BOOK REVIEWS

Books reviewed in this article: Boundary Control and Legal Priniciples . Curtis M. Brown , Walter G. Robillard and Donald A. Wilson . Lost Initiatives: Canada's Forest Industries, Forest Policy, and Forest Conservation . R. Peter Gillis and Thomas R. Roach . The Navajo Atlas: Resources, People, and History of the Dine Bikeyah . James M. Goodman . The City and the Sign . M. Gottdiener AND Alexandros Ph . Lagopoulos , EDS. The Comfortable House: North American Suburban Architecture 1890–1930 . Alan Gowans . Arabic-Islamic Cities. Building and Planning Principles . Besim Salim Hakim . Contemporary Climatology . Ann Henderson -Sellers and Peter J. Robinson . A Trace of Desert Waters . Samuel G. Houghton . Geography, Resources and Environment. Vol. 1: Selected Writings of Gilbert F. White. Vol. 2: Themes from the Work of Gilbert F. White . Robert W. Kates AND Ian Burton , ED. Spatial Dimensions of Unemployment and Underemployment (A Case Study of Rural Punjab) . Gopal Krishan . Maps of the Holy Land: Cartobibliography of Printed Maps, 1475–1900 . Compiled by Eran Laor , assisted by Shoshana Klein . The Geography of Third World Cities . Stella Lowder . A Perspective on U.S. Farm Problems and Agricultural Policy . Lance Mc Kinzie , Timothy G. Baker AND Wallace E. Tyner . Soil Erosion and Its Control. R.P.C . Morgan , ED Geopolitics . Patrick O'Sullivan . Landscape, Meanings and Values . Edmund C. Penning -Rowsell AND David Lowenthal , EDS.     

Assessing the applicability of OpenStreetMap data to assist the validation of land use/land cover maps

The validation of land use/land cover (LULC) maps is usually performed using a reference database consisting of a sample of points or regions to which the ‘real’ class is assigned. This assignment is usually performed by specialists using photointerpretation (PI) of high-resolution imagery and/or field visits, which are time consuming and expensive processes. The aim of this article is to assess if the data available in the collaborative project OpenStreetMap (OSM) may be used as a source of data to assist the creation of these reference databases, reducing the time spent and costs associated with their generation. For this aim, two case studies were used, where the validation of the Global Monitoring for Environment and Security Urban Atlas (UA) was performed. The used methodology requires the harmonization of the data available in OSM with the UA nomenclature, and the subsequent creation of a LULC map from the OSM data. This map was then compared to UA to assess the similarity of the regions mapped in both. To test the usefulness of OSM data to assess the accuracy of UA, a sample of points was created and two reference databases generated, one assigning the data extracted automatically from OSM to the points where these data were available, and PI for the remaining points, and the other using only PI. The accuracy assessment of UA for the two case studies was then made building confusion matrixes and computing accuracy indicators. The results showed that for the two study areas, only low percentages of points had to be photo interpreted in the first reference database (respectively, 12% and 2% for the two study areas), decreasing the work load considerably. The results obtained with both reference databases are comparable for level 1 classes. For level 2 classes, worse results were obtained for some classes, showing that the OSM data used are not enough to create reliable reference data.     

广东省城镇建设用地经济密度差异时空特征及影响机理

基于广东省21个地级市的城镇建设用地经济密度数据,利用ArcGIS空间分析、泰尔指数、重心模型等方法分析了1996―2008年广东省城镇建设用地经济密度差异的时空特征,并构建面板数据模型对其影响机理进行了探讨。结果表明：1）1996―2008年,广东省城镇建设用地经济密度总体差异波动增大,城镇建设用地经济密度重心向西北偏移;2）广东省各城市之间城镇建设用地经济密度差异显著,空间格局上存在较明显的集聚和峰值效应;3）广东省各城市之间城镇建设用地经济密度的相对发展速度差别较大,按基础水平和提高速度的差异划分为4种类型区,其中基础高密度提高较慢类型区和基础低密度提高较慢类型区涉及城市数量较多;4）随着产业结构的优化、资本与劳动力投入规模的增大、交通区位的改善和科技水平的提升,广东省城镇建设用地的经济效益将会得到不断提高。     

结合被动微波和光学遥感的“超级寒潮”广东 地表温度特征及其对马铃薯生长的影响

利用被动微波可穿透云层的优势,基于GCOM-W1/AMSR2（Global Change Observation Mission-Water/ Advanced Microwave Scanning Radiometer 2）星载被动微波传感器的多通道亮度温度数据,反演了2016年1月下旬“超级寒潮”过程的广东省每日地表温度,分析了寒潮过程中广东省地表温度的时空变化特征。结果表明：在寒潮前后,广东省地表温度呈现出明显的先下降而后上升的趋势,寒潮过程带来的地表最低温度在广东北部大部分地区达到了277 K（4℃）,西南大部分地区为280~282 K（7~9℃）,其余大部分地区278~279 K（5~6℃）;降温幅度在广东南部地区达到了8~12 K（8~12℃）,北部大部分地区为5~7 K（5~7℃）。此外,利用归一化植被指数（NDVI）对植被生长的指示作用,基于HJ-1 A/B卫星的CCD传感器的多通道反射率数据,计算了近3年冬季广东省典型马铃薯种植区域马铃薯叶片的NDVI值,结果表明：马铃薯叶片的NDVI值在此次寒潮过程后出现了明显的下降,大部分地区（55.4%）马铃薯NDVI降低了0.1~0.2,部分地区（17.2%）马铃薯NDVI下降了0.2~0.3;进一步对比此次“超级寒潮”后同时段的前2年数据,发现寒潮后马铃薯叶片NDVI相对于正常年份也低了0.2,表明马铃薯叶片NDVI下降的主要原因是寒潮带来的低温,而不只是马铃薯的正常老化现象。NDVI的降低表明大部分地区马铃薯生长受到了抑制,马铃薯生长状况的这一变化也通过现场调查得到了证实。     

灌区中居民点与水土资源邻近关系——以张掖绿洲为例

干旱区内陆河流域的核心在于水,核心区域在于绿洲。灌区是构成绿洲的最基本单元。论文应用最邻近距离指数(NNI),分析了张掖绿洲灌区中居民点与水浇地及渠系之间的空间耦合关系,结果表明:在张掖大小共39个灌区中,有22个灌区的NNI值<0.5,灌区中居民点总体表现为聚集分布态势,但空间差异明显,沿山灌区居民点聚集程度明显高于绿洲中腹灌区,映射出不同灌区水资源的基本约束力。从微观角度考察,居民点与水浇地、渠系、道路之间的平均临近距离从沿山独立灌区-绿洲边缘灌区-绿洲中腹灌区逐步增加,说明沿山灌区水浇地、渠系与居民点的关系更密切。灌区中居民点与渠系、水浇地表现出显著的"亲水型"和"亲地型","质点"(居民点)-"廊道"(渠系和路网)-"域面"(土地)之间存在非常密切的相互依存关系。     

Modeling spatial and temporal change of soil erosion based on multi-temporal remotely sensed data

In order to monitor the pattern, distribution, and trend of land use/cover change (LUCC) and its impacts on soil erosion, it is highly appropriate to adopt Remote Sensing (RS) data and Geographic Information System (GIS) to analyze, assess, simulate, and predict the spatial and temporal evolution dynamics. In this paper, multi-temporal Landsat TM/ETM+ remotely sensed data are used to generate land cover maps by image classification, and the Cellular Automata Markov (CA_Markov) model is employed to simulate the evolution and trend of landscape pattern change. Furthermore, the Revised Universal Soil Loss Equation (RUSLE) is used to evaluate the situation of soil erosion in the case study mining area. The trend of soil erosion is analyzed according to total/average amount of soil erosion, and the rainfall (R), cover management (C), and support practice (P) factors in RUSLE relevant to soil erosion are determined. The change trends of soil erosion and the relationship between land cover types and soil erosion amount are analyzed. The results demonstrate that the CA_Markov model is suitable to simulate and predict LUCC trends with good efficiency and accuracy, and RUSLE can calculate the total soil erosion effectively. In the study area, there was minimal erosion grade and this is expected to continue to decline in the next few years, according to our prediction results.     

The effects of land consolidation on the ecological connectivity based on ecosystem service value: A case study of Da’an land consolidation project in Jilin province

Land consolidation has a profound impact on landscape patterns and ecological functions at various scales through engineering and biological measures. In recent years, China invests more than 100 billion RMB yuan on land consolidation each year. To understand how land consolidation affects landscape patterns and ecosystems, we investigated the ecosystem service value and the ecological connectivity in a consolidated area of Da’an city from 2008 to 2014 using a revised ecological connectivity index. The results indicated that land consolidation has certain negative influences on the ecosystem services in this area. The total ecosystem service value will decrease by nearly 30% in the late stage of consolidation. This decrease is caused by the loss of ecosystem service of the wetland and grassland, despite a sensible increase of cultivated land. In addition, land consolidation could change the ecological connectivity as well as the land use structure. Up to 85% of the entire area will be in low connectivity in the late stage of consolidation, representing a 6.23% increase in the total coverage compared to pre-consolidation. Finally, the different connectivity landscape and their key areas can be identified by the revised ecological connectivity index effectively. This study is helpful to trace out the relationships between landscape pattern and ecological process, and provides insights for ecological planning and designing of land consolidation in this area. We suggest that more attentions should be paid to improve the quality and ecosystem service value per unit area of the landscape, to establish ecological compensation mechanism of wetland losses, and to create the ecological corridors along the least accumulated impendence surface in the key areas during land consolidation.     

地理学研究范式的思考

地理学主要关注陆地表层自然和人文要素的空间分异规律研究,针对这一复杂系统的不同问题应该选择不同的研究方式。本文在思考以往地理学研究方式的基础上,将地理学研究范式概括为：地理经验科学研究范式、地理实证科学研究范式、地理系统科学研究范式和地理大数据研究范式。对不同地理科学问题应选取不同的范式加以研究,对有些复杂科学问题应采用多种研究范式加以解决。     

全球土地覆被时空变化与中国贡献

20世纪下半叶以来全球土地覆被发生了剧烈变化,人类活动对土地覆被变化的影响成为“人类世”最为显著的特征之一。科学评估全球土地覆被变化的时空过程和新态势,分析中国在其中扮演的角色和地位并提出优化路径,成为中国在可持续发展领域应对全球百年未有之大变局的核心任务之一。本文基于多源土地覆盖数据,运用地理空间分析方法定量刻画了全球土地覆被变化的时空演化过程,从景观尺度分析了地类间的转化关系以及全球“变绿”和森林覆盖度的变化趋势,揭示了中国对全球土地覆被时空变化的贡献。结果表明,1992—2015年全球土地覆被经历了显著变化,全球土地覆被变化度在南美洲中部、撒哈拉以南的非洲、中亚、东南亚和东亚等地形成显著的热点区。中国森林覆盖率从1990年的12.98%增至2020年的23.34%,湿地面积增长1908 km²,为维护全球生态安全贡献了力量,同时在城市用地增长、草地和其他用地减少等方面也有一定的限制作用。与全球其他国家不同,中国城市扩张占用耕地面积居全球第一位,高达7.3万km²。1999—2019年全球叶面积指数存在全球性的显著提高趋势。中国以仅占全球6.6%的植被面积,贡献了全球20%左右的叶面积增加量,引领了全球“变绿”过程。1990—2020年全球森林覆盖度变化呈现出空间集聚性。中国森林面积增长62.84万km²居全球前列,其中西南林区和秦巴山区是林地增长的主要区域,长三角、粤港澳大湾区和内蒙古东部部分地区是森林覆盖度降低的主要区域。中国未来应进一步提升经济社会发展与生态保护的均衡协调度,持续推进美丽中国建设,为全球生态安全和可持续发展贡献更大力量和更多经验。     

土地持续利用的五维空间分析

土地资源的持续利用是人类社会发展的基础，文章较为系统地提出了时间，空间，用途，技术和制度是实现土地资源持续利用的五维空间，并对各维度的内涵进行了较为深入的分析。其中，土地持续利用的时间维主要表现为从伦理角度考虑如何在代际间合理分配土地资源，使代际间利益之和最大；空间维则要求实现土地利用在空间上的合理布局；胜任维要求将土地资源合理配置到各种用途上，从而使人们从土地所提供的产品和劳各中获得的总效用最大；技术维选择意味着土地利用的直接或间接技术的选用能够保证土地的永续使用；制度维要求制度建设适应土地利用情况的变化，通过消除不同的土地制度之间存在着的外部利润来实现土地资源的最优配置。