非洲外商直接投资的时空变化与影响因素

基于2006—2017年非洲52个国家FDI数据以及其经济、政治、资源等数据,运用泰尔指数和面板数据固定效应模型对非洲外商直接投资的时空变化与影响因素进行研究。研究结果表明：1）非洲FDI流入量整体呈现出波动上升的趋势,其中北非呈现下降趋势,西非和中非呈现出波动上升的趋势,东非的上升趋势相对稳定且强势,南部非洲地区波动变化显著,趋势不明显;随着非洲经济发展,五大区域中北非和西非的FDI流入量最多,呈现出“两强三弱”的区域分布格局。2）非洲FDI总体差异呈现出缓慢上升趋势,年际变化呈现出“减—增—减”的波动;影响FDI总体差异的主要因素是区域内部差异,西非、南部非洲和中非区域内部的差异尤为明显,其中西非内部差异贡献最大。3）经济社会环境因素整体上对非洲FDI影响有限,但局部对西非影响较大;经济发展水平对东非、南非的外资流入起着积极作用,而对西非起着抑制作用;对外开放度对西非起着消极影响;聚集效应对西非、中非、北非的作用有限。政治制度因素整体上对非洲外资具有显著的作用,但局部对北非和东非作用有限。资源禀赋因素总体上是外企对非洲区位选择的决定性因素,但局部对北非和东非影响不大。基础设施因素总体上对非洲大陆FDI的流入量影响不大,但对南部非洲地区除外。     

东非油气资源开发的历史透视与现状解析

东非油气资源开发始于一战前,二战后出现第一个勘探高峰期。随着冷战结束,东非油气资源开发的力度不断加大,国际能源公司纷纷入驻。在中小型能源公司的积极开拓下,于2006年以后相继取得重大勘探成果。东非油气资源已呈现出分布广、储量大的特点,并吸引一批国际大型能源公司的投资,加快了能源产业的发展,推动了能源立法的建设。随着东非在全球能源版图中地位的凸显,地区外大国在该地区的博弈也日趋激烈。东非各国则获得发展的新机遇,并将推进地区一体化进程。然而,若东非各国不能妥善处理政府能力问题、腐败问题、经济结构问题、利益分配问题、恐怖主义问题等,将有可能陷入"资源诅咒"的陷阱中。     

21世纪以来非洲跨国移民空间格局及其对FDI影响

运用ArcGIS软件与DPS软件,结合世界银行数据库与《非洲统计年鉴》等,分析21世纪以来非洲跨国移民空间格局及其对FDI影响,结果表明:基于目的地国、原籍国的跨国移民分别集中于北非地区与撒哈拉以南的非洲,其中前者呈现以"摩洛哥-埃及-苏丹"为中心的集聚格局,而后者先以科特迪瓦最为集中,随后逐渐被南非所取代;北非地区F...     

RUSLE applied in a GIS framework: Calculating the LS factor and deriving homogeneous patches for estimating soil loss

The RUSLE (Revised Universal Soil Loss Equation) is integrated within a GIS framework to calculate soil loss spatially. For this module, algorithms and procedures were developed to derive the slope length factor (L) and steepness factor (S) from a DEM, then integrated with the R, K, C, and P factors to develop homogeneous patches (sub‐units) within each field or river basin. Soil loss is determined for each patch within a study unit, and then combined to determine the fields' or river basin's average annual and total soil loss. Two case studies are presented. The first case study, in central Massachusetts, compares estimated soil loss values obtained for individual fields using the Idrisi RUSLE module to USDA‐NRCS RUSLE field data. While soil loss results were similar, the RUSLE module allows fields to be partitioned into more similar units than practical in the field. This permits detailed spatial analysis of soil‐loss patterns. The second case study compares soil‐loss estimates for a catchment in southwestern Flanders, Belgium. This model–model comparison contrasts the results from the RUSLE module to the WATEM model—a grid cell based model based on the USLE/RUSLE but conceptualized in a multi‐flow context. Results between the predicted soil losses utilizing the two different approaches are significantly correlated. However, estimated soil losses are consistently higher for the WATEM model. This likely reflects the differences between how the two models compute L as well as the contribution of ephemeral gullies and flow convergence which are incorporated in WATEM but not in RUSLE.     

Preliminary evidence of environmental changes at Lake Bambili (Cameroon, West Africa) since 24,000 BP

Preliminary analyses of diatoms, phytoliths, and siliceous protozoan plate records in a 16 m sediment core from Lake Bambili (Cameroon, West Africa; 2264 m AMSL) provide evidence of pronounced climatic changes in the West Cameroon Highlands since ~24,000 ¹⁴ C yrs BP. Percentages of planktonic diatoms rose with increased precipitation:evaporation ratios around 24,000 BP, ~15,000-9500 BP, and ~2400-2000 BP. Since 15,000 BP, Bambili appears to have experienced climatic changes of comparable timing and magnitude, but with signs in opposition to those registered in the West African lowlands. Much of this pattern may be attributable to variability in montane stratiform cloud formation, which in turn is related to paleo-wind regimes and upwelling dynamics in the Gulf of Guinea.     

Localization and characterization of populations vulnerable to climate change: Two case studies in Sub-Saharan Africa

Future climate change potentially can have a strong impact on the African continent. Of special concern are the effects on food security and the restricted adaptive capacity of Africa's poverty stricken population. Targeted policy interventions are, therefore, of vital importance. While there is a broad consensus on selection of climate and agricultural indicators, a coherent spatial representation of the populations' vulnerability is still subject to debate, basically because important drivers at household and institutional level are captured at the coarser (sub)-national level only. This paper aims to address this shortcoming by capitalizing on available spatially explicit information on households, food security institutions and natural resources to identify and characterize vulnerable groups in climate change prone areas of East and West Africa. First, we identify and localize groups with varying degrees of vulnerability, using food security and health indicators from georeferenced household surveys. Second, we characterize these vulnerable groups using statistical techniques that report on the frequency of occurrence of household characteristics, social bonding, remittances and agro-ecological endowments. Third we localize areas where climate change conditions affect production of major staple crops even after a maximum adaptation of crop rotations. Fourth, we characterize the vulnerable groups in the climate change affected areas and compare their profiles with the overall assessment to elucidate whether generic or climate change targeted policies are required. Since climate change will impact predominantly on agricultural production, our analysis focuses on the rural areas. For West Africa, we find that vulnerable groups in areas likely to be affected by climate change do not fundamentally differ from vulnerable groups in the study area in general. However, in East Africa there are remarkable differences between these groups which leads to the conclusion that in this part of Africa, poverty reducing strategies for climate change affected areas should differ from generic ones.     

HYENAS AND HUMANS IN THE HORN OF AFRICA*

ABSTRACT. The spotted hyena (Crocuta crocuta), the most common large carnivore in the highlands and lowlands of Ethiopia, Eritrea, and Somalia, has occupied both a scavenging niche and a predatory position at the top of the food chain. My own field explorations on this animal and the observations of travelers document its long and ambivalent association with people in the Horn of Africa. Spotted hyenas in this region have mostly lived in anthropogenic contexts rather than, as in East Africa, on wildlife. Tolerated as efficient sanitation units, hyenas have removed garbage and carrion from towns. They have also destroyed livestock, killed people, and eaten corpses. Famine, epidemics, and armed conflict have provided opportunities for unbridled anthropophagy. The past and present coming together of human and hyena in this multiethnic region can be viewed as a vestige of a primeval African ecological relationship that dates far back in prehistory. Biological processes offer a deeper framework than culture with which to grasp the inherent contradiction of the hyena/human relationship past and present.     

Coupling Conservation and Livelihoods for Sustainable Management of Protected Areas in East Africa

Strengthening research efforts to understand the combined impacts of conservation and livelihoods in protected areas (PAs) will increase the collective contribution that PAs can make towards meeting global goals for sustainable development in the next decade. As an example of such efforts, in 2014 the Chinese Academy of Sciences (CAS), the Kenya Wildlife Service (KWS) and the United Nations Environment Programme (UN Environment) jointly initiated the “Sustainable Management of Protected Areas in East Africa” project. This paper provides a brief overview of the project’s research background, goals and research tasks. The study is based on a look at the PA management system in East Africa and a review of the literature on the impact of PAs in the region. Results show that East African nations have expanded the coverage of PAs and established a complex set of PA management systems over the past century. The mandate for PAs in East African nations has changed recently from protecting biodiversity to alleviating poverty and supporting livelihoods. However, a combination of human activities and ecological processes inside and outside of PAs may not only impact biodiversity and ecosystem function over the long term, but also pose a threat to the capacity of PAs to maintain livelihoods and alleviate poverty in the local communities around them. The state of existing research in the field suggests there is an enormous need for additional research, the purpose of which is to help PA managers and policy-makers in East Africa understand how to achieve win-win outcomes for both ecosystems and human well-being. Against this background, the CAS-KWS-UN Environment joint research project aims to understand the dynamic interactions between ecosystems and human well-being around PAs in East Africa and identify good practices for PA management to reconcile conservation targets with the livelihood demands of local communities. It is intended that this research be shared with interested parties throughout the developing world. Significant progress has been made in the implementation of the project, in terms of data collection, exchanges of researchers, and the completion of case studies. In the coming year, success stories and examples of failures of PA management in the region will be systematically summarized and shared among scientists, managers and decision makers worldwide. Given its blueprint for building a “Beautiful China”, China can both supplement and benefit from East African knowledge and experience of PA management. This joint research effort promotes Sino-African cooperation on PA research and management.     

Exploring the potential of perennial crops in reducing soil erosion: A GIS-based scenario analysis in southern Tuscany,Italy

Preserving soils is a major challenge in ensuring sustainable agriculture for the future. Soil erosion by water is a critical issue in the Mediterranean regions and usually occurs when high-erosive precipitation is in temporal association with poor vegetation cover and density. Modelling soil erosion risks over large spatial scales suffers from the scarcity of accurate information on land cover, rainfall erosivity and their intra-annual dynamics. We estimated the soil erosion risk on arable land in a Mediterranean area (Grosseto Province, southern Tuscany, Italy) and investigated its potential reduction as a response to the change in intra-annual distribution of land cover due to the increase of perennial forage crops. A GIS-based (R)USLE model was employed and a scenario analysis was performed by setting criteria for raising the performance of perennial forage crops. Statistical data on agricultural crops provided an insight into current intra-annual land cover dynamics. Rainfall erosivity was computed on the basis of 22-year hourly precipitation data. The model was used to: i) quantify the potential soil losses of arable land in the study area, ii) identify those areas highly affected by erosion risks iii) explore the potential for soil conservation of perennial crops, thereby enabling appropriate preventive measures to be identified. The erosion rates, averaged over an area of about 140’000 ha, are estimated to 33.42 Mg ha⁻¹ y⁻¹. More than 59% of the study area was subjected to soil losses higher than 11 Mg ha⁻¹ y⁻¹ (from moderate to severe erosion) and the highest rates are estimated for steep inland areas. Arable land with severe soil erosion rates (higher than 33 Mg ha⁻¹ y⁻¹) represent about 35% of the whole study area. The risk of soil loss by water erosion in the study area is estimated to be reduced on average by 36% if perennial crops are increased in terms of 35% of the total arable land. The soil erosion data produced compared well with the published local and regional data. This study thus provides useful preliminary information for landscape planning authorities and can be used as a decision support tool in quantifying the implications of management policies.     

基于TOPSIS法的非洲区域经济社会综合发展水平评价

通过构建区域经济社会综合发展水平指标体系,结合TOPSIS方法与变异系数法确定权重,从经济生产、人口与健康、基础教育和产业结构水平4个方面出发,对2012年非洲52个主要国家的区域经济社会综合发展水平进行定量评价与比较,研究表明：非洲地区区域经济社会发展水平呈现出“南北发达,中部落后”的空间分布格局,区域经济社会综合发展水平北非＞南非＞东非＞中非＞西非;中非、西非地区人口与健康水平与南非、北非和东非地区差距较大,发展滞后;基础教育水平呈现“阶梯式”空间格局,南非与北非地区基础教育水平较高,中非与东非地区其次,西非地区相对落后;产业结构的地域差异较大,西非和东非地区产业结构水平较低,中非、南非和北非地区相对较高。在此基础上,提出了针对非洲区域经济社会发展特点,展开对非援助与合作的建议。     

Sub-fossil Chironomidae from East Africa. 2. Chironominae (Chironomini and Tanytarsini)

This paper and a companion article present illustrated guides to the identification of sub-fossil chironomid larvae (Insecta: Diptera: Chironomidae) preserved in the sediments of low- and mid-elevation lakes in East Africa. They are based on analysis of surface-sediment death assemblages from 61 lakes located in the humid to semi-arid environments in equatorial East Africa (Uganda, Kenya, Tanzania), supplemented with similar surface-sediment samples from 12 lakes in the Horn of Africa (Ethiopia), and sub-recent core samples from six lakes in Kenya and two in Uganda. We analyzed about 11,000 specimens and identified 98.4% of these to species, species group, genus, or tribe level, depending on current -taxonomic knowledge of the various considered genera and the taxonomic resolution of preserved diagnostic features. We distinguished 90 different sub-fossil morphotypes, of which 16 are Tanypodinae, 19 are Orthocladiinae, and 55 are Chironominae. In this paper we focus on the subfamily Chironominae (tribes Chironomini and Tanytarsini). The diagnostic characters distinguishing these morphotypes from each other resemble differences at the species level in the better-known Holarctic fauna, hence we consider most of our morphotypes equivalent to morphological species or groups of closely related species. Given that core samples yielded only seven morphotypes not also found in the surface-sediment samples, the current inventory of 90 taxa likely represents the large majority of distinct sub-fossil chironomid larval types to be found in East African lakes, excluding the few very large Rift lakes, cold-water lakes above treeline, and special standing-water environments such as fens and bogs. Consistent use of a single set of morphological characters to identify both fossil and living chironomid larvae would ensure exchangeability of information between modem and paleoenvironmental studies on aquatic invertebrate communities in African lakes, and increase the relevance of paleoenvironmental reconstructions to water-quality evaluations aimed at sustainable management of scarce, fluctuating surface-water resources in tropical East Africa.     

Kenya's regional ambitions or China's Belt‐and‐Road? News media representations of the Mombasa‐Nairobi Standard Gauge Railway

Kenya's Standard Gauge Railway (SGR), and its construction and financing by China, exemplifies the prominence accorded to mega‐infrastructural projects in contemporary economic development, as well as the dependence this has engendered on external loans. Alongside, multiple geographies intertwine in the SGR which is both a component of China's global ‘Belt and Road Initiative’ (BRI), as well as an East African regional link between coastal Kenya and neighbouring landlocked countries. In most popular and academic analyses, the role of China is emphasized over the SGR's positioning within East Africa. Does this then lead to an undermining of the meanings that are attached to the SGR within Kenya? This article seeks to add Kenyan perspectives to the debate over China's infrastructural loans by examining the range of news media discourses that have emerged around the SGR. Utilizing the theoretical lens of South‐South cooperation and African agency, this study analyzes how material infrastructure becomes meaningful within the context of a political superstructure. For Kenya, this political superstructure is shaped not only by Kenya‐China relations, but also by infrastructural competitions within East Africa, as well as within Kenya itself.     

1996-2015年非洲人口扩张区域类型划分与区域演变分析

采用总人口和劳动力等直接指标单独测度,结合出生率、死亡率、少年系数和老年系数等指标进行综合测度,分析1996—2015年非洲51个国家（地区）人口扩张区的数量变化、空间分布及演化特征,并对比了不同测度指标和方法之间的差异。发现：①总人口扩张区的比重虽高,但扩张程度有所放缓,地域分布整体呈现“南北弱、中部强”的特征,其在东非地区缩减明显;②劳动力扩张区较总人口扩张区扩张程度更为明显,两者在北非和南非部分地区差异较大,其地域分布整体呈现“北退南进”的变化过程;③“劳动力增长率大于总人口增长率”地区比重高于“总人口增长率大于劳动力增长率”,且差距有不断拉大的趋势,前者以北非地区西北部、西非地区几内亚湾沿岸较为集中,后者主要集中分布在中非、东非与西非部分地区;④基于综合指标结果显示,重度扩张型占有较高的比重,中度扩张型增速较快,轻度扩张型占比呈波动下降;⑤综合指标与单一指标结果有一定的趋同性,但区别也比较明显,综合指标在综合性、前瞻性方面有一定优势。     

Wind erodibility of major soils in the farming-pastoral ecotone of China

Wind erosion and desertification are severe problems in China's farming-pastoral ecotone. In this study, wind erodibility of five major soils in both uncultivated and simulated cultivated conditions, were determined through wind tunnel tests at nine wind speeds ranging from 10 to 26 m s⁻¹. The average wind erosion rate (g m⁻² min⁻¹) under the uncultivated condition (q₀) for the five soils could be set in the order: chestnut soil (28.5)>brown soil (24.8)>sierozem (21.8)>chernozem (19.9)>fixed sandy soil (11.4). The highest natural wind erosion might take place in the semi-arid steppe zone where the Chestnut soils predominate. Cultivation can significantly accelerate wind erosion, the mean wind erosion rate under the cultivated condition (q_c) for all five soils was 743.7 g m⁻² min⁻¹ in the following order: sandy soil (3313.2)>brown soil (227.2)>chernozem (221.8)>sierozem (85.1)>chestnut soil (81.2). For both the uncultivated and cultivated soil samples, the relationship between wind erosion rate (q) and wind speed (U) could be expressed in general as q=A e^BU (A and B are constant coefficients). There was a critical wind speed for each soil type except for the sandy soil. Below the critical wind speed, cultivation reduced wind erosion rate possibly due to soil clodiness and roughness effects. Above the critical speed, cultivation greatly intensified wind erosion rates due to the break down of the original soil structure. The critical wind speed measured at 20 cm above the soil surface was 20 m s⁻¹ for the brown soil, 14 m s⁻¹ for chernozem and the chestnut soils, and 10 m s⁻¹ for the sierozem. Among the five tested soils, the high wind erosion rate of the cultivated sandy soil showed its extreme sensitivity to cultivation, possibly because of the structureless nature of the loose sand. The “effect of cultivation on wind erosion” index, η (=q_c/q₀), increased exponentially with the increase of wind speed, indicating that under higher wind speed conditions, cultivation could result in more severe wind erosion.     

Authigenic clays in East Africa: Regional trends and paleolimnology at the Plio–Pleistocene boundary, Olduvai Gorge, Tanzania

Ultrafine clays (<0.1 m) from six East African basins show wide chemical variability that can be conveniently described as the octahedral cation index (OCI), calculated as octahedral element ratio Mg/(Al+Fe). Values range from dioctahedral clays with OCI < 0.1 (upland soils/detrital sources) to trioctahedral clays with OCI > 4 (saline, alkaline lake deposits). The association of Mg-rich clays with saline, alkaline conditions provides a paleochemical proxy in sedimentary contexts. The octahedral chemistry of central-basin clays from paleolake Olduvai (1.79 Ma) records two lake expansions, with an intervening lake contraction, over 18,000 years. The initial lake expansion correlates well with the marine record of increased African humidity, but the subsequent drying episode does not, suggesting that some high-frequency environmental oscillations in East Africa may occur independent of obliquity and precession control. The clay record correlates well with the fossiliferous and archaeologically rich stratigraphy of the lake margin, and suggests that fossils and artifacts accumulated on the exposed lake margin over <4000 years. The chemistry of clays is a potentially powerful tool to add to multi-proxy studies in basins with alkaline waters, particularly in stratigraphic intervals that lack pollen, calcareous, or siliceous microfossils.     

Sub-fossil Chironomidae from East Africa. 1. Tanypodinae and Orthocladiinae

This paper and a companion article present illustrated guides to the identification of sub-fossil chironomid larvae (Insecta: Diptera: Chironomidae) preserved in the sediments of low- and mid-elevation lakes in East Africa. They are based on analysis of surface-sediment death assemblages from 61 lakes located in the humid to semi-arid environments of equatorial East Africa (Uganda, Kenya, Tanzania), supplemented with similar surface-sediment samples from 12 lakes in the Horn of Africa (Ethiopia), and sub-recent core samples from six lakes in Kenya and two in Uganda. We analyzed about 11,000 specimens and identified 98.4% of these to species, species group, genus, or tribe level depending on current -taxonomic knowledge of the various genera considered and the taxonomic resolution of preserved diagnostic features. We distinguished 90 different sub-fossil morphotypes, of which 16 are Tanypodinae, 19 are Orthocladiinae, and 55 are Chironominae. Diagnostic characters distinguishing these morphotypes from each other resemble differences at the species level in the better-known Holarctic fauna, hence we consider most of our morphotypes equivalent to morphological species or groups of closely related species. In this paper we focus on the Tanypodinae and Orthocladiinae, with special attention to the high taxon richness among the Pentaneurini. Patterns of cephalic setation were found to facilitate identification of Tanypodinae both at the genus and species level, and contributed to improved taxonomic resolution in sub-fossil East African material. High taxon richness and numerical abundance of the Orthocladiinae in our study lakes indicates that a considerable number of African Orthocladiinae is adapted to warm standing-water environments.     

Reconstructing fluctuations of a shallow East African lake during the past 1800 yrs from sediment stratigraphy in a submerged crater basin

The sedimentology of an 8.22-m long core of late-Holocene deposits in the submerged Crescent Island Crater basin of Lake Naivasha, Kenya, is used to reconstruct decade-scale fluctuations in lake-surface elevation during the past 1800 yrs. Lake-depth inference for the past 1000 yrs is semi-quantitative, based on (1) relationships between lake level and bottom dynamics predicted by wave theory, and (2) historical validation of the effects of lake-level fluctuation and hydrologic closure on sediment composition in Crescent Island Crater and nearby Lake Oloidien. In these shallow fluctuating lakes, organic-carbon variation in a lithological sequence from clayey mud to algal gyttja is positively correlated with lake depth at the time of deposition, because the focusing of oxidized littoral sediments which dilute autochthonous organic matter before burial is reduced during highstands. The lake-level reconstruction for Lake Naivasha agrees with other adequately dated lake-level records from equatorial East Africa in its implication of dry climatic conditions during the Mediaeval Warm Period and generally wet conditions during the Little Ice Age. Crescent Island Crater survived widespread aridity in the early-19th century as a fresh weedy pond, while the main basin of Lake Naivasha and many other shallow East African lakes fell dry and truncated their sediment archive of Little Ice Age climatic variability.     

Water content and land use history controlling soil CO2 respiration and carbon stock in savanna soil and groundnut fields in semi-arid Senegal

Decomposition of soil organic carbon (SOC) regulates the partitioning between soil C-stock and release of CO₂ to the atmosphere and is vital for soil fertility. Agricultural expansion followed by decreasing amounts of SOC and soil fertility is a problem mainly seen in tropical agro-ecosystems where fertilizers are in short supply. This paper focuses on factors influencing temporal trends in soil respiration measured as CO₂ effluxes in grass savanna compared with groundnut (Arachis hypogaea L.) fields in the semi-arid part of Senegal in West Africa. Based on laboratory experiments, soil CO₂ production has been expressed as a function of temperature and soil water content by fit equations. Field measurements included soil CO₂ effluxes, soil temperatures and water contents. Effluxes in grass savanna and groundnut fields during the dry season were negligible, while effluxes during the rainy season were about 3–8 μmol CO₂ m^?2 s^?1, decreasing to less than 1 μmol by the end of the growing season. Annual soil CO₂ production was simulated to be in the range of 31–38 mol C m^?2. Furthermore, a controlled water addition experiment revealed the importance of rain during the dry season for the overall turnover of soil organic matter.     

2001-2010年非洲大气PM2.5污染浓度空间格局演化

基于NASA的全球大气PM2.5年均污染浓度栅格数据,通过对非洲行政边界矢量化、分区统计各国大气PM2.5浓度均值及建立空间数据库,利用重力模型、ESDA模型及GIS空间统计分析方法,对非洲52个主要国家（地区）2001 – 2010年间的大气PM2.5污染浓度时空格局特征演化进行探究,并依据时间序列特征将研究对象划分为8类。研究结果表明：（1）2001-2010年非洲大气PM2.5污染浓度大致呈现“中间高、南北低;西部高、东部低”的空间特征;其中高值区集中分布在非洲西部几内亚湾附近的尼日利亚、刚果与喀麦隆等国家,低值区则广泛地分布在北非、南非以及非洲东南部印度洋沿岸地区或岛屿。（2）基于ESDA模型的空间自相关分析发现PM2.5浓度“高-高”热点区主要集聚在几内亚湾附近主要国家,“低-低”冷点区集中在东南部印度洋沿岸的南非、莫桑比克与马达加斯加岛。（3）时序上2001-2010年非洲PM2.5年平均污染浓度呈现明显下降趋势,其中32个国家（占研究区总数的61.54%）2010年PM2.5污染年均浓度低于2001年。（4）从自然环境条件及社会经济因素两方面浅析其空间格局主要成因：几内亚湾沿岸是非洲PM2.5污染最严重的地区,因其人口稠密且高度依赖石油产业;非洲东南部地区PM2.5污染最轻,得益于其良好的自然环境条件及低污染的支柱产业。