Landscape Effects of Land Consolidation Projects in Central China——A Case Study of Tianmen City,Hubei Province

The goal of land consolidation in China is still to develop agricultural production. The study of landscape effects of land consolidation projects （LCPs） faces many difficulties because of the lack of government＇s interest and data. This paper, taking Tianmen City of Hubei Province in Central China as an example, presents a methodology for analyzing landscape effects of LCPs by GIS and Fragstats3.3. It describes landscape effects with indexes of Patch Density （PD）, Largest Patch Index （LPI）, Landscape Shape Index （LSI）, Interspersion and Juxtaposition Index （IJI）, Aggregation Index （AI）, and Shannon＇s Diversity Index （SHDI）, showing more regular shape, simpler structure and less habitat diversity after LCPs. It computes ten landscape indexes of four categories of patches including Cultivated Land, Road, Water Channel, and River and Pond. The indexes show that 1） cultivated land becomes more fragmental in patch area, less irregular in patch shape and more concentrated in block; 2） the transport capacity of roads and irrigation and drainage capacity of water channels have been improved; 3） the landscape change of river and pond can be summarized as decreasing scale, more regular shape, reducing connectivity and diversity of the class. LCPs can facilitate agricultural production as well as protect cultivated land and food security. However, it is doubted that the increase of cultivated land from LCPs results from the reducing in landscape diversity of water area.     

长春市不同土地利用生境土壤甲虫群落结构特征

在长春市郊区天然次生林、农田、防护林和市区公园绿地等典型土地利用生境共捕获土壤甲虫32科598只,其中幼虫13科312只,成虫25科286只。应用个体密度、类群数量、群落多样性、丰富度和均匀度等指数,研究土壤甲虫的群落生态结构特征,了解土地利用差异对土壤甲虫群落结构的影响。研究结果表明:长春市不同土地利用生境凋落物的移除对土壤甲虫群落结构没有产生显著影响;农田土壤甲虫群落类群数、个体密度和多样性的降低源于生境作物品种单一和周期性的农田生产活动,防护林在空间上起着相邻农田物种交流廊道的作用;提高生境土壤甲虫群落类群数、个体密度和多样性的关键之一是保持生境类型的复杂性。     

1990—2018年长沙市土地利用变化对生态系统服务价值的影响

评估生态系统服务价值(Ecosystem Service Values,ESV)有利于衡量生态系统服务供给潜力和生态效益的大小,对城市生态规划与土地利用管控起到重要的支撑作用。选择长沙市为研究区域,基于1990、2000、2010和2018年4期土地利用现状遥感监测数据集,利用ArcGIS软件和经本地化校正的当量因子法,分析1990—2018年间的土地利用变化特征,并探讨土地利用变化对ESV的影响。结果表明: ①1990—2018年长沙市土地利用变化轨迹以耕地→林地互相转化以及建设用地对耕地、林地的侵占为主; ②1990—2018年长沙市的ESV共减少53.17×10⁸ 元,降幅3.59%,除水域外各类ESV均呈下降趋势,林地和耕地服务价值减少最明显; ③在各单项服务功能中,水文调节的价值最大,其次是气候调节,两者之和占总价值的54%; ④“退耕还林”“退田还湖”“兴工强市”等政策引起的土地利用变化势必对ESV造成影响,城市快速扩张、土地开发会导致ESV不断下降。综合分析认为,在调整研究区土地利用结构、优化土地配置时应充分重视水域、林地等生态系统服务价值较高的土地利用类型,减缓ESV的下降趋势。     

干旱区水资源可持续有效利用探讨─—以新疆为例

水资源是干旱荒漠区资源组合中最稀缺的资源。水资源是绿洲形成、发展的物质基础,水资源利用与经济发展之间存在互动关系。本文在阐述水资源与绿洲经济发展关系的基础上,分析了新疆水资源利用现状及存在的问题,最后提出水资源持续有效利用对策。     

"VALUING THE TROPICS": DISCOURSES OF DEVELOPMENT IN THE FARM AND FOREST SECTORS OF FRENCH INDOCHINA, circa 1900–40

The paper examines how land and forest management policies were elaborated in French Indochina circa 1900–40. It places their development in the context of a scientific and economic discourse about the value of land and forest resources, the most appropriate ways in which they might be exploited and the relationship between colonial science and indigenous knowledge. By focusing on debates and laws relating to the development of small‐scale and plantation farming systems (Land Code legislations) and forest management and exploitation (Forest Code legislations) the paper seeks to ground arguments about Western conceptions of the “tropics” within a discussion of national policy development and impacts. Focusing primarily on Cochinchina and Annam (southern and central Vietnam) and drawing on materials from French archives, the paper shows how changes in both attitudes and legislation have had lasting consequences on systems of property rights in forest management and on the place and status of indigenous peoples in Indochina.     

Building Temporal Topology in a GIS Database to Study the Land‐Use Changes in a Rural‐Urban Environment

This article addresses the issue of linking temporal and spatial information into a GIS database structure to investigate the land‐use changes in a rural‐urban region over a thirty‐five‐year period. More specifically, it describes the application of a programming package developed to build temporal topology in an historical land‐use GIS database to efficiently perform spatiotemporal queries. The program was created within the MapInfo environment using MapBasic language. Different types of information, such as the rate of change, the relationship between the change of land use and zoning regulations, and land‐use succession were extracted from the database. A user‐friendly interface was also developed to easily address spatiotemporal queries to the database. This approach represents a flexible and performing tool for scientists and planners who need to efficiently capture essential spatiotemporal information required for geographical inquiry and decision‐making.     

黄河三角洲土地利用与土地覆被的质量变化

土地利用／土地覆被变化（LUCC）在全球环境变化与可持续发展研究中占有重要地位。其质量变化尤能反映人类开发活动的环境效应。运用遥感信息土地分类和植被指数提取、土壤定点采样实测和统计分析相结合的方法，研究了黄河三角洲地区数年至20余年的土地利用／土地覆被的质量变化。其在区域总体上向好的方向发展，但在内部地段间存在着差异和不平衡。盐渍土改造的任务仍然十分艰巨。地力下降的隐患不可忽视。进而分析了变化的驱动力并提出土地持续利用对策。     

珠江三角洲土地利用变化与工业化和城市化的耦合关系

在分析珠江三角洲1990～2000年土地利用变化趋势和特征的基础上，根据土地利用的综合变动系数将珠江三角洲划分为4种土地变化类型，即剧变型、缓变型、相对稳定型和稳定型，并总结了不同变化类型的特征。进一步研究了工业化、城市化发展阶段与土地利用变化类型的关系，结果显示，处于不同工业化、城市化阶段的县市，其土地利用变化也明显不同，且与工业化、城市化进程和状态具有一定的内在关系；最后对产业非农化、城市化与土地利用变化的耦合系数进行了研究，发现各市县的产业非农化、城市化和土地利用变化的耦合系数，与土地利用的综合变动系数具有很高的一致性，按照产业非农化、城市化和土地利用变化耦合系数，在一定程度上可以判断土地变化的类型。     

Post‐Palaeozoic uplift history of southeastern Australia revisited: Results from a process‐based model of landscape evolution

Digital elevation models (DEMs) are widely relied upon as representations of the Earth's topographic morphology. The most widely used global DEMs available are ETOPO5, TerrainBase and JGP95E at a 5‐arc‐minute spatial resolution, and the GTOPO30 and GLOBE (version 1) global DEMs at a 30‐arc‐second spatial resolution. This paper presents the results of intercomparisons of these global DEMs over Australia, and with the GEODATA 9‐arc‐second DEM (version 1) of Australia. These DEMs were also compared to an independently produced, altimeter‐derived orthometric height database. This allows not only a totally independent assessment of the quality of these different DEMs over Australia, but also an insight into the ERS‐1 radar altimeter's ability to measure orthometric heights on land. The results of all these comparisons reveal large differences among the DEMs, with the greatest difference between JGP95E and ETOPO5 (mean 49 m, standard deviation ±274 m). The comparison with the altimeter‐derived database shows good agreement with the version 1 GEODATA DEM (mean 2 m, standard deviation ±27 m), thus demonstrating that the altimeter is a viable method for quality assessment of DEMs in lowland regions. A further conclusion is that the representation of the Australian land surface in both the JGP95E and TerrainBase global DEMs is more accurate than the higher resolution GLOBE (version 1) global DEM, even though JGP95E displays a disparity along the 140°E meridian because of the different data sources used in its construction.     

中国建设用地变化的空间分异特征

采用变异系数、希尔指数与空间自相关方法对我国2002—2008年建设用地变化的区域差异及空间相关性进行了探讨。结果显示:(1)2002—2008年我国区域建设用地的变化差异总体上呈减小趋势,但区域差异仍较为明显。(2)我国区域建设用地的增长呈现明显的空间二元结构,东部地区"高高"聚集,西部地区"低低"聚集。当前我国土地利用处于"倒U"型变化曲线的顶部区域,土地利用的压力依然很大,应根据土地利用变化的差异性及空间相关性,科学地制定区域土地供给政策。