + RHF gave a smaller air temperature difference than fogging at a height equal to or lower than 0.5 m. A model based on the heat pump performance curves was constructed to predict its power consumption and good predictions of the variation over the day were obtained. The power consumption of the heat pump was 104.8 Wh/square m/d (from 13:00 to 18:00 h) under our test conditions in Madrid. The RHF-HP system may only be appropriate for cooling greenhouses under certain circumstances, e.g., when growing high value crops or when cost is not a limiting factor, as its initial investment cost is about Euros 38/m.

Este estudo analisou as variações sazonais e anuais dos fluxos de calor sensível e latente, armazenados pelo dossel vegetativo de floresta tropical úmida, bem como a taxa de infiltração de água no solo em duas parcelas experimentais, uma com exclusáo de chuva e outra submetida às condições reais de precipitação pluvial. Os dados aqui usados foram obtidos do projeto ''Estudo da Seca da Floresta (ESECAFLOR), subprojeto do Experimento de Grande Escala da Biosfera-Atmosfera na Amazônia (LBA), conduzido na reserva florestal de terra firme em Caxiuaná, PA. Os dados de temperatura e umidade relativa do ar foram coletados no perfil da floresta amazônica, em intervalos de 8 m, deSd e a superfície até 32 m, durante o ano de 2008, em intervalos horários, para se determinar os fluxos de calor sensível e latente armazenados nos período chuvoso (fevereiro, março e abril) e menos chuvoso (setembro, outubro e novembro). Os resultados indicaram que o fluxo de calor sensível armazenado no dossel da floresta no ano de 2008, foi 167,93 W m-2 e o fluxo de calor latente armazenado foi de 5184,38 W m-2. A taxa de infiltração de água do solo na floresta foi reduzida drasticamente nos primeiros minutos do início do experimento, independentemente das condições de umidade do solo e, em seguida, ela apresentou comportamento quase constante ao longo do tempo. | This study assessed the seasonal and annual variations in both sensible and latent heat storage fluxes in the canopy air-space of tropical rainforest, as well as the infiltration rate in soil in two experimental plots one with exclusion of rainfall and other under actual rainfall. The data used in this study were obtained during the ''Long-term drought impact on water and carbon dioxide fluxes in Amazonian Tropical Rainforest Experiment'' (ESECAFLOR) which is subproject of Large Scale Biosphere Atmosphere Experiment in Amazon forest (LBA), carried out in Caxiuaná National Forest, Pará, Brazil. The air temperature and relative humidity data were collected in a forest profile for each 8 m height layer throughout the 2008 year in order to determine the sensible and latent heat storage fluxes during the rainy season (February, March and April) and less rainy season (September, October and November). The results indicated that sensible heat stored flux in rainforest canopy during the 2008 year was 167.93 W m-2, while the latent heat stored was 5184.38 W m-2. The infiltration rate in the forest was dramatically reduced in the first minutes of the experiment, regardless of soil moisture conditions, and then it presented almost constant behavior throughout the time.

Este trabajo viene a ser un estudio inicial del manejo del agua en el método por inundación practicado por los agricultores en Venezuela. Mediante observaciones hechas en el campo, el especialista puede darse cuenta en forma bastante precisa de cuales son las condiciones y formas de trabajo, y luego con conocimiento de causa, se han tratado de sugerir algunas modificaciones con el fin de conseguir economía del uso en el agua de riego y orientar un mejor manejo de los suelos que permita su conservación en condiciones apropiadas de producción. Se hacen algunas consideraciones en relación a deficiencias detectadas en el uso del agua de riego, para hacer luego algunas recomendaciones para mejorar el manejo del agua en el método de inundación para el cultivo de arroz de riego. Se detalla la caracterización del medio físico natural en el sistema de riego río Guárico en cuanto a sus condiciones climatológicas e hidrológicas; suelos representativos del área; problemas de drenaje y sus soluciones, aspectos de extensión agrícola. (Resumen Julia Brito, 2009).

Permafrost in Arctic watersheds limits soil biological activity to a thin, seasonally thawed active layer that contributes water to streams. In many hillslopes, relatively wet drainage features called water tracks have distinct freeze-thaw patterns that affect groundwater flow and storage, and thus the export of heat and solutes to Arctic streams. This study uses groundwater flow and energy transport models to examine potential controls on the timing and duration of freeze–thaw conditions and the magnitude of temperature fluctuations within water tracks and their adjacent hillslopes. The simulated length of the active-layer thaw season varies by 1 month over the range of snow-cover and mean annual air-temperature scenarios simulated. The timing and duration of freezing is particularly sensitive to depth and duration of snow cover. Thus, the deeper snowpack covers that can accumulate in water tracks contribute to their more persistent thaw conditions and their ability to conduct groundwater downslope. A three-dimensional simulation shows that during the summer thaw season, the water track captures groundwater laterally from half way across the hillslope. The models presented here elucidate key mechanisms driving small-scale variation in the active-layer thermal regime of tundra hillslopes, which may be responsible for changes in drainage-network geometry and Arctic biogeochemical fluxes under a warming climate.

Temporal and spatial changes of the hydrological cycle are the consequences of climate variations. In addition to changes in surface runoff with possible floods and droughts, climate variations may affect groundwater through alteration of groundwater recharge with consequences for future water management. This study investigates the impact of climate change, according to the Special Report on Emission Scenarios (SRES) A1B, A2 and B1, on groundwater recharge in the catchment area of a fissured aquifer in the Black Forest, Germany, which has sparse groundwater data. The study uses a water-balance model considering a conceptual approach for groundwater-surface water exchange. River discharge data are used for model calibration and validation. The results show temporal and spatial changes in groundwater recharge. Groundwater recharge is progressively reduced for summer during the twenty-first century. The annual sum of groundwater recharge is affected negatively for scenarios A1B and A2. On average, groundwater recharge during the twenty-first century is reduced mainly for the lower parts of the valley and increased for the upper parts of the valley and the crests. The reduced storage of water as snow during winter due to projected higher air temperatures causes an important relative increase in rainfall and, therefore, higher groundwater recharge and river discharge.

Temperature, discharge, and stable isotope ratios of five karst springs in a mountainous area of Zigui County, Hubei Province, Central China, were analyzed. The purpose was to illustrate the heat exchanges linked to circulation depth in the exposed karst water systems through the development of a method for estimating heat input and heat flux during a rainstorm. Meteorological water in the study area conformed to a local meteoric water line (δD = 8.37 δ¹⁸O + 12.99) with a mean δ¹⁸O elevation gradient of −4.0‰ km⁻¹, which was used to estimate mean circulation depths of 209–686 m. The mean spring temperatures defined a vertical gradient of −5.4 °C km⁻¹, which resembled that of the stable atmosphere of the Earth, indicating that the thermal response patterns are mainly controlled by surface air temperature. Thermal convection after rainfall events dominated heat exchange between baseflow and recharge water, leading to a warmer and colder recharge during summer and winter, respectively, whereas thermal conduction dominated the heat exchange only between groundwater, surrounding geology, and the interface air under a condition of no rainfall, resulting in only small temperature variations of the baseflow. Successful application of the method for estimating heat exchange showed that the characteristics of shallow circulation, strong karstification, and well-developed epikarst readily allowed disruption of the thermal balance of the Yuquandong system, resulting in a poor heat regulation capacity, a larger variation of heat input, a lower mean heat flux, and lower baseflow temperatures compared to those of the Dayuquan system.

The McMurdo Dry Valleys (MDVs), Antarctica, exist in a hyperarid polar desert, underlain by deep permafrost. With an annual mean air temperature of −18 °C, the MDVs receive <10 cm snow-water equivalent each year, collecting in leeward patches across the landscape. The landscape is dominated by expansive ice-free areas of exposed soils, mountain glaciers, permanently ice-covered lakes, and stream channels. An active layer of seasonally thawed soil and sediment extends to less than 1 m from the surface. Despite the cold and low precipitation, liquid water is generated on glaciers and in snow patches during the austral summer, infiltrating the active layer. Across the MDVs, groundwater is generally confined to shallow depths and often in unsaturated conditions. The current understanding and the biogeochemical/ecological significance of four types of shallow groundwater features in the MDVs are reviewed: local soil-moisture patches that result from snow-patch melt, water tracks, wetted margins of streams and lakes, and hyporheic zones of streams. In general, each of these features enhances the movement of solutes across the landscape and generates soil conditions suitable for microbial and invertebrate communities.

Contributions of groundwater to the soil-water balance play an important role in areas with shallow water tables. The characteristics of daytime and nighttime water flux using non-weighing lysimeters were studied from June to September 2012 and 2013 in the extremely arid Xinjiang Uyghur Autonomous Region in northwestern China. The study consisted of nine treatments: three surface conditions, bare soil and cotton plants, each with water tables at depths of 1.0, 1.5, and 2.0 m; and plastic mulch with a water table at 1.5 m but with three percentages of open areas (POAs) in the plastic. The groundwater supply coefficient (SC) and the groundwater contribution (GC) generally varied with surface conditions. Both SC and GC decreased in the bare-soil and cotton treatments with increasing depth of the groundwater. Both SC and GC increased in the plastic-mulch treatment with increasing POA. Average nighttime GCs in the bare-soil treatments in July and August (the midsummer months) were 50.8–60.8 and 53.2–65.3 %, respectively, of the total daily contributions. Average nighttime GCs in the cotton treatments in July and August were 51.4–60.2 and 51.5–58.1 %, respectively, of the total daily contributions. The average GCs in June and September, however, were lower at night than during the daytime. Soil temperature may thus play a more important role than air temperature in the upflow of groundwater.