Assessing the spatial distribution of crop areas using a cross-entropy method

While crop production statistics are reported on a geopolitical – often national – basis, we often need to know, for example, the status of production or productivity within specific sub-regions, watersheds, or agro-ecological zones. Such re-aggregations are typically made using expert judgments or simple area-weighting rules. We describe a new, entropy-based approach to the plausible estimates of the spatial distribution of crop areas. Using this approach tabular crop production statistics are blended judiciously with an array of other secondary data to assess the areas of specific crops within individual ‘pixels’—typically 25–100 km² in size. The information utilized includes crop production statistics, farming system characterization, satellite-based interpretation of land cover, biophysical crop suitability assessments, and population density. An application is presented in which Brazilian state level production statistics are used to generate pixel level crop area data for eight crops. To validate the spatial allocation we aggregated the pixel estimates to obtain synthetic estimates of municipality level areas in Brazil, and compared those estimates with actual municipality statistics. The approach produced extremely promising results. We then examined the robustness of these results compared to simplified approaches to spatializing crop production statistics and showed that, while computationally intensive, the cross-entropy method does provide more reliable spatial allocations.     

中国智力资源空间分布及其影响因素研究

现代社会已步入知识经济时代。知识经济显著特点就在于信息、知识等各种类型的智力资源取代工业经济的资本上升成为新的、决定性的终极资源和核心生产要素。在研究智力资源涵义的基础上，选取了投入、产出、环境支持、智力资源4个系统30个不同指标，运用数理统计方法中的因子分析来定量研究中国智力资源空间分布特点，从而进一步分析出影响中国智力资源的空间分布的4个主要因素：经济发展程度、行政区标准问题、历史因素和区域文化模式不同。     

“数字空间”与“深空测绘”及其支撑技术

在对未来空间对抗的需求和测绘保障范围的拓展进行分析的基础上,提出了“数字空间”的构想和实施空间测绘(深空测绘)的发展思路;提出了“数字空间”的内涵和建立“数字空间”的技术与服务体系。“数字空间”建设应作为天空地一体数字化战场的核心内容,并为空间环境的认知与利用、控制空间以及空间目标的探测、识别、分类等技术手段提供全面的信息支撑。     

上海市工业布局调整初探

上海市是中国重要工业基地之一。改革开放以来,随着市场经济体制的逐步建立,上海市工业空间结构呈现出内环线以内以劳动密集型的轻工业为主、内外环线之间以技术密集型高新技术产业为主、外环线以外远郊地区以资本密集型的重化工业为主的空间格局。从总体上看,从城市中心向外,单位土地面积工业生产产出效率逐渐降低、劳动密集程度逐渐减少、资本密集程度逐渐增加、对上海市总体经济规模贡献率逐渐加大、对周围环境影响逐渐增强的圈层结构特征十分明显。另外,上海市工业布局的实践表明,除了原燃料、市场、劳动力的价格及其运费以及集聚外,级差地租、现代交通设施、劳动就业也是影响工业布局的重要因子。从优化工业布局出发,上海市今后一段时期,应大幅度提高工业用地效益、建设科学合理的工业生产基地、制定相应的工业空间结构调整配套政策,以保证区域工业的健康发展     

中国新亚欧大陆桥经济带旅游资源结构及开发布局研究

从中国新亚欧大陆经济带中选出具有较高管理类别和一定代表性的53处旅游景区作为研究样本，采用定性与定量相结合的方法，在对其旅游资源的类型结构、空间结构、界值结构和开发层次结构依次结构做出分析的基础上，提出了该经济带旅游资源开发的基本思路、空间结构模式和时空组织系统；接着分别探索了5大旅游区旅游资源的合理开发利用；最后针对这一经济带旅游资源开发中存在的突出问题，就其战略措施进行了讨论。     

龙口市水资源优化调度系统的设计与应用研究

水资源优化调度非常复杂，需要考虑各种供水水源与国民经济各部门的需水要求在时空分布上的差异，还要考虑地表水与地下水之间的转化关系、地表水库与地下水库之间的补偿调节，并根据这些变化，在一定调度原则下，确定供水在不同地区、部门、行业及企业之间的分配，使水资源效益最大。介绍了龙口市水资源优化调度系统的构建方法、调度模式及应用效果。     

Structural patterns of land types and optimal allocation of land use in Qinling Mountains

1 IntroductionMountains，as one of the huge ecosystems in the world, play a significant role during human evolution and development[1]. As the treasury of ecological resources[2], mountains have faced the challenge of the degradation of their eco-environment and the difficulty in their regional poverty relief because of human unsuitable exploitation. The 53rd Conference of United Nations has claimed the year 2002 as the International Mountains Year and called on each country to pay attention…     

石家庄台网的台站布局与地震处理精度分析

本文描述了石家庄台网的台站布局,分析了地震数据处理精度与网内台站的记录质量、台站仪器的放大倍数、地震发生部位及地震震级的关系。     

Comprehensive evaluation method for sediment allocation effects in the Yellow River

Scientific evaluation of the sediment allocation effects in the Yellow River plays an important role in the comprehensive harnessing of the Yellow River. A new evaluation index system for sediment allocation has been established using the Analytic Hierarchy Process, and six main evaluation indexes have been selected for this study. The calculation methods and evaluation criteria of each evaluation index are proposed. The evaluation criterion of bankfull discharge in the upper reach is 2,000 m³/s, that of Tongguan elevation in the middle reach is 325.7 m, and that of bankfull discharge in the lower reach is 4,000 m³/s. The evaluation criteria of water volume and sediment volume into the Yellow River are 25 billion m3/a and 300 million t/a, respectively, and that of sediment volume into the sea to maintain stability of the estuary is 130–260 million t/a. The comprehensive evaluation method and grade index are proposed, and the effect of sediment allocation in the Yellow River from 1960 to 2015 is evaluated. The comprehensive evaluation grades in different periods are determined. The evaluation results objectively reflect the situation of sediment allocation in the Yellow River, and the new comprehensive evaluation method can be applied to evaluate the sediment allocation scheme of the Yellow River in the future.