基于GIS的城市土地扩展研究--以安徽马鞍山市城区为例

城市扩展研究无论对于缄市理论研究还是对于城市管理都有重要参考价值;以马鞍山市城区为例来研究城市用地扩展规律;用地理信息系统的方法获取过去不同时相的城市实体范围和面积,分析了不同时段的城市扩展过程,发现马鞍山城市扩展速度具有阶段性,城市扩展具有明显的方向性;经济发展和人口增加是城市土地扩展的决定性因素;对其他与缄市扩展相关的因素也进行了分析。     

The emergence of urban agriculture: Sydney,Australia

Across the world the phenomenon of urban agriculture (UA) is defining itself after emerging from a mainly grass-roots response, evidenced in the Sydney Metropolitan Region by the Hawkesbury Harvest phenomenon and the Sydney Food Fairness Alliance, to powerful global forces which are negatively and paradoxically impacting on the quality of life of urban and farming communities. In the developed world these major forces include: (1) urban sprawl and its progressive sterilization of agricultural lands; (2) the supermarket dominance of food chains; (3) the fast food industry and associated health problems such as obesity; (4) globalization. The community-based promotion and marketing of local agriculture is causing some governments and public and private organizations throughout the world to recognize UA as a strategic mechanism to enable urban communities to deal with food security in the context of neo-liberalism, climate change, pandemics, natural disasters, human and environmental health, carbon footprint, biosecurity/terrorism, peak oil, waste management, and landscape and natural resource management. This paper explores the history of UA in the Sydney region. It is a narrative that allows for UA in the Greater Sydney Metropolitan area to draw on the experiences of other developed countries where UA is establishing its position.     

Adaptation in agriculture: historic effects of heat waves and droughts on UK agriculture

Extreme weather events are expected to increase in frequency and/or severity under climate change. Recent examples of these types of events, such as the heat wave in Europe in 2003, have caused considerable damage to crops and agriculture and substantial economic damage. If similar damage was incurred every time such an event occurred in the future, it would cause increasingly serious loss to social welfare and the economy as the frequency or intensity of these events increased. However, agriculture has a history of adapting to shocks, and in this paper we aim to determine whether there has been a systematic reduction in damage from historic extreme events over time in the agricultural sector in the UK. The impact of comparable droughts or heat waves over the past four decades is compared, and for many commodities there appears to have been a reduction in damage over time, to the point where recent events have had a minimal impact on production, indicating that the sector is relatively well adapted to the current climate. We discuss whether this type of adaptation can be sustained into the future under more rapid rates of change, or whether the ‘low-hanging’ fruits of adaptation have been picked.     

面向规划国土数据融合的深圳市土地利用分类体系研究

研究目的：整合规划和国土分类标准,促进规划和国土数据融合;根据管理需求细分用地类型,支撑精细化管理。研究方法：采用实地调研、需求分析、对照转换、征求意见、实践验证等研究方法,对整合原则、分类标准异同点、对应关系、地类细分及编码等关键环节进行研究。研究结果：制定了一套深圳市土地变更调查工作地类及其与规划和国土分类标准之间的对应关系。研究结论：深圳市2011年调查实践表明,采用工作地类进行调查,不但可以通过一次调查获取两套适用于城市规划、土地规划、用地审批、执法监察等精细化管理的数据,而且在数据获取源头为规划和国土数据的无缝融合打下基础。     

An African success: the case of conservation agriculture in Zimbabwe

This paper highlights the limiting factors of agricultural production in Zimbabwe and presents conservation agriculture (CA) as a potential solution to address many of these challenges. CA, based on the three principles of minimum soil disturbance, crop residue retention and crop rotations, targets low soil fertility, moisture deficits and low management standards through the use of soil-fertility-enhancing technologies (precision fertilizer application, crop rotations, sequencing and interactions), improved moisture use efficiency and higher standards of agronomic management practices. The paper also explains the role of CA in natural resource conservation as increasing productivity will reduce the land under crop production and increase the area under natural vegetation. Trends in the development of CA in the past five years and its current status in the country are explained, with the roles of different stakeholders outlined. Evidence on the impact of CA on both food security and the environment is presented. In conclusion, the paper looks at the various factors that may affect the spread of CA to different agro-ecological zones in the country.     

Ecosystem-based adaptation in cities: An analysis of European urban climate adaptation plans

Ecosystem-based adaptation (EbA) measures have been increasingly promoted in the literature, as well as in policies and practices, for their environmental and socio-economic co-benefits. The recent scientific literature has shown a growing interest to assess climate adaptation plans at the urban level, in recognition of the important role played by urban areas in addressing climate change challenges. However, little information is available on the combination of these two issues, i.e., the actual inclusion of EbA measures in climate adaptation plans at the urban level. This paper addresses this gap by developing a framework to analyze the treatment of EbA in urban level climate planning, and apply it to a sample of climate adaptation plans in Europe. The framework consists of a classification of EbA measures, and a scoring system to evaluate how well they are reflected in different components of the plans. The results suggest that there is in general good awareness in plans of EbA measures, and of their potential role in addressing climate change challenges. However, their treatment in climate adaptation plans at the urban level often lacks sufficient baseline information, as well as convincing implementation actions. The paper concludes by offering recommendations to improve future practice, in terms of enhancing the baseline information to improve the proposal and design of EbA measures, improving the treatment of co-benefits associated to EbA measures, and strengthening coordination with other planning tools. Possible future development of this works include the integration of the proposed EbA classification, and the analysis of a larger sample of territorial plans.     

An accelerating treadmill and an overlooked contradiction in industrial agriculture: Climate change and nitrogen fertilizer

In this article, we explore if and why farmers are responding to the impacts of climate change with practices that increase greenhouse gas emissions. Our examination focuses on heavy rainfall events and Midwestern corn farmers' nitrogen fertilizer management. Due to climate change, the frequency and intensity of heavy rain events is increasing across the Midwest. These events increase nitrogen loss to the environment and introduces economic risks to farmers. Drawing from a theoretical framework that merges O'Connor's second contradiction of capitalism and Schnaiberg's treadmill of production, we argue farmers' responses to these events reflect the second contradiction, increasing contributions to climate change, and are shaped by treadmill‐like political‐economic pressures. We examine this using a qualitative sample of 154 farmers across Indiana, Iowa, and Michigan. Given profit imperatives, adapting farmers in our sample primarily used increased nitrogen application rates to reduce their vulnerability to heavy rains. As nitrogen rate is directly associated with nitrous oxide emissions, this adaptive strategy is effective but increases agricultural contributions to climate change. This preliminarily suggests that the political‐economic structure encourages farmers to respond to climate change in ways that accelerate the environmental contradictions of industrial agriculture.     

转型期资源城市建设用地集约利用区域差异研究——以太原市为例

本文依据《城市建设用地节约集约利用评价操作手册》,对太原市区域建设用地节约集约状况进行了定量评价,并对评价总指数进行土地利用类型判定,对太原市建设用地节约集约区域差异状况进行了分类概括,并对差异形成原因进行了深入分析。     

An innovative means of urban land development: A case study of Trichur in India

Summary

For more than seven decades, several Indian states have used the plot reconstitution technique in managing urban land development. Recently, Kerala, a small southern state, has experimented with this technique for the first time in a scheme in Trichur. The Trichur experience is unique in that it incorporates significant innovations over a somewhat similar method of land readjustment which is widely practiced in the Asian‐Pacific region. Formulated for complete cost‐recovery, the Trichur project incorporates the active cooperation of the landowners and officials, and is a time‐bound programme to complete all land development and building construction works within six years of the finalization of the scheme proposals.

This paper attempts to explore the use of this innovative means of land development in Trichur with a view to assessing the potentiality and constraints in its use, and identifying critical areas where further refinements would be desirable. Based on fieldwork in the state and intensive interviews, the paper finds the Trichur experience to be of great importance as a viable strategy of urban land development and management. The paper concludes with some recommendations on legal and institutional aspects, and stresses the need for refinements in the scheme preparation and information dissemination for transferability and wider application of the technique.     

Climate resilient urban development: Why responsible land governance is important

In less-developed countries, the major global pressures of rapid urbanization and climate change are resulting in increased vulnerability for urban dwellers. Much of the climate impact is concentrated in urban and coastal areas, as urban development spreads into areas that are hazard-prone. Often this development is dominated by poor quality homes in informal settlements or slums on informal or illegally occupied or subdivided land.Urban development needs to be more climate-resilient to meet the post millennium development goals (MDGs) agenda. One of the elements in achieving climate-resilient urban development is the degree to which climate change adaptation and risk management are mainstreamed into two major elements of land governance, viz. securing and safeguarding of land rights, and planning and control of land-use.This paper proposes ways in which the growth of human settlements can be better managed through responsible governance of land tenure rights, and effective land-use planning to reduce vulnerability, provide adequate access to safe land and shelter, and improve environmental sustainability.     

Agriculture and the city: A method for sustainable planning of new forms of agriculture in urban contexts

Contemporary cities are threatened by urban development decreasing the overall environmental quality and fragmenting natural and agricultural landscapes. As a result of this fragmentation the number of Non Urbanized Areas (NUAs) present in urban contexts is dramatically decreasing. These areas include cultivated land, Abandoned Farmlands, Grassland, Woods and Shrubs that are often located at the peri-urban cities’ fringes. Among NUAs, farmlands and other forms of urban and peri-urban agriculture provide all three major categories of ecosystem services, provisioning, regulating and cultural services. Recently, New Forms of Urban Agriculture (NFUA) have gained increasing attention from researchers for their promising multifunctionality. Incorporating NFUA into the urban environment will thus improve the sustainability of cities, taking advantage of the multiple benefits and services they can provide.This paper presents a method for the characterisation of NUAs in terms of their physical, ecological and social features. These areas are analysed with different criteria and related indicators structured according to a GIS-based Multi Criteria Suitability Model. The proposed model checks the suitability of transformation of the NUAs toward NFUA, thereby enhancing their ecological and social function as well as accessibility and overall connectivity. Different scenarios of spatial configurations for NFUA have been explored with a sensitivity analysis on the values of used indicators. The method was tested for the municipality of Catania, south Italy, an urban context characterised by a relevant shortage of public green spaces and services.     

Agronomic considerations for urban agriculture in southern cities

Urban and peri-urban agriculture (UA) provide a significant contribution to the total food requirements of cities, especially in southern cities of the developing world. Increasing food production in UA is therefore a necessity for increasing the food security of the urban poor. Urban environments are inherently different from rural environments and these differences in environmental conditions are expected to impact differently on crop growth. This review describes agronomic issues that are unique to UA and identifies possible interventions to address them. The constraints that can significantly differ include temperature, air quality, solar radiation and climate. The growth-limiting and growth-reducing factors that affect actual production in UA include water availability, nutrient supply, soil degradation, pests and soil pollution. The interventions addressing these constraints require action at both field level, and municipal or regional levels. The food security of the urban poor will therefore require coordinated efforts and cooperation between the farmers who produce food and the planners and policy makers who manage the supporting systems such as markets, inputs and land registration.     

城市社区环境质量评价体系的探讨

我国城市社区一级环境质量评价尚处起步阶段,仅有的成果多采用定性描述和简单分等归类等方法;因受主观因素和评价指标选取合理性(如,光、热环境和土地利用等方面指标的遗漏)等诸多因素影响,评价的结果一直有待商榷;选取评价指标,采用Delphi法与AHP法相结合的方法确定各指标权重,建立了更为科学的评价体系,进而将城市社区环境质量评价由定性评价转化为定量评价.     

Ecological response to urban development in a changing socio-economic and climate context: Policy implications for balancing regional development and habitat conservation

Rapid land use/cover changes (LUCC) have triggered severe habitat degradation over recent decades. Existing studies mainly focus on how LUCC per se affects habitat quality, while less attention is paid to the integration of LUCC, socio-economic development and climate change as a land use system, and to investigate their synergistic impacts on habitat quality. This study addresses this issue by incorporating a top-down system dynamic model, a bottom-up cellular automata and a habitat quality assessment model. The potential impacts of urban growth, socio-economic development and climate change on habitat quality of Hubei Province, China, were predicted under the four IPCC RCP scenarios. Overall, construction land was predicted to expand fast whereas forested land and cultivated land to shrink significantly from 2015 to 2030, but RCP 2.6 and 4.5 scenarios may maintain higher habitat quality compared with RCP 6.0 and 8.5 scenarios. Severe habitat degradation is likely to occur in the megacity’s surrounding ecosystems under RCP 2.6 and 8.5 scenarios, while the degradation is more likely to occur in middle-sized and small cities under RCP 4.5 and 6.0 scenarios. Further, our findings suggest that fixed asset investments and technology innovation play important roles in mitigating the negative impacts of urban and socio-economic development on habitat quality. This study should provide a useful approach for decision makers to design alternative development scenarios and to strike a balance between regional development and habitat conservation.     

Gender and conservation agriculture in East and Southern Africa: towards a research agenda

It is remarkable that despite wide-ranging, in-depth studies over many years, almost no conservation agriculture (CA) studies consider gender and gender relations as a potential explanatory factor for (low) adoption rates. This is important because CA demands new ways of working with the farm system. Implementation will inevitably involve a reallocation of men's and women's resources as well as having an impact upon their ability to realize their gender interests. With respect to intra-household decision-making and the distribution of benefits, CA interventions have implications for labour requirements and labour allocation, investment decisions with respect to mechanization and herbicide use, crop choice, and residue management. CA practice may impact upon the ability of households to source a wide variety of crops, wild plants, and insects and small animals for household nutrition. Gender biases in extension service design can sideline women. This paper examines the limited research to date on the interactions between CA interventions and gender in East and Southern Africa, and, based on the gaps observed, sets out a research agenda. It argues that attention to gender in CA is particularly timely given the increasing interest in CA as a means of adapting to climate change.     

Agriculture on the edge: strategies to abate urban encroachment onto agricultural lands by promoting viable human-scale agriculture as an integral element of urbanization

In the Greater Vancouver region (Canada) tensions exist where urbanization encroaches onto agricultural land. A recently issued white paper proffered ideas to stimulate discussion on land-use plans and public policies to encourage and enhance agriculture while accommodating a doubling of the region's population. It evoked a visceral response from local and regional politicians, planners and agrologists who saw it as an heretical attempt to undermine land conservation. Proponents saw innovative strategies to ameliorate entrenched antipathy between competing perspectives. The core arguments and corresponding critique, outlined in this paper, bring to light elements of a broader debate about the vitality and sustainability of agriculture in British Columbia, as elsewhere, centring on issues of food security (supply) and food sovereignty (control) within two competing agricultural paradigms: human-scale agri-food systems and conventional industrial agri-business. Municipal enabled agriculture (MEA) is advanced as a catalyst for the full integration of the agri-food system within the planning, design, function, economy and community of cities and vice versa. MEA can make significant contributions to local and regional economies and has the potential to alter the way communities are designed to reduce unsustainability, planned to incorporate resilience, and organized so that they flourish socially and culturally.     

Agricultural climate change mitigation: carbon calculators as a guide for decision making

The dairy industry is receiving considerable attention in relation to both its significant greenhouse gas (GHG) emissions, and its potential for reducing those emissions, contributing towards meeting national targets and driving the industry towards sustainable intensification. However, the extent to which improvements can be made is dependent on the decision-making processes of individual producers, so there has been a proliferation of carbon accounting tools seeking to influence those processes. This paper evaluates the suitability of such tools for driving environmental change by influencing on-farm management decisions. Seven tools suitable for the European dairy industry were identified, their characteristics evaluated, and used to process data relating to six scenario farms, emulating processes undertaken in real farm management situations. As a result of the range of approaches taken by the tools, there was limited agreement between them as to GHG emissions magnitude, and no consistent pattern as to which tools resulted in the highest/lowest results. Despite this it is argued, that as there was agreement as to the farm activities responsible for the greatest emissions, the more complex tools were still capable of performing a ‘decision support’ role, and guiding management decisions, whilst others could merely focus attention on key issues.     

Policy, milk and the Dar es Salaam peri-urban zone: a new future for an old development theme?

This paper provides an analysis of 50 years of policy aimed at ensuring an adequate milk supply to Dar es Salaam, Tanzania. Despite a variety of policy approaches and initiatives, providing the city with milk continues to be problematic. The use of the peri-urban zone for dairy production is one of several recurring themes, however, even with an expanding market there has been relatively little development of commercial dairying in this zone. This history is used to assess the more recent interest in the potential contribution of the peri-urban zone to sustainable urban food supplies. The paper argues that policy and development initiatives along these lines must specifically consider the relative suitability of the peri-urban zone vis-à-vis the production of specific commodities as well as potential market opportunities. Those interested in promoting peri-urban agriculture as an element of more sustainable cities cannot afford to take a narrow view that ignores either agro-ecological, economic and regional realities.     

A paradigm for persistence: a vital challenge for the agricultural academy

The further economic development of modern, multi-functional and responsible agricultural and food systems must be set within a global context of ecological sustainability and social responsibility. This presents all of those who are concerned with such development, with a much more complex challenge than that posed by the relatively straightforward goals of the Green Revolution to increase production of staple grains in the pursuit of food security on a national scale. It is thus crucial that leaders within institutions of research and higher education in agriculture and related disciplines across the entire world come to terms with the intellectual, moral, practical and political challenges that are fundamental to this systemic change of focus. The situation demands nothing less than a paradigmatic revolution in education, research and extension with implications for the adoption of a very different strategic role for universities with respect to how they critically engage with the multi-stakeholders of entire agri-food systems.     

Valuing ecosystem services of urban forests and open spaces: application of the SEEA framework in Australia*

Around two‐thirds of the global population will live in cities by 2050 requiring large urban infrastructure development. Decision‐makers and planners usually rely on standard economic accounting methods for urban planning and investments on infrastructure assets. However, standard methods fail to account for the ecosystem services benefits that living infrastructure (e.g. urban forests, open spaces) provides to city dwellers. This could generate socially inefficient configurations of urban spaces and compromise the achievement of long‐term urban sustainability targets. In this analysis, we applied a stochastic whole‐of‐life benefit–cost analysis following the System of Environmental‐Economic Accounting (SEEA) framework to compare alternative long‐term management strategies for living infrastructure in Canberra, Australia. Spatially explicit data, i‐Tree Eco and benefit transfer methods were used to estimate the stocks and flows ecosystem services benefits of urban forests and irrigated open spaces from 2018 to 2070. Our analysis suggests that a ’30 per cent canopy cover expansion’ scenario has the highest benefit–cost ratio, while the business as usual scenario, where a net loss of 400 trees is expected per year, offers the lowest benefit–cost ratio. Scenarios of expanding versus not expanding irrigated open spaces in the future both result in a benefit–cost ratio of approximately two.