关键词： 气候变化   玉米   气候生态适应性   区划   雨养农业区   甘肃省  

摘要： 以甘肃省雨养农业区55个气象站1971—2015年气温和降水实测资料为基础,根据玉米生长发育对气象条件的需求,运用综合评判法筛选出7月平均气温、≥10℃积温和年降水量作为玉米种植适宜性气候区划指标。采用线性倾向率法、累积距平、ArcGIS空间分析技术及Mann-Kendall法对研究区气候指标的时空变化特征及其突变进行了分析,结合玉米种植地理分布信息,建立适宜度评价模型,对气候变化背景下玉米种植适宜区的空间分布变化进行分析。结果表明:(1)近45 a来,甘肃省雨养农业区7月平均气温和≥10℃积温均呈明显的上升趋势,以0.29、98.13℃·10 a^(-1)的速率显著增暖,并分别于1994年、2000年发生突变;年降水量总体呈减少趋势,存在强烈波动变化,以-2.57 mm·10 a^(-1)的速率缓慢下降,1988年发生突变。(2)从空间分布来看,7月平均气温和≥10℃积温总体呈现出由北向南、由西向东递增的格局;降水量空间变化不规律,研究区中部降水少,四周降水较多。(3)气候变化导致研究区玉米可种植区域向高海拔地区移动,海拔上移了500 m,玉米种植的界限发生了较明显的空间位移,北移、西扩显著,从陇中、陇东、陇南地区扩展至甘南地区,适宜于种植的耕地总面积达2.27×10^(6) hm^(2),比2000年前增加了5.85×10^(4) hm^(2),在总耕地面积的基础上增加了2.4%,其中最适宜区增加最为显著,达15.9%。玉米种植适宜程度区划的区域分配有差异,2000年后甘肃省雨养农业区玉米种植最适宜区耕地面积较之前增加3.84×10^(5) hm^(2),次适宜区、适宜区和不适宜区耕地面积分别缩小2.54×10^(5) hm^(2)、7.1×10^(4) hm^(2)和5.9×10^(4) hm^(2)。

关键词： 世界粮食安全   粮食市场   主产国   农产品供应链   双循环   谷物出口   极端性   应对气候变化  

摘要： 民为国基,谷为民命。保障粮食安全、牢牢端稳中国饭碗是全面建成小康社会的基础工程。2020年新冠肺炎疫情肆虐全球,各国采取社交隔离措施以及临时性关闭边境政策,如小麦出口国俄罗斯等、大米出口国越南等明确暂停谷物出口,巴西等大豆主产国港口转运困难,对全球农产品供应链与粮食市场保障造成了严重冲击。与此次疫情交织叠加,极端性气候增多、灾害频发,区域性与结构性粮食生产受阻迹象显露,致使全球陷入粮食安全危机之中。据《2020年世界粮食安全和营养状况报告》显示,2020年,新冠疫情可能导致食物缺乏的人数新增8 300万,预计世界饥饿人口数量到2030年将超过8.4亿。

关键词： 气候变化   农业生产   应对措施   建议  

摘要： 通过分析河西走廊主要农业生产区武威、张掖、酒泉3市2008~2017年间的气候变化特征及其对农业生产的影响和农户应对气候变化所采取的措施,提出加强培育新品种、加强农业基础设施的优化、合理科学调整农作物种植结构及布局等农业生产应对建议。

关键词： 气候变化   农业风险   农业保险   风险管理  

摘要： 理解气候变化条件下农户农业保险购买行为,有助于完善我国农业保险制度。通过构建"气候变化、农业风险与农户农业保险购买行为"的分析框架,利用地级市气候数据和农户微观数据进行匹配展开实证分析。研究表明:气候变化对农户农业保险购买行为有显著的促进作用,但对不同生产目的的农户存在异质性影响。仅当经营目标从满足自家消费转向为追求市场利润时,才诱致农户购买农业保险的强烈需求。中介作用机制分析表明,因气候变化产生的两类农业风险对农户购买农业保险的中介作用存在差异。其中,气候变化形成的土壤退化风险具有渐进性。农户在农业生产之前,能够结合土壤板结等物理性质来调整农业生产要素供给,降低风险损失。这使得农户低估风险的严重性,不愿购买农业保险,即中介效应不显著。而气候变化形成的病虫害风险属于突发性风险,农户难以通过事前风险防控来分散风险,由此强化了农户的损失厌恶感,并转化为对保险的需求,即中介效应显著。

关键词： 气候变化   农业生产   病虫害   农作物产量  

摘要： 气候变暖不仅使高温天气的持续时间变长,局部地区干旱问题变得严重,而且导致台风、寒流等反常气候的频发,对人类正常生产生活造成了较大干扰。尤其是与气象变化密切相关的农业生产,“减产降质”问题成了亟待解决的农业问题之一。认识是解决问题的第一步,因此本文立足于全球变暖这一显著的气候变化趋势,从气象灾害和病虫害两个角度分析了对农业生产造成的影响,并结合气候研究和生产实践提出了当前降低气象损害的措施,希望为稳定农业生产发展提供参考。

关键词： Climate change   Adaptation barriers   Productivist agriculture   Post-productivist agriculture   Multifunctional agriculture   Governance   Developing countries  

摘要： Agriculture stands as the basis of human life, and it is important to sustain affordable food provision of this support system through powerful adaptation to climate change as the worldwide effects of climatic hazards are becoming more evident. Specifically, some semiarid and arid areas of developing countries are more vulnerable to the impacts of climate change. To reduce vulnerability of these regions, realizing context-specific impediments of robust adaptation to climate change is necessary. Also, it is imperative to consider anticipated transformations of agricultural systems that are required to enhance resilience of agriculture in coping with climate change. Therefore, this study aims to investigate major adaptation barriers in agriculture sector of Fars province, Iran. It also attempts to identify if any transformation from productivist agricultural systems is needed. To achieve these objectives, the group analytic hierarchy process was conducted with representatives from local government, academic institutes and farmers. The results revealed that local stakeholders prioritized barriers to adaptation, differently, and they showed various levels of concern about the importance of some barriers. However, they identified the governance and policy-related issues as the most important barriers. The results also indicated that transformational adaptation of agriculture sector from productivist to multifunctional farming system is required in order to enhance its resilience under uncertain climatic conditions. Some recommendations are offered to eliminate barriers of agricultural adaptation to climate change and also facilitate transformational adaptation of agriculture, in the developing world.

关键词： Climate change   Risk perception index   Adaptation strategies   Riverine char dwellers   Agricultural adaptation  

摘要： Farmers in the riverine char islands of Bangladesh are frequently affected by climate change due to their proximity to the river and heavy reliance on agriculture for their livelihoods. The present study evaluates char dwellers? risk perceptions and agricultural adaptations to climate change. Survey data were collected from 98 households, and focus group discussions were conducted using a semi-structured questionnaire from Rydas Bari char under the Gaibandha District of Bangladesh. A standardized risk perception index was created using a four point Likert scale against sixteen climatic events. In addition, a binary logit model was used to estimate the influence of socioeconomic characteristics of sample households on the decision to choose climate change adaptation strategies. Findings suggest that droughts, river erosion, and floods are the major climatic risks perceived by char dwellers. Additionally, results from a climate vulnerability index portray similar findings that char respondents are more exposed to diverse climatic hazards. The study further investigates local adaptation mechanisms in agriculture with regards to major climatic events. In response to the existing climate change risks, the char inhabitants employ several adaptation strategies in agriculture such as implementing new or alternative farming practices, changing planting times, and cultivating short-duration varieties. The llogit analysis suggests that household age, family size, annual income, farm size, farm ownership and farming experience have a significant influence on farmers? adaptation choices. Household access to education, early warning by extension agents, information on improved agricultural technologies, access to off-farm sources of income and incorporating char people during policy design can effectively enhance farmers? resilience and help reduce vulnerability.

关键词： continuous treatment   hybrid solar still   saline oily wastewater   SOWAT   sustainability   wastewaters  

摘要： Access to drinking water and sanitation are among the goals adopted by the United Nations in its 2030 Agenda for Sustainable Development. However, in poor and low-income countries, this goal has not yet been reached. This is caused by several lacks in the technological mastery of water and wastewater treatment processes, fresh water and sanitation networks, and, finally, financial resources. Increasing the success chances to reach this goal should not happen by copying centralized water and sanitation systems used in high-income countries. Rather efforts need to be made towards energy-efficient decentralized water and wastewater treatment facilities, using simple and sustainable low-cost technologies. The present paper suggests solar wastewater treatment (SOWAT) as an easy decentralized and sustainable wastewater treatment. It combines three steps of conventional wastewater treatment (i.e., pretreatment, biological treatment, and disinfection) by using a single treatment step conducted in a single equipment: solar still. It is has been experimentally tested to treat saline, domestic, municipal, and industrial wastewaters. All obtained results have recorded significant removal of inorganic, organic, bacteriologic, and metallic pollution. For community and industrial use, a new design of a hybrid SOWAT micro-plant proposes the integration of a pretreatment stage and a smart multi-source heating system. It is decentralized because it is powered by solar energy, other renewable energies, recovered flared gas, or conventional energy. Its continuous operation during the decrease or absence of solar radiation, by night, is expected to increase its daily production from 255% to 1,500%.

关键词： System dynamics   Agriculture   Climate change adaptation   Leverage points analysis   Water management  

摘要： Context: Participatory modeling approaches provide opportunities for collective action responding to challenges of community resource limitations. In the context of climate change, challenges arise from the potential limitations of water availability and resulting conflicts within the agricultural sector. Northeast Lower Saxony is the region with the highest irrigation intensity in Germany due to the sandy soils with low water holding capacity, the cultivation of crops with high water demand, and a negative climatic water balance during the summer months. Water resources will become more limited as a consequence of climate change. Simultaneously, the irrigation demand will most likely increase due to intensified crop cultivation. Objective: Responding to these challenges, we developed a novel method to identify leverage points for effective climate change adaptation measures. We applied this method to analyze opportunities for climate change adaptation within the agricultural sector in Northeast Lower Saxony. Furthermore, we assessed the potential of stakeholders to implement adaptation measures that correspond to the identified leverage points on different time scales. Methods: Our leverage point analysis is based on a qualitative system dynamics model that was developed within a participatory modeling framework. We analyzed parameters, feedback loops, and typical system archetypes within the model. Leverage points that were related to the design and the intent of the model emerged during the iterative model building process. Subsequently, we introduced a rating system to evaluate the potential of each leverage point to be successful as a climate change adaptation measure. We provide a point-by-point analysis of the potential of key stakeholders to implement adaptation measures. Results and conclusions: The leverage points analysis was applied to the case study of Northeast Lower Saxony. It revealed that collective action is needed to cope with these challenges. De

关键词： Environment   food nutritional value   food safety   greenhouse gases   sustainable agriculture  

摘要： Climate change, with increasing temperatures and atmospheric carbon dioxide levels, constitutes a severe threat to the environment and all living organisms. In particular, numerous studies suggest severe consequences for the health of crop plants, affecting both the productivity and quality of raw material destined to the food industry. Of particular concern is the reduction of proteins and essential micronutrients as iron and zinc in crops. Fighting this alarming trends is the challenge of Climate-Smart Agriculture with the double goal of reducing environmental impacts (use of pesticides, nitrogen and phosphorus leaching, soil erosion, water depletion and contamination) and improving raw material and consequently food quality. Organic farming, biofertilizers and to a lesser extent nano-carriers, improve the antioxidant properties of fruits, but the data about proteins and micronutrients are rather contradictory. On the other hand, advanced devices and Precision Agriculture allow the cultivations to be more profitable, efficient, contributing more and more to reduce pest diseases and to increase the quality of agricultural products and food safety. Thus, nowadays adoption of technologies applied to sustainable farming systems is a challenging and dynamic issue for facing negative trends due to environmental impacts and climate changes.