5 resultados para irrigation management

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Watershed services are the benefits people obtain from the flow of water through a watershed. While demand for such services is increasing in most parts of the world, supply is getting more insecure due to human impacts on ecosystems such as climate or land use change. Population and water management authorities therefore require information on the potential availability of watershed services in the future and the trade-offs involved. In this study, the Soil and Water Assessment Tool (SWAT) is used to model watershed service availability for future management and climate change scenarios in the East African Pangani Basin. In order to quantify actual “benefits”, SWAT2005 was slightly modified, calibrated and configured at the required spatial and temporal resolution so that simulated water resources and processes could be characterized based on their valuation by stakeholders and their accessibility. The calibrated model was then used to evaluate three management and three climate scenarios. The results show that by the year 2025, not primarily the physical availability of water, but access to water resources and efficiency of use represent the greatest challenges. Water to cover basic human needs is available at least 95% of time but must be made accessible to the population through investments in distribution infrastructure. Concerning the trade-off between agricultural use and hydropower production, there is virtually no potential for an increase in hydropower even if it is given priority. Agriculture will necessarily expand spatially as a result of population growth, and can even benefit from higher irrigation water availability per area unit, given improved irrigation efficiency and enforced regulation to ensure equitable distribution of available water. The decline in services from natural terrestrial ecosystems (e.g. charcoal, food), due to the expansion of agriculture, increases the vulnerability of residents who depend on such services mostly in times of drought. The expected impacts of climate change may contribute to an increase or decrease in watershed service availability, but are only marginal and much lower than management impacts up to the year 2025.

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INTRODUCTION Out-migration from mountain areas is leaving behind half families and elderly to deal with managing the land alongside daily life challenges. A potential reduction of labour force as well as expertise on cropping practices, maintenance of terraces and irrigation canals, slope stabilization, grazing, forest and other land management practices are further challenged by changing climate conditions and increased environmental threats. An understanding of the resilience of managed land resources in order to enhance adaptation to environmental and socio-economic variability, and evidence of the impact of Sustainable Land Management (SLM) on the mitigation of environmental threats have so far not sufficiently been tackled. The study presented here aims to find out how land management in mountains is being affected by migration in the context of natural hazards and climate change in two study sites, namely Quillacollo District of Bolivia and Panchase area of Western Nepal, and which measures are needed to increase resilience of livelihoods and land management practices. The presentation includes draft results from first field work periods in both sites. A context of high vulnerability According to UNISDR, vulnerability is defined as “the characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard”.Hazards are another threat affecting people’s livelihood in mountainous area. They can be either natural or human induced. Landslides, debris flow and flood are affecting peopleGood land management can significantly reduce occurrence of hazards. In the opposite bad land management or land abandonment can lead to negative consequences on the land, and thus again increase vulnerability of people’s livelihoods. METHODS The study integrates bio-physical and socio-economic data through a case study as well as a mapping approach. From the social sciences, well-tested participatory qualitative methodologies, typically used in Vulnerability and Capacity Analyses, such as semi-structured interviews with so-called ‘key informants’, transect walks, participatory risk and social resource mapping are applied. The bio-physical analysis of the current environmental conditions determining hazards and structural vulnerability are obtained from remote sensing analysis, field work studies, and GIS analysis The assessment of the consequences of migration in the area of origin is linked with a mapping and appraisal of land management practices (www.wocat.net, Schwilch et al., 2011). The WOCAT mapping tool (WOCAT/LADA/DESIRE 2008) allows capturing the major land management practices / technologies, their spread, effectiveness and impact within a selected area. Data drawn from a variety of sources are compiled and harmonised by a team of experts, consisting of land degradation and conservation specialists working in consultation with land users from various backgrounds. The specialists’ and land users’ knowledge is combined with existing datasets and documents (maps, GIS layers, high-resolution satellite images, etc.) in workshops that are designed to build consensus regarding the variables used to assess land degradation and SLM. This process is also referred to as participatory expert assessment or consensus mapping. The WOCAT mapping and SLM documentation methodologies are used together with participatory mapping and other socio-economic data collection (interviews, questionnaires, focus group discussions, expert consultation) to combine information about migration types and land management issues. GIS and other spatial visualization tools (e.g. Google maps) will help to represent and understand these links. FIRST RESULTS Nepal In Nepal, migration is a common strategy to improve the livelihoods. Migrants are mostly men and they migrate to other Asian countries, first to India and then to the Gulf countries. Only a few women are migrating abroad. Women migrate essentially to main Nepali cities when they can afford it. Remittances are used primarily for food and education; however they are hardly used for agricultural purposes. Besides traditional agriculture being maintained, only few new practices are emerging, such as vegetable farming or agroforestry. The land abandonment is a growing consequence of outmigration, resulting in the spreading of invasive species. However, most impacts of migration on land management are not yet clear. Moreover, education is a major concern for the respondents; they want their children having a better education and get better opportunities. Linked to this, unemployment is another major concern of the respondents, which in turn is “solved” through outmigration. Bolivia Migration is a common livelihood strategy in Bolivia. In the area of study, whole families are migrating downward to the cities of the valleys or to other departments of Bolivia, especially to Chapare (tropics) for the coca production and to Santa Cruz. Some young people are migrating abroad, mostly to Argentina. There are few remittances and if those are sent to the families in the mountain areas, then they are mainly used for agriculture purpose. The impacts of migration on land management practices are not clear although there are some important aspects to be underlined. The people who move downward are still using their land and coming back during part of the week to work on it. As a consequence of this multi-residency, there is a tendency to reduce land management work or to change the way the land is used. As in Nepal, education is a very important issue in this area. There is no secondary school, and only one community has a primary school. After the 6th grade students have therefore to go down into the valley towns to study. The lack of basic education is pushing more and more people to move down and to leave the mountains. CONCLUSIONS This study is on-going, more data have to be collected to clearly assess the impacts of out-migration on land management in mountain areas. The first results of the study allow us to present a few interesting findings. The two case studies are very different, however in both areas, young people are not staying anymore in the mountains and leave behind half families and elderly to manage the land. Additionally in both cases education is a major reason for moving out, even though the causes are not always the same. More specifically, in the case of Nepal, the use of remittances underlines the fact that investment in agriculture is not the first choice of a family. In the case of Bolivia, some interesting findings showed that people continue to work on their lands even if they move downward. The further steps of the study will help to explore these interesting issues in more detail. REFERENCES Schwilch G., Bestelmeyer B., Bunning S., Critchley W., Herrick J., Kellner K., Liniger H.P., Nachtergaele F., Ritsema C.J., Schuster B., Tabo R., van Lynden G., Winslow M. 2011. Experiences in Monitoring and Assessment of Sustainable Land Management. Land Degradation & Development 22 (2), 214-225. Doi 10.1002/ldr.1040 WOCAT/LADA/DESIRE 2008. A Questionnaire for Mapping Land Degradation and Sustainable Land Management. Liniger H.P., van Lynden G., Nachtergaele F., Schwilch G. (eds), Centre for Development and Environment, Institute of Geography, University of Berne, Berne

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The response of montane and subalpine hay meadow plant and arthropod communities to the application of liquid manure and aerial irrigation – two novel, rapidly spreading management practices – remains poorly understood, which hampers the formulation of best practice management recommendations for both hay production and biodiversity preservation. In these nutrient-poor mountain grasslands, a moderate management regime could enhance overall conditions for biodiversity. This study experimentally assessed, at the site scale, among low-input montane and subalpine meadows, the short-term effects (1 year) of a moderate intensification (slurry fertilization: 26.7–53.3 kg N·ha−1·year−1; irrigation with sprinklers: 20 mm·week−1; singly or combined together) on plant species richness, vegetation structure, hay production, and arthropod abundance and biomass in the inner European Alps (Valais, SW Switzerland). Results show that (1) montane and subalpine hay meadow ecological communities respond very rapidly to an intensification of management practices; (2) on a short-term basis, a moderate intensification of very low-input hay meadows has positive effects on plant species richness, vegetation structure, hay production, and arthropod abundance and biomass; (3) vegetation structure is likely to be the key factor limiting arthropod abundance and biomass. Our ongoing experiments will in the longer term identify which level of management intensity achieves an optimal balance between biodiversity and hay production.

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Pleural infection is a frequent clinical condition. Prompt treatment has been shown to reduce hospital costs, morbidity and mortality. Recent advances in treatment have been variably implemented in clinical practice. This statement reviews the latest developments and concepts to improve clinical management and stimulate further research. The European Association for Cardio-Thoracic Surgery (EACTS) Thoracic Domain and the EACTS Pleural Diseases Working Group established a team of thoracic surgeons to produce a comprehensive review of available scientific evidence with the aim to cover all aspects of surgical practice related to its treatment, in particular focusing on: surgical treatment of empyema in adults; surgical treatment of empyema in children; and surgical treatment of post-pneumonectomy empyema (PPE). In the management of Stage 1 empyema, prompt pleural space chest tube drainage is required. In patients with Stage 2 or 3 empyema who are fit enough to undergo an operative procedure, there is a demonstrated benefit of surgical debridement or decortication [possibly by video-assisted thoracoscopic surgery (VATS)] over tube thoracostomy alone in terms of treatment success and reduction in hospital stay. In children, a primary operative approach is an effective management strategy, associated with a lower mortality rate and a reduction of tube thoracostomy duration, length of antibiotic therapy, reintervention rate and hospital stay. Intrapleural fibrinolytic therapy is a reasonable alternative to primary operative management. Uncomplicated PPE [without bronchopleural fistula (BPF)] can be effectively managed with minimally invasive techniques, including fenestration, pleural space irrigation and VATS debridement. PPE associated with BPF can be effectively managed with individualized open surgical techniques, including direct repair, myoplastic and thoracoplastic techniques. Intrathoracic vacuum-assisted closure may be considered as an adjunct to the standard treatment. The current literature cements the role of VATS in the management of pleural empyema, even if the choice of surgical approach relies on the individual surgeon's preference.