The role of rural-rural migration as a survival strategy in the Sahelian zone of the Sudan —

Taking the example of Burush, N Darfur, Sudan, the authors analyse the role of migration as a survival strategy in the desertification-stricken Sahelian zone. It is being argued that the rual-rual migration plays a greater role than the rual-urban migration among the Berti ethnic group of northern Darfur. Their high mobility within their own area is part of their traditional economic pattern for coping with aridity and high rainfall variability     

The responses of different ethnic groups in the Sudan to rural-urban migration

The ethnic identities of the various population groups in the Sudan are a product of their specific natural and social environments. The migration of these groups to the towns, especially to Greater Khartoum, involves a drastic change of cultural norms and values. However, the capability of change and the subsequent results are strongly conditioned by the specific background of each ethnic group and by the conditions in its area of origin. This is being proved by a comparative study on three ethnic groups in the Sudan: the Nuba, the Zaghawa and the Hadandawa.     

The Zaghawa and the Midob of North Darfur – A comparison of migration behaviour

Two ethnic groups of North Darfur, the Zaghawa and the Midob, are being compared as regards their migration behaviour and their identification in their destination areas. Both groups have severely suffered as a result of the drought phase of the last three decades, during which more than half of the Zaghawa and Midob have migrated southwards and to the towns. Despite the similarity of the two ethnic groups, being non-Arab agropastoralists who are socially and politically marginalised both within Darfur and within the Sudan, they show marked differences in their migration behaviour and ethnic solidarity. The Zaghawa migrants are considerably more economically successful than the Midob migrants. The main reasons are: – The Zaghawa started their outmigration earlier than the Midob. Thus, they could establish ethnically-based networks in Libya and the Gulf countries, to which Zaghawa migrants can resort to make a good start in their destination areas. By the time the Midob started their migration in the 1980s, the conditions of employment in the Arab oil countries had worsened. – The Zaghawa show a strong clan solidarity. They readily lend money to young members of their clan to cover the high costs of travelling to the Arab oil countries for work, where many of them have already established themselves. – The Midob, both in the Sudan and abroad, have much less resources available. The only country open for them outside the Sudan is Libya. Lacking capital, the Midob go there on camels, mostly illegally. Having no connections in Libya, except those to other poor Midob there, they usually try to work in herding sheep and goats, which is not a lucrative profession. This revised version was published online in July 2006 with corrections to the Cover Date.     

The subsistence crisis and migration in the Sahelian Zone of the Sudan —

Burush is a small village in the N Sahelian Zone of the Sudan, whose population are basically sedentary agriculturists. The recurring drought conditions of the last two decades have significantly influenced the local resource base, so that the subsistence of the majority of the households was highly challenged. Nevertheless, the people are still surviving and resisting. The explanation of this resistence can be sought in the endogenous coping mechanisms adopted by the people. One of these mechanisms is migration, especially the seasonal labour migration of the heads and grown-up members of households, which used, even in good years, to be highly integrated in the strategies of survival of the majority of households. However under the recurring crop failures and the growing competition in the seasonal labour opportunities, this seasonal migration is changing gradually into stays of longer duration in the traditional destinations of seasonal labour. On the other hand, the male members of households are actively involved in migration of long duration, especially into the urban centres. Yet, the constributions of these migrant members to the subsistence of their households are limited, because of the rising costs of living in uurban centres as compared with the incomes. The rehabilitation of Burush lies obviously in the development of long-term strategies which aim at strengthening the endogenous resilience mechanisms.     

Rural-urban migration and the problem of town planning —

The conurbation of Khartoum has been long the main destination area of the rural-urban migration in the Sudan. The town-planning office has become unable to provide the inmigrant masses with the least required housing infrastructure. The result is that the inmigrants have been living for some decades now in squatter areas without any right of residence. The way from the formation of a squatter settlement which is officially non-existent and illegal to a demarcated residential area is long and tedious. The author describes this process using the example of Um Badda which is a traditional destination area of inmigrants. The analysis shows that the officials of the town-planning treat the ethnic groups on unequal basis with a strong bias against southern Sudanese.     

Journeys to the street: the complex migration geographies of Ugandan street children

Children have generally been afforded little attention in migration research or unsatisfactorily included within family migration. Although they are an important consideration in family decisions to move, children also engage in autonomous, independent migration. Further, researchers now argue for the need to situate migration within political, economic and social conditions to obtain a full understanding of why people migrate. Through the use of children-centred research methods, and in-depth interviews with key informants, this paper considers children's journeys to the street in Uganda. By integrating an analysis of Ugandan street children's spatial origins with the familial and societal contexts of their migration decisions, this research highlights the complexity of their migration. In addition, an exploration of the impact of changing social, spatial and temporal conditions on street children's movements illustrates that their journeys are far more than just single processes.     

Nyimang women in urban settlements

Rural-urban migration is a widespread process in Sudan. Male migration from the Nuba mountains to Khartoum already started during the colonial time. Up to the present, the percentage of women under the migrants has rapidly increased. The women follow their husbands or move together with their families to the capital. Their living conditions in Khartoum differ from those in rural areas. The migrant women have less opportunities to work outside the house or to move to other housing areas, so that they only have contacts with members of their ethnic group living in the same neighbourhood. Besides the social problems, the women are confronted with economic difficulties. Their aim, to save money for remigration, is nearly impossible to attain.     

Vulnerabilities and migration in Small Island Developing States in the context of climate change

The unique characteristics of Small Island Developing States and structural vulnerabilities they face in terms of development have earned them particular consideration in the development agenda. This article sheds light on some of the vulnerabilities that these countries face, making particular reference to their environmental and economic vulnerabilities. It then highlights the ambiguous role that international migration plays in the recreation of those vulnerabilities.     

Effects of fault activities on hydrocarbon migration and accumulation in the Zhu I Depression,Pearl River Mouth Basin,South China Sea

Faults can act as either conduits or barriers for hydrocarbon migration, because they have complicated anisotropic flow properties owing to their complicated three-dimensional structures. This study focuses on the Zhu I Depression, Pearl River Mouth Basin (PRMB), China. In this area, hydrocarbon migration and accumulation occurred over a relatively short period of time and were contemporaneous with fault activation, so the characteristics of hydrocarbon accumulations can be used to deduce the effect of active faults on hydrocarbon migration and accumulation. This study addresses the effect of fault activity on flow properties during hydrocarbon migration through a quantitative and comparative analysis of fault activity vs hydrocarbon accumulation. The fault slip rate and shale smear factor parameters were used to characterise faulting and elucidate its effect on hydrocarbon migration and accumulation. Active faults are generally excellent vertical conduits with strong fault activation resulting in vertical migration of most hydrocarbons and little preservation; traps near faults with fault slip rates greater than 20 m/Ma rarely contain commercial oil and gas accumulations. Faulting can form shale smear, which, if continuous, can act as a barrier to hydrocarbon migration. An active fault can allow hydrocarbon transport from deeper formations and to be trapped by continuous shale smear in shallower strata. Most of the oil and gas in the Zhu I Depression have accumulated near faults with a moderate fault slip rate (<20 m/Ma) and development of continuous shale smear (SSF<4–6).     

多孔介质界面对重非水相液体迁移过程影响的图像法研究

重非水相液体(dense nonaqueous phase liquid,DNAPL)污染土壤和地下水的问题已引起广泛关注,研究其在不同粒径多孔介质及其界面的运移特征形态是确定污染区域、修复治理土壤和地下水环境的前提。文章通过室内试验研究多孔介质界面对DNAPL运移与分布特性的影响。首先在二维砂槽上进行DNAPL污染物的入渗试验,试验过程中用数码相机拍照,将DNAPL扩散过程以图像的形式记录下来;然后用AutoCAD对图片进行处理,绘制出DNAPL迁移过程的锋面变化图。结果表明:DNAPL入渗过程中,迁移主要受到重力作用与毛细作用的控制,毛细作用力随着介质粒径的增大逐层减小,重力作用逐渐起主导作用使污染物入渗速度逐层增大;介质结构影响DNAPL的迁移形态,介质粒径逐层增大,DNAPL污染物的渗流面与指进扩散宽度逐层减小,扩散方式由面状变为指状;在不同粒径介质界面介质结构发生突变时,DNAPL迁移锋面线曲率也相应变大,此时DNAPL的迁移呈现“凸”型特征,另外,不同的界面横向扩散的滞留宽度不同,随着介质粒径的增大,界面的横向扩散宽度相对变短。     

The middle space of migration: A case study on brokerage and recruitment agencies in Nepal

Foreign employment has become a global phenomenon. With the increasing commercialisation and formalisation of transnational labour migration, recruitment agencies and agents have gained importance. The paper aims to contribute to a more differentiated understanding of the role and the practices of the main actors in the middle space of migration, the brokers in the recruitment process for transnational migration. Based on empirical material from Nepal, it argues that the detected negative reputation of labour brokers is only partially justified. Besides common bad practices and fraud cases, recruiters perform important roles for the facilitation of transnational mobility and present the necessary infrastructure for labour migration. They connect people and places, establish networks and can play an important role in making migration safer. Brokers are important facilitators in supporting alternative income strategies and new livelihood options of people. At the same time they are entrepreneurs in a competitive and risky economic field, confronted with multifaceted constraints. As long as the gap between the dreams of potential migrants and the reality of marginality in Nepal remains wide, labour brokers might persist as important middlemen for global work. Thus, migration brokerage is likely to remain big business.     

Migration: Causes and effects —

Drought, desertification and lack of development have been the main causes of migration in the rural areas of Western Sudan. The author tackles the different migration patterns followed in the area of Omodiat Burush and the factors influencing these migrations. It is found that high preference is given to rural-rural migration either on a seasonal basis or a permanent one. The latter is directed towards Burush village which attracts the inhabitants of the surrounding villages by the relative availability of educational, health and marketing services. Seasonal migration, on the other hand, is an important coping strategy against crop failure and famine risks.     

油气初次运移理论新探

应用渗流力学的基本原理,研究油气初次运移的机制问题。研究认为,油气的初次运移是以连续相、而不是以溶液相和扩散相的形式进行的;油气初次运移的动力是浮力,因而初次运移的方向是向上的;油气初次运移所需的时间与源岩的渗透能力有关,与油气的粘度有关,还与源岩的厚度有关;油气藏的异常高压是一种暂时的压力状态,气藏的异常高压多于油藏,新生油气藏多于古油气藏;油气初次运移的通道就是源岩的粒间孔隙,源岩的非均质性和微裂缝对油气初次运移十分不利,因形成微油气藏而降低油气运移效率;源岩的厚度越大,越有利于油气聚集;“倒灌”现象是不存在的,缺少基本的动力驱动,基岩油气藏的形成是二次运移过程中侧向运移的结果。初次运移与二次运移具有相同的动力机制、运移相态和运移方向,因而两者是完全统一的。     

Fractionation of azaarenes during oil migration

A comparative study of alkylbenzoquinolines in crude oils and rock extracts (bitumens) from Japan and Sumatra shows that the ratios of nitrogen-masked isomers (NMIs) to nitrogen-exposed isomers (NEIs), and the ratio of higher homologs to lower homologs is higher in crude oils than in corresponding bitumens. Also, a regular increase in the ratios of NMIs to NEIs with increasing migration distance is observed for a series of crude oils from the Sarukawa Oil Field, northeastern Japan. These results are attributed to the preferential migration of NMIs caused by their weak adsorption on clay minerals and/or their low solubility in interstitial water, and the selective removal of lower honologs caused by their irreversible adsorption onto clays during oil migration, which are regarded as geochromatographic phenomena. It is suggested that those ratios can be used to estimate the degree of fractionation of oils during primary and secondary migration.     

Women's migration and quality of life in Turkey

Turkey's urban growth has been unprecedented for the last two decades with women playing an increasingly substantial role in its development. In this context, we examine determinants of women's migration and quality of life in cities in 1990 (the most recent published census of Turkey) and onwards. Factor analysis of provincial data identified three quality of life dimensions: affluence, deprivation, and housing. Substantial disparities in quality of life indices exist between men and women, urban and rural milieu, and geographic regions. Migrants, especially women, still tend to move with their families but they prefer provinces with high scores on (relative) urban affluence and avoid deprived, rural provinces. Thus Istanbul, Ankara, and southern coastal provinces are preferred destinations. Policy implications for urban growth, regional development, and gender equality relative to migration are discussed.     

A method for avoiding artifacts in the migration of deep seismic reflection data

Conventional wave-equation-based migration of deep seismic reflection data can produce severe artifacts, which appear as broad circular arcs or “smiles”, due to the existence of apparent truncations of reflections on the stack section arising from poor signal penetration, changes in orientation of the acquisition profile, and the existence of strong overlying lateral velocity variations. These artifacts limit the interpretation of deep seismic profiles, because they obscure weak reflections and reflection truncations that may, e.g., indicate the presence of subsurface faults. Here I present a new migration algorithm, in which each sample of the stack is migrated to a short linear segment whose position and dip are determined by its original position on the stack, an estimate of the local apparent dip at that point, and a user-specified migration velocity. No subjective interpretation of reflections on the stack section is required, and the algorithm produces no arc-like migration artifacts. The degree of lateral smearing can be easily controlled, allowing reflection truncations to be revealed. In practice, the algorithm is most effectively applied to data that have been coherency-filtered to remove low amplitude noise, which would otherwise be preserved.     

Land, ethnic, and gender change: Transnational migration and its effects on Guatemalan lives and landscapes

Migration to the United States of America from Guatemala effects many aspects of Guatemalan life. We document, through extensive ethnographic fieldwork, how migrants and their remittances effect gender relations, ethnicity, land use, and land distribution. Our evidence is drawn from research in four communities. San Pedro Pinula and Gualán represent communities of eastern Guatemala. San Cristóbal Totonicapán is an Indigenous town in Guatemala’s western highlands, and San Lucas is a lowland frontier community in the Guatemalan department of Ixcán, which borders Chiapas, Mexico. Our results reveal that migrants and their remittances, both social and tangible, result in significant changes in land use and land distribution in Ixcán. Migrant money permits the conversion of rainforest into cattle pasture and also results in the accumulation of land in the hands of migrants. In terms of land use, we see in San Pedro Pinula that migrant money also allows the Pokoman Maya to make small entries into the Ladino (non-indigenous) dominated cattle business. In San Pedro Pinula, the migration and return of Maya residents also permits them to slowly challenge ethnic roles that have developed over the last five centuries. When we look at how migration effects gender roles in Gualán and San Cristóbal we also note that migration and social remittances permit a gradual challenge and erosion of traditional gender roles in Guatemala. We point out, however, that migration-related changes to traditional gender and ethnic roles is gradual because migrants, despite their increased earnings and awareness, run into a social structure that resists rapid change. This is not the case when we examine land transformations in Ixcán. Here, migrants encounter few barriers when they attempt to put their new money and ideas to work. Despite the advantages that migration brings to many families, especially in the face of a faltering national economy and state inactivity regarding national development, we conclude that migration and remittances do not result in community or nation-wide development. At this stage migrant remittances are used for personal advancement and very little money and effort is invested in works that benefit communities or neighborhoods. We call for continued studies of the effects of international migration on Guatemalan hometowns that build on our initial studies to better understand the longer-term ramifications of migration in a country where no community is without migrants.     

Migration from Eastern Gezira into greater Khartoum

This paper is an attempt to investigate the role of rural-urban migration in the population integration process and national identity in Sudan. Although migration is considered as an important mechanism in integration, yet its effect cannot be easily detected if urban life fails to challenge the culture and norms of migrants. In this case study the role of migration is limited by the status of the urban and the purely traditional background of migrants. Population integration is a central issue in the Sudan with its high level of pluralism, ethnic and cultural complexity. It is assumed that migration is an essential factor to challenge such complexity. This paper is part of a research programme financed by the Deutsche Forschungsgemeinschaft (DFG) — Identity in Africa — Processes of Development and Change — initiated and sponsored by H. Ruppert and F. N. Ibrahim, University of Bayreuth.     

Desertification,famine, and the 1988 rainfall —

The 1988 good rainy season in the Sudan raised the hopes that desertification/land degradation and shortage of food so markedly observed in Western Sudan have been elevated. This was particularly so as large quantities of grains were produced in the mechanized rain-fed agricultural schemes in the clay plains of Eastern Sudan. But the field work carried by the author in the Umm Ruwaba district of Kordofan region in July/August 1989 shows that, although there has been some improvement in the crop production situation, desertification/land degradation and shortage of food produced locally are still prevailing in the district. The people are still living below the poverty line, but they are able to cope because of remittances from members of the families working abroad and because of donations of food by some world organizations.     

Age-specific net migration patterns in the municipal formations of Russia

This paper analyses the spatial patterns of internal migration in Russia using data on net migration gain/loss in 2200 municipal formations (MFs) in Russia for the 2012–2013 period. These MFs are grouped into age categories that correspond with different life-course stages. We define 16 classes of MFs with similar migration balance patterns for multiple age groups and characterize the most typical classes. The results of our analysis show that age-specific migration patterns are determined by the spatial characteristics of MFs—in particular, a municipality’s localization in the centreperiphery system and the advantages of the geographic location (e.g., resort area, natural resources). We find that a city’s population size and administrative status are also important migration factors. In addition, we reveal differences in inter-regional and intra-regional migration and define their structural characteristics. An analysis of age-specific net migration contributes to our understanding of internal migration factors and allows us to assess the impact of migration on a municipality’s age structure. In large cities and regional centres, migration results in younger populations, while in peripheral areas, it speeds up population ageing. In most of the MFs that we analysed, the migration of youth and adults ‘moves’ in opposite directions. This factor accelerates the impact of migration on the population age structure in areas of destination and origin and significantly influences a municipality’s current and prospective demographic parameters as well as the population’s patterns of settlement and spatial concentration or de-concentration both nationally and regionally.