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11.
Drought is a complex natural hazard with social and environmental implications. Satellite information is increasingly used to support decision-makers in preventing or coping with the negative impacts of drought. The integration of local and scientific knowledge to support drought monitoring is still far from being the main procedure in the development of drought monitoring and early warning systems. This study aimed at assessing the degree of convergence between satellite information on the effect of droughts on rangeland vegetation, from time series analysis, and farmers’ perception of drought in North-West Patagonia, Argentina. We characterised the scientific evidence of drought in terms of duration, spatial distribution, most severe years and recovery for the period 2000–2018 by identifying inter-annual NDVI changes. Farmers’ perceptions and experiences of drought were studied with open-ending interviews, with respect to occurrence, duration and recovery for that period. Satellite information matched farmers’ perception of drought at a regional scale, emphasising the value of remote sensing tools in supporting regional policy decision-making. However, farmers’ perceptions and recall of past drought impacts were more diverse than satellite information at a local level, highlighting the need for knowledge integration at finer scales.  相似文献   
12.
The development of an effective spatial data infrastructure (SDI) often occurs in a fragmented organizational environment requiring a high level of inter-organizational collaboration. Different organizations from various jurisdictions need to work together closely when agreeing on how they will jointly register, store, use and share data and how they will make their data available to the wider society. However, this collaboration is generally regarded as very difficult. For example people often resist data sharing across organizational boundaries due to loss of control, power and independency. Organizational issues are thus considered one of the fundamental constraints to inter-organizational sharing of spatial data.  相似文献   
13.
The farm size and productivity debate has been limited by the focus on land or labor productivity, generally showing respective productivity advantages to smaller or larger sized farms. Our purpose is to provide new perspectives on the debate by bringing together evidence from a set of novel case studies in both rich and poor countries. Common to them are the adoption of total factor productivity (TFP) as the comparative performance measure, and the reliance on panels of farm micro data. The present article presents a synthesis of findings from five case studies in (i) Malawi, Tanzania, and Uganda; (ii) Bangladesh; (iii) Brazil; (iv) Australia; and (v) the United States. The preponderance of evidence from these studies suggests that there is no single economically optimal agrarian structure; rather, it appears to evolve with the stage of economic development. Certain farm sizes face relative productivity advantages, such as small farms in Africa. But with economic and market growth, that smallholder advantage will likely attenuate, moving toward constant and eventually increasing returns to size. Yet, importantly, small farms may be quite dynamic, and need not be a drag on agricultural growth until perhaps well into the development process.  相似文献   
14.
This article reviews the past and potential future roles of land tenure reforms and land markets in Sub-Saharan Africa (SSA) as responses to population growth in the process of land use intensification and livelihood transformation. The farm size distribution and the existence of an inverse relationship (IR) between farm size and land productivity in SSA and the implications of this relationship for efficiency and equity are investigated. More secure property rights and removal of restrictions on land markets have the potential to create both efficiency and equity benefits, but there are high risks of elite capture of large land areas with inefficient and inequitable outcomes. This situation is the case not only in land-abundant areas but also in urban and peri-urban areas where increasingly larger proportions of people will make their living. Increasing population pressure in densely populated rural areas contributes to more rapid rural–urban migration, and creating alternative livelihood opportunities for the migrating youth population is essential to achieving economic development with social stability.  相似文献   
15.
Over the last decade, Zambia has witnessed a rapid increase in the number of medium-scale “emergent farms” cultivating 5–20 ha of land. This study analyzes the factors underpinning this growth. We find that the growth of emergent farmers in Zambia is primarily attributable to land acquisition by salaried urbanites and by relatively privileged rural individuals. We found little evidence to support the hypothesis that the rise of emergent farmers primarily represents a process of successful accumulation by farmers who began farming with less than 5 ha of land, a situation faced by more than 95% of farming households. We argue that these outcomes are the result of Zambia’s land administration and agricultural spending policies. Rising concentration of landholdings in Zambia raises serious questions about the potential of current agricultural growth to act as a vehicle for broad based economic growth and poverty reduction.  相似文献   
16.
Applying the hedonic approach to land prices, this article investigates the capitalization of public services and pure amenities in a cross section of German communities. Possible spillover effects from neighboring municipalities are explicitly included in the analysis and prove to be of considerable importance. Estimates of the impacts of local attributes on land prices are obtained taking into account the spatial structure among unobserved variables. The results confirm that differences in land prices are largely attributable to local conditions and policies. This implies a significant degree of mobility as well as high estimation of local attributes on the part of German households.  相似文献   
17.
To halt the decline of biodiversity in New Zealand, the government has formulated a strategy of maintaining and restoring a full range of remaining natural habitats to a healthy functioning state. Many indigenous forest remnants exist on private land, and these could be utilised to increase biodiversity. Resources for conservation of forest remnants are limited, so they must be used wisely to deliver the greatest possible biodiversity gain. This paper presents a rapid method for valuing the biodiversity of a region's indigenous forest remnants to help prioritise conservation resources. The region is divided into environmentally distinct areas called land environments. A detailed land-cover map is derived from satellite imagery and used to estimate the proportion of natural habitats remaining in each land environment; from this the biodiversity value of any forest remnant may be calculated. The method is rapid and does not require detailed biodiversity information. When combined with conservation costs, it may be used to create a priority list of forest remnants for conservation. The Manawatu/Wanganui region of New Zealand is used as a case study to demonstrate the method.  相似文献   
18.
近年来,电网企业在系统内部正在大力开展土地权属清理完善工作。随着不动产物权管理的有关法规政策不断完善,不动产登记已成为维护企业合法财产权益的重要环节。文章旨在提出电网企业完善土地权属管理需要解决的问题及改进措施,并对取得效益进行分析。  相似文献   
19.
彭学玉  郭志忠  赵先军 《价值工程》2010,29(31):183-184
为缩短产品开发周期,降低成本及提高产品质量,CAE技术越来越多的运用在注塑成型的模具设计中。本文基于AMI对接收器上盖在注射成型过程中的成型缺陷进行预测和优化,为探讨注塑成型应用CAE的方法提供借鉴。  相似文献   
20.
中国城镇化过程中的土地利用问题及政策走向   总被引:9,自引:0,他引:9  
中国是一个人口多人均耕地少的国家,随着经济的高速增长和城镇化的快速发展,土地资源的约束越来越突出.论文简述了中国在城镇化快速发展过程中的耕地保护和土地利用政策,分析了现阶段城镇化发展过程中存在的土地利用问题,探讨了当前和今后一个时期中国在土地利用与耕地保护方面的政策走向.  相似文献   
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