共查询到20条相似文献，搜索用时 625 毫秒
1.
Crystele Leauthaud Stéphanie Duvail Olivier Hamerlynck Jean-Luc Paul Hubert Cochet Judith Nyunja Jean Albergel Olivier Grünberger 《Global Environmental Change》2013,23(1):252-263
Wetlands are highly dynamic and productive systems that have been under increased pressure from changes in land use and water management strategies. In Eastern Africa, wetlands provide resources at multiple spatial and temporal levels through farming, fishing, livestock ownership and a host of other ecosystem services that sustain the local economy and individual livelihoods. As part of a broader effort to describe future development scenarios for East African coastal wetlands, this qualitative study focuses on understanding the processes by which river water depletion has affected local food production systems in Kenya's Tana River Delta over the past 50 years, and how this situation has impacted residents’ livelihoods and well-being. Interviews performed in six villages among various ethnic groups, geographical locations and resource profiles indicated that the agro-ecological production systems formerly in place were adapted to the river's dynamic flooding patterns. As these flooding patterns changed, the local population diversified and abandoned or adopted various farming, fishing and livestock-rearing techniques. Despite these efforts, the decrease in water availability affected each subcomponent of the production systems under study, which led to their collapse in the 1990s. Water depletion negatively impacted local human well-being through the loss of food security. The current study provides a detailed account of the dynamics of agro-ecological production systems facing the effects of river water depletion in a wetland-associated environment in Sub-Saharan Africa. 相似文献
2.
The Amazon region has been undergoing profound transformations since the late ‘70s through forest degradation, land use changes and effects of global climate change. The perception of such changes by local communities is important for risk analysis and for subsequent societal decision making. In this study, we compare and contrast observations and perceptions of climate change by selected Amazonian communities particularly vulnerable to alterations in precipitation regimes. Two main points were analysed: (i) the notion of changes in the annual climate cycle and (ii) the notion of changes in rainfall patterns. About 72% of the sampled population reports perceptions of climate changes, and there is a robust signal of increased perception with age. Other possible predictive parameters such as gender, fishing frequency and changes in/planning of economic activities do not appear overall as contributing to perceptions. The communities’ perceptions of the changes in 2013–2014 were then compared to earlier results (2007–2008), providing an unprecedented cohort study of the same sites. Results show that climate change perceptions and measured rainfall variations differ across the basin. It was only in the southern part of the Amazon that both measured and perceived changes in rainfall patterns were consistent with decreased precipitation. However, the perception of a changing climate became more widespread and frequently mentioned, signalling an increase in awareness of climate risk. 相似文献
3.
Aerosols make a considerable contribution to the climate system through their radiative and cloud condensation nuclei effects, which underlines the need for understanding the origin of aerosols and their transport pathways. Seasonal distribution of mineral dust around the globe and its correlation with atmospheric circulation is investigated using satellite data, and meteorological data from ECMWF. The most important sources of dust are located in North Africa, the Middle East and Southwest Asia with an observed summer maximum, and East Asia with a spring peak. Maximum dust activity over North Africa and the Middle East in summer is attributed to dry convection associated with the summertime low-pressure system, while unstable weather and dry conditions are responsible for the spring peak in dust emission in East Asia. Intercontinental transport of mineral dust by atmospheric circulation has been observed, including trans-Atlantic transport of North African dust, trans-Pacific transport of Asian dust, and transport of dust from the Middle East across the Indian Ocean. The extent of African dust over the Atlantic Ocean and its latitudinal variation with season is related to the large-scale atmospheric circulation, including seasonal changes in the position of the intertropical convergence zone (ITCZ) and variation of wind patterns. North African aerosols extend over longer distances across the North Atlantic in summer because of greater dust emission, an intensified easterly low level jet (LLJ) and strengthening of the Azores-Bermuda anticyclonic circulation. Transport of East Asian aerosol is facilitated by the existence of a LLJ that extends from East Asia to the west coast of North America. 相似文献
4.
Vivek N. Mathur Stavros Afionis Jouni Paavola Andrew J. Dougill Lindsay C. Stringer 《Climate Policy》2014,14(1):42-62
The literature on equity and justice in climate change mitigation has largely focused on North–South relations and equity between states. However, some initiatives (e.g. the Clean Development Mechanism (CDM), the Reducing Emissions from Deforestation and Forest Degradation programme (REDD), and voluntary carbon markets (VCMs)) are already establishing multi-level governance structures that involve communities from developing countries in global mitigation efforts. This poses new equity and justice dilemmas: how the burdens and benefits of mitigation are shared across various levels and how host communities are positioned in multi-level governance structures. A review of the existing literature is used to distill a framework for distinguishing between four axes of climate justice from the perspective of communities. Empirical evidence from African and Asian carbon market projects is used to assess the distributive and procedural justice implications for host communities. The evidence suggests that host communities often benefit little from carbon market projects and find it difficult to protect their interests. Capacity building, attention to local power relations, supervision of business practices, promotion of projects with primarily development aims and an active involvement of non-state actors as bridges between local communities and the national/international levels could potentially contribute towards addressing some of the key justice concerns.Policy relevance International negotiations on the institutional frameworks that are envisaged to govern carbon markets are proceeding at a rather slow pace. As a consequence, host countries and private-sector actors are making their own arrangements to safeguard the interests of local communities. While several standards have emerged to guide carbon market activity on the ground, distributive as well as procedural justice concerns nevertheless remain salient. Four empirical case studies across Asia and Africa show that within the multi-scale and multi-actor carbon market governance, local-level actors often lack sufficient agency to advance their claims and protect their interests. This evidence suggests that ameliorating policy reforms are needed to enhance the positioning of local communities. Doing so is important to ensure future acceptability of carbon market activity in potential host communities as well as for ensuring their broader legitimacy. 相似文献
5.
As the cornerstone of biodiversity conservation, the core value of protected areas (PAs) is to maintain an area’s natural conditions (both day and night) and to restrict human-caused disturbances to biology and the environment. Although the value of PAs has been universally recognized, light pollution within them is worsening as a result of the widespread use of artificial illumination devices. Previous studies have focused on light pollution in PAs and evaluated light radiation using nighttime light imagery. However, given the scale and span of these studies (national scale and over short periods), PA light pollution research should be advanced further. In this paper, we conducted long-term (1992–2018) monitoring and evaluation of light pollution in African PAs using aligned multi-sensor NTL data. The results showed that 1) Africa PAs were impacted by increasingly severe artificial lights during 1992–2018, with all three light indices showing an accelerating increasing trend. 2) The number of light-polluted PAs also rapidly increased, with more than 80% of PAs experiencing aggravated light pollution as of 2018. Different types of PAs had heterogeneous light pollution, which penetrates indiscriminately into all PA regulation levels. 4) Light pollution in African PAs was divided into three types, including outside invasion, internal sources, and mixed pollution. 5) Human activity intensity surrounding the PAs was highly correlated with light pollution within them, with a maximum effect distance of approximately 245 km. This paper provides new approaches for understanding the patterns of light pollution within PAs, and is a valuable reference for future PA planning. 相似文献
6.
A 15 member ensemble of 20th century simulations using the ECHAM4–T42 atmospheric GCM is utilized to investigate the potential predictability of interannual variations of seasonal rainfall over Africa. Common boundary conditions are the global sea surface temperatures (SST) and sea ice extent. A canonical correlation analysis (CCA) between observed and ensemble mean ECHAM4 precipitation over Africa is applied in order to identify the most predictable anomaly patterns of precipitation and the related SST anomalies. The CCA is then used to formulate a re-calibration approach similar to model output statistics (MOS) and to derive precipitation forecasts over Africa. Predictand is the climate research unit (CRU) gridded precipitation over Africa. As predictor we use observed SST anomalies, ensemble mean precipitation over Africa and a combined vector of mean sea level pressure, streamfunction and velocity potential at 850 hPa. The different forecast approaches are compared. Most skill for African precipitation forecasts is provided by tropical Atlantic (Gulf of Guinea) SST anomalies which mainly affect rainfall over the Guinean coast and Sahel. The El Niño/Southern Oscillation (ENSO) influences southern and East Africa, however with a lower skill. Indian Ocean SST anomalies, partly independent from ENSO, have an impact particularly on East Africa. As suggested by the large agreement between the simulated and observed precipitation, the ECHAM4 rainfall provides a skillful predictor for CRU precipitation over Africa. However, MOS re-calibration is needed in order to provide skillful forecasts. Forecasts using MOS re-calibrated model precipitation are at least as skillful as forecast using dynamical variables from the model or instantaneous SST. In many cases, MOS re-calibrated precipitation forecasts provide more skill. However, differences are not systematic for all regions and seasons, and often small. 相似文献
7.
For almost two decades, politicians have been negotiating temperature limits to which anthropogenic global warming should be restricted, and 2 °C has emerged as benchmark for danger. However, there has been a lack of scientific research into the implications of such a change for African climate. This study aims to provide information for mitigation debates; through an examination of temperature and precipitation changes in Africa associated with 1 °C, 2 °C, 3 °C, and 4 °C of global warming. Data from Global Climate Models show little significant precipitation change at 1 °C, then larger anomalies at 2 °C which are strengthened and extended at 3 °C and 4 °C, including a wet signal in East Africa, and dry signals in Southern Africa, the Guinea Coast, and the west of the Sahel. Some of the models project changes with potential for severe societal implications. Despite the uncertainty attached to these projections, they highlight risks associated with 2 °C and beyond. Using these findings as a framework for impact assessment and evaluation, further research has the potential to uncover the implications of global warming for African regions. 相似文献
8.
Although ‘peri-urban’ and ‘rur-urban’ growth patterns are now prominent in previously rural areas of Latin America, there has been little exploration of the implication of these patterns for social vulnerability to hazards and adaptive capacity for hazard management. A case study of flooding in the Upper Lerma River Valley, Mexico, illustrates how livelihood and land use change in these peri-urban spaces have altered residents’ perceptions of risk and loss, while public officials are adhering to a traditional sectoral and structural interpretation of flooding as an agricultural problem, managed by agricultural and water agencies. The current system of treating flooding as an agricultural problem, managed by agricultural and water agencies, does not address the increased role of urbanization as a driver of flooding and water risk in the valley. The resulting mismatch in policy potentially exacerbates regional vulnerability in face of rising flood losses. Enhancing adaptive capacity in this context requires a new vision of the populations and communities of the region as an integrated system, supported by institutions that facilitate cross-scale and intersectoral planning. 相似文献
9.
East African food security as influenced by future climate change and land use change at local to regional scales 总被引：3，自引：0，他引：3
Nathan Moore Gopal Alagarswamy Bryan Pijanowski Philip Thornton Brent Lofgren Jennifer Olson Jeffrey Andresen Pius Yanda Jiaguo Qi 《Climatic change》2012,110(3-4):823-844
Climate change impacts food production systems, particularly in locations with large, vulnerable populations. Elevated greenhouse gases (GHG), as well as land cover/land use change (LCLUC), can influence regional climate dynamics. Biophysical factors such as topography, soil type, and seasonal rainfall can strongly affect crop yields. We used a regional climate model derived from the Regional Atmospheric Modeling System (RAMS) to compare the effects of projected future GHG and future LCLUC on spatial variability of crop yields in East Africa. Crop yields were estimated with a process-based simulation model. The results suggest that: (1) GHG-influenced and LCLUC-influenced yield changes are highly heterogeneous across this region; (2) LCLUC effects are significant drivers of yield change; and (3) high spatial variability in yield is indicated for several key agricultural sub-regions of East Africa. Food production risk when considered at the household scale is largely dependent on the occurrence of extremes, so mean yield in some cases may be an incomplete predictor of risk. The broad range of projected crop yields reflects enormous variability in key parameters that underlie regional food security; hence, donor institutions’ strategies and investments might benefit from considering the spatial distribution around mean impacts for a given region. Ultimately, global assessments of food security risk would benefit from including regional and local assessments of climate impacts on food production. This may be less of a consideration in other regions. This study supports the concept that LCLUC is a first-order factor in assessing food production risk. 相似文献
10.
11.
Rural development policies in many Organization for Economic Co-operation and Development (OECD) member countries promote sustainable landscape management with the intention of providing multiple ecosystem services (ES). Yet, it remains unclear which ES benefits are perceived in different landscapes and by different people. We present an assessment of ES benefits perceived and mapped by residents (n = 2,301) across 13 multifunctional (deep rural to peri-urban) landscapes in Europe. We identify the most intensively perceived ES benefits, their spatial patterns, and the respondent and landscape characteristics that determine ES benefit perception. We find outdoor recreation, aesthetic values and social interactions are the key ES benefits at local scales. Settlement areas are ES benefit hotspots but many benefits are also related to forests, waters and mosaic landscapes. We find some ES benefits (e.g. culture and heritage values) are spatially clustered, while many others (e.g. aesthetic values) are dispersed. ES benefit perception is linked to people’s relationship with and accessibility to a landscape. Our study discusses how a local perspective can contribute to the development of contextualized and socially acceptable policies for sustainable ES management. We also address conceptual confusion in ES framework and present argumentation regarding the links from services to benefits, and from benefits to different types of values. 相似文献
12.
Anne M. Larson 《Global Environmental Change》2011,21(2):540-549
Numerous authors have stressed the importance of guaranteeing and protecting the tenure and human rights of indigenous and other forest-based communities under schemes for reducing emissions from deforestation and forest degradation (REDD, or REDD+); and important international indigenous organizations have spoken out strongly against REDD+. This article examines two specific issues that present risks for local communities: rights to forests and rules for resource use. It draws on the findings of a study conducted by the Center for International Forestry Research (CIFOR) on forest tenure reforms in selected countries in Asia, Africa and Latin America from 2006 to 2008. The study underlines the numerous obstacles faced by communities after rights are won, in moving from statutory rights to their implementation and to access to benefits on the ground. It argues that there is currently little reason to expect better results from national policies under REDD+ without binding agreements to protect local rights. 相似文献
13.
2011年极端天气和气候事件及其他相关事件的概要回顾 总被引：1，自引：1，他引：0
2011年世界各地极端天气事件频发。1月,朝鲜半岛经历1945年来最长的寒潮天气;同期,强暴风雪袭击美国,1亿人受影响;4月8日,持续干旱大风导致德国北部小镇遭遇沙尘暴;7～10月的季风强降水致使泰国遭遇自1942年以来最严重的洪灾;高温少雨致使东非地区、南美洲地区的古巴经历严重干旱;9月北极海冰的体积达历史最小。5～9月,我国平均高温日数为1961年以来历史同期次多,多地刷新高温历史极值;2011年我国平均年降水量创60年来最低,多地遭遇严重干旱;而华西和黄淮经历异常严重秋汛。 相似文献
14.
Desmond Manatsa Yushi Morioka Swadhin K. Behera Caxston H. Matarira Toshio Yamagata 《Climate Dynamics》2014,42(5-6):1259-1274
The interannual variability of East African ‘short rains’ (EASR) and its link with the Mascarene High (MH) variation are explored, using observations and reanalysis data. Correlation and composite analyses for flood and drought events reveal that the EASR variability is strongly linked to the MH zonal displacement, in particular, the zonal movement of the MH eastern ridge. When the MH eastern ridge is anomalously displaced to the west (east) of its normal position, the south east (SE) trade winds over the South Indian Ocean (SIO) anomalously strengthen (weaken). This enhances (reduces) the relatively cool and dry SE trade winds and induces cold (warm) sea surface temperature anomaly in the SIO. As a result, convection over the western equatorial SIO is suppressed (enhanced) and leads to rainfall deficits (excess) over East Africa. Droughts in East Africa are associated with a westward migration of the MH eastern ridge, while the relationship is less clear for flood events and their link to an eastward migration of the MH. Therefore, the zonal migration of the MH eastern ridge provides a novel indicator for the EASR extremes especially droughts. This revelation has immense social application for rainfall forecast over East Africa where rainfall deficits have become more prevalent against the background of deteriorating conventional forecasts for EASR droughts. 相似文献
15.
Marjo Vierros 《Climatic change》2017,140(1):89-100
Blue carbon refers to the considerable amounts of carbon sequestered by mangroves, seagrass beds, tidal marshes and other coastal and marine vegetated ecosystems. At the present time, carbon market mechanisms to compensate those conserving blue carbon ecosystems, and thus reducing carbon emissions, are not yet in place. The ecosystem services provided by coastal vegetated ecosystems extend beyond their carbon storage capacity, and include their contribution to fishery production; shoreline protection; provision of habitat for wildlife and migratory species; flood water attenuation; nutrient cycling, pollution buffering; as well as their cultural, spiritual, subsistence and recreational uses. Because these services are of high economic, social and cultural value, the management and protection of blue carbon ecosystems could build collaboration between climate change and biodiversity practitioners on the national and international level. Such collaboration would also allow for the transfer of lessons learned from coastal management and conservation activities to carbon mitigation projects, and would include the need to work closely together with indigenous peoples and local communities. Resulting management activities on the local level could utilize and strengthen traditional knowledge and management systems related to blue carbon ecosystems, and increase both the resilience of biodiversity and that of coastal communities, as well as provide for long-term storage of blue carbon. While the challenge of scaling up local initiatives remains, some concrete examples already exist, such as the network of locally-managed marine areas (LMMAs) in the Pacific and beyond. 相似文献
16.
Desmond Manatsa Barnabas Chipindu Swadhin K. Behera 《Theoretical and Applied Climatology》2012,110(1-2):115-128
The decadal shift in the relationship between the Indian Ocean Dipole (IOD) and the East African rainfall is investigated using historical observational data. The climate system for equatorial East Africa (EEA) during the October to December (OND) ‘short rains’ season is characterised by spatiotemporal variations of the equatorial East African rainfall (EEAR). Therefore, the EEAR index is derived from the first principal component of the empirical orthogonal function analysis (EOF) of the EEA’s rainfall domain. The IOD, which has been linked with the EEAR in the previous studies, is the main climate mode controlling the tropical Indian Ocean during the OND period. It is usually represented by a dipole mode index based on the zonal gradient of SST anomalies in the tropical Indian Ocean. Therefore the climate modes, IOD and EEAR, are assumed to form a two-node network of subsystems which primarily control the climate of equatorial East Africa during the OND period. The collective behaviour of these climate modes is investigated through the examination of their representative indices for the period 1901 to 2009 using simple statistical techniques. The results suggest that the interaction between these two climate modes, which comprise the network, is not predominantly linear as previously assumed, but is characterised by shifts which are determined by the coupling and synchronisation processes of the tropical systems. In cases where synchronisation is preceded by an abrupt increase in coupling strength between the two subsystems, the established synchronous state is destroyed and a new climate state emerges such as in the years 1961 and 1997. This alteration in the regional climate is accompanied by notable changes in the regional rainfall and IOD variations. But in those events where synchronisation is followed by a sudden loss in coupling strength, the climate state is not disturbed and no shift in the climate of equatorial East Africa is noticed as in 1918. This climate shift mechanism appears to be consistent with the theory of synchronised chaos and is useful for long range predictions of the East African short rains. 相似文献
17.
Shem O. Wandiga Maggie Opondo Daniel Olago Andrew Githeko Faith Githui Michael Marshall Tim Downs Alfred Opere Christopher Oludhe Gilbert O. Ouma Pius Z. Yanda Richard Kangalawe Robert Kabumbuli James Kathuri Eugene Apindi Lydia Olaka Laban Ogallo Paul Mugambi Rehema Sigalla Robinah Nanyunja Timothy Baguma Pius Achola 《Climatic change》2010,99(3-4):473-497
Endemic malaria in most of the hot and humid African climates is the leading cause of morbidity and mortality. In the last twenty or so years the incidence of malaria has been aggravated by the resurgence of highland malaria epidemics which hitherto had been rare. A close association between malaria epidemics and climate variability has been reported but not universally accepted. Similarly, the relationship between climate variability, intensity of disease mortality and morbidity coupled with socio-economic factors has been mooted. Analyses of past climate (temperature and precipitation), hydrological and health data (1961–2001), and socio-economics status of communities from the East African highlands confirm the link between climate variability and the incidence and severity of malaria epidemics. The communities in the highlands that have had less exposure to malaria are more vulnerable than their counterparts in the lowlands due to lack of clinical immunity. However, the vulnerability of human health to climate variability is influenced by the coping and adaptive capacities of an individual or community. Surveys conducted among three communities in the East African highlands reveal that the interplay of poverty and other socio-economic variables have intensified the vulnerability of these communities to the impacts of malaria. 相似文献
18.
I. Kuhnel 《Meteorology and Atmospheric Physics》1991,46(3-4):185-195
Summary Based on ESSA-satellite imagery for the period July 1969–June 1970, this study investigates spatial and temporal variations of East African cloudiness. The major results of this work show that the mean annual cloud amounts over East Africa are lower than those in adjacent tropical areas. One of the main reasons for this is the quasi-meridional alignement of the ITCZ over East Africa during the winter months. Within the area itself, the highest mean annual cloud amount values can generally be found in a diagonally oriented zone extending from the eastern Congo Basin to the Ethiopian Highlands. In contrast to the cloudiness north of the equator, which is dominated by oscillation periods in the range of 30–60 days, the cloudiness fluctuations encountered south of the equator show periodicities around 2 days (in the western part) and 20 days (in the eastern part), respectively. The different oscillation patterns, which are roughly separated by the Rift Valley area (longitudinally) and the equator (latitudinally), resemble the signals of the adjacent (African and Asian) monsoon regimes. However, during the winter months oscillation periods around 40 days can be found north of the equator, whereas a quasi-biweekly oscillation appears over the coastal areas in summer. Further details of the seasonal variability of East African cloudiness are discussed.With 8 Figures 相似文献
19.
Linking vulnerability, adaptation, and resilience science to practice: Pathways, players, and partnerships 总被引：7，自引：1，他引：7
Coleen Vogel Susanne C. Moser Roger E. Kasperson Geoffrey D. Dabelko 《Global Environmental Change》2007,17(3-4):349-364
Vulnerability, adaptation and resilience are concepts that are finding increasing currency in several fields of research as well as in various policy and practitioner communities engaged in global environmental change science, climate change, sustainability science, disaster risk-reduction and famine interventions. As scientists and practitioners increasingly work together in this arena a number of questions are emerging: What is credible, salient and legitimate knowledge, how is this knowledge generated and how is it used in decision making? Drawing on important science in this field, and including a case study from southern Africa, we suggest an alternative mode of interaction to the usual one-way interaction between science and practice often used. In this alternative approach, different experts, risk-bearers, and local communities are involved and knowledge and practice is contested, co-produced and reflected upon. Despite some successes in the use and negotiation of such knowledge for ‘real’ world issues, a number of problems persist that require further investigation including the difficulties of developing consensus on the methodologies used by a range of stakeholders usually across a wide region (as the case study of southern Africa shows, particularly in determining and identifying vulnerable groups, sectors, and systems); slow delivery of products that could enhance resilience to change that reflects not only a lack of data, and need for scientific credibility, but also the time-consuming process of coming to a negotiated understanding in science–practice interactions and, finally, the need to clarify the role of ‘external’ agencies, stakeholders, and scientists at the outset of the dialogue process and subsequent interactions. Such factors, we argue, all hinder the use of vulnerability and resilience ‘knowledge’ that is being generated and will require much more detailed investigation by both producers and users of such knowledge. 相似文献
20.
Protected areas are increasingly prone to violent extremism spillover, with dramatic consequences for both local people and wildlife populations. Due to the influence of violent extremist groups, science and policy generally fade away. We outline the case of the W-Arly-Pendjari complex of protected areas in West Africa (Burkina Faso, Benin, and Niger), 62% of which is currently under the control of violent extremist groups. The last large population of West African elephants may soon disappear if no action is taken. We discuss the roles of conservation science and policy in protected areas under violent extremism spillover, namely (i) maintaining and reinforcing international support, (ii) authentically engaging local communities in conservation and management strategies, and (iii) planning long-term conservation and security strategies. 相似文献