6,081 research outputs found

    Assessment of check dams’ role in flood hazard mapping in a semi-arid environment

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    This study aimed to examine flood hazard zoning and assess the role of check dams as effective hydraulic structures in reducing flood hazards. To this end, factors associated with topographic, hydrologic and human characteristics were used to develop indices for flood mapping and assessment. These indices and their components were weighed for flood hazard zoning using two methods: (i) a multi-criterion decision-making model in fuzzy logic and (ii) entropy weight. After preparing the flood hazard map by using the above indices and methods, the characteristics of the change‐point were used to assess the role of the check dams in reducing flood risk. The method was used in the Ilanlu catchment, located in the northwest of Hamadan province, Iran, where it is prone to frequent flood events. The results showed that the area of ‘very low’, ‘low’ and ‘moderate’ flood hazard zones increased from about 2.2% to 7.3%, 8.6% to 19.6% and 22.7% to 31.2% after the construction of check dams, respectively. Moreover, the area of ‘high’ and ‘very high’ flood hazard zones decreased from 39.8% to 29.6%, and 26.7% to 12.2%, respectively

    An assessment of the global impact of 21st century land use change on soil erosion

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    Human activity and related land use change are the primary cause of accelerated soil erosion, which has substantial implications for nutrient and carbon cycling, land productivity and in turn, worldwide socio-economic conditions. Here we present an unprecedentedly high resolution (250 × 250 m) global potential soil erosion model, using a combination of remote sensing, GIS modelling and census data. We challenge the previous annual soil erosion reference values as our estimate, of 35.9 Pg yr−1 of soil eroded in 2012, is at least two times lower. Moreover, we estimate the spatial and temporal effects of land use change between 2001 and 2012 and the potential offset of the global application of conservation practices. Our findings indicate a potential overall increase in global soil erosion driven by cropland expansion. The greatest increases are predicted to occur in Sub-Saharan Africa, South America and Southeast Asia. The least developed economies have been found to experience the highest estimates of soil erosion rates

    Assessing, valuing and protecting our environment- is there a statistical challenge to be answered?

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    This short article describes some of the evolution in environmental regulation, management and monitoring and the information needs, closely aligned to the statistical challenges to deliver the evidence base for change and effect

    Avaliação da erosão atual do solo na Bacia do Rio Piranga, em Minas Gerais

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    The objective of the present study was to apply the Revised Universal Soil Loss Equation (RUSLE) using GIS tools to the Piranga River Basin (PRB), Zona da Mata region, Minas Gerais state, in order to assess the current soil erosion (CSE). The maps of rainfall erosivity (R), soil erodibility (K), topographic factor (LS), and use and management of soils (CP) were developed from a geographical model adjusted for Southeastern Brazil, soil, Digital Elevation Model (DEM) and land use maps, respectively. It was observed that, in general, more than 77% of the basin presents soil losses smaller than 2.5 Mg ha-1 yr-1 being classified as “slight” current soil erosion, which mainly occurred due to the predominance of Latosols especially covered with forests. Furthermore, high soil losses rates were observed in areas with the combination of high LS values and Cambisols covered with pasture, representing 1.69% of the basin area. The use of the RUSLE model integrated to GIS showed to be an effective tool for assessing the current soil erosion in a basin’s scale, providing subsidies for adopting management and conservation practices of the soil and the water in PRB.O presente estudo teve como objetivo aplicar a Equação Universal de Perda de Solo Revisada (RUSLE), utilizando Sistema de Informação GeogrĂĄfica (GIS), na bacia hidrogrĂĄfica do rio Piranga (BHRP), na Zona da Mata Mineira, a fim de avaliar a erosĂŁo atual do solo (EAS). Os mapas de erosividade das chuvas (R), erodibilidade do solo (K), fator topogrĂĄfico (LS) e uso e manejo dos solos (CP) foram desenvolvidos a partir de um modelo geogrĂĄfico ajustado para o sudeste brasileiro, mapas de solo, Modelo Digital de Elevação (MDE) e uso do solo, respectivamente. Foi observado que, em geral, mais de 77% da bacia apresentou perdas de solo menores que 2,5 Mg ha-1 ano-1, sendo classificada como perda de solo “ligeira”, que ocorreu principalmente devido Ă  predominĂąncia de Latossolos cobertos com florestas. AlĂ©m disso, altas taxas de perdas de solo foram observadas em ĂĄreas com altos valores de LS e Cambissolos cobertos com pastagens, o que representa 1,69% da ĂĄrea da bacia. O uso da RUSLE integrado ao SIG mostrou ser uma ferramenta eficaz para avaliar a erosĂŁo atual do solo em grande escala, fornecendo subsĂ­dios para a adoção de prĂĄticas de manejo e conservação do solo e da ĂĄgua na BHRP

    Determinants of Adoption of Rainwater Management Technologies among Farm Households in the Nile River Basin

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    Agriculture is the main sector of the Ethiopian economy, as is the case in many sub-Saharan African countries. In this region, rainfall distribution is extremely uneven both spatially and temporally. Drought frequently results in crop failure, while high rainfall intensities result in low infiltration and high runoff, causing soil erosion and land degradation, which contribute to low agricultural productivity and high levels of food insecurity. High population growth and cultivation of steep and marginal lands, together with poor land management practices and lack of effective rainwater management strategies, aggravate the situation. Over the past two decades, the Government of Ethiopia has attempted to address these issues through the large-scale implementation of a range of soil and water conservation measures, including stone terraces, soil bunds and area enclosures. Despite these efforts, adoption of the interventions remains low. Studies from the Ethiopian Highlands show that the adoption of rainwater management technologies is influenced by a variety of factors, including biophysical characteristics such as topography, slope, soil fertility, rainfall amount and variability. However, even when technologies are appropriate to a particular biophysical setting, they may not be implemented, because farmers usually consider a variety of factors when making their decisions to adopt technologies. Thus, gaining an understanding of the factors that influence the adoption of rainwater management technologies is crucial for improved management of land and water resources. In this context, this study has been carried out within the framework of the Nile Basin Development Challenge (NBDC) project of the CGIAR Challenge Program on Water and Food (CPWF), which aims to improve rural livelihoods and their resilience through a landscape approach to rainwater management in the Ethiopian part of the Blue Nile River Basin

    Analysis of the peasants’ livelihood strategies in the Paute basin of Ecuador

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    The article analyses the livelihood of peasant farmers in the rural area of three parishes in the Paute basin in Ecuador. First, the article presents the gathered empirical data of the study sites, respectively the Pichacay in the Santa Ana parish, Caldera in the Javier Loyola parish, and Llavircay in the Rivera parish. Applying the Chayanovian and van der Ploeg interpretation frames, three types of peasant households could be distinguished, based upon their specific organizational forms of producing and reproducing their livelihoods. The article concludes that a more in-depth analysis is needed in the peasant’s art of farming, particularly in their core balance of being conditioned by and linked to as well as resistant to the capitalist economy.El artículo analiza la forma de sustento de los campesinos en el área rural de tres parroquias de la cuenca del Paute en Ecuador. En primer lugar, el artículo presenta los datos empíricos recopilados de los sitios de estudio, respectivamente Pichacay en la parroquia Santa Ana, Caldera en la parroquia Javier Loyola y Llavircay en la parroquia Rivera. Aplicando el marco de interpretación de Chayanov y van der Ploeg, se podrían distinguir tres tipos de hogares campesinos, basados en sus formas organizativas específicas de producir y reproducir sus medios de vida. El artículo concluye que es necesario un análisis más profundo del arte campesino de la agricultura, particularmente en su balance central de estar condicionado y vinculado y resistir a la economía capitalista

    Building a Composite Indicator to Measure Environmental Sustainability Using Alternative Weighting Methods

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    Environmental sustainability in agriculture can be measured through the construction of composite indicators. However, this is a challenging task because these indexes are heavily dependent on how the individual base indicators are weighted. The main aim of this paper is to contribute to the existing literature regarding the robustness of subjective (based on experts’ opinions) weighting methods when constructing a composite indicator for measuring environmental sustainability at the farm level. In particular, the study analyzes two multi-criteria techniques, the analytic hierarchy process and the recently developed best-worst method, as well as the more straightforward point allocation method. These alternative methods have been implemented to empirically assess the environmental performance of irrigated olive farms in Spain. Data for this case study were collected from a panel of 22 experts and a survey of 99 farms. The results obtained suggest that there are no statistically significant differences in the weights of the individual base indicators derived from the three weighting methods considered. Moreover, the ranking of the sampled farms, in terms of their level of environmental sustainability measured through the composite indicators proposed, is not dependent on the use of the different weighting methods. Thus, the results support the robustness of the three weighting methods considered

    Prospects for sustainable intensification of smallholder farming systems in Ethiopian highlands

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    2017 Summer.Includes bibliographical references.This dissertation examines the prospects of sustainable agricultural intensification by rural farming households in Ethiopia. Although widely accepted as the new paradigm for agricultural development in sub-Saharan Africa, several research and empirical questions still surround the concept of sustainable intensification, particularly its operationalization. Efforts to promote, measure and monitor progress towards sustainable intensification are hampered by the lack of quantifiable indicators at the farm level, as well as the uncertainty over the relationship between intensification and sustainability. This dissertation contributes to this knowledge gap by examining the relationship between agricultural intensification and sustainability, with a view to determine if sustainable paths of agricultural intensification are possible within the smallholder farming systems of Ethiopian highlands. To help better execute the research inquiry, and achieve the main goal of this study, the themes of this dissertation are addressed through three separate but interrelated essays, on top of the introductory and conclusion chapters. The first essay, presented in chapter two, examines the drivers and processes shaping agricultural intensification by smallholder farmers. This chapter contributes to the literature by providing evidence of how agricultural intensification depends on a wide range of factors, whose complex interactions give rise to different intensification pathways. The implication is that, even in a region that is undergoing the process of agricultural intensification, households are likely to respond differently to intensification incentives and production constraints, and thus pursue different paths of agricultural intensification. The second essay, chapter three, develops a methodological framework for defining elements of sustainability based on observed, context-specific priorities and technologies. Farm-level indicators of agricultural sustainability are developed using insights drawn from literature, and adapted to the Ethiopian context through consultations with agricultural experts and key stakeholders in the agricultural sector. A Data Envelopment Analysis (DEA) framework is applied to synthesize the selected indicators into a relative farm sustainability index, thus reducing subjectivity in the sustainability index. A generalized linear regression model applied on the computed sustainability scores shows that farm size, market access, access to off farm income, agricultural loans, access to agricultural extension and demonstration plots are key drivers of agricultural sustainability at the farm level. Despite being applied to the Ethiopian context; the methodology has broader policy implications and can be applied in many contexts. The third essay, chapter four, examines the relationship between agricultural intensification and relative farm sustainability, and identifies four clusters of farmers depending on their relative levels of intensification and sustainability. The main thrust of this essay is to examine whether farmers who are highly productive are also sustainable, and whether systems that are relatively more sustainable are mostly on the highly productive farms. The results show that of the farms that are relatively most intensive, in terms of the gross value of crop output per hectare, only 27 percent are relatively more sustainable. Of the farms that are relatively most sustainable, about 60 percent are more intensive. Overall, only 10 percent of the farms were both highly intensive and relatively more sustainable. In order to understand the typology of farmers that are likely to embark on sustainable paths of agricultural intensification, multivariate methods of Principal Components Analysis (PCA) and Cluster Analysis (CA) were used to cluster farmers according to their common characteristics. Multinomial Logit (MNL) regression models were used to model the probability of cluster membership as well as the likelihood of farmers embarking on different intensification trajectories. is used to analyze the odds of embarking on a sustainable intensification path. The results suggest that increasing farmers' access to technical information through demonstration plots and government extension services, addressing farm liquidity constraints, improving market access, as well fostering crop-livestock interactions, significantly increases the likelihood of sustainable intensification

    Creating a climate for food security: the business, people & landscapes in food production

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    AbstractBalancing human and environmental needs is urgent where food security and sustainability are under pressure from population increases and changing climates. Requirements of food security, social justice and environmental justice exacerbate the impact of agriculture on the supporting ecological environment. Viability of the Australian rural economy is intrinsically linked to food production and food security requiring systematic evaluation of climate change adaptation strategies for agricultural productivity.This food-systems research drew on global climate change literature to identify risks and adaptation. The transdisciplinary team applied specialist experience through collaboration in social science, economics and land-management to provide comprehensive methods to engage researchers and decision-makers making decisions across the food-system. Research focus on the dairy and horticulture sectors in the SW-WA and SEQld provided a comparative context in food-systems and regional economies. Expert knowledge was engaged through a series of panel meetings to test and challenge existing practice applying conceptual and empirical approaches in Structural Equation, Value-Chain, Supply-Chain modelling and Analytical Hierarchy modelling. This iterative action-research process provided immediate generation and transfer of expert knowledge across the involved sectors. The scenarios and adaptive strategies provide evidence-based pathways to strengthen food-systems; account for climate change mitigation and adaptation; and weather-proof regional economies in the face of climate change. Balancing human and environmental needs is urgent where food security and sustainability are under pressure from population increases and changing climates. Requirements of food security, social justice and environmental justice exacerbate the impact of agriculture on the supporting ecological environment. Viability of the Australian rural economy is intrinsically linked to food production and food security requiring systematic evaluation of climate change adaptation strategies for agricultural productivity.This food-systems research drew on global climate change literature to identify risks and adaptation. The transdisciplinary team applied specialist experience through collaboration in social science, economics and land-management to provide comprehensive methods to engage researchers and decision-makers making decisions across the food-system. Research focus on the dairy and horticulture sectors in the SW-WA and SEQld provided a comparative context in food-systems and regional economies. Expert knowledge was engaged through a series of panel meetings to test and challenge existing practice applying conceptual and empirical approaches in Structural Equation, Value-Chain, Supply-Chain modelling and Analytical Hierarchy modelling. This iterative action-research process provided immediate generation and transfer of expert knowledge across the involved sectors. The scenarios and adaptive strategies provide evidence-based pathways to strengthen food-systems; account for climate change mitigation and adaptation; and weather-proof regional economies in the face of climate change. The triple-bottom-line provided a comprehensive means of addressing social, economic and ecological requirements, and the modelling showed the interacting dynamics between these dimensions. In response to climate change, the agricultural sector must now optimise practices to address the interaction between economic, social and environmental investment. Differences in positions between the industry sector, the government and research sectors demonstrate the need for closer relationships between industry and government if climate change interventions are to be effectively targeted. Modelling shows that capacity for adaptation has a significant bearing on the success of implementing intervention strategies. Without intervention strategies to build viability and support, farm businesses are more likely to fail as a consequence of climate change. A framework of capitals that includes social components - cultural, human and social capital-, economic components -economic and physical capital - and ecological components -ecological and environmental capital - should be applied to address capacities. A priority assessment of climate change intervention strategies shows that strategies categorised as ‘Technology & Extension’ are most important in minimising risk from climate change impacts. To implement interventions to achieve ‘Food Business Resilience’, ‘Business Development’ strategies and alternative business models are most effective. ‘Research and Development’ interventions are essential to achieve enhanced ‘Adaptive Capacity’.The individual components of TBL Adaptive Capacity can be achieved through ‘Policy and Governance’ interventions for building ‘Social Capital’ capacity, ‘Research and Development’ will develop ‘Economic Capital’, and ‘Business Development’ strategies will build ‘Ecological Capital’.These strategic interventions will promote food security and maintain resilience in local food systems, agricultural production communities and markets, global industrial systems, and developing world food systems. Climate change mitigation and adaptation interventions reflect a rich conceptualisation drawing from the Australian context, but also acknowledging the moral context of global association.Please cite this report as:Wardell-Johnson, A, Uddin, N, Islam, N, Nath, T, Stockwell, B, Slade, C 2013 Creating a climate for food security: the businesses, people and landscapes in food production, National Climate Change Adaptation Research Facility, Gold Coast, pp. 144.Balancing human and environmental needs is urgent where food security and sustainability are under pressure from population increases and changing climates. Requirements of food security, social justice and environmental justice exacerbate the impact of agriculture on the supporting ecological environment. Viability of the Australian rural economy is intrinsically linked to food production and food security requiring systematic evaluation of climate change adaptation strategies for agricultural productivity.This food-systems research drew on global climate change literature to identify risks and adaptation. The transdisciplinary team applied specialist experience through collaboration in social science, economics and land-management to provide comprehensive methods to engage researchers and decision-makers making decisions across the food-system. Research focus on the dairy and horticulture sectors in the SW-WA and SEQld provided a comparative context in food-systems and regional economies. Expert knowledge was engaged through a series of panel meetings to test and challenge existing practice applying conceptual and empirical approaches in Structural Equation, Value-Chain, Supply-Chain modelling and Analytical Hierarchy modelling. This iterative action-research process provided immediate generation and transfer of expert knowledge across the involved sectors. The scenarios and adaptive strategies provide evidence-based pathways to strengthen food-systems; account for climate change mitigation and adaptation; and weather-proof regional economies in the face of climate change. The triple-bottom-line provided a comprehensive means of addressing social, economic and ecological requirements, and the modelling showed the interacting dynamics between these dimensions. In response to climate change, the agricultural sector must now optimise practices to address the interaction between economic, social and environmental investment. Differences in positions between the industry sector, the government and research sectors demonstrate the need for closer relationships between industry and government if climate change interventions are to be effectively targeted. Modelling shows that capacity for adaptation has a significant bearing on the success of implementing intervention strategies. Without intervention strategies to build viability and support, farm businesses are more likely to fail as a consequence of climate change. A framework of capitals that includes social components - cultural, human and social capital-, economic components -economic and physical capital - and ecological components -ecological and environmental capital - should be applied to address capacities. A priority assessment of climate change intervention strategies shows that strategies categorised as ‘Technology & Extension’ are most important in minimising risk from climate change impacts. To implement interventions to achieve ‘Food Business Resilience’, ‘Business Development’ strategies and alternative business models are most effective. ‘Research and Development’ interventions are essential to achieve enhanced ‘Adaptive Capacity’.The individual components of TBL Adaptive Capacity can be achieved through ‘Policy and Governance’ interventions for building ‘Social Capital’ capacity, ‘Research and Development’ will develop ‘Economic Capital’, and ‘Business Development’ strategies will build ‘Ecological Capital’.These strategic interventions will promote food security and maintain resilience in local food systems, agricultural production communities and markets, global industrial systems, and developing world food systems. Climate change mitigation and adaptation interventions reflect a rich conceptualisation drawing from the Australian context, but also acknowledging the moral context of global association
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