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1.
Climate variability and change mitigation and adaptation policies need to prioritize land users needs at local level because it is at this level that impact is felt most. In order to address the challenge of socio-economic and unique regional geographical setting, a customized methodological framework was developed for application in assessment of climate change vulnerability perception and adaptation options around the East African region. Indicators of climate change and variability most appropriate for the region were derived from focused discussions involving key informants in various sectors of the economy drawn from three East African countries. Using these indicators, a structured questionnaire was developed from which surveys and interviews were done on selected sample of target population of farming communities in the Mt. Kenya region. The key highlights of the questionnaire were vulnerability and adaptation. Data obtained from respondents was standardized and subjected to multivariate and ANOVA analysis. Based on principle component analysis (PCA), two main vulnerability categories were identified namely the social and the bio-physical vulnerability indicators. Analysis of variance using Kruskal-Wallis test showed significant statistical variation (P ≤ 0.05) in the perceived vulnerability across the spatial distribution of the 198 respondents. Three insights were distinguished and were discernible by agro-ecological zones. Different vulnerability profiles and adaptive capacity profiles were generated demonstrating the need for prioritizing adaptation and mitigation efforts at local level. There was a high correlation between the bio-physical and social factor/livelihood variables that were assessed.  相似文献   

2.
Agriculture is one of the most vulnerable sectors to climate change. The current vulnerability assessments through traditional fragmented sectoral methods are insufficient to capture the effects on complex agricultural systems. Therefore, the traditional methods need to be replaced by integrated approaches. The objective of this study is to propose a holistic vulnerability assessment method for agricultural systems. By aggregating both agro-ecological and socio-economic information, we develop an agricultural systems vulnerability index (ASVI) which allows for (i) a classification of geographical units according to their vulnerability level, (ii) an identification of key determinants of vulnerability for each unit and (iii) an assessment of adaptation policy scenarios considering their effects on the sustainability of the analysed systems. The proposed method is applied in the Khorezm region of Uzbekistan—a representative irrigated agricultural region in the lower Amu Darya river basin. A decision support tool is used to facilitate multi-criteria decision analysis, including the computation of the index and performing sensitivity analysis of the results. The assessment for Khorezm reveals significant spatial differences of vulnerability levels due to a variation of contributing factors, e.g. natural resources, water productivity, rural-urban ratio. It reveals also that feasible land and water management policies could reduce the vulnerability in Khorezm, particularly in the districts with the poorest agro-ecological conditions. Overall, the proposed method could support national and local authorities in the identification of sustainable adaptation policies for the agriculture sector.  相似文献   

3.
Nitrates leaching from agricultural land in Hamadan, western Iran   总被引:2,自引:0,他引:2  
Nitrogen (N) is vital for plant and microbial growth and rather large amounts are required by most arable and horticulture plants. High nitrate (NO3) levels of water supplies have been attributed to leaching from the soil and into water systems. In the arid and semi-arid regions, irrigation water carries NO3 into groundwater. This study was conducted to investigate NO3 pollution of groundwater in Hamadan, western Iran. The water samples were mostly taken from domestic and community wells. In this area, the drinking water supply comes mainly from groundwater sources. Nitrate concentrations in the well samples varied from 3 to 252 with the average of 49 mg l−1. Results showed that of 311 wells, 196 (63%) had levels less than 50 mg l−1 and 115 (37%) had levels in excess of the 50 mg l−1 NO3. Agriculture is the dominant land use in the area and application of N fertilizers clearly has an impact on groundwater. If agricultural losses remain stable, it could be expected that the concentration of NO3 in groundwater will reach or exceed the international recommendations for drinking water (50 mg l−1) in the future. Irrigation with high NO3 groundwater can minimise the requirement for N fertilizers. To maintain yield increase and minimise NO3 pollution of the groundwater, best management practices, for N fertilizer use should be applied and excessive fertilizer application prevented.  相似文献   

4.
To prepare agricultural systems for climate change, scientists need to be able to effectively engage with land managers and policy makers to explore potential solutions. An ongoing challenge in engagement is to distil the complexity of climate-change-management-change interactions in agro-ecological systems to identify responses that are most important for adaptation planning. This paper presents an approach for selecting climate change scenarios to provide a focal point for engaging with stakeholders to evaluate adaptation options and communicate assessment outcomes. We illustrate how scenarios selected with the approach can be used by evaluating climate change impacts and an adaptation option for livestock industries in the north-east Australian rangelands. Climate change impacts on forage production, animal liveweight gain and soil loss are found to track projected climate changes in four pasture communities; increasing by up to 50% and declining by up to 110% in response to doubled atmospheric carbon-dioxide (CO2), 4°C warming, and +20% to ?40% changes in mean annual rainfall. The effectiveness of reducing grazing pressure as an adaptation option shows a similar response; resulting in higher forage production (up to 40%), animal liveweight gains (up to 59%) and gross margins (up to 40%), and reduced soil erosion (down by 91%) per hectare relative to the baseline management. The results show that a few key scenarios may be selected to represent the range of global climate model (GCM) projections for use in assessing and communicating impacts and adaptation; simplifying the assessments and allowing limits to the effectiveness of adaptation options to be explored. The approach provides a framework for capturing and communicating trends in climate change impacts and the utility of options, which are required for successful engagement of stakeholders in finding viable adaption responses.  相似文献   

5.
Continuous cropping in the absence of external nutrient inputs to soils has led to the expression of poorly productive patches in farmers’ fields of western Kenya. Farmers attempting to correct these conditions are often confused by the spatial and symptomatic irregularity of affected plants and, until recently, no soil management product was commercially available that is specifically formulated to restore soil fertility to these patches. PREP-PAC consists of 2.0 kg of Minjingu rock phosphate (RP), 200 g of urea, seeds of various symbiotic nitrogen-fixing food legumes, rhizobial inoculant, gum arabic seed adhesive, lime for seed pelleting, and instructions for the use of these materials. It is intended for addition to 25 m2 and produced at a cost of $ 0.56 per unit. The general principle is to apply slowly available RP sufficient for several cropping seasons with readily available nitrogenous fertilizer and to intercrop farmer’s maize (Zea mays) with a legume that provides residual fixed-nitrogen and organic inputs to the soil. This approach was tested in on-farm experiments conducted in collaboration with several grassroots rural development organizations. An experiment examined interactions between PREP-PAC components in a maize–soybean (Glycine max) intercrop in nutrient-depleted soils with sandy and clayey surface horizons. The treatments included ±RP, ±urea, and ±inoculants arranged as a 23 factorial with four replicates at each location. Total value of the intercrops ranged between $ 0.83 in the unamended plots and $ 2.44 in plots treated with PREP-PAC. Significant positive effects were observed with the addition of RP (P<0.001), urea (P=0.04), and inoculant (P=0.01) and in interactions between RP and urea (P=0.02) or inoculant (P=0.07). The return ratio to PREP-PAC investment was 2.6 in the sandy soil and 3.7 in the clay. PREP-PACs were tested on-farm in 52 symptomatic patches containing maize–bean intercrops with and without an improved variety of climbing Phaseolus vulgaris cv. Flora. Unamended patches (25 m2=0.0025 ha) produced 1.6 kg maize and 0.08 kg bean. With addition of PREP-PAC containing Flora, yields increased to 4.1 kg maize and 1.1 kg bean (P<0.001 for both crops). Improvement in bean yield during the first cropping season nearly offset PREP-PAC’s investment costs. PREP-PAC is a strategic approach because all of its ingredients, except for urea, originate from East Africa, and are relatively inexpensive; the product is intended for distribution through existing retail and development networks.  相似文献   

6.
Recent interest in sustainable forest management planning in the Yukon has coincided with growing public awareness of climate change, providing an opportunity to explore how forestry plans are incorporating climate change. In this paper, the Strategic Forest Management Plans for the Champagne and Aishihik First Nations Traditional Territory (CATT) and the Teslin Tlingit Traditional Territory (TTTT) are examined for evidence of adaptation to climate change. For each plan, management policies and practices that are also recognized as ways to adapt to climate change are identified to provide information on the incremental costs and benefits of additional adaptation efforts. A typology for classifying sustainable forest management plans according to how they address climate change is proposed and applied to the CATT and TTTT plans. This typology, which may be useful to any future retrospective assessments on how successful these or other sustainable forest management plans have been in addressing and managing the risks posed by climate change, consists of a matrix that categorizes plans into one of four types; (1) proactive-direct, (2) proactive-indirect, (3) reactive-direct, and (4) reactive-indirect. Neither of the plans available for the southern Yukon explicitly identifies climate change vulnerabilities and actions that will be taken to reduce those vulnerabilities and manage risks. However, both plans have incorporated some examples of ‘best management practices’ for sustainable forest management that are also consistent with appropriate climate adaptation responses. Even in a jurisdiction facing rapid ecological changes driven by climate change, where there is a relatively high level of awareness of climate change and its implications, forestry planning processes have yet to grapple directly with the risks that climate change may pose to the ability of forest managers to achieve the stated goals and objectives of sustainable forest management plans.
J. L. InnesEmail:
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7.
The processes of nutrient depletion and soil degradation that limit productivity of smallholder African farms are spatially heterogeneous. Causes of variability in soil fertility management at different scales of analysis are both biophysical and socio-economic. Such heterogeneity is categorised in this study, which quantifies its impact on nutrient flows and soil fertility status at region and farm scales, as a first step in identifying spatial and temporal niches for targeting of soil fertility management strategies and technologies. Transects for soil profile observation, participatory rural appraisal techniques and classical soil sampling and chemical analysis were sampled across 60 farms in three sub-locations (Emuhaia, Shinyalu, Aludeka), which together represent much of the variability found in the highlands of western Kenya. Five representative farm types were identified using socio-economic information and considering production activities, household objectives and the main constraints faced by farmers. Soil fertility management and nutrient resource flows were studied for each farm type and related to differences in soil fertility status at farm scale. Farm types 1 and 2 were the wealthiest; the former relied on off-farm income and farmed small pieces of land (0.6–1.1 ha) while the latter farmed relatively large land areas (1.6–3.8 ha) mainly with cash crops. The poorest farm type 5 also farmed small pieces of land (0.4–1.0 ha) but relied on low wages derived from working for wealthier farmers. Both farm types 1 and 5 relied on off-farm earnings and sold the least amounts of farm produce to the market, though the magnitude of their cash, labour and nutrient flows was contrasting. Farms of types 3 and 4 were intermediate in size and wealth, and represented different crop production strategies for self-consumption and the market. Average grain yields fluctuated around 1 t ha−1 year−1 for all farm types and sub-locations. Grain production by farms of types 4 and 5 was much below annual family requirements, estimated at 170 kg person−1 year−1. Household wealth and production orientation affected the pattern of resource flow at farm scale. In the land-constrained farms of type 1, mineral fertilisers were often used more intensively (ca. 50 kg ha−1), though with varying application rates (14–92 kg ha−1). The use of animal manure in such small farms (e.g. 2.2 t year−1) represented intensities of use of up to 8 t ha−1, and a net accumulation of C and macronutrients brought into the farm by livestock. In farms of type 5, intensities of use of mineral and organic fertilisers ranged between 0–12 kg ha−1 and 0–0.5 t ha−1, respectively. A consistent trend of decreasing input use from farm types 1–5 was generally observed, but nutrient resources and land management practices (e.g. fallow) differed enormously between sub-locations. Inputs of nutrients were almost nil in Aludeka farms. Both inherent soil properties and management explained the variability found in soil fertility status. Texture explained the variation observed in soil C and related total N between sub-locations, whereas P availability varied mainly between farm types as affected by input use.  相似文献   

8.
This work presents a framework for viewing agricultural adaptation, emphasizing the multiple spatial and temporal scales on which individuals and institutions process information on changes in their environment. The framework is offered as a means to gain perspective on the role of climate variability and change in agricultural adaptation, and developed for a case study of Australian agriculture. To study adaptation issues at the scale of individual farms we developed a simple modelling framework. The model highlights the decision making element of adaptation in light of uncertainty, and underscores the importance of decision information related to climate variability. Model results show that the assumption of perfect information for farmers systematically overpredicts adaptive performance. The results also suggest that farmers who make tactical planting decisions on the basis of historical climate information are outperformed by those who use even moderately successful seasonal forecast information. Analysis at continental scales highlights the prominent role of the decline in economic operating conditions on Australian agriculture. Examples from segments of the agricultural industry in Australia are given to illustrate the importance of appropriate scale attribution in adapting to environmental changes. In particular, adaptations oriented toward short time scale changes in the farming environment (droughts, market fluctuations) can be limited in their efficacy by constraints imposed by broad changes in the soil/water base and economic environment occuring over longer time scales. The case study also makes the point that adaptation must be defined in reference to some goal, which is ultimately a social and political exercise. Overall, this study highlights the importance of allowing more complexity (limited information, risk aversion, cross-scale interactions, mis-attribution of cause and effect, background context, identification of goals) in representing adaptation processes in climate change studies.  相似文献   

9.
While Carbon (C) sequestration on farmlands may contribute to mitigate CO2 concentrations in the atmosphere, greater agro-biodiversity may ensure longer term stability of C storage in fluctuating environments. This study was conducted in the highlands of western Kenya, a region with high potential for agroforestry, with the objectives of assessing current biodiversity and aboveground C stocks in perennial vegetation growing on farmland, and estimating C sequestration potential in aboveground C pools. Allometric models were developed to estimate aboveground biomass of trees and hedgerows, and an inventory of perennial vegetation was conducted in 35 farms in Vihiga and Siaya districts. Values of the Shannon index (H), used to evaluate biodiversity, ranged from 0.01 in woodlots through 0.4–0.6 in food crop plots, to 1.3–1.6 in homegardens. Eucalyptus saligna was the most frequent tree species found as individual trees (20%), in windrows (47%), and in woodlots (99%) in Vihiga and the most frequent in woodlots (96%) in Siaya. Trees represented the most important C pool in aboveground biomass of perennial plants growing on-farm, contributing to 81 and 55% of total aboveground farm C in Vihiga and Siaya, respectively, followed by hedgerows (13 and 39%, respectively) and permanent crop stands (5 and 6%, respectively). Most of the tree C was located in woodlots in Vihiga (61%) and in individual trees growing in or around food crop plots in Siaya (57%). The homegardens represented the second C pool in importance, with 25 and 33% of C stocks in Vihiga and Siaya, respectively. Considering the mean total aboveground C stocks observed, and taking the average farm sizes of Vihiga (0.6 ha) and Siaya (1.4 ha), an average farm would store 6.5 ± 0.1 Mg C farm?1 in Vihiga and 12.4 ± 0.1 Mg C farm?1 in Siaya. At both sites, the C sequestration potential in perennial aboveground biomass was estimated at ca. 16 Mg C ha?1. With the current market price for carbon, the implementation of Clean Development Mechanism Afforestation/Reforestation (CDM A/R) projects seems unfeasible, due to the large number of small farms (between 140 and 300) necessary to achieve a critical land area able to compensate the concomitant minimum transaction costs. Higher financial compensation for C sequestration projects that encourage biodiversity would allow clearer win–win scenarios for smallholder farmers. Thus, a better valuation of ecosystem services should encourage C sequestration together with on-farm biodiversity when promoting CDM A/R projects.  相似文献   

10.

With socioeconomic development, the shift from staple food-based to diversified and nutrition-dense diet types will put pressure on land resources in Africa. In order to elaborate the impact of dietary pattern on arable land resources, we classify all African countries into five clusters according to their dietary characteristics and the change patterns of diet, and assess how much land needed for each cluster to feed its people from 1961 to 2011. We then quantify the contributions of dietary pattern, along with population growth and agricultural technology, to the land requirements for food (LRF) for each cluster. Most clusters’ dietary patterns in Africa were dominated by staple food and at low nutritional levels, lagging far behind those of developed regions, with great potential for change. Throughout the whole time period, population growth, rather than diet, was the major driver of the LRF. But after 1991, the contribution of dietary pattern gradually increased and exceeded the contribution of agricultural productivity for all five dietary clusters. Our results show that more research should focus on how to sustainably increase animal-derived food productivity. Meanwhile, a call for more researches needs to focus on the diet and its impact on food and nutrition security, especially in less-developed areas. As the African cities have been rapidly sprawling, it is important to focus on the interaction between food security and urbanization in Africa.

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11.
In the northernmost region of Japan (Hokkaido Island), earlier onsets of thick snowcover in recent years (post 1980) have reduced the penetration depth of soil frost, resulting in over-winter survival of unharvested small potato (Solanum tuberosum) tubers that emerge as weeds in the spring in rotation crop fields. To prevent the occurrence of potato weeds, a method was developed to manipulate soil-frost depths by artificially controlling snowcover thickness, guided by a simple numerical model that simulates soil freezing-thawing processes using daily mean air temperature and snowcover thinckness as input variables. The method involves removal of snowcover to expose the soil surface in the beginning of winter until the soil freezes to a sufficient depth. After that time, snow is deposited back or allowed to accumulate naturally to prevent further penetration of frost, which may cause undesirable delay in the seeding of spring crops. Field trials indicated that the model predicted frost depths within several centimeters of observed values, when measured temperature and snowcover thickness were used as model input. Based on the field and laboratory data, a soil temperature of −3°C is necessary for complete elimination of potato tubers. To achieve this temperature in potato-burial zones without causing excessive freezing, an optimal frost depth is 0.3 to 0.4 m. The method is being adopted by progressive potato producers in the region, who use tractor-mounted snow ploughs to manipulate snowcover over a large scale. This is an emerging new technology for agricultural adaptation to climate variability.  相似文献   

12.
This paper explores the lessons learned by leaders in agricultural adaptation planning in order to assist other jurisdictions to develop adaptation strategies. It seeks to identify effective institutional, participatory and collaborative processes involved in designing agricultural adaptation strategies at the national and sub-national levels in Germany, Finland, the United Kingdom, the United States and Canada. Its methodology is based on review of agricultural adaptation policy documents, research initiatives, stakeholder engagement processes, and cross-sectoral collaborations as well as interviews with key informants such as leaders and actors in adaptation planning. The gathered data show that early adapters have an improved regional and national understanding of climatic impacts, and of the risks to agriculture before the initiation of the planning process. The results indicate that the interplay between bottom-up and top-down initiatives has been crucial in the development of adaptation strategies. The former has provided rich and robust participation in designing, implementing and monitoring adaptations, while the latter was important for prioritizing and legitimizing the development of strategy. It also provided access to high-level decision makers and funding. The results of the study suggest that fostering cross-sectoral collaborations—especially by focusing on broader questions such as the role of agriculture in society—has become an important part of adaptation planning. Finally, our results also stress that adaptation planning in agriculture could be enhanced by skills development and mutual learning across stakeholder groups, research and policy-makers, and through the ongoing interactive development of institutional capabilities.  相似文献   

13.
14.
The production of tropical agricultural commodities, such as cocoa (Theobroma cacao) and coffee (Coffea spp.), the countries and communities engaged in it, and the industries dependent on these commodities, are vulnerable to climate change. This is especially so where a large percentage of the global supply is grown in a single geographical region. Fortunately, there is often considerable spatial heterogeneity in the vulnerability to climate change within affected regions, implying that local production losses could be compensated through intensification and expansion of production elsewhere. However, this requires that site-level actions are integrated into a regional approach to climate change adaptation. We discuss here such a regional approach for cocoa in West Africa, where 70 % of global cocoa supply originates. On the basis of a statistical model of relative climatic suitability calibrated on West African cocoa farming areas and average climate projections for the 2030s and 2050s of, respectively, 15 and 19 Global Circulation Models, we divide the region into three adaptation zones: (i) a little affected zone permitting intensification and/or expansion of cocoa farming; (ii) a moderately affected zone requiring diversification and agronomic adjustments of farming practices; and (iii) a severely affected zone with need for progressive crop change. We argue that for tropical agricultural commodities, larger-scale adaptation planning that attempts to balance production trends across countries and regions could help reduce negative impacts of climate change on regional economies and global commodity supplies, despite the institutional challenges that this integration may pose.  相似文献   

15.
16.
Managing risk by adapting long-lived infrastructure to the effects of climate change must become a regular part of planning for water supply, sewer, wastewater treatment, and other urban infrastructure during this century. The New York City Department of Environmental Protection (NYCDEP), the agency responsible for managing New York City’s (NYC) water supply, sewer, and wastewater treatment systems, has developed a climate risk management framework through its Climate Change Task Force, a government-university collaborative effort. Its purpose is to ensure that NYCDEP’s strategic and capital planning take into account the potential risks of climate change—sea-level rise, higher temperature, increases in extreme events, changes in drought and flood frequency and intensity, and changing precipitation patterns—on NYC’s water systems. This approach will enable NYCDEP and other agencies to incorporate adaptations to the risks of climate change into their management, investment, and policy decisions over the long term as a regular part of their planning activities. The framework includes a 9-step Adaptation Assessment procedure. Potential climate change adaptations are divided into management, infrastructure, and policy categories, and are assessed by their relevance in terms of climate change time-frame (immediate, medium, and long term), the capital cycle, costs, and other risks. The approach focuses on the water supply, sewer, and wastewater treatment systems of NYC, but has wide application for other urban areas, especially those in coastal locations.  相似文献   

17.
18.
Agriculture consumes more than two-thirds of global fresh water out of which 90 % is used by developing countries. Freshwater consumption worldwide is expected to rise another 25 %by 2030 due to increase in population from 6.6 billion currently to about 8 billion by 2030 and over 9 billion by 2050. Worldwide climate change and variability are affecting water resources and agricultural production and in India Ganga Plain region is one of them. Hydroclimatic changes are very prominent in all the regions of Ganga Plain. Climate change and variability impacts are further drying the semi-arid areas and may cause serious problem of water and food scarcity for about 250 million people of the area. About 80 million ha out of total 141 million ha net cultivated area of India is rainfed, which contributes approximately 44 % of total food production has been severely affected by climate change. Further changing climatic conditions are causing prominent hydrological variations like change in drainage density, river morphology (tectonic control) & geometry, water quality and precipitation. Majority of the river channels seen today in the Ganga Plain has migrated from their historic positions. Large scale changes in land use and land cover pattern, cropping pattern, drainage pattern and over exploitation of water resources are modifying the hydrological cycle in Ganga basin. The frequency of floods and drought and its intensity has increased manifold. Ganga Plain rivers has changed their course with time and the regional hydrological conditions shows full control over the rates and processes by which environments geomorphically evolve. Approximately 47 % of total irrigated area of the country is located in Ganga Plain, which is severely affected by changing climatic conditions. In long run climate change will affect the quantity and quality of the crops and the crop yield is going to be down. This will increase the already high food inflation in the country. The warmer atmospheric temperatures and drought conditions will increase soil salinization, desertification and drying-up of aquifer, while flooding conditions will escalate soil erosion, soil degradation and sedimentation. The aim of this study is to understand the impact of different hydrological changes due to climatic conditions and come up with easily and economically feasible solutions effective in addressing the problem of water and food scarcity in future.  相似文献   

19.
Bovine spongiform encephalopathy (BSE) has been documented in 28 countries and adversely affected farmers and rural communities around the world. Our study examines the impacts of and adaptive responses of producers to BSE in western Canada. Moreover, it explores the role that holistic management (HM), and its combined focus on environmental, social, and economic sustainability, might play in mitigating the effects of BSE. One survey was sent to 835 HM producers and another to 9,740 producers across Manitoba, Saskatchewan, and Alberta. The disease, and concomitant climate change and low commodity prices, had devastating impacts on both groups. Yet, HM producers were much more optimistic about their ability to adapt to BSE and the future of agriculture than their non-HM counterparts. Social networks, namely HM clubs and the larger HM community, enabled these producers to mitigate the impacts of BSE. Agronomic responses, especially those associated with rotational grazing and increases in on-farm biodiversity were also important. That HM has been such an effective adaptive response to BSE indicates the importance of this and other grassroots responses to rural crises, whether they be associated with zoonotic diseases or indeed environmental change as a whole.  相似文献   

20.
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