Regional interdependence and forest “transitions”: Substitute deforestation limits the relevance of local reversals

Using case studies and concepts we suggest that constraints upon aggregate or global forest transition are significantly more severe than those upon local forest reversals. The basic reason is that one region's reversal can be facilitated by other regions that supply resources and goods, reducing the demands upon the region where forests rise. Many past forest reversals involve such interdependence. For ‘facilitating regions’ also to rise in forest requires other changes, since they will not be receiving such help. We start by discussing forest-transitions analysis within the context of Environmental Kuznets Curves (EKCs), for a useful typology of possible shifts underlying transitions. We then consider the historical Northeast US where a regional reversal was dramatic and impressive. Yet this depended upon agricultural price shocks, due to the Midwest US supplying food, and also upon the availability of timber from other US regions. Next we consider deforestation in Amazônia, whose history (like the Northeast US) suggests a potential local role for urbanization, i.e. spatial concentration of population. Yet inter-regional issues again are crucial. For cattle and soy, expansion of global demands may give to Amazonia a role more like the Midwest than the Northeast US. In addition, across-region interdependencies will help determine where reversal and facilitation occur. Finally we discuss the constraints upon very broad forest transition.     

Integrated economic-hydrologic water modeling at the basin scale: the Maipo river basin

Increasing competition for water across sectors increases the importance of the river basin as the appropriate unit of analysis to address the challenges facing water resources management; and modeling at this scale can provide essential information for policy makers in their resource allocation decisions. This paper introduces an integrated economic‐hydrologic modeling framework that accounts for the interactions between water allocation, farmer input choice, agricultural productivity, non‐agricultural water demand, and resource degradation in order to estimate the social and economic gains from improvement in the allocation and efficiency of water use. The model is applied to the Maipo river basin in Chile. Economic benefits to water use are evaluated for different demand management instruments, including markets in tradable water rights, based on production and benefit functions with respect to water for the agricultural and urban‐industrial sectors.     

绿水资源研究进展及评述

[目的]基于蓝水绿水概念,综述总结国内外绿水资源的研究进展和发展趋势,以期为国内绿水模拟和绿水管理研究提供相关参考依据。[方法]通过文献分析法和比较归纳法,阐述了绿水资源在水资源评估规划中的重要作用和开发利用潜力,评价了国内外绿水模拟的研究方法、研究进展与局限性因素,分析了气候变化和人类活动对绿水资源的影响,探讨了流域绿水管理的基本理念与应用发展。[结果](1)绿水资源表示水循环通过降水渗透入土壤非饱和层并由植物蒸腾或土壤蒸发返回大气层的水汽,是农业作物生产的重要基础,但是通常被传统流域水资源管理所忽视。(2)绿水模拟分析结果表明,全球尺度的陆地水资源总量中绿水资源平均占65%,全球尺度农业用地(作物生产期)的绿水资源比例平均占82%,因此绿水的开发利用潜力相对较大,忽视绿水资源量可能会低估水资源可用性。(3)绿水参数率定、遥感ET数据校准、时空尺度转换和不确定性分析等关键问题是提升绿水模拟精度的重点研究方向。(4)基于气候变化和人类活动影响下,水资源稳定性相对减弱的可能趋势,将绿水纳入流域水资源管理体系,有利于客观评估水资源量,能够为应对解决水缺乏、水波动与水冲突等水资源问题拓宽思路。(5)绿水管理是合理优化配置流域蓝水绿水资源,协调平衡流域整体社会经济与生态环境效益,且兼顾上下游公平效率的新型流域水资源开发管理模式。[结论]应对水资源问题的两个基本方向即“开源节流”,绿水资源作为开源的重要方向,绿水管理作为节流的基本措施,理应受到重点关注。绿水概念和绿水管理是在水量平衡基础上,实现流域水资源合理优化配置及高效利用的可行途径。     

水足迹视阈下河北省农业用水驱动因素分析

目的 河北省地下水超采严重、水资源长期供需不平衡的背景下，探究河北省农业用水真实消耗情况及其驱动因素，对水资源安全、可持续利用具有重要意义。方法 文章基于作物需水量和作物实际用水量测度河北省农业生产蓝水足迹及绿水足迹，利用LMDI模型解析河北省农业用水变化的影响因素及驱动机理。结果 结果显示，2002—2018年河北省农业水足迹数量呈波动下降趋势，技术效应、种植规模效应和节水效应对河北省农业水足迹变化呈增量效应，其中技术效应对水足迹数量变化的正向驱动贡献值最大，这说明农业技术应用、规模效应带动和节水成效保障加快河北省农业节约用水进程；管理效应和种植结构效应对河北省农业水足迹数量变化呈减量效应，这说明水利化程度、农业种植结构给河北省农业节水带来一定程度的压力。结论 河北省水资源优化配置和高效利用，应重点强化农业节水技术、节水管理和结构调整。推广高效节水灌溉技术，推进水肥一体化建设；加大节水政策的宣传和培训力度，提高设施维护保持能力；优化各地区种植结构，持续推进“一季休耕，一季雨养”的种植模式，提升水资源和种植结构的匹配度，从而减轻河北省水资源短缺压力。     

陕西省农业灌溉水资源保障程度及空间差异分析

[目的]文章选取2016年陕西省各市区农业灌溉水资源相关数据,分析其对粮食生产的影响,进而计算出陕西省及其各市区农业灌溉水资源对粮食生产保障程度,最终总结其存在的空间差异,并提出差异化的解决措施,以保障陕西省粮食安全。[方法]选用农业灌溉水资源保障度分析模型,针对陕西省各市区的水资源供需情况、粮食种植结构及产量和农作物灌溉情况,对陕西省及其各市区的农业灌溉水资源保障程度进行计算,研究其空间差异性。[结果]陕西省农业灌溉水资源保障度为101.84%,基本上能满足农业灌溉用水需求,但已迫近水资源供给紧张的边缘。陕西省农业灌溉水资源保障度呈显著的空间差异,关中地区农业灌溉水资源保障度P为82.20%,农业灌溉水资源轻度缺乏,属于资源型缺水现象;陕北地区农业灌溉水资源保障P为112.38%,影响该地区农业生产发展;陕南地区农业灌溉水资源保障P为145.92%,农业灌溉水资源丰富,灌溉耕地能够得到用水保障。[结论]农业灌溉水资源对粮食生产具有重要的作用,陕西省农业灌溉用水资源存在较大的空间差异性,需要参考不同地区的农业灌溉水资源保障度数值,采取不同的节水策略,以保障粮食安全生产。     

农业水权市场综合框架体系及案例分析

以较为成熟的水权市场建设和水权制度改革理论与实践为支撑,以对多个农业水权市场的实地调研为基础,提出融合制度基础、经济动力、交易参与人、第三方保护和设施基础等5大模块,涵括14个要素的农业水权市场综合框架体系,阐明了各要素之间的内在联系。以澳大利亚维多利亚州、智利Limarí流域和中国石羊河流域为例,在农业水权市场综合框架体系下对3个国家农业水权市场进行分析,进而从水权法律体系、水资源产权管理制度、水权信息共享度、水权交易媒介等多个方面总结出建立健全农业水权市场的必要条件及建议,旨在给我国积极探索建立农业水权市场的决策者们提供参考。     

中亚农业水资源脆弱性空间格局及分区研究

[目的]农业水资源脆弱性是指在自然条件变动或人为条件干扰的前提下,衡量农业水资源系统影响农业可持续发展能力的指标,其评价对于农业水资源管理至关重要。在自然、社会以及人类活动变化条件下,农业水资源脆弱性研究可以结合暴露度、敏感度和适应度综合表达,这为实现农业用水系统的高效运作提供可能。研究目的是分析中亚农业水资源脆弱性空间格局,并对其进行分区与评价,为农业水资源管理提供科学依据。[方法]以中亚为研究区,依据水资源脆弱性概念框架,从暴露度、敏感度和适应度等3个指标中选取18个指标建立农业水资源脆弱性指标体系,采用等权重法和主成分分析法确定指标权重,对1992—2017年中亚农业水资源脆弱性空间格局及分区进行研究。[结果](1)中亚农业水资源暴露度、敏感度、适应度和脆弱性空间差异显著。受作物生育期的降水量、平均气温和相对湿润度指数影响,农业水资源暴露度大致由西南向东北降低;农业水资源敏感度主要受农业用水比例和农田灌溉定额影响,表现为从南到北降低的变化;农业水资源适应度受农业水分生产率和施政效率影响较大,表现为从南到北逐渐升高的变化;农业水资源脆弱性主要受敏感度和适应度因素影响,表现为自东北向西南升高的趋势。(2)根据中亚农业水资源脆弱性空间分布特征,将其划分为北部微度脆弱区、中北部轻度脆弱区、中南部中度脆弱区、南部重度脆弱区和西南部极度脆弱区5个大区,根据各分区农业水资源脆弱性地理特征,提出未来发展方向和对策。[结论]由于农业水资源供需矛盾不断加剧、水资源利用效率较低导致农业水资源脆弱性较高,因此管理农业水资源和调整农业生产布局成为中亚农业发展的重要问题。     

Exploring customer heterogeneity with a scale-extended latent class choice model: Experimental evidence drawn from urban water users

The search for improved water pricing is central to urban water reform in many countries. Establishing efficient water prices is notoriously difficult, not least because different customers have different demands for water and yet they are presently faced with a one-size-fits-all approach to pricing and service. This is especially challenging where water availability fluctuates widely, as is the case in many parts of Australia, because the impacts of exposure to episodic periods of scarcity can differ markedly. There is now substantial interest in the notion of ‘unbundling’ the water product to provide a better fit between customers' preferences and the level of service received. Following this trend, this study provides important insights into householders' willingness to pay for a range of flexible water options using a choice experiment. The paper reports a relatively underemployed extension to the latent class modelling framework to investigate preference heterogeneity towards urban water products, including purchasing services that involve the provision of environmental and amenity outcomes. The work adds to studies that use choice data to reveal heterogeneity while improving our understanding of household customers' demands. Overall, it also brings into focus questions about the future management of water in urban contexts.     

Economic Risk and Water Quality Protection in Agriculture

Producers' and consumers' risk perceptions and preferences can affect perceived costs and benefits of agricultural water quality protection. Many studies find that integrated pest management actually reduces economic risks to farmers. Results from crop rotation and conservation tillage studies are mixed, while nutrient management studies indicate a potential for higher risk compared with conventional practices. Uncertainty about pollution damages to water resources is likely also to increase the perceived benefits of a given quantity of water quality protection practices. Public policies to reduce uncertainty about the costs and benefits of water quality protection practices may produce net social benefits.     

THE AGRICULTURAL POTENTIALS OF CANADA'S RESOURCES AND TECHNOLOGY*

Canada's agricultural potential during the 1980's will be constrained by the availability and prices of productive agricultural land, water, energy, labour, and technology. Resources for further expansion of agricultural production are becoming increasingly scarce. Past expansions were made possible largely by the substitution of cheap fossil energy for expensive labour. Further expansion will necessitate new technology that is both energy saving and labour saving. A multifaceted program involving government, farmers, and other components of the food system is needed to achieve Canada's agricultural potentials. Agricultural expansions in the 1990's will depend first upon the success of the programs designed for the 1980's and second upon new scientific knowledge and technological adaptations. Without a massive and well coordinated effort to meet the needs of agriculture, Canada could become a food deficit nation before the end of this century. Le potentiel de ?Agriculture du Canada durant les 1980's va être contraint par la disponibilité et le pri.x de la terre, ?eau, ?energie, le travail et la technologie productive. Les ressources pour ?avancement de la production agricoie deviennent de plus en plus rare. Les expansions du passé ont été possible par la substitution de ?énergie fossile pour le travail dispendieux. Un autre anvancement va nécessiter une nouvelle technologie qui sauvera ?energie et le travail. Un programme qui comprend le gouvernement les fermiers et touts les autres constituents du système alimentaire est nécessaire si le Canada va achever son potential agricoie. Les expansions agricoles des 1990's vont depéndre premièrement du succès des programmes developpés pour les 1980's et deuxièment de nouvelles connaissances scientifique et de nouvelles adaptations technologigues. Sans un effort massif et sans un grand effort coordonné dans le domaine de ?agriculture, le Canada peut devenir un pays qui manque de la nourriture avant la fin du siècle.     

ZonAgri: A modeling environment to explore agricultural activities and water demands on a regional scale

To design integrated water management for a whole region, all agricultural activities need to be taken into account together with their irrigation water requirements and agricultural outputs. The aim of this paper is to present a modeling environment, called ZonAgri, that allows agricultural activities to be represented at regional scale and enables prospective scenarios concerning these activities to be tested. The modeling of agricultural activities is based on typologies of farms and production units (i.e. plant cropping systems) using a simple framework. A region is designated as a set of “sectors” that correspond to geographical spaces; each sector is designated as a weighted (by strength) sum of “farms”. A “farm” is designated as a weighted (by size) sum of “production units” that can be linked with specific geographical “sites” in the region. Each “production unit” consumes inputs and produces outputs that can have prices. This framework allows the aggregated calculation of inputs and outputs, as well as of the incomes of farms, sites or sectors. Scenarios can be built to change the original values or to envisage changes that may occur over a period of several years. The results of multi-year simulations make up the database. The information contained in the database can be requested by area or by sector, and can be mapped and exported to be used in a GIS. Maps of agricultural activities or water demand can then be superimposed on maps of water resources and hydraulic facilities to check if they are consistent.     

Variations in ecosystem services in response to paddy expansion in the Sanjiang Plain,Northeast China

The ecosystem of the Sanjiang Plain in China has dramatically changed in the past four decades. This study investigated the history of paddy field expansion in the Sanjiang Plain and discovered the ecosystem service variations in response to paddy expansion. Integrating a series of Landsat images, we obtained the paddy expansion history from 1976 to 2015. Then, we calculated ecosystem service values (ESVs) to estimate the ecosystem service variations caused by paddy expansion in the Sanjiang Plain. The results indicate that the paddy area increased from 404,789–2,598,449 ha during 1976–2015, leading to a decline in the total ecosystem service values by 11288.04 million dollars. The largest decline in ESVs in response to paddy expansion was caused by wetland reclamation (9998.54 million dollars). Apart from agricultural products and gas regulation functions, the ESVs provided by other functions all showed a declining trend. Paddy expansion in the Sanjiang Plain increased agricultural product function at the expense of the decline of other functions. In future management practices, the rational allocation of water resources and paddy distribution are necessary in order to achieve sustainable development of both water resources and agricultural production. Some suggestions including coculture systems, restoring habitats for aquatic species, farm management that fosters biodiversity in paddy fields are provided for future sustainability.     

Responses to climate change and farming policies by rural communities in northern China: A report on field observation and farmers’ perception in dryland north Shaanxi and Ningxia

To address land degradation and rural poverty the Chinese government has put in place a series of land conversion programmes in the Loess Plateau area in northern China. In addition to problems arising from unsustainable land use, water resource availability driven in part by climatic forcing is also a threat to livelihoods in this region. To understand climate impacts on farming practice in poor areas of China, field observation and village reconnaissance took place in the summer of 2009 in three selected counties of Shaanxi and Ningxia Province, northern China. Semi-structured interviews were undertaken with householders in rural communities aiming to explore the impacts of recent climate and environmental changes and the role of land management practices on individual and community livelihood incomes as well as individual understanding and engagement with these concepts. The findings were complemented with secondary agricultural, economic and climatic data from the study regions. Respondents argued that land conversion programmes improved income potential, sustainability of livestock grazing and environmental quality in the region. However, water availability was thought to increasingly limit agriculture and human wellbeing in some of the regions with water resources becoming notably scarcer. Understanding of climate change as a concept varied amongst farmers potentially hampering the ability to adapt existing farming practices to maximise livelihood incomes sustainably. Positive effects of the government's land management schemes were unevenly distributed within villages and amongst regions, often linked to a lack of knowledge transfer and shared resources resulting in marginalised households and/or communities. Off-farm labour (in many cases relating to young adult rural to urban migration) appears a crucial source of income for households in the study region. Respondents in Ningxia expressed reservations about the future prospect of productive farming if the water availability continued to diminish.     

太湖水量分配方案实施保障措施探讨

分析近几年环太湖河流出入湖逐日水量,依据各河道出入湖水量所占比例,提出近期在环太湖出入湖主要河流分别建设17个水资源自动测报站点,即可控制80%以上的出入湖水量,通过建立并完善太湖水资源预报和监控系统,为太湖水量分配方案的顺利实施奠定坚实的基础,为流域水资源统一管理提供科学依据。     

我国农业用水利益相关者研究进展与展望

[目的]我国农业用水占全国总用水量的60%以上,农业是耗水大的产业,而农业用水的利用率低、浪费严重,是长期存在的问题。近年来逐渐聚焦利益相关者研究,希望通过探究农业用水系统中各利益相关者的互动行为,来提高改革效率、改善治理方式,从而实现水资源的高效利用。[方法]文章利用文献分析法,通过搜集国内农业用水利益相关者研究的相关文献,总结利益相关者界定、利益诉求确定和利益主体博弈上的研究成果,提炼研究方法,为未来的研究提供指导。[结果]该文总结已有文献中提出利益相关者共19个,并提出了各利益相关者在研究中出现的频次。利益相关者的研究方法主要运用了"Mitchell的评分法""文氏图法"和"利益相关者图解法"。[结论]目前,国内对于农业利益用水利益相关者的研究非常有限,存在主要问题包括:利益相关者理论单一、研究内容较为宏观、研究不够深入。在未来研究中可以实现多学科理论的结合,同时选择研究对象时可以更有针对性,研究更加深入。     

民国时期和田地区耕地大面积撂荒及其影响因素研究

位于塔里木盆地南缘干旱及风沙区的新疆和田绿洲，生态环境极其脆弱。民国政府1939年开始在和田地区大力推行垦荒运动，至1944年主要农业区六县耕地面积平均增长103．7％；然而1945年后各县耕地面积却呈明显减少趋势，1948年与1944年比较，耕地面积减少了25．6％，有51．6％的垦荒新增耕地被撂荒地抵消。根据档案资料分析，此时期水资源状况基本稳定，不是耕地大面积撂荒的决定性因子，但却是制约各地区人口数量、垦荒规模和耕地面积总水平的关键因子。地区人口增长过多引发对耕地面积的需求扩大，对耕地灌溉甲水的需求随之增长，由此呈现出农田灌溉水不足的表象，造成地区人口、耕地水平与水资源承载力相互关系失调；即影响和田地区耕地撂荒的关键是当地水资源总量与人口规模、耕地面积总水平的平衡关系，突破这个平衡就必然引起耕地的撂荒。     

Trade-offs of European agricultural abandonment

Agricultural land abandonment is a policy challenge, especially for areas with unfavorable conditions for agriculture and remote and mountainous areas. Agricultural abandonment is an important land use process in many world regions and one of the dominant land use change processes in Europe. Previous studies have shown that abandonment can have both positive and negative effects on several environmental processes, influenced by location and scale. Preferred policies and management of these areas are debated given concerns for the loss of (traditional) agricultural landscapes and potential impacts on biodiversity and ecosystem services. We present a European-scale impact assessment of the possible effects of agricultural abandonment, based on eight indicators that are on the forefront of the agricultural abandonment debate. Using a multi-scale modelling approach, we expect between 71.277 and 211.814 km² of agricultural abandonment in 2040. Impacts on the indicators and trade-offs between the impacts are spatially variable. A typology of typical trade-off bundles at a 1 km² resolution resulted in four typical trade-off clusters. All clusters identified are characterized by a loss of agriculture-related values, such as agro-biodiversity and cultural heritage. For two clusters, this was accompanied by positive effects on indicators such as carbon sequestration, nature recreation and mammal habitat suitability. Overall, our results indicate that location and scale are key to assess the trade-offs originating from agricultural abandonment in Europe. Identification of typical trade-offs bundles can help to distinguish potential desirable outcomes of agricultural abandonment and assist in targeting measures to areas that face similar management challenges.     

Agricultural technology and land use futures: The UK case

This paper explores how agricultural technology has interacted with recent land use in the UK and how it might do so in the next 50 years. From 1960 to 1985, farmers successfully used technology to increase the output of crop and animal products per unit of land and particularly of labour. This reduced the number of people employed in agriculture, and promoted larger and more specialised farm enterprises. Between 1985 and 2006, food prices were relatively low, and although labour productivity continued to increase, land productivity remained relatively static. However during this period, farmers started to address the effects of agriculture on reduced water quality and habitat loss.For established agricultural products, technological innovation tends to have an incremental effect, working through genetic improvement, the removal of abiotic and biotic stress (e.g. crop nutrition and protection, irrigation and drainage, and animal nutrition, health and housing) and the substitution of labour. Whereas the first two processes tend to be scale-neutral, the substitution of labour is usually easiest to achieve on larger farms. Other key areas for technological innovation include addressing air, soil and water quality, biodiversity, waste reduction, and information management. Over the next 50 years, large step-changes in land use arising from agricultural technology are predicted to arise from the development of new markets for agricultural products. A strong bioenergy sector will strengthen the links between crop commodity and energy prices and will have a major effect on future land use. Climate change and the regulation of greenhouse gas emissions will alter the relative profitability of crop and animal production systems. Lastly, increased public awareness of the links between food, health and the environment could substantially shift the demand for specific agricultural products.Continual improvements in agricultural technology are pivotal to providing society with the flexibility to balance the challenges of improving human well-being with the management of the planet's ecosystem. Increased technological innovation increases the probability that agricultural land can be used for other purposes, but the exact relationship is dependent on trade and environmental policies. The large external effects of agriculture mean that decisions regarding the adoption of future technologies should be taken by farmers working with other stakeholders.     

科罗拉多河水资源分配模式评析及其借鉴

在不同历史阶段,位于美洲的科罗拉多河适用多种基于特定目的的水资源分配模式。这些模式表现出早期社会水资源分配中水权私权性质的主导地位,主管部门运用经验主义的渐进立法模式,采取利益相关方广泛参与和协商的管理方式,践行体现社会公平的公平合理利用原则,促进了科罗拉多河水资源合理利用。从化解问题、开发利用和生态保护角度看,这些进程和模式的经验及教训对中国类似问题具有借鉴价值。有关主管部门需要建立全流域整体规划开发模式,建立健全跨境河流开发利用法律体系,与流域国建立专门的联合管理机构,并大力建设水利工程设施。     

Effect of soil heterogeneity on the welfare economics of biofuel policies

Biofuel policies (blend mandate or tax credit) have impacts on food and energy prices, and on land-use. The magnitude of these effects depends on the market response to price, and thus on the agricultural supply curve, which, in turn, depends on the land availability (quantity and agronomic quality) and relative prices. To understand these relationships, we develop a theoretical framework with an explicit representation of land heterogeneity. The elasticity of the supply curve is shown to be non-constant, depending on land heterogeneity and the availability of land for agricultural expansion. This influences the welfare economics of biofuels policies, and the possible carbon leakage in land and fuel markets. We emphasize that the impacts of biofuel policies on welfare and land-use change depend strongly on the potential development of the agricultural sector in terms of expansion and intensification, and not only on its current size.