Gezira Scheme between state and market: some remarks on the privatization of irrigation in Sudan

This paper is a study of so-called privatization of the great Sudanese Gezira Scheme, under the structural and budgetary problems of the country. Nothwithstanding the official declaration, in reality privatization affected the project just in nominal way. Indeed, two factors play against it: the resistance of the State, which wants to hold the management of the national strategic resources, and the resistance of the territory itself which — as autopoietic system — reacts against any attempt to change its own structure. The islamic renewal(tajdid) can be considered as a way to solve the dilemma between development and social consent, under these new conditions.     

Taphonomy and site formation on California's Channel Islands

Inhabited by humans for over 12,000 calendar years, California's Channel Islands contain thousands of archaeological sites, ranging from dense shell middens and villages to small lithic scatters and camps. Similar to many islands around the world, the Channel Islands have a dearth of burrowing animals and limited historical development leading to generally good preservation of archaeological constituents and relatively high stratigraphic integrity. Despite these favorable preservation conditions, numerous natural and cultural processes have impacted the island's archaeological record. Channel Islands archaeologists, however, have given relatively limited attention to the effects of taphonomic and formation processes. The authors provide an overview of taphonomic and formation processes affecting Channel Islands archaeology, illustrating the importance of regional taphonomic syntheses in the management, preservation, and interpretation of archaeological sites. These data also demonstrate the significance of detailing formation processes in islands and other areas where burrowing rodents and other disturbances are thought to be absent or limited. © 2006 Wiley Periodicals, Inc.     

黄河“八七”分水方案的适应性评价与提升策略

黄河"八七"分水方案是流域水资源管理的重要依据。颁布30余年来,黄河流域自然环境、经济社会等发生了显著变化,亟需科学认识分水方案对环境变化扰动的适应性。运用动力系统原理构建分水方案适应性的动力微分方程和综合评价模型,从敏感性、稳定性、抗力和恢复力4个方面建立包含20个指标的适应性评价指标体系,定量评价1999年以来分水方案的适应性,并采用HP（Hodrick-Prescott）滤波识别适应性变化趋势。结果表明:分水方案对环境变化的适应性良好,19年中63.2%的年份适应性值大于1;适应性先升后降,2005年达到峰值,之后逐渐降低,2014年起适应性值小于1,表现为不适应。分析影响分水方案适应性的主要因素,提出分水方案调整策略,为支撑流域水资源管理提供方向参考。     

Disaster risk management in agriculture: tragedies of the smallholders

Agriculture sector is exposed to a variety of risks and uncertainties which can lead to sizeable losses in crop yields and alter farm incomes. Risk management is, therefore, an essential element of the overall farm management process. Farmers have number of options in managing farm risks; however, smallholders, due to their small operations and limited financial capabilities, find it difficult to adopt sophisticated risk management strategies to overcome yield and income instabilities at farm level. This study is, therefore, designed to investigate the enabling environment for small farmers to manage climatic risks at farm level. A total of 330 sampled respondents from Khyber Pakhtunkhwa Province of Pakistan are randomly selected for the study using multistage sampling technique. Analysis of variance technique is employed to compare the risk management adoption decision of small, medium and large farmers. A post hoc analysis is also performed to highlight the difference in means and the magnitude of differences. The results indicate that smallholders have significantly lower access to credit (both formal and informal), formal information sources along with significantly higher perceptions of pest and diseases. Smallholders are also at the tail end in the adoption of precautionary savings and agricultural credit to manage climatic risk at farm level. The study urges for risk management policies particularly in favor of the small farmers and intervention in the existing information and credit provision programs to facilitate smallholders in managing farm risks.     

病毒与细菌等微生物在地球生物演化史上的作用

病毒与细菌统称为微生物。病毒与细菌之害是生物生存遭遇到的最大的灾害,不仅在人类社会历史上留下了深重灾难,而且在地球生物演化史上也是大灭绝的重要推手。虽然病毒和细菌难以形成实体化石,但却以一种特殊的分子化石成为了侦探地质时期生物大灭绝的神针。本文以地球微生物学为指导,以蓝细菌和绿硫细菌分子化石为例,综合有关研究成果,解读了微生物学、病毒和细菌以及微生物岩的有关知识,帮助人们认识地球生物演化史上二次重要的大灭绝事件。本文还从人类演化过程中的农业革命,阐明了人菌共生关系及带来的启示。     

欧盟地区环境地质科学研究现状、战略及启示

欧盟是世界环境保护与可持续发展的主要倡导者和推动者,在环境地质科学研究方面积累了大量先进的理念、经验和做法。在论述欧盟环境管理基本理念的基础上,从填图、监测、机理研究3个方面分析了欧盟地区环境地质调查和科学研究工作现状,概括总结了其在环境地质领域的科学发展战略重点,梳理出各成员国地质调查机构从传统地质调查工作向服务生态管理的现代地质调查工作转变的发展路线。在此基础上,提出了对中国环境地质调查和研究工作的启示:加强地质环境生态服务功能评估;加强统一的地质环境监测体系建设;开展地球关键带三维地质调查与监测;加强地质环境事件快速响应基础研究。     

浙江慈溪市土地生态质量调查和评估

土壤、大气、水和农产品质量共同构成土地生态质量的内涵。通过慈溪市基本农田质量调查试点项目,开展了高精度土壤地球化学调查和农产品、灌溉水、大气质量调查,建立了土地生态质量评估模型。以土壤地球化学质量评估为基础,进行了大气、水、农产品综合质量评估,以及慈溪市农用地土地生态质量评价。评价显示,慈溪市农用地土地生态质量绝大部分优良,只有局部如城市周边等地存在生态风险。试点成果为浙江省国土资源特别是基本农田的数量、质量和生态管护并重的精细化管理提供了示范和依据。     

The key role of supply chain actors in groundwater irrigation development in North Africa

The role played by supply chain actors in the rapid development of groundwater-based irrigated agriculture is analyzed. Agricultural groundwater use has increased tremendously in the past 50 years, leading to the decline of water tables. Groundwater use has enabled intensification of existing farming systems and ensured economic growth. This “groundwater economy” has been growing rapidly due to the initiative of farmers and the involvement of a wide range of supply chain actors, including suppliers of equipment, inputs retailers, and distributors of irrigated agricultural products. In North Africa, the actors in irrigated production chains often operate at the margin of public policies and are usually described as “informal”, “unstructured”, and as participating in “groundwater anarchy”. This paper underlines the crucial role of supply chain actors in the development of groundwater irrigation, a role largely ignored by public policies and rarely studied. The analysis is based on three case studies in Morocco, Tunisia and Algeria, and focuses on the horticultural sub-sector, in particular on onions and tomatoes, which are irrigated high value crops. The study demonstrates that although supply chain actors are catalyzers of the expansion of groundwater irrigation, they could also become actors in adaptation to the declining water tables. Through their informal activities, they help reduce market risks, facilitate credit and access to subsidies, and disseminate innovation. The interest associated with making these actors visible to agricultural institutions is discussed, along with methods of getting them involved in the management of the resource on which they depend.     

Brutal presence or convenient absence: The role of the state in the politics of flooding in informal Accra,Ghana

This paper argues that human vulnerability to flood hazards in urban slums in developing countries is greatly affected by the positioning and activities of their city governments. As a result, the paper explores the central role of city authorities in the production of flood vulnerability in selected informal settlements in Accra, Ghana. Using a case study research design, the study draws on multiple qualitative methods to gather evidence including: document review, focus group discussions, flood victims’ interviews, institutional consultation and field observation. The paper reveals two main positions of state and city authorities in Accra’s perennial floods: first, being present and complicit in informal urbanization through their involvement in the politics of land management in flood prone zones; and second, being absent through their inaction in informal growth in flood-risk areas. To each of these positions of the urban state, there are emerging responses from residents and other non-state actors operating within and outside these informal communities. The paper proposes a re-examination of the current structure and processes of urban governance, state-community engagements and urban citizenship in informal communities.     

Soil properties and moisture characteristics and their relationship with crop mid-day stress in the Sudan Gezira

This study is mainly about the relationship of the moisture holding and release capacity of soils with their texture, particularly the clay fraction. Soil samples collected from various sites in the Sudan Gezira were analysed for physical and chemical properties and moisture characteristics. Generally the soils were clayey except the recent alluvium which was loamy. The pH was alkaline and the electric conductivity < 1.0 dS m^–1. The studied soils were calcareous and very poor in organic matter, their intermediate to high water holding capacity being due mainly to the presence of large quantities of clay. Matric potentials of –0.4 to –1.5 MPa reduced soil moisture for all types of soils but the effects were not necessarily quantitatively equal. Permanent wilting point — moisture content at – 1.5 MPa — varied widely (10.5 – 22.0%) amongst the different soils and this was mainly attributed to texture and mineralogy of the soil clays. Bulk density decreased with increase in clay content. Calcium carbonate content was found to have no apparent relationship with the moisture content of these soils. The amount of silt fraction seems to have an overriding effect on the relationship between soil moisture availability in the recent alluvium soil and its subsequent release to growing plants. The results are discussed in relation to the phenomenon of mid-day stress observed in all grown crops of the Sudan Gezira.     

A no-camp policy: Interrogating informal settlements in Lebanon

As fewer refugees move into formal camps, what kinds of non-camp spaces are emerging and how does that challenge the ways in which we understand the management and politics of refuge? This paper seeks to shed light on this question through an analysis of informal settlements in Lebanon. The Syrian crisis has displaced millions of people, most of whom have moved into neighbouring countries such as Jordan, Lebanon and Turkey. The Lebanese government, faced with a longer history of Palestinian camps and their militarization has refused to allow the establishment of official refugee camps for Syrians. As a result of this ‘no camp’ policy, Syrians are forced to either live in private rented accommodation in towns and cities throughout the country, or in informal settlements (ISes) built on private, often agricultural land. These informal settlements are built and developed through a complex assemblage of humanitarianism, hospitality, security, economic and political considerations. In this paper, I look at the physical and social spaces of informal settlements in the Bekaa Valley, Eastern Lebanon, examining how differential access to aid, support, security and tacit recognition by the state has led to variations amongst them. In doing so, I expose how an informalized response to the crisis through a system of deregulation is enabling refugee spaces to emerge that are visible, yet unrecognized, flexible, yet precarious. These spaces destabilize the city/camp dichotomy by drawing together elements of both. In engaging with debates on informality, the paper contributes to a growing critical literature on refugee geographies and seeks to expand beyond the reductive narratives of refugee camps, thereby offering insights into refugee futures in increasingly uncertain times.     

A nine-step approach for developing and implementing an “agricultural drought risk management plan”; case study: Alamut River basin in Qazvin,Iran

Occurrence of drought, as an inevitable natural climate feature, cannot be ceased while happening. However, costs of the consequences could be alleviated using mature scientific integrated approaches. To reduce the amount of damage, it is required to provide “Contingency” and “Mitigation” action plans. For this reason, development of efficient operating instructions for various regions based on weather conditions and field studies is needed as well as having a sophisticated understanding of socioeconomic situations. This paper describes an approach to provide the first national agricultural drought risk management plan for a river basin in Iran country as a pilot. The study lasted for 3 years as a national technical research project for the “soil conservation and watershed management research institute.” To reach the objectives, besides holding workshops and specialized think-tank meetings, field researches were done. Based on the socioeconomic data sources in the basin and the results of meetings by participation of local managers and residents, the final plan was developed. Moreover, in order to carry out this research, different climatic, agricultural and local information were collected in the watershed. In the next steps, potential risks and vulnerabilities of various agricultural sectors due to the hazard were evaluated. In this study, a nine-step approach to develop an agricultural drought risk management plan proposing different scientific–managerial phases based on the latest experts’ opinions, released international scientific best practices, and existing conditions governing the region was followed. With respect to the average income of US$ one million from agriculture and animal husbandry in the river basin, total drought loss varies from US$ 86,000 to US$ 258,000 for a range of light to very intense drought conditions, respectively. The setup of these nine executive phases defined monitoring, forecasting, and warning steps in working teams and managed the subprograms in partnership with stakeholders and decision-makers to mitigate the rate of drought damage from 30 to 47% (depending on the severity of the drought condition).

     

农业生态环境的数字化研究

土地退化已成为全球性重大的环境问题之一,中国是一个土地退化十分严重的国家,松嫩平原的盐碱荒漠化严重制约农牧业的可持续发展。因此,应用新技术、新方法对农业生态环境进行研究和管理是一项迫切的任务。文章提出农业生态环境的新概念,建立了农业生态环境系统模型,进行模拟研究。由于该方法在信息存储、管理和应用方面存在较大的局限性,笔者继而建立了农业生态环境信息系统模型,扩大对空间信息的应用。但该信息系统缺乏信息共享的功能,而且不能对海量的信息进行空间化、数字化和一体化的管理。笔者以多学科的理论和多种技术方法为基础,借鉴数字地球的研究成果,研制了吉林西部农业生态环境数字信息系统。该系统具有存储、管理海量空间数据的功能和信息共享功能,可在统一的用户界面下进行农业生态环境评价、预测、仿真和规划等方面的系列、连续研究,并可实现模拟结果的可视化。该系统具有扩充性、移植性等优点,因此,具有推广价值。     

沉积盆地物质来源综合研究——以南堡老第三纪亚断陷盆地为例

重矿物分析对于判断沉积盆地的物源方向和物源区的母岩性质是有效的,但具有局限性：①对无重矿物或者仅能提供极少量重矿物的母岩判别力较差;②它不能准确判断物源区沉积物的主要运移通道。因此,进行盆地物源分析还需要重视综合研究,即①通过重矿物的矿物学、重矿物组合研究,判断物源区的母岩类型,推测母岩岩性演化;②通过沉积岩矿物成分与结构研究,判别物源区是否存在重矿物无法辨认的母岩类型和沉积物的搬运距离;③通过沉积体系分析,尤其是砂分散体系的编图,能有效地判断物源区的方位和圈定各物源的具体影响范围;④利用古构造图判别物源区的主要沉积物运移通道及其方位;⑤编制沉积盆地－物源区古环境图,以此来弥补重矿物分析物源所带来的缺陷。     

中蒙边界中东段地层划分与对比

中国与蒙古交界地区,早前寒武系—新生界分布广泛,地层划分系统差别较大。根据近年来内蒙古地层年代划分研究成果,初步对中蒙边界中东段蒙古地层岩石、化石进行了整理与划分,并以中国出露的地层为参照,进行中蒙边界中东段地层划分与对比。结果表明,中蒙边界中东段地层具有连续性,可以统一划分对比。     

Characteristics, threats and opportunities of landfill scavenging: The case of Gaborone-Botswana

In Gaborone, as in other large cities in the developing world, individuals try to make a living by engaging in novel occupations such as landfill scavenging. This paper reports on a research conducted in the Gaborone landfill, the largest in Botswana. The study content-analyzed available literature from other countries. It also relied mainly on direct field observations. The discussions on and answers to closed and interview schedules by stakeholders, affected- and- interested – persons, provided the information on the threats and opportunities related to the landfill site and its informal management activities. This on-going case study lends credence to the potential of scavenging in sustaining livelihoods among those who cannot secure employment in the formal urban market. Scavenging tends to be useful although it may hazardous to the informal entrepreneurs. Taking all the threats into consideration, the decommissioning and closure of the landfill seems inevitable, in spite of the apparent short-term livelihood opportunities it provides to the informal sector.     

Disaster education for landslide risk reduction: an experience in a public school in Rio de Janeiro State,Brazil

Public policies for reducing the disaster risk associated with landslides in Brazil, based almost solely on the implementation of engineering works to stabilise hillsides, have proved ineffective, with this type of disaster becoming more common and more severe. There is therefore an urgent need to form a culture that encourages the public to participate directly in disaster management and develops community capacity, which requires a broad disaster education programme on formal, non-formal and informal levels. Given the recent approach to the topic, this study aims to contribute to the development of a disaster education methodology for landslides, based on an experience that was coordinated by the authors within formal education. The experience was implemented in a state school in the city of Niterói (Rio de Janeiro State, Brazil) which is recurrently affected by disasters associated with landslides. The issue of disasters associated with landslides was addressed in a one-semester course, using the theory of meaningful learning and a range of pedagogical tools in both theory and practical classes, for a total period of 16 h. The educational activities were preceded by a landslide risk perception survey and teacher training. The study concluded that the course promoted interactive and participatory learning, a connection to the real problem in the field and an affective relationship with the issue.     

Soil quality evaluation under different land management practices

Sustainable agricultural production requires prudent management backed by reliable information that accurately elucidates the complex relationships between land management practices and soil quality trends. Therefore, this study investigates the influence of management on soil properties acquired at different depths, and yields, at five different field sites within Ohio, USA. The principal management systems considered were no till with or without manure and cover crops, natural vegetation (NV) or forest, and conventional tillage (CT) defined as farms with surface residue cover (<30 %). Analyses of variance (ANOVA), correlation analyses, stepwise regression, and the principal component analyses (PCA) were used to elucidate and model the link between four different management practices and the soil physical and chemical properties. The ANOVA results indicate that the available water capacity and electrical conductivity (EC) were the major variables affected by management. In contrast, soil pH, bulk density (ρ _b), porosity, soil organic carbon (SOC), and total nitrogen (TN), were invariable with management, yet only pH and EC did not significantly vary with the interaction of soil type and management effects. In comparison, the PCA results suggest that SOC, TN, porosity, ρ _b, and EC were the major determining factors controlling yield variability. Interestingly, the derived models revealed that the highest yields, notably 10 and 2.7 Mg ha^?1 for corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) occurred in soils under CT management. Quantifying the nexus between soil properties and management choices as demonstrated in this study, can provide critical insight for sustainable agricultural production.     

基于GIS的地下水信息管理系统分析

GIS支持下的地下水信息管理系统开发是当前水资源管理研究的热点之一，它能够根据用户的触发指令，借助基础软件和特定的功能模块，将离散的数据整合为符合用户需求的知识信息以辅助决策。通过对地下水信息的内容、组成及其特征的分析，刻画了系统内部的数据流、信息流和知识流。在分析系统用户类型及层次的基础上，抽象出系统用户一功能规约表。基于对开发原则、开发工具和开发模式的分析和讨论，给出一种可行的基于GIS的地下水信息管理系统逻辑模型。     

Hurricane-borne African Locusts (Schistocerca gregaria) on the Windward Islands

The research applies a geographic perspective to the interface of biotic, atmospheric and socio-economic factors. Wind as a factor in biotic distributions helps explain the existence and quality of life on many isolated islands. In the late summer of 1988, there were reports of African desert Locust (Schistocerca gregaria) invasion of the Windward Islands. The event was historically unprecedented, and agricultural experts in the eastern Caribbean were alarmed. A tentative hypothesis was that Hurricane Joan provided the transport mechanism. An alternative hypothesis is suggested here. The discussion helps explain why transatlantic African Desert Locust migrations are so unusual. Analysis is based on primary and secondary data sources that include synoptic weather maps, formal and informal scientific reports, written correspondence with agricultural experts in the impact area, and newspaper coverage of the invasion.