【摘 要】
：
Understanding the spatial and temporal variations of cropping systems is very important for agricultural policymaking and food security assessment,and can provide a basis for national policies regardi
【出 处】
：
Journal of Geographical Sciences
论文部分内容阅读
Understanding the spatial and temporal variations of cropping systems is very important for agricultural policymaking and food security assessment,and can provide a basis for national policies regarding cropping systems adjustment and agricultural adap
其他文献
目前,国内缺少对集沙仪集沙效率问题的深入研究。采用风洞实验手段,就新型平口式集沙仪对不同粒级颗粒的收集效率进行了研究。结果表明:该集沙仪对1~0.85、0.85~0.5、0.5~0.25、0.5~0.1、0.25~0.1、0.1~0.05、<0.1、0.25mm粒级颗粒收集效率较高、对<0.25mm粒级颗粒收集效率较低的特点。该集沙仪的集沙效率不是随着...
This paper analyses the features and dynamic changes of the spatial layout of air transportation utilization among different provinces in China. It makes use of data for the airport throughput and soc
Village is an important implementation unit of national poverty alleviation and development strategies of rural China, and identifying the poverty degree, poverty type and poverty contributing factors
叶片形态特征与功能性状可以反映植物采取的协同或权衡策略。测定了塔里木河下游不同地下水埋深下荒漠河岸林建群种胡杨(Populus euphratica)的叶片解剖结构、叶片水力导度、叶片δ13 C值,探讨了胡杨结构性状指标和功能指标对地下水埋深的响应,叶片水力传输能力与叶片解剖结构变化趋势,以及叶片水力参数、解剖结构与水分利用效率的相关关系。结果表明:(1)胡杨叶片结构指标(叶片厚度、表皮厚度、栅栏
Household CO_2 emissions were increasing due to rapid economic growth and different household lifestyle. We assessed per capita household CO_2 emissions(PHCEs) based on different household consuming d
沙产业对沙漠的生态环境改善和社会经济发展具有巨大的贡献,在当前全球气候变化的背景下更是迎来新的契机。结合数理统计以及SWOT分析等研究方法综合分析和评价毛乌素沙地气候变化、生态环境变化以及内外资源条件。结果表明:(1)在气候变暖的背景下,毛乌素沙地降水有所增加,风速逐渐减小,植被覆盖率不断提高,气候条件和生态环境条件逐渐改善。(2)毛乌素沙地土地、光热、水、旅游及政策等资源条件具有明显的优势。毛乌
Land is critical to society by providing foods,fuel,fibers and many other ecosystem services that support production functions,regulate risks of natural hazards,or provide cultural and spiritual servi
The Belt and Road Initiative(BRI)–a development strategy proposed by China – provides unprecedented opportunities for multi-dimensional communication and cooperation across Asia,Africa and Europe.In t
This study developed a comprehensive system to evaluate the intensity of cropland use and evolution of cropland use in the Huang-Huai-Hai Plain.Delphi-entropy methods were adopted to determine the wei
Increasing soil organic carbon(SOC) sequestration is not only an efficient method to address climate change problems but also a useful way to improve land productivity.It has been reported by many stu