查看更多>>摘要：With the development of the concept of urban heritage and accepting the inherent dynamics of city, the heritage integrity has shifted from a static to a more dynamic concept, which accepts that physical changes can occur over time without negatively impacting heritage significance. This study focuses on the concept of dynamic integrity, its role in the scholarly discussion of urban heritage conservation, and its importance in practicing urban conservation. To achieve that, this paper evaluates the success of the Rehabilitation Plan of Karim-Khan Zand Complex, located in Shiraz, Iran based on public perceptions and collective memory. The main research questions revolve around whether the project has been successful in providing people with an integrated image of the historical condition of the complex as it was built in the 18th century; whether people acknowledge the changes and demolitions of the area done in the process of reconstructing the complex as its origin; and whether people's collective memories of the complex were respected in the process. Mental mapping was used to measure the success of the project in strengthening structural integrity and semi-structured interviews were conducted to evaluate dynamic integrity. The results of this study show that people had memories and values associated with some of the contemporary architectural and urban features that were removed by practitioners to make the area look as it was in the 18th century. Also, despite demolishing buildings and urban features associated with people's collective memory, people did not fully perceive the structural integrity proposed by the project. This research suggests that before any physical manipulation is begun to strengthen the structural integrity of the urban heritage, it is necessary to identify the values to which people feel connected, and engage a more dynamic approach toward the concept of integrity in the conservation of urban heritage. Collective memories of people encompass values of urban heritage, and if conserved properly, can ensure the continuity of heritage values over time.
查看更多>>摘要：Even though China has increased grain output in the past decade and greatly contributed to reducing global hunger, the country is still confronted with intense food security pressure due to its huge population base and severe loss of farmland. It has become increasingly important to fully exploit yield gaps (the difference between potential and actual yields) of all staple grains and to identify priority areas in order to achieve the UN sustainable development goal of zero hunger by 2030. The objective of this study was to calculate the production and yield gaps for rice (Oryza sativa L.), wheat (Triticum aestivum L.), and corn (Zea mays L.) across 31 provinces of mainland China, and then to propose sustainable ways to exploit the production and yield gaps in relation to the availability of natural resources and the ecological conditions of the various regions. The yield potential was estimated by assuming that certificated cultivars were adopted in each agricultural ecological zone (AEZ) and that state-of-the-art technologies and best management practices were used. The results suggested that the gross potential productivity of the three staple grains of mainland China in 2016 was 8.86 x 108 tons, with a production gap of 2.99 x 108 tons. Corn exhibited the greatest yield gap. The highest potential productivity was observed in the Northeast Plain and the Huang-Huai-Hai/North China Plain, accounting for 26.35% and 35.91% of the country's total potential productivity, respectively. The greatest yield gaps were also found in these two plains. To narrow yield gaps, farmland infrastructure, especially irrigation facilities, should be improved, and field management should be strengthened for the provinces with the greatest gaps. However, in view of natural resource constraints (e.g., water shortages in Northern China), water-saving measures and techniques have been encouraged throughout mainland China and the planting of high water-consuming crops such as rice has been discouraged and should be reduced and replaced by other crops in the North China Plain and Northwest China. Using presently available cultivars and field management technologies, China still has great potential to increase grain production and improve food security by closing exploitable yield gaps through the use of suitable production methods based on existing natural resource capacity and ecological status.
查看更多>>摘要：The Barcelona superblock is an urban neighbourhood transformation strategy, with which car-based traffic is redirected away from streets that are inside a 3 x 3 urban block configuration. This urban design concept promises opportunities for alternative street use such as the transformation of street space into urban green space. The potential to foster urban green space due to superblock design is however unclear, particularly outside of the original Barcelonan context. Concerning urban densification, fostering urban green space is particularly relevant to achieving dense and green cities. In this study, potential superblocks are identified in all major Swiss cities and the current urban green space is quantified. This analysis reveals distinct differences of superblock opportunities and urban green space between different cities and allows pinpointing opportunities for expanding urban green space. Considering the nine largest Swiss cities, between 3% and 18% of the current street network was simulated to be potentially suitable for superblock implementation to transform the streetscape and increase urban green space. The variation of current urban green space coverage across all potential individual superblock sites that have high urban density ranges considerably from a few percentages to above 30%. The presented results allow the exploration of urban green space opportunities at street and block-level arising from super blocks in Switzerland. For example, when considering a citywide superblock implementation scenario, the potential street area is relatively high for Basel whilst at the same time showing relatively low current availability of urban green space. For creating detailed design or transformation strategies based on the explored superblock sites, more integrated analysis to evaluate potential benefits as well as disservices of such urban transformation is required.
查看更多>>摘要：Urban expansion is an important manifestation of urbanisation. Based on the impervious surface aggregation density (ISAD) method, this study extracts the urban built-up areas (UBA) range of 12 major cities in the north and south of China from 1995 to 2015. Comprehensive use of the urban centre of gravity, fractal dimension, compactness, urban spatial morphological expansion mode, urban expansion speed, and other indicators was applied to explore the spatio-temporal evolution characteristics of urban expansion. The statistical method GeoDectector (GD) was used to analyse the impact of economic, transportation, natural environment, and social factors on urban expansion. Results show that the 12 cities were shown to have different expansion characteristics and spatio-temporal evolution characteristics. Most northern cities had single-core expansion, while most southern cities had multi-core expansion. Most of the spatial forms of cities tended to be discretized, and the urban expansion process of southern cities was obviously more rapid than that of northern cities. GeoDectector revealed that urban expansion in both the north and south was mainly related to population and economy. Social factors explain the expansion of southern cities, and while the intensity was stronger than that of the northern cities, the natural factors were opposite, and the traffic factors were not significantly different. This analysis confirms the differences in economic development between the north and south of China and provides a scientific reference for the formulation of national-scale urban development policies. In the context of global urbanisation, the results from this study will provide a Chinese sample for understanding the temporal and spatial characteristics of urban expansion, which can serve as a good reference value for other countries and regions worldwide, especially for urbanisation research in developing countries.
查看更多>>摘要：Mountain grazing systems, based since ancient times on common land, are finding it increasingly challenging to ensure their economic viability. Although marginal in productive terms, these systems are high-value natural areas that provide multiple benefits for society (e.g. biodiversity and ecosystem services). They are usually studied from an institutional or local perspective, but little is known about how mountain common land interacts with policies at a higher level, e.g. the Common Agriculture Policy (CAP) in Europe. This study assesses the contribution of the commons to the persistence of mountain sheep grazing systems in Europe under the CAP. To that end, we analyse economic and land use data on 20 farms in the mountain common grazing lands of Aralar (Basque Country, northern Spain). We find that CAP payments associated with common land account for 42% of net margin while the resources extracted from common grazing lands in the summer months provide on average 30% of annual energy requirements, which equates to 22.5% of farms' net margins. We conclude that under the current CAP the common land can play a key role in securing additional resources for the small farmers who engage in low-input traditional management practices that sustain these valuable grazing systems. The way in which existing intertwined institutions adapt to the emergence of new, higher level conditions such as the CAP will determine the future of ever-changing mountain commons.
Netshipale, A. J.Raidimi, E. N.Mashiloane, M. L.de Boer, I. J. M....
13页
查看更多>>摘要：South Africa implemented land reform for the past two decades to contribute to addressing challenges posed by inequality, poverty and unemployment. Systematic classification of farming system types in land reform is lacking, and distinguishing the types with common characteristics (e.g. farm size, land use activities and livelihood strategies) is essential for implementing targeted agricultural development. In addition, understanding the drivers that lead to different farming system types might contribute to policy making and design of well-suited management options. We investigated 50 land reform farms in the Waterberg District, South Africa. We used principal component analysis (PCA) and two-step cluster analysis to assess the diversity of farming system types and factors driving such diversity. Indicators characterising the ruminant, monogastric, horticulture and crop farming, land use, and economic importance were collected to assess the target-farms and included in the PCA. Four farming system types were distinguished: crop plus ruminants-CR, horticulture-H, ruminants-R, and monogastric-M. The presence of type CR and R was driven by land reform policies which transferred farms of large sizes (+/- 1160 ha) for extensive resource use, in cognisance of the semi-arid conditions of the study area. Land reform policies drove the presence of the type H and M by targeting capital endowed farmers and areas with potential for horticulture, and by ensuring that farmers are physical capital endowed. Capital endowed farmers were in all four identified farming system types, be that as it may, limited external physical and financial capital support restricted capital poor farmers to type CR and M.
查看更多>>摘要：Encountered with scarce land resources in contemporary time, mankind has been seeking for solutions to improve land resource carrying capacity to sustain urban development. The development pattern of urban agglomeration has been well received globally in recent years as an alternative strategy to improve land resource carrying capacity. Many countries have been committing to urban agglomeration development plans with the expectations of gaining "1 + 1 > 2Effect " from utilizing land resources between cities. However, few existing studies have conducted in examining whether and to what extent "1 + 1 > 2Effect " on land resource carrying capacity can be gained through implementing urban agglomeration strategy. This paper presents an investigation on whether urban agglomeration can bring "1 + 1 > 2Effect " to cities from the specific perspective of land resource carrying capacity. An analysis model is developed for assisting the investigation by using Difference-in Differences method. The Pearl River Delta region in China is selected as a case urban agglomeration to assist empirical research. The results from this study suggest that urban agglomeration development plan can bring limited "1 + 1 > 2Effect " from the perspective of land resource carrying capacity and contributes to the improvement of economic performance between cities within the urban agglomeration. The findings nevertheless also indicate that land resource carrying capacity cannot be improved exclusively by implementing urban agglomeration development plan. Critical issues are addressed for more attention during implementing urban agglomeration strategies. The paper provides valuable references for policymakers to understand the effects of urban agglomeration on land use and sheds light on the importance of researching on the impacts of urban agglomeration.
Baldini, CarolinaMarasas, Mariana EdithTittonell, PabloDrozd, Andrea Alejandra...
18页
查看更多>>摘要：Globally, urban areas are expanding onto high-quality agricultural soils and natural environments reducing the area available for food production. The Horticultural Belt of La Plata is one of the main horticultural areas in South America. It is a productive territory that lacks clear spatial planning, resulting in serious socioenvironmental problems. Our main objectives were to quantify areas with different land-use aptitude across the region, and to identify areas of potential land-use conflict, detecting those areas that should be prioritized in the development of landscape planning policies. We implement the analytical hierarchy process multicriteria analysis method and a weighted linear combination procedure of factors standardization. We observed a strong influence of urbanization in determining land use in those areas where high/very high aptitude for urbanization and for horticulture overlap. Competition for land use between open field horticulture and greenhouses was observed too. Our research reveals the market influence and the current trend towards intensification of land use that usually prevails in planning strategies. We identified elements that could take part of a multifunctional network of green spaces, made them spatially explicit, and defined a core area for the protection of horticultural production. Finally, we propose recommendations for territorial planning aimed at improving the conditions for the development of more sustainable productive landscapes, a problem that predominates across the world.
查看更多>>摘要：We compile a panel dataset from official surveys of 2010-2015 to study how China's latest rural land titling program affected households' long-term agricultural investment. Applying the DD method and the PSM-DD method, we find that the rural land titling program had a positive effect on households' land-related invest-ment (measured by the application of organic fertiliser). In addition, we present 3 pieces of evidence which support the view that the positive investment effect was due to enhanced incentives as a result of improved land tenure security. First, the investment effect was significant for land-related investment, but not significant for non-land-related investment (measured by the purchase of agricultural machinery). Second, the investment ef-fect was stronger for the households that saw a greater improvement in their land tenure security. Third, the investment effect on households' own contracted land was stronger than that on their rented-in land, unless the households had long-term (i.e., more than one year) written rental contracts for their rented-in land.
查看更多>>摘要：Over the past 40 years, brownfield remediation has become an important issue of urban economic transition and revival, providing many social, economic, and environmental benefits to cities. Identifying urban candidate brownfield sites is an essential task of brownfield projects, but few attempts have been made to create a comprehensive dataset of their spatial distribution in China. This paper presents a new method for identifying urban candidate brownfield sites using multi-source data, including current urban land use maps, Baidu heat maps, business data, and Baidu street view. Our method for identifying urban candidate brownfield sites consists of four steps: (1) preparing and processing the basic data while screening potential contaminated sites using a current urban land use map, mapping the geographical coordinates of operating and non-operating businesses, and calculating the Baidu heat index; (2) integrating spatial multi-source data; (3) screening the intensity of use and the degree of abandonment for suspected sites in Baidu street view; and (4) conducting field surveys. The method was proposed and tested using a case study in the central region of Changchun, China, and 146 candidate brownfield sites were identified. The new data that we collected and our methodology can be used as quantitative and universally applicable tools within a discriminant analytical model framework, for urban geography, urban design, and landscape architecture. The resulting maps for urban candidate brownfields could also provide local government agencies with a technical reference for brownfield remediation.
NSTL
Elsevier