How soil conservation affects the catchment sediment budget – a comprehensive study in the north Ethiopian highlands

An overall approach to assess the effectiveness of soil conservation measures at catchment scale is the comparison of sediment budgets before and after implementation of a catchment management programme. In the May Zeg‐zeg catchment (187 ha) in Tigray, north Ethiopia, integrated catchment management has been implemented since 2004: stone bunds were built in the whole catchment, vegetation was allowed to re‐grow on steep slopes and other marginal land, stubble grazing abandoned, and check dams built in gullies. Land use and management were mapped and analysed for 2000 and 2006, whereby particular attention was given to the quantification of changes in soil loss due to the abandonment of stubble grazing. Sediment yield was also measured at the catchment's outlet. A combination of decreased soil loss (from 14·3 t ha^–1 y^–1 in 2000 to 9·0 t ha^–1 y^–1 in 2006) and increased sediment deposition (from 5·8 to 7·1 t ha^–1 y^–1) has led to strongly decreased sediment yield (from 8·5 to 1·9 t ha^–1 y^–1) and sediment delivery ratio (from 0·6 to 0·21). This diachronic comparison of sediment budgets revealed that integrated catchment management is most effective and efficient and is the advisable and desirable way to combat land degradation in Tigray and other tropical mountains. Copyright © 2009 John Wiley & Sons, Ltd.     

What's on top for geography teachers? National Certificate of Educational Achievement and the prioritization of professional development

Geography teachers' work is influenced by multiple education policy initiatives. Professional development opportunities emerge to support these policy changes and associated compliance issues. This paper reports the results of a survey in which geography teachers self‐reported their knowledge and prioritized professional development needs. The data indicate that some compliance issues associated with assessment policy reform have largely been resolved, while more substantive assessment and course design issues continue to be prioritized for professional development. However, professional development that continues to focus on assessment reform may marginalize geography teachers' engagement with concurrent curriculum and pedagogical policy initiatives.     

Drivers of afforestation in Northern Vietnam: Assessing local variations using geographically weighted regression

This article identifies drivers of forest transition in a province of Northern Vietnam between 1993 and 2000 by applying geographically weighted regression (GWR) analysis to remotely sensed and statistical data. The regression model highlighted the spatial variation of the relationship between the percentage of land afforested and its proximate causes. Factors identified as having a major impact on afforestation are: the presence or proximity of a wood-processing industry, the distance to highways, and land allocation to households. Whereas the two former variables are in most areas of the province positively correlated with afforestation, an unexpected negative correlation was observed for the latter. The analysis of these results, supported by an in-depth knowledge of the area and of the political context, leads to the conclusion that, during the time period considered, afforestation was largely driven by state organisations on protected state-owned land, and forestry was not a significant component of household economic activities.     

Policy narratives, landholder engagement, and oil palm expansion on the Malaysian and Indonesian frontiers

Over recent decades a structural transformation has affected agriculture in the frontier areas of Malaysian Borneo and Outer Island Indonesia with the rapid conversion of agricultural lands, fallows, and formerly forested areas into oil palm. These frontiers have similar positions in the international political economy of oil palm and have complementary resource endowments. In both cases, state planners face the common challenges of finding a disciplined labour force, delivering land for estate development, maintaining local legitimacy, and dealing with local contestation. Yet there are significant differences in systems of governance and policy frameworks regarding land, shifting capacity of state actors to facilitate the transformation of these agrarian frontiers, and changing degrees of local, national and international contestation. Considering the generic and the specific elements at play in each case, this paper argues that analogous policy narratives have shaped the ways in which landholders have been engaged in the process of oil palm expansion in Malaysia and Indonesia. In both cases, with the shift from state-led to neoliberal governance approaches to agricultural development, the 'frontier' has been created and transformed through policy narratives that facilitate the conversion of whole landscapes into oil palm. This has been achieved by obscuring indigenous forms of agriculture and land tenure, while creating reserves of available 'state' or 'idle' customary land, and counterpoising smallholder 'marginality' and 'backwardness' to the modernity of contemporary estate agriculture.     

The high wire act: a comparison of British transatlantic foreign policies in the Second World War and the war in Iraq, 2001–2003

Drawing upon ideas from critical geopolitics, this paper compares the role that the British government plays within the contemporary transatlantic alliance with that played by Churchill's government during the Second World War. It argues that the Blair government's approach to foreign policy has parallels with Churchill's – that it should act as a bridge between the US and European governments. From this basis the paper reflects upon geopolitical change since 1945, re-evaluating the reasons for foreign policy failures during the Iraq War. Belying the assumption that these were caused by Blair's failures at diplomacy, it argues that failure was the result of an outdated geopolitical strategy.     

基于多代理模型的城市土地利用博弈模拟

以美国达拉斯北部地区为例,通过建立基于多代理的人类系统和自然系统的耦合互动模型,研究不同土地管理策略的有效性.自然系统包含土地覆盖变化、流域水文动力学和野生动物栖息地生态系统.人类系统包括土地利益相关者(地主、屋主、开发商、政府)的影响土地利用变化价值观.系统强调自然对土地利用决策的反馈机制,不同类型代理相对空间位置的重要作用,以及同一类别中不同类型代理在特定情形下的相互转化.研究进行了两类模拟,一是模拟初始化的若干情景,包括不同类型地主和户主的分布、不同类型政府以及经济模型的假定;二是模拟主动式土地政策的实施效果.模拟结果表明,当政府购置保留地时考虑土地拥有者的价值观,较之单纯基于机会或生态因素更能导致有效的增长管理策略.     

1949年以来中国农村土地制度变迁对土地沙漠化变化的影响

1949年以来我国农村土地制度经历了多次重大变革,每个阶段的土地制度对于沙漠化扩展或逆转有什么影响,是值得深入探讨的理论问题.使用土地制度变化与沙漠化扩展比较的分析方法,得出如下结论:我国沙漠化面积的扩展和逆转,都与我国农村土地制度的变迁紧密相联.集体所有的土地制度,由于缺乏有效的激励机制,造成沙漠化土地的迅速蔓延.而农村土地使用权分配的制度设计,无法兼顾经济发展与生态保护的双重目标.沙漠化治理需要新的制度安排.     

珠江三角洲产业空间协调的政策取向

珠三角在经济发展水平提高的同时,空间发展的矛盾和冲突也在加剧,而产业空间的协调问题首当其冲,直接影响到产业结构的调整升级和土地资源的集约利用。通过人均GDP和第三产业所占比重的判断,认为珠三角核心区优势产业虽然出现"走出去"和产业转移的迹象,但扩散的时机尚未完全成熟。因此,在产业空间协调的重点和方向上,应该是强化产业的空间集聚。在产业空间协调的基本策略方面,需要在大的空间尺度中进行产业协调;通过政府的推动与适度干预,引导企业向资金、技术密集型转向;加强空间集聚,提高空间利用效率。     

供地政策对土地市场配置效率影响的经济学分析——理论研究与实践检验

在界定协议供地政策和招拍挂供地政策含义和建立分析假说的基础上,首先对2种供地政策对市场结果的影响进行了比较分析.分析的结果是:相对于招拍挂供地政策形成的市场价格而言,协议出让引起了大量的土地刎短缺.接着分析了2种供地政策对经济福利的影响,与招拍挂供地政策相比,协议供地政策对土地资源配置的效率低下,存在着经济福利的无谓损失.最后,用现实数据对前文的经济学分析进行了检验,检验的结果与前文的分析是一致的.     

人居环境评价在城市规划政策研究中的工具性作用

从认识论的视角出发,提出人居环境评价作为一种工具,在城市规划与城市发展政策中具有三个层面的作用,一是表达,二是交流与合意,三是分析和决策。结合上述观点,对国内外相关研究的进展进行了评述。结果表明,目前,我国人居环境评价的研究成果大部分定位于空间表述,以交流与合意,分析和决策为目标的研究很少,因此限制了研究成果在政策中的深层次应用。为了改变这一现状,急需加强人居环境的价值化评价和政策效果的分析,使人居环境评价上升为更高级的研究工具,以便在政策实践中发挥更大作用。