The Government of Honduras piloted and adopted a major new data platform, “Agua de Honduras” that provides data on hydrology, vegetative cover, soil properties, along with future climate scenarios. Implemented by the Centro Internacional de Agricultura Tropical (CIAT) and contributing to the CGIAR Research Program on Water, Land and Ecosystems (WLE), the platform has been aiding water management decisions, including being used 150 times to identify rainwater harvesting sites and influencing at least one local land investment decision.

Water is one of the most important resources in agriculture and must be used efficiently, especially in irrigated agriculture. Accordingly, the objective of this study was: (i) to simulate the daily soil water balance (SWB) and the irrigation requirement of maize at the physiographic region level in Rio Grande do Sul (RS); (ii) to simulate the evapotranspiration deficit in non-irrigated areas, for different regions and sowing dates; and (iii) to quantify the requirement for supplementary irrigation, through the simulation of the soil water balance, and to estimate the water demand for the current area irrigated by a center pivot in some hydrographic basins of RS. The SIMDualKc model was used in the SWB simulation, for sowings on 10/05 and 10/20, for the 2010/2011 to 2021/2022 harvests. The input data in the model were the soil physical and water characteristics, meteorological data, crop data, soil cover, percolation parameters, and surface runoff, additionally to non-standard information, such as basal crop coefficients (Kcb) for the four phases of the crop development curve. The SWB showed that there are differences in the water requirement and irrigation requirements of maize for the Physiographic Regions of RS, which is due to meteorological and edaphoclimatic factors. The SWB indicated a lower water requirement for sowings performed on 10/20 for most regions, with the exception of Serra do Nordeste. Higher values of evapotranspiration (ETc) were found for the physiographic region of the Serra do Sudeste, while a higher necessity for supplementary irrigation was observed for the physiographic region of the Encosta Inferior do Vale do Nordeste. Lower ETc values were found in the southeastern region of the state, for the physiographic regions of the Grandes Lagoas, Depressão Central, and Litoral, which also have the lowest water requirements. The highest current evapotranspiration deficit (ETc act) was 214 mm and 204 mm, for the sowing dates of 10/05 and 10/20, respectively, in the region of Campanha-Bagé. The highest consumption of water for irrigation occurred in the hydrographic basins of Alto Jacuí, Ijuí, and Piratini. The Piratini hydrographic basin occupies the highest percentage of flow, with about 7.3% of the basin flow for the 10/05 sowing and 7.2% for the 10/20 sowing. The simulation of the water balance proved to be important for quantifying the water requirement of maize and the supplementary irrigation depth during the cycle, in order to estimate the water withdrawn from the springs in the different watersheds. | Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES | A água é um dos recursos mais importante na agricultura e deve ser utilizada da forma eficiente, principalmente na agricultura irrigada. Adequadamente, o objetivo deste estudo foi: (i) simular o balanço hídrico do solo (BHS) sequencial diário e a necessidade de irrigação de milho em nível de região fisiográfica no Rio Grande do Sul (RS); (ii) simular o déficit da evapotranspiração em áreas não irrigadas, para as diferentes regiões e datas de semeadura; e (iii) quantificar a necessidade de irrigação suplementar, através da simulação do balanço hídrico do solo, e estimar a demanda de água para a área atual irrigada por pivô central em algumas bacias hidrográficas do RS. O modelo SIMDualKc foi utilizado na simulação do SWB, para semeaduras em 05/10 e 20/10, para as safras de 2010/2011 a 2021/2022. Os dados de entrada no modelo foram as características físico-hídricas do solo, dados meteorológicos, dados da cultura, cobertura do solo, parâmetros da percolação e escoamento superficial, além das informações não-padrão, como os coeficientes de cultura basal (Kcb) para as quatro fases da curva de desenvolvimento da cultura. O SWB demonstrou que existem diferenças no requerimento hídrico e necessidade de irrigação do milho para as Regiões Fisiográficas do RS o que se deve aos fatores meteorológicos e edafoclimáticos. O SWB indicou menor requerimento hídrico para semeaduras realizadas em 20/10 para a maioria das regiões, com exceção da Serra do Nordeste. Maiores valores de evapotranspiração (ETc) foram encontrados para a região fisiográfica da Serra do Sudeste, ao passo que a maior necessidade de irrigação suplementar foi observada para a região fisiográfica da Encosta Inferior do vale do Nordeste. Menores valores de ETc foram encontrados na região sudeste do estado, para as regiões fisiográficas das Grandes Lagoas, Depressão Central e Litoral, que também apresentam as menores necessidades hídricas. O maior déficit de evapotranspiração atual (ETc act) foi de 214 mm e 204 mm, para as datas de semeadura de 05 e 20/10, respectivamente, na região da Campanha-Bagé. Os maiores consumos de água para irrigação se deram para as bacias hidrográficas de Alto Jacuí, Ijuí e Piratini. A bacia hidrográfica de Piratini ocupada o maior percentual de vazão, com cerca de 7,3% da vazão da bacia para a semeadura de 05/10 e 7,2% para a semeadura em 20/10. A simulação do balanço hídrico se mostrou importante para a quantificação do requerimento hídrico do milho e lâmina de irrigação suplementar durante o ciclo, para fins de estimar a água retirada dos mananciais nas diferentes bacias hidrográficas.

Se exponen algunos criterios sobre la calidad del agua para riego en lo que respecta a salinidad, sodicidad y toxicidad. Se señalan los parámetros a determinar cuando se evalúa la calidad de agua que incluyen Ph, contenido total de sales disueltas. Contenido de K, Cl, Na, B, índice de Mg, relación de adsorción de Na, Carbonato de Sodio residual y dureza. Se indican las normas de calidad de aguas de riego y su clasificació

Se exponen algunos criterios sobre la calidad del agua para riego en lo que respecta a salinidad, sodicidad y toxicidad. Se senalan los parametros a determinar cuando se evalua la calidad de agua que incluyen Ph, contenido total de sales disueltas. Contenido de K, Cl, Na, B, indice de Mg, relacion de adsorcion de Na, Carbonato de Sodio residual y dureza. Se indican las normas de calidad de aguas de riego y su clasificacio.

Endotherms dissipate heat to the environment to maintain a stable body temperature at high ambient temperatures, which requires them to maintain a balance between heat dissipation and water conservation. Birds are relatively small, contain a large amount of metabolically expensive tissue, and are mostly diurnal, making them susceptible to physiological challenges related to water balance and heat dissipation. We compiled total evaporative water loss (TEWL) measurements for 174 species of birds exposed to different temperatures and used comparative methods to examine their relationships with body size, ambient temperature, precipitation, diet, and diel activity cycle. TEWL in the thermoneutral zone (TNZ) was associated primarily with body mass and activity phase. Larger and more active-phase birds, with their higher metabolic rates, lost more water through evaporation than smaller, resting-phase birds, particularly at higher thermal exposures. However, maximum temperature of the natural habitat became an important determinant of TEWL when birds were exposed to temperatures exceeding the TNZ. Species from hotter climates exhibited higher TEWL. Adaptation to arid climates did not restrict evaporative water loss at thermal conditions within the TNZ, but promoted evaporative water loss at exposures above the TNZ. The TEWL of granivores, which ingest food with low water content, differed little from species with other food habitats under all thermal conditions. The effects of environmental covariates of TEWL were dissimilar across thermal exposures, suggesting no evidence for a tradeoff between water conservation in the TNZ and heat dissipation at exposure to higher temperatures. Thus, birds may be able to acclimate when climate change results in the need to increase heat dissipation due to warming, except perhaps in hot, arid environments where species will need to depend heavily upon evaporative cooling to maintain homeothermy.

Climate change is at the top of the development agenda in Central America. This region, together with the Caribbean, is highly vulnerable to the effects of climate change in Latin America. Climate change is manifesting itself through higher average temperatures and more frequent droughts that result in higher water stress, and through the rising frequency of extreme weather events such as tropical storms, hurricanes, floods and landslides, all of which pose significant challenges in the rural water supply and sanitation sector. The paper starts with a review of the historic data on temperature and precipitation trends in Central America and particularly at the regional level in Nicaragua. The data reveal a clear trend of the growing climate variability, increased water stress for crops, and greater frequency of extreme weather events. The rising intensity and frequency of ex-treme weather events is among the most critical risks to the region's development agenda, and they translate into high economic losses. This paper examines the impacts and implications of potential climate change on water resources in Nicaragua and makes key recommendations to integrate climate change and rural water supply and sanitation policies and programs in a way that increase resilience to current and future climate conditions. | 0

Este artículo describe el estudio realizado para la elaboración de una normativa que caracterice térmicamente los sistemas compactos de calentamiento de agua mediante energía solar residenciales en la República Argentina. La motivación para este trabajo la origina el hecho de instalación de equipos sin un conocimiento cabal de las prestaciones que estos dan para distintas condiciones climáticas y de descarga. Se propone la utilización de una Norma IRAM, basada en estándares internacionales, que permite ensayar un sistema compacto, dando como resultado una ecuación que estima la producción diaria de energía que proporcionaría una descarga completa del equipo. Se explican las tecnologías a las cuales aplica la norma y se comentan las mediciones que deben hacerse. Se remite este estudio a una norma existente en la Unión Europea, que toma por defecto la evaluación en cuatro ciudades de distintas regiones geográficas. Se hace un análisis comparativo en base a las latitudes de distintas ciudades de la República Argentina. Como ejemplo, se realizan estimaciones de predicción anual de un mismo equipo para dos ciudades distintas, observándose diferencias notables en fracción solar obtenida. Se proponen finalmente una serie de aspectos a trabajar para lograr un mejor aprovechamiento de la energía solar térmica residencial. | This paper describes a study performed in order to develop a standard to thermally characterize residential compact solar water heaters of the Argentine Republic. The motivation for this work originated from the installation of systems without a well-known service that they can provide for different climatic conditions and hot water demands. The use of an IRAM norm is proposed, which is based on international standards. This norm allows testing a compact system, giving as a result an equation to estimate the daily hot water production for a whole discharge of the storage. Different technologies to which this norm applies are explained and de measurements to perform are described. This study is based in a standard of the European Union, which takes four cities of different geographical regions as default to perform de evaluation following the standard indications. A comparative analysis is made based on different latitudes of Argentine cities. As an example, estimations to predict the annual energy production of the same system for two different cities were made, and notable differences in solar fraction were obtained. Finally, a series of aspects are considered, in order to work looking for a better residential solar thermal energy use. | Asociación Argentina de Energía Solar