994 resultados para Agriculture--Chile--Maps


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"January 1996."

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The promoters of the large groundwater developments implemented in the 1970's paid little attention to the effects of pumping on soil moisture. A field study, conducted in 1979 in the Tern Area of the Shropshire Groundwater Scheme, revealed that significant quantities of the available moisture could be removed from the root zone of vegetation when drawdown of shallow watertables occurred. Arguments to this effect, supported by the field study evidence, were successfully presented at the Shropshire Groundwater Scheme public inquiry. The aim of this study has been to expand the work which was undertaken in connection with the Shropshire Groundwater Scheme, and to develop a method whereby the effects of groundwater pumping on vegetation can be assessed, and hence the impacts minimised. Two concepts, the critical height and the soil sensitivity depth, formulated during the initial work are at the core of the Environmental Impact Assessment method whose development is described. A programme of laboratory experiments on soil columns is described, as is the derivation of relationships for determining critical heights and field capacity moisture profiles. These relationships are subsequently employed in evaluating the effects of groundwater drawdown. In employing the environmental assessment technique, digitised maps of relevant features of the Tern Area are combined to produce composite maps delineating the extent of the areas which are potentially sensitive to groundwater drawdown. A series of crop yield/moisture loss functions are then employed to estimate the impact of simulated pumping events on the agricultural community of the Tern Area. Finally, guidelines, based on experience gained through evaluation of the Tern Area case study, are presented for use in the design of soil moisture monitoring systems and in the siting of boreholes. In addition recommendations are made for development of the EIA technique, and further research needs are identified.

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In addition to enhance agricultural productivity, synthetic nitrogen (N) and phosphorous (P) fertilizer application in croplands dramatically altered global nutrient budget, water quality, greenhouse gas balance, and their feedbacks to the climate system. However, due to the lack of geospatial fertilizer input data, current Earth system/land surface modeling studies have to ignore or use over-simplified data (e.g., static, spatially uniform fertilizer use) to characterize agricultural N and P input over decadal or century-long period. We therefore develop a global time-series gridded data of annual synthetic N and P fertilizer use rate in croplands, matched with HYDE 3,2 historical land use maps, at a resolution of 0.5º latitude by longitude during 1900-2013. Our data indicate N and P fertilizer use rates increased by approximately 8 times and 3 times, respectively, since the year 1961, when IFA (International Fertilizer Industry Association) and FAO (Food and Agricultural Organization) survey of country-level fertilizer input were available. Considering cropland expansion, increase of total fertilizer consumption amount is even larger. Hotspots of agricultural N fertilizer use shifted from the U.S. and Western Europe in the 1960s to East Asia in the early 21st century. P fertilizer input show the similar pattern with additional hotspot in Brazil. We find a global increase of fertilizer N/P ratio by 0.8 g N/g P per decade (p< 0.05) during 1961-2013, which may have important global implication of human impacts on agroecosystem functions in the long run. Our data can serve as one of critical input drivers for regional and global assessment on agricultural productivity, crop yield, agriculture-derived greenhouse gas balance, global nutrient budget, land-to-aquatic nutrient loss, and ecosystem feedback to the climate system.

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Tackling societal and environmental challenges requires new approaches that connect top-down global oversight with bottom-up subnational knowledge. We present a novel framework for participatory development of spatially explicit scenarios at national scale that model socioeconomic and environmental dynamics by reconciling local stakeholder perspectives and national spatial data. We illustrate results generated by this approach and evaluate its potential to contribute to a greater understanding of the relationship between development pathways and sustainability. Using the lens of land use and land cover changes, and engaging 240 stakeholders representing subnational (seven forest management zones) and the national level, we applied the framework to assess alternative development strategies in the Tanzania mainland to the year 2025, under either a business as usual or a green development scenario. In the business as usual scenario, no productivity gain is expected, cultivated land expands by ~ 2% per year (up to 88,808 km²), with large impacts on woodlands and wetlands. Despite legal protection, encroachment of natural forest occurs along reserve borders. Additional wood demand leads to degradation, i.e., loss of tree cover and biomass, up to 80,426 km² of wooded land. The alternative green economy scenario envisages decreasing degradation and deforestation with increasing productivity (+10%) and implementation of payment for ecosystem service schemes. In this scenario, cropland expands by 44,132 km² and the additional degradation is limited to 35,778 km². This scenario development framework captures perspectives and knowledge across a diverse range of stakeholders and regions. Although further effort is required to extend its applicability, improve users’ equity, and reduce costs the resulting spatial outputs can be used to inform national level planning and policy implementation associated with sustainable development, especially the REDD+ climate mitigation strategy.

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RESUMEN INTRODUCCION: Los riesgos psicosociales en los últimos años han venido tomando importancia debido a que están íntimamente relacionados con el desarrollo de enfermedades producidas por el estrés tanto en la población general como en la comunidad trabajadora. De esta manera los riesgos psicosociales se convierten en un foco de interés cuando de prevención en el trabajo se trata. OBJETIVO: Identificar los factores de riesgo psicosocial a los cuales se encuentran expuestos los trabajadores de una empresa agrícola y alimenticia ubicada en Chile en el año 2016. MÉTODOS: Se llevó a cabo un estudio de corte transversal con datos secundarios procedentes de 194 trabajadores. Se incluyeron variables socio-demográficas, laborales y las relacionadas con el riesgo psicosocial. Como instrumento se utilizó el cuestionario ISTAS 21, que permite la evaluación y prevención de dicho riesgo, mide las dimensiones de la exposición psicosocial y de la salud, el estrés y la satisfacción. En el análisis descriptivo en las variables cuantitativas se calcularon las medidas de tendencia central media, mediana y medidas de dispersión como rango y desviación estándar. En las cualitativas se calculó la frecuencia absoluta y porcentaje, se utilizó el programa estadístico SPSS versión 22. RESULTADOS: El mínimo de edad fue de 25 y el máximo de 55 años. Los grupos etarios predominantes fueron entre 25-30 años y 36-45 años. Se observó que la mayoría de los miembros de esta organización estuvo conformada por hombres. El nivel alto de riesgo psicosocial percibido por los trabajadores por porcentaje en tres de las cinco dimensiones se registró de la siguiente manera: Trabajo activo y posibilidades de desarrollo (48.5%); apoyo social y calidad de liderazgo (52.0%) y doble presencia (52.6%). Las subdimensiones que más se vieron afectadas por el riesgo alto fueron: influencia en el trabajo (69.4%); control sobre el tiempo de trabajo (53.1%); posibilidades de desarrollo en el trabajo (50.0%); claridad de rol (66.8%); calidad de la relación con superiores (52.6%), compañeros (48.8%) y carga de tareas domésticas (50.0%). CONCLUSIONES: El nivel de riesgo psicosocial percibido por los trabajadores fue de Riesgo Alto en tres de las cinco dimensiones del cuestionario SUSESO ISTAS-21 (dimensión Trabajo activo y posibilidades de desarrollo; apoyo social y calidad de liderazgo y doble presencia). A partir de estos hallazgos se concluye que si hay presencia importante de situaciones desfavorables para la salud mental de los trabajadores y un riesgo psicosocial alto que es necesario enfrentar a través de la implementación de estrategias encaminadas a reducir el riesgo en las subdimensiones que más alto riesgo presentaron.