开放条件下重庆地区城镇化对土地利用效率的影响及区位差异

经济开放和城镇化大幅度促进经济增长是中国30年经济持续增长的重要经验。内陆地区经济赶超更加受到人地耦合系统脆弱性的挑战。在对国内外关于城镇化与土地利用关系相关文献述评的基础上,以重庆40个区县为例,通过对其城镇化水平、开放度、技术水平、区位指数及城镇建设用地综合效率进行测算,采用多元回归方法实证分析了重庆40个区县在开放条件下城镇化对土地利用效率的影响及机制。研究发现:区位因素并不像在沿海地区一样对土地利用效率起着显著性作用;土地利用效率的高低严重依赖于物质资本投入密度,而不是人力资本投入密度;极低的人力资本积累和大量缺乏训练的劳动力涌入城市,降低了城市土地利用效率并提高了经济系统的脆弱性;城镇化极为显著地促进了土地利用效率,而开放度的促进作用却不明显,二者并没有形成理论上提升土地利用综合效率的合力。     

泛珠江三角洲区域经济开放的趋势分析

通过分析泛珠江三角洲地域结构演变对区域经济开放的影响和九省区(除两个特别行政区)国际开放度、区际开放度的测算结果及排名对比,探讨了中国式区域经济开放模式及制度和转型经济下该区域经济开放的路径。即从目前测算结果来看,泛珠江三角洲区域经济二元化开放整体上依然是国际开放度大于区际开放度,然而从地缘结构演变、国际国内和区际环境以及地缘优势来看,该区域在今后长远发展趋势上将会呈现出区际开放大于国际开放的趋势。这一分析结果印证了泛珠江三角洲经济圈的建立,顺应了当今世界经济和中国经济发展之大势。     

Economic development in tropical Africa from a geographical perspective: a comparative study of African economies

Tropical Africa is often seen to have problem economies that are very much alike and suffer from the same development problems. This view is questioned in exploratory analyses of levels of wealth, spatial productivity, the structure of the economy and aspects of the openness of economies and the way they have changed between 1965 and 1995. The analyses reveal differences between economies in both degree and kind. Change to economies was not unidirectional so that they became more disparate and differentiated. The exploratory analyses were extended using factor analysis as a diagnostic tool on a 19-variable by 25 country data set for 1985, 1990 and 1995. This confirmed the findings of the exploratory analyses and revealed changes in the structure of the factors reflecting development in the period. The results are discussed in the context of the literature in a search for explanation and policy formulation.     

World heritage and landscape change – heritage buildings and their changed visibility in the coastal landscape of Vega,Norway

Part of the Vega archipelago in north-western Norway is a cultural landscape listed as a UNESCO World Heritage site. Its buffer zone comprises most of the main island of Vega, where agriculture is an important land use. The authors describe interdisciplinary research carried out in the buffer zone. The research revealed the significant role of agriculture for the maintenance of the traditional open coastal landscape. The finding was further underlined by the fact that many visitors to the site never reach the outer archipelago, which is the core of the listed site. Based on interpretations of aerial photographs, land cover maps were produced for three cross-sections in time (1965, 1986, and 2009). A further reclassification of the land cover was performed to capture the change in openness due to change in land cover. Viewshed maps of each building found on the aerial photographs were overlain with the openness classes to capture the visual consequences of the buildings due to changes in land cover. A marked decrease in open land surrounding the buildings was found in the study area, which comprised Holand and Floa-Kjul in Vega Municipality, which in turn comprises the islands of the Vega archipelago. The regrowth of the land seemed to be happening regardless of building category.     

测绘遥感信息工程国家重点实验室十年建设与创新

回顾了测绘遥感信息工程国家重点实验室自1989年建室以来10年的历程,重点展示了10年来的研究成果,成果产品化、人才培养与对外开放方面所做的工作。在总结经验的基础上提出了国家重点实验室的发展必须抓好5个方面的工作,对同类实验室建设具有一定的借鉴价值。     

WHITHER CHINA'S MARKET ECONOMY? THE CASE OF LIJIN ZHEN

ABSTRACT. Soon after Deng Xiaoping became China's premier in 1978, a program of reform and openness was initiated. Its goals were to introduce free-market mechanisms into the command economy, to eliminate Mao-era inefficiencies, and to bring China to parity with developed countries of the West and to a leadership role among Asia's newly industrialized countries. Drastic changes quickly transformed China's planned economy into one of mixed-market socialism. Although the economic achievements have been impressive and commendable at the national and provincial levels, questions have been raised as to the role of economic reform and openness in the growth and development of Chinese cities. To answer them, we examine Lijin Zhen, the seat of Lijin County, Shandong Province.     

国际工序贸易的空间经济分布效应研究——克鲁格曼开放度假说的再考察

基于开放经济新中心是否与封闭经济原有中心空间重合的视角,以中国为背景对国际工序贸易影响空间经济分布的三大渠道进行理论阐释,在全球价值链背景下重新考察克鲁格曼的开放度假说。在理论分析基础上,借助加工贸易集聚熵指数和空间赫希曼-赫芬达尔指数（及校正地理集中指数）分别度量各省国际工序贸易嵌入程度和空间经济集聚水平,以中国23个省2001~2016年的面板数据构建动态面板模型,利用差分和系统广义矩估计对提出的理论假说进行实证分析和稳健性检验。结果表明：与开放度假说相反,国际工序贸易促进省域空间经济集聚;且工序贸易对经济集聚的促进作用在沿海要大于内陆。     

Assessing the potential for leaf-off LiDAR data to model canopy closure in temperate deciduous forests

Estimates of canopy closure have many important uses in forest management and ecological research. Field measurements, however, are typically not practical to acquire over expansive areas or for large numbers of locations. This problem has been addressed, in recent years, through the use of airborne light detection and ranging (LiDAR) technology which has proven effective in modeling canopy closure remotely. The techniques developed to use LiDAR for this purpose have been designed and evaluated for datasets acquired during leaf-on conditions. However, a large number of LiDAR datasets are acquired during leaf-off conditions since their primary purpose is to generate bare-earth Digital Elevation Models. In this paper, we develop and evaluate techniques for leveraging small-footprint leaf-off LiDAR data to model leaf-on canopy closure in temperate deciduous forests.We evaluate three techniques for modeling canopy closure: (1) the canopy-to-total-return-ratio (CTRR), (2) the canopy-to-total-pixel-ratio (CTPR), and (3) the hemispherical-viewshed (HV). The first technique has been used widely, in various forms, and has been shown to be effective with leaf-on LiDAR datasets. The CTRR technique that we tested uses the first-return LiDAR data only. The latter two techniques are new contributions that we develop and present in this paper. These techniques use Canopy Height Models (CHM) to detect significant gaps in the forest canopy which are of primary importance in estimating closure.The techniques we tested each showed good promise for predicting canopy closure using leaf-off LiDAR data with the CTPR and HV models having particularly high correlations with closure estimates from hemispherical photographs. The CTRR model had performance on par with results from previous studies that used leaf-on LiDAR, although, with leaf-off data the model tended to be negatively biased with respect to species having simple and compound leaf types and positively biased for coniferous species. The CTPR and HV models also showed some slight negative biases for compound-leaf species. The biases for the CTPR and HV models were mitigated when the CHM data were smoothed to fill in small gaps. The CHM-based models were robust to changes in the CHM model resolution which suggests that these methods may be applicable to a variety of small-footprint LiDAR datasets. In this research, the new CTPR and HV methods showed a strong ability to predict canopy closure using leaf-off data, however, future work will be needed to test the applicability of the models to variations in LiDAR datasets, forest types, and topography.     

地形开度和差值图像阈值分割原理相结合的黄土高原沟沿线提取法

鉴于地形正负开度对地貌的良好表达且具有分析尺度灵活性这一重要特性,本文提出一种借助地形正负开度及其差值图像阈值分割的黄土地貌沟沿线提取方法。首先,计算DEM的地形正负开度,对正负开度进行差值运算以得到开度差值图;然后,对开度差值图进行阈值处理以得到研究区正负地形空间分布特征;最后,借助数学形态学原理完成对二值化开度差值图正负地形边界——沟沿线的自动提取。试验采用高分辨率DEM数据对陕西洛川塬部分地区进行沟沿线信息提取。结果表明,与其他提取技术方法相比,该方法不仅增强了地貌基本形态特征在沟沿线提取过程中的作用与影响,同时也在一定程度上实现了沟沿线提取的精确化和自动化。     

Assessing China’s human-environment relationship

Journal of Geographical Sciences - China’s coupled human-environment system (CHES) is assessed here via a systems schema that emphasizes the complex interactions of components and their...