Value of Climate Forecasts for Adjusting Farming Strategies in Sub-Saharan Africa

Sustaining and increasing crop production and productivity has to be a major policy thrust for developing countries. Using a simulation approach different production strategies were evaluated conditioned on climate information to derive optimal strategies to help farmers reduce risk and increase productivity. By examining the existence of options in this case planting dates the study provides an analyses of the expected value and risks associated with changing decisions based on the availability of climate forecasts. The 15-March planting date produced the highest mean yield for the two cultivars examined although 1-April, 15-April and 1-May plantings had one to zero probability of crop failures compared to 15-March with crop failures in 4 out of 20 years. Results indicate losses of between 25 and 35 kg/day due to delays in planting from 15-March planting to 1-June planting for the 120- and 150-day cultivar. El niño years were associated with positive yield deviations for both cultivars and most planting dates. Farmers are known to make tactical adjustments to their management in light of information perceived relevant to the prospects of forthcoming crop. Although in its present form most current forecast products do not provide information on onset of the rainfall, however the information they do provide could play a crucial role in helping farmers reduce the risks posed by climatic variability.     

Mobile phones and safety in developing countries: Evidence from Sub-Saharan Africa

This paper is concerned with the relationship between safety and mobile phones with particular reference to Sub-Saharan Africa; and looks at a range of geographical contexts: non-violent, conflict and post-conflict situations. The main part of the paper reports on recent findings of extensive field-work into the use of mobile phones in 11 countries in Sub-Saharan Africa. The findings are important partly because from a welfare view, it is use rather than mere adoption that generates actual benefits to consumers. What the survey finds is that use of the mobile phone is mainly for safety-related purposes and that the countries that fare highest in terms of usage are drawn from the richest and poorest members of the sample. In explaining these results I draw heavily on the relationships and interactions between poverty, inequality and crime. For example, the dominance of Southern African countries is ascribed to their exceptionally high levels of inequality, which, in turn, are due partly to the unequal effects of resource abundance.     

Seasonal Forecasting for Climate Hazards: Prospects and Responses

One of the most promising developments for early warning of climate hazards is seasonal climate forecasting. Already forecasts are operational in many parts of the tropics and sub-tropics, particularly for droughts and floods associated with ENSO events. Prospects for further development of seasonal forecasting for a range of climatichazards are reviewed, illustrated with case studies in Africa, Australia, the U.S.A. and Europe. A critical evaluation of the utility of seasonal forecasts centres on vulnerability, communicationchannels, and effective responses. In contrast to short-term prediction, seasonal forecasts raise new issues of preparedness and the use of information.     

青海省东部地区气候变化与ENSO事件关系

ENSO(厄尔尼诺-南方涛动)事件的发生会影响区域气候变化。通过对青海东部地区5个站点1959~2005年的降水、气温资料、干燥度和海表温度距平(SSTA)与南方涛动指数(SOI)的月序列进行相关性分析和周期性谱分析,探讨了区域气候变化与ENSO事件的关系。结果表明,1959~2005年青海省东部地区气候趋于暖干,并且冬春季变化趋势显著;暖事件的发生对该区域降水、气温及干燥度的变化影响较大,且气温对ENSO事件的响应要大于降水;ENSO事件对该区域的气候变化有两到三个月的影响期,EI Nino事件的发生对当月的影响较大,而La Nina事件的发生对该区域有两到三个月的持续影响期;降水距平及气温距平与ENSO事件存在短期相同的变化趋势,且该地区气候变化受南方涛动影响明显。     

Rainfall Variability and Changes in Southern Africa during the 20th Century in the Global Warming Context

Rainfall variability and changes in Southern Africa over the 20th century areexamined and their potential links to the global warming discussed. After a shortreview of the main conclusions of various experiments with Global AtmosphericModels (GCM) forced by increased concentrations of greenhouse gases for SouthernAfrica, a study of various datasets documents the observed changes in rainfall featuresat both daily and seasonal time steps through the last century. Investigations of dailyrainfall parameters are so far limited to South Africa. They show that some regionshave experienced a shift toward more extreme rainfall events in recent decades.Investigations of cumulative rainfall anomalies over the summer season do notshow any trend to drier or moister conditions during the century. However, closeexamination reveals that rainfall variability in Southern Africa has experiencedsignificant modifications, especially in the recent decades. Interannual variabilityhas increased since the late 1960s. In particular, droughts became more intense andwidespread. More significantly, teleconnection patterns associated with SouthernAfrican rainfall variability changed from regional before the 70s to near global after,and an increased statistical association to the El Niño – Southern Oscillation (ENSO) phenomenon is observed. Numerical experiments with a French GCM indicate that these changes in teleconnections could be related to long-term variations in the Sea-Surface-Temperature background, which are part of the observed global warming signal.     

‘Where is the life in farming?’: The viability of smallholder farming on the margins of the Kalahari, Southern Africa

This paper investigates the ways in which national and regional policies relate to farming activities and concerns amongst the rural population in an area of southern Africa. The struggle to make a living through farming was a common theme to emerge from research about changing livelihoods in response to both variability in the environment and changes in policy. This local discourse echoed regional debates about land and agrarian reform in post-apartheid South Africa and the uncertain future of mixed farming in Botswana. It also raised broader questions about the viability of the future of small-medium-scale farming systems in rural areas in Africa, especially those within dynamic dryland environments such as the Kalahari. This paper looks specifically at the links between poverty and asset holding and aims to identify the ways in which people are or are not able to utilise or mobilise these assets in times of need. We argue that this can vary significantly between seemingly similar settlements, and similar households and that understanding this complexity is the key to recognising how future interventions many impact upon people’s lives. Too often, in the quest to produce understandings of poverty and livelihoods, the complexity, incongruity and reality of day-to-day practices are overlooked. Thus we seek to draw out the interactions between policy and natural resource use, and the capital asset changes involved in these interactions, which influence the sustainability of livelihoods and the differing levels of poverty and vulnerability.     

Farming as a livelihood source for the urban poor of Nakuru, Kenya

Farming among urban dwellers in Sub-Saharan Africa is a common phenomenon. The present study, carried out in a medium-sized town in Kenya, not only confirmed this but also showed that farming by urban dwellers in the rural areas was even more important for these households’ livelihoods than farming in town. However, those who could benefit most from farming, i.e. the urban poor, appeared to be underrepresented among urban farming households and those urban poor who did farm, either in urban or in rural areas, performed worse than the farming non-poor. The importance of farming as a livelihood source is illustrated by the fact that in years with very little or no harvest due to drought, many of the poor farming households faced food shortages.     

气候变化对山东降水及极端天气气候事件的影响分析

根据新中国成立以来山东省气温资料进行分析,从温度变化来反映山东气候变暖的趋势;在此基础上根据山东省近60年的水文资料分析气候变化对山东降水及极端天气气候事件的影响。结果表明,60年来山东气候呈变暖趋势,随着气候的变化,山东省年降水量呈减少的趋势,并导致极端天气气候事件出现频率及强度呈增大趋势。     

Short communication: collection of isoseismal maps for South Africa

An atlas of isoseismal maps for South Africa, dating from as far back as 1932–2005, is provided. This work involved searching through historical reports to find records of macroseismic effects. In many instances, when there was a large tremor, questionnaires were distributed to local towns to assess the severity of the tremor and the damage it caused. Based on the results of these questionnaires and site investigations, isoseismal maps were drawn. These isoseismal maps were revisited and digitised for this study. Five additional isoseismal maps were prepared by the authors based on the results of questionnaires alone. Most isoseismal maps in the historical record use the Modified Mercalli scale. All maps are hence provided according to this scale. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

末次冰消期东亚季风区西北缘气候快速变化事件

通过对中卫剖面和米浪沟湾剖面的年代学与高分辨率气候地层记录的研究,认为末次冰消期东亚季风区西北缘发生气候快速变化事件,它可分辨出古仙女木、波令、老仙女木、阿勒鲁德、IACP和新仙女木等6个气候阶段,并可与格陵兰冰心(GISP2)检出的6个气候阶段相对比。气候快速变化事件以快速变化、不稳定、多波动为特征,表现为冷干-暖湿-冷干-凉湿-暖干-冷干-冷湿的交替变化。冰消期冬、夏季风有较为复杂的消长关系,冰阶时二者互为消长,间冰阶时并不完全互为消长。冬季风在波令和阿勒鲁德暖期较新仙女木冷期强盛,这是北半球高纬度海区海冰面积在暖期缩小、冷期扩大而影响亚洲大陆蒙古一西伯利亚高压暖期增强、冷期减弱的结果;夏季风则与格陵兰冰心δ^18O的变化具有一致性,其强弱与北半球高纬地区有紧密联系,这种联系可能不是通过季风锋面降水带建立起来的,而可能是海冰面积变化导致厄尔尼诺-南方涛动(ENSO)爆发造成的。     

西天山山区气候变化与灌区绿洲气候效应

对近40a西天山山区气候变化的特点及其变化趋势进行了分析,并以阿克苏源流区、阿克苏灌区以及叶尔羌河灌区的14个气象站的观测资料(1961—2000年)为基础,重点研究了灌区的气候变化及绿洲气候效应.20世纪90年代以来,各区域的气温增高,降水增多,其中在源流地区降水增加幅度最大,而沙尘暴、浮尘和大风日数都有明显的下降.最后,讨论了气候变化与绿洲发展的关系.     

东北非与中国胶东造山型金矿对比及对非洲找矿勘查的启示

东北非是一个快速兴起的世界级金矿省,发育大量造山型金矿床。选择东北非努比亚地盾代表性造山型矿床进行总结梳理,认为区内金矿成矿可能受控于努比亚地盾地块拼帖后挤压/压扭向张扭剪切转换的过程,绿片岩相-角闪岩相变质基性火山岩是主要赋矿围岩,剪切带(断层)为主要控矿构造。通过对比,发现努比亚地盾矿集区与胶东矿集区类似,在大规模金成矿前均经历了洋壳俯冲过程,除赋矿围岩和成矿时代区别明显外,在控矿构造、矿化类型、矿物组合、成矿流体等方面较相似。结合控矿因素与找矿标志对比,针对努比亚地盾造山型金矿的找矿勘查提出具体建议：通过遥感和地质图修编圈定找矿远景区;利用地球化学测量和地质图草测等圈定找矿靶区;利用蚀变填图、反循环钻探,结合电磁测量,追踪隐伏矿体;通过矿床理论研究和矿田构造分析,支撑矿床(点)深部找矿。     

玉龙雪山冰川变化对ENSO事件的响应

应用独立性检验方法就ENSO事件对我国云南丽江地区降水、温度和冰川变化影响进行了相关分析. 结果表明丽江降水与ENSO事件有密切关系, MEI值为负时下一年降水量增加, MEI正值与下一年降水量减少相对应. 丽江气温与ENSO事件关系显著, MEI值为负时下一年气温降低, MEI正值与下一年气温增加对应. 利用夏季降水量和气温设计了冰川积累量指数并与MEI进行对比分析, 发现当年MEI值与下一年的冰川积累指数存在一定相关关系, 并影响未来的冰川的变化, MEI为正时冰川将会退缩, MEI值为负时冰川将会前进.     

A Conceptual Framework for Enhancing the Utility of Rainfall Hazard Forecasts for Agriculture in Marginal Environments

Semi-arid and dry sub-humid areas (especially in the tropics) are characterized by high inter-annual and intra-seasonal rainfall variability. Agriculture, which employs the bulk of the rapidly increasing populations, is largely rain-fed, low-input based and highly resource dependent. Recent spates of drought have, therefore, exacerbated the now-too-familiar specter of famine and starvation in these areas with glaring examples being the recurring episodes in sub-Saharan Africa since the great Sahel drought of 1969–1973. A great need for accurate and timely hazard forecast products in aid of agriculture thus exists.Several schemes are currently employed by various agencies around the globe in this direction. There does remain, however, a gap between product provision and user expectations. This paper examines this gap suggesting a five-point framework within which it can be addressed as an action agenda for the climate science community. The paper posits that changes are possible to existing methodologies (related to three of these points), which, within the context of current science, can greatly enhance the utility of forecast products for agriculture in marginal areas. The remaining two points have, however, been identified as requiring additional applied research and necessary pointers for addressing these issues are provided. First is the need for appropriate impact-related indicators for intra-seasonal and interannual rainfall variability that are easy to compute, amenable to forecasting and follow closely the experiences of farmers in marginal areas. The second is a consideration of appropriate forecast information formatting and communication medium that guarantee effective feedback between forecast producers and users. Specific examples of the status quo and of work currently underway are cited from southern Africa – a region currently attracting international attention as a result of recent droughts and the threat of famine.     

Africa in the rise of rights-based development

This paper explores the rise of rights-based development (RBD) and its endorsement by prominent international institutions (such as the United Nations) and International Development Agencies (IDAs) like the World Bank. It situates RBD in global political context and analyses it in relation to the international politics of development, especially the politics of neo-liberal adjustment policies in Africa. The paper shows how RBD emerged against a backdrop of debate about four international issues associated with neo-liberalism and its discontents, namely globalisation and uneven development; capability and good governance; human rights and human development; and NGOs in the politics of development. Debates about those four issues keep repositioning the state as the central actor in RBD, and holding the state accountable for development (or the lack thereof) under international law. The paper’s basic point is that state-centric RBD is paradoxical and highly political. Greater accountability is being demanded of states––especially in Africa––from the same neo-liberal forces (such as the World Bank) charged with weakening state capacity, undermining democracy, and diminishing state authority. In terms of international power relations and the politics of development, RBD does signal something of a willingness to rethink certain aspects of the dominant neo-liberal agenda. And yet adjusted states are being subjected––in the name of RBD––to novel methods of international surveillance and forms of conditionality. States are ultimately held responsible for human rights violations, even when it is non-state actors (and their neo-liberal policies) that caused those rights to be violated in the first place. RBD is, therefore, a partial answer (at best) to the questions of empowerment and change raised by critics of neo-liberalism.     

Old inherited origin for the present near-bimodal topography of Africa

Africa’s landscape is dominated by a manifold of second-order epeirogenic structures superimposed on a first-order bimodal topography. Bivariate regression analysis of Africa’s surface topography shows that this is a complexly folded surface with regionally elevated areas in southern and eastern Africa, and a topographically low northern and western Africa. The apparent spatial relationships between these features are analysed using anomaly correlation between surface topography and free-air gravity anomalies. Occurrences of positively correlated features between gravity and topography in Africa are found to be limited to second-order epeirogenic features. Geophysical modelling and geologic evidence indicate that Africa’s bimodal topography is genetically distinct from these second-order features, and linked to sources as deep as the sublithospheric mantle. The age, measured and modelled elevation of the bimodal topography require that topographic uplift of south-central Africa be episodic. We infer from our findings together with relative sea-level changes, that the near-bimodality of Africa’s topography is an ancient feature inherited at least from upper Paleozoic times. Our reconstructed paleotopography suggests that Africa was largely a low-lying continent dominated by its cratons, and that basement distribution disregards the present-day uplift patterns of Africa.     

中东部非洲地质构造单元与成矿区带划分

本文通过总结前人研究资料,认为中东部非洲主要由太古宙克拉通及其周缘的元古代活动带和显生宙沉积组成,并将中东部非洲划分为16个地质构造单元。中东部非洲矿产资源丰富,不同的地质构造单元的矿产资源种类亦不相同。其优势矿种主要有金、铜、钴、钨、锡、铌、钽、镍和宝石矿;金分布在克拉通内的新太古宙花岗绿岩带;铜钴产于新元古代卢菲利安弧层状沉积变质岩内;钨锡铌钽主要产于中元古代基巴拉带造山期后的锡石花岗岩内,多为伟晶岩或石英脉型;镍产于基巴拉带早期的镁铁-超镁铁质岩中;宝石矿多产于高级变质岩内;能源矿产主要位于显生宙陆内盆地及滨海盆地内。     

非洲地质勘查项目风险控制初探

针对高风险的地质勘查和复杂多变的国际环境,确保国外地质勘查项目的顺利实施,确保"走出去"战略取得实效,成为每一位地质人面临的新课题。通过阐述非洲地勘项目存在的5种风险,并提出了风险控制的建议。     

Volunteer tourism: The case of Habitat for Humanity South Africa

Volunteer tourism as a subset of alternative tourism is the focus of analysis. This paper contributes to the limited writings on volunteer tourism by investigating the activities in South Africa of Habitat for Humanity, a grassroots ecumenical Christian organization that works in partnership with communities to eliminate poverty through the provision of shelter. A profile of the volunteer tourist and of their tourism experience in South Africa is presented which is based largely upon the return of 123 questionnaires from volunteer tourists in South Africa working with the local branch of Habitat for Humanity. This revised version was published online in August 2006 with corrections to the Cover Date.     

西北非构造演化与油气成藏组合特征

西北非油气资源丰富,是我国石油公司海外油气勘探的重要区块。受泛非、加里东、海西、阿尔卑斯运动的影响,西北非构造演化经历了泛非期基底形成、古生代稳定陆块演化、中生代裂陷、新生代反转隆升的复杂过程,发育三叠、伊利兹、锡尔特等多个超大型含油气盆地。主要有两套成藏组合:撒哈拉地台为主的古生代成藏组合、北部大陆边缘为主的中新生代成藏组合。