Agent‐based modeling for ex ante assessment of tree crop innovations: litchis in northern Thailand

This study uses an agent‐based model for ex ante assessment of agricultural innovations. The model builds on whole farm mathematical programming (MP) and extends the methodology with a spatial representation of the system, the heterogeneity of farm households and landscapes, and the interaction between farm households. We apply the model in a northern Thai watershed to study the potential of four innovations to increase the profitability of litchi orchards. Cost‐benefit analysis shows that each innovation would increase the profitability of litchi growing; however, the results of the agent‐based model show that at current price levels these innovations alone would not be enough to stem the decline in the area under litchis. The model was validated and the sensitivity of the results tested for variations in the irrigated water supply and liquidity. We report on how farmers responded to these results and discuss the implications for other areas in northern Thailand.     

水利产业投资存在的问题及对策

分析水利产业的内涵和当前水利产业投资现状,指出当前水利产业投资现状的主要问题是水利产业投资主体单一,水利产业内部投资结构失衡及其原因,提出水利产业投资对策：加大国家对水利建设的投入力度,建立合理的投资回收与补偿机制,建立投资风险约束机制,构建流域机构为出资人代表的水利投融资主体和积极探索多种融资渠道。     

Bridging the gap between research and planning practice concerning landscape in Swedish infrastructural planning

A number of government documents provide for the fact that the surrounding landscape is to be considered when any infrastructure is built in Sweden. However, only certain aspects of the landscape are dealt within the various types of documents involved in the planning process. There has been considerable research into landscape, both in Sweden and abroad; unfortunately, however, this research has not been utilized by infrastructure planners. This paper discusses the reasons for this gap between research and planning practice as regards landscape, as well as problems with current infrastructure sector efforts concerning the landscape. Furthermore, the paper proposes ways in which current working methods can be changed by improving knowledge of the character of landscapes, a matter that is a structural element of the European Landscape Convention (ELC).     

Risk and risk management in organic and conventional cash crop farming in Norway

This study presents empirical insight into organic and conventional cash crop farmers' perceptions of risk and risk management strategies, and identifies socio-economic variables linked to these perceptions. The data originate from a questionnaire survey of farmers in Norway. The results indicate that organic farmers perceived themselves to be less risk averse than conventional farmers. For both groups, crop prices and yield variability were the two top rated sources of risk, followed by institutional risks. The two groups evaluated risk management strategies quite similarly; favoured strategies were good liquidity and to prevent and reduce crop diseases and pests. The farmers' evaluation of sources of risk and choice of risk strategies depended on various socio-economic variables. The importance of institutional risks implies that policy makers should be cautious about changing policy capriciously and they should consider strategic policy initiatives that give farmers more long-term reliability.     

Modernization of a peasant crop in Colombia: evidence and implications

The survival of the small-farm sector in the process of agricultural modernization in Latin America has been a concern for many authors and institutions. It is generally believed that the small-farm sector is bypassed in the process of agricultural development. The authors analyze modernization of bean/maize cropping systems in Southern Colombia. Prices, production practices and profitability are compared for 1975 and 1989. By means of a production function, the effects of allocative efficiency, technical efficiency and technical change on productivity and profitability are analyzed. The observed changes reflect very well the price trends over the period. Between 1975 and 1989, total factor productivity increased by 50%. Bean/maize producers almost doubled returns to land and labor. Increased technical efficiency had most effect on profitability, followed by technical change. Allocative efficiency had more impact on yields than on profitability because it was associated with high input costs. Considerable opportunities for further productivity increases were identified. Conclusions on the nature of the modernization process are drawn. Implications for agricultural policy, research and the role of the small farm in agricultural development are derived.     

鹤岗市农村人饮工程存在的问题及对策

论述了鹤岗市的人饮的现状、人饮普及率等相关情况,对鹤岗市人饮在解决农村人饮工程建设中存在的一些突出问题进行了总结,并提出了相应的对策.     

我国农作物秸秆资源的分布、利用与开发策略

农作物秸秆的利用主要体现在农村能源、牲畜饲料、还田肥料和工业原料等4个方面;通过对我国农作物秸秆资源的应用现状、总量和区域分布的分析,认为我国部分地区农作物秸秆资源浪费严重;提出了建立完善的约束和激励机制等政策性建议。     

山东省粮食生产系统的动态关联分析

根据灰色关联理论和模型,分析了山东省粮食总产量与各影响因子的动态关联程度;认为影响山东省粮食生产的首要制约因素是粮食单产,其次是农业自然灾害和复种指数,而农业机械总动力、化肥施用量和农村用电量对粮食产量影响较小;提出了加大农业科技投入、加快中低产田改造、加强农田水利建设、发展节水技术等稳定发展粮食生产的对策。     

城市规划对地价的控制和影响

城市地价不仅仅是指目前土地利用结构下的土地价格现状,更为重要的是土地未来发展溢价,即规划预期地价。从城市整体层面上看,城市未来地价的高低主要取决于城市土地配置的合理程度、用地功能布局及城市基础设施的发展水平,以及城市建设总体容量控制标准,这些主要是由城市规划决     

黑龙江省森林植物园观果树种的引种及应用

介绍了黑龙江省森林植物园引种成功的观果树种及其在园林绿化中的应用情况和建议.     

British discretion in Dutch planning: Establishing a comparative perspective for regional planning and local development in the Netherlands and the United Kingdom

Regional planning and development is continuing to take an important role in planning agendas throughout Europe. In the United Kingdom (UK), the planning system has been reformed during the last decades, marking a noticeable shift from a development-led towards a more plan-led system. In the Netherlands, strictly regulated growth-control policies have been abandoned to some degree, in favor of more decentralized planning policies featuring negotiated development. Dutch planners have been specifically interested in a more British approach, that is, a more discretionary and development-led type of approach to spatial planning. In this paper, we will discuss current efforts in Dutch regional planning to adopt new principles for planning delivery and will provide a comparative perspective between spatial planning in the UK and the Netherlands. This paper discusses the changing structure of planning delivery in both countries. At the same time, it establishes a framework for identifying critical lessons for Dutch regional planning practice as opposed to planning in the UK. Three characteristics are pivotal for the comparison: (1) the establishment of comprehensive principles for project coordination; (2) options for the settlement of planning gain, packaging interests, and regional redistribution; and (3) the institution for development-oriented planning and discretion for planning decisions. The evidence used is based on a literature review of recent debates in both countries and illustrative cases, including the Dutch ‘Heart of the Heuvelrug’ plan.     

虚拟城市场景的构建及其在城市规划中的应用

随着虚拟现实及其相关技术的发展,数字地球、数字中国、数字城市越来越受到人们的关注,三维虚拟场景的构建是数字城市的基础,具有十分广泛的实用价值和应用前景,本文对以CityMaker为平台的虚拟场景的构建及其在城市规划中的应用进行了简单的概述和探讨.     

食品抽样工作中存在问题与解决办法

食品安全抽样作为食品安全管理中的关键一环,是评估食品安全状况的重要依据.通过对食品展开安全抽检,能及时发现其中所存在的问题,就能避免出现食品安全隐患.本文对食品抽样工作中存在的问题进行分析,并提出相应的解决措施,以保障食品抽样工作开展的合法性、科学性和公正性.     

Soil,water and crop management alternatives in rainfed agriculture in the Sahel: an economic analysis

Most agriculture in the Sahel Region is carried out under rainfed conditions where low and uncertain soil moisture levels limit productivity. Improved soil, water and crop management practices are required to reverse the steady decline in per capita food production and sustain output over the long term. Several technological innovations and related farm management practices are evaluated in a case study of a typical farm in Mali. Through use of a soil-water balance model and a whole-farm economic model an optimal mix of these measures is identified. Compared to a base case where no modern inputs are utilized, the combination of animal traction (oxen team), low levels of NPK fertilizer, tied-ridges, traditional long-season food grain crops and early planting was most effective: food grain output was 35% higher than with the traditional base case; soil erosion was reduced by 72%; and even with residual future soil erosion damage capitalized into current income, net farm income was larger by a factor of almost 45.     

Historical and critical review of spatial and transport planning in the Netherlands

The spatial and transport planning have geographical, economic and environmental constraints and are closely linked to the social and political conditions of each country as well as are well under the influence of globalization forces. This makes it all a highly complex issue and requires a better understanding of the background and products of policies and the interaction of a number of key determinant factors in policy-making and implementation. Within this large picture, the long-term review of different cases may provide useful discussions for the guidance and reinforcement of policy assessment. Therefore, the primary aim of this study is to critically analyze the planning in the Netherlands through examining the issues of governing structure, spatial policy-making, and transport re-structuring. The leading characteristic of the Netherlands is the scarcity of usable land that has raised high and early awareness on spatial development issues and its connections with natural and environmental protection. The functioning of planning systems, and policy aims and measures within the planning documents since the end of the 1950s, have been reviewed and the key planning concepts have been examined by bringing in general and current discussions on the issues. The success and failure in past policy-making and implementations have been highlighted. The policies of the current spatial and transport planning documents have been evaluated by their main policy titles such as compact city, network of cities and sustainable mobility. There is a general consensus that the Netherlands has been developed into a well planned and organized society and has designed leading policies such as the ABC firm location policy. However, a number of issues such as increasing vehicle kilometres, urban decline and sprawl, and some gaps in policy making remain to be the critical planning challenges.     

Visual amenity and housing in the countryside-Scottish local planning authority approaches

In recent years, farming has lost some of its former pre-eminence in Britain's rural economy. At the same time, there have been increasing and often conflicting new demands on countryside resources. In such a situation, planning has been encouraged to adopt a more flexible approach to development. The challenge for planning today is to allow development and yet at the same time protect the visual amenity of the countryside. A recent study has examined how Scottish planning authorities have responded to this challenge in relation to housing in the countryside. The study found that there was some variation in approach to housing development in the countryside throughout Scotland. A number of authorities, especially those in remote rural areas, were prepared to adopt a relaxed approach to housing development. Nevertheless many authorities continue with a strong protectionist stance on the location and scale of housing in the countryside. Moreover, the emphasis currently being placed on attempts to influence the design of housing introduces a new dimension in local authorities' attempts to safeguard the visual amenity of the countryside.