山地城市土地覆盖变化对地表温度的影响

针对山地城市复杂的城市地貌和下垫面类型,本文使用TM、DEM、ETM⁺等遥感影像资料,提取了重庆市土地利用覆盖类型;借助TM、MSS等遥感数据的红外波段,反演出1988年和2000年的地表温度。分析了重庆市近十年的土地覆盖变化及其对地表温度的影响,结果表明,在1988~2000年间,研究区土地覆盖变化明显,特别是城市土地覆盖面积有显著增加。土地覆盖类型的变化会改变地表温度的空间分布,尤其是城市土地的扩展会提高地表温度。对山地、丘陵、平坝、陡坡四种耕地的地表温度进行了深入分析与研究,结果表明:山地城市土地覆盖变化引起了植被覆盖度的变化,而植被覆盖度的变化又相应地影响了地表温度的变化,植被覆盖度每下降10%,地表温度上升0.49K。     

浅谈3S技术及其在土地管理中的应用现状与发展趋势

土地管理是国家为维护土地制度、调整土地关系、合理组织土地利用所采取的行政、经济、法律和技术的综合措施。土地作为一种不可再生资源,如何科学地利用和有效地管理对可持续发展有比较重要的意义。本文主要概述了土地管理中的土地资源调查、土地利用总体规划、土地资源动态监测、土地评价、土地整理等的应用现状,并结合3S技术的发展探讨了其应用趋势。     

Green space planning and land use: An assessment of urban regional and green structure planning in Greater Copenhagen

Geografisk Tidsskrift, Danish Journal of Geography 106(2):7–20, 2006

In its Regional Plan of 2005, The Greater Copenhagen Authority (abbreviated as “HUR” in Danish) places special emphasis on the future recreational values associated with the regional green structure. In this paper, the development of the urban green structure in Greater Copenhagen is elaborated upon, focusing on land use changes and the effectiveness of regionally coordinated planning measures. EU MOLAND data are used to analyse the development of the region's green structure during the period 1954 to 1998. Analysis of two “green wedges” within the green structure illustrates that the development of the green recreational areas is the result of both formal and more informal planning initiatives. Development has shown equal phases that correspond to the applied regional planning measures and the general economic conditions. However, local preferences in the involved municipalities likewise have played an important role and have resulted in different urbanisation pressure within the two wedges. Land use has transformed from an agricultural to a primarily recreational landscape. In some areas, however, urbanisation pressure has resulted in residential and green industrial areas instead of the planned recreational land use. Based on its historical development it is concluded that future preservation and development of the green structure in Greater Copenhagen requires regional planning measures to be incorporated into municipal plans. In this way the increasingly independent municipalities will comply to objectives of the Regional Plan 2005.     

Hydrological response of an afforested catchment in a Mediterranean humid mountain area: a comparative study with a natural forest

The effects of afforestation on water resources are still controversial. The aim of this paper is to (i) analyse the hydrological response of an afforested area in the Central Pyrenees and (ii) compare the hydrological response of an afforested area with the response observed in a natural undisturbed forest. The Araguás catchment was cultivated until the 1950s, and then afforested with pines in an effort to control the active degradation processes. The hydrological response was variable and complex, because the discharge was generated by a combination of distinct runoff processes. The hydrological response showed that (i) afforestation produced moderate peak discharges, stormflows and recession limbs, and long rising limbs; (ii) no one single variable was able to explain the hydrological response: rainfall volume and intensity did not explain the hydrological response and antecedent rainfall and initial discharge (indicating antecedent moisture conditions) did play an important role; (iii) seasonal differences were observed suggesting different runoff generating processes; and (iv) the effect of forest cover on peak discharges became less important as the size of the hydrological event increased. The stormflow coefficient showed a clear seasonal pattern with an alternation between a wet period, when the catchment was hydrologically responsive, and a dry summer period when the catchment rarely responded to any event, and two transitional periods (wetting and drying). Compared with a natural forest, the afforested area recorded greater flows and peak discharges, faster response times and shorter recession limbs. Afforestation reduces the water yield and the number of floods compared with non‐vegetated areas and abandoned lands. Copyright © 2016 John Wiley & Sons, Ltd.     

祁连山南麓退耕地主要植物群落植冠层的截留性能

退耕地人工群落植冠层的截留能力,是群落生态效益的重要组成部分,这一研究不仅可以掌握退耕还林还草工程作用的机理,还可以更好地指导工程实践,促进工程建设步伐。通过“简易吸水法”,可以快速掌握退耕地植冠层的最大截留潜力。青海省大通县退耕较早、平均年龄约10a以上的青海云杉、华北落叶松等几种人工群落,它们的林冠截留量较高,平均达1．93mm,为当地3种截留量最高、林龄50a之上天然群落的61％。青海云杉、华北落叶松、白桦、青杨、中国沙棘等退耕地人工群落的截留量,基本上显示出与林龄之间呈线性或Cubic、Quadratic正相关关系。在植物群落分层截留、消化吸收降雨的这一空间垂直序列中,植冠层截留量虽然较低,平均仅1．29mm(0．25～2．38mm),但植冠层的主要作用还在于减轻、缓冲雨水直接打击地面,改变降水的侵蚀性危害,而这些作用要远远高于截留量自身的区区数量。     

A sub-pixel analysis of urbanization effect on land surface temperature and its interplay with impervious surface and vegetation coverage in Indianapolis,United States

This study developed an analytical procedure based upon a spectral unmixing model for characterizing and quantifying urban landscape changes in Indianapolis, Indiana, the United States, and for examining the environmental impact of such changes on land surface temperatures (LST). Three dates of Landsat TM/ETM+ images, acquired in 1991, 1995, and 2000, respectively, were utilized to document the historical morphological changes in impervious surface and vegetation coverage and to analyze the relationship between these changes and those occurred in LST. Three fraction endmembers, i.e., impervious surface, green vegetation, and shade, were derived with an unconstrained least-squares solution. A hybrid classification procedure, which combined maximum-likelihood and decision-tree algorithms, was developed to classify the fraction images into land use and land cover classes. Correlation analyses were conducted to investigate the changing relationships of LST with impervious surface and vegetation coverage. Results indicate that multi-temporal fraction images were effective for quantifying the dynamics of urban morphology and for deriving a reliable measurement of environmental variables such as vegetation abundance and impervious surface coverage. Urbanization created an evolved inverse relationship between impervious and vegetation coverage, and brought about new LST patterns because of LST's correlations with both impervious and vegetation coverage. Further researches should be directed to refine spectral mixture modeling by stratification, and by the use of multiple endmembers and hyperspectral imagery.     

宁夏土地利用时、空变化及其驱动机制

利用1990年和2000年两期遥感图像,通过遥感和GIS空间分析方法,研究了1990-2000年宁夏回族自治区的土地利用动态变化情况.宁夏土地利用变化最主要的特点是耕地增加,草地和未利用土地的减少,城镇居民建设用地有小规模快速增长,其它土地利用变化处于动态平衡中.空间变化表明,土地利用变化随自然和社会经济条件不同有不同程度和幅度的变化.宁夏土地利用变化的驱动机制,以反映人类活动强度和区域社会经济情况的人类活动综合度和距居民地距离因子,及自然属性方面的海拔与坡度对土地利用变化的驱动作用最显著,说明人类活动和社会经济的发达程度是宁夏土地利用变化的基本驱动力,而自然的限制因素海拔与坡度等则一定程度上限制了变化的分布.由于人口和社会经济发展的压力,宁夏在原有耕地分布基础上,新增耕地较多的位于远离灌渠、道路和居民地的地区,而且海拔和坡度均趋于不合理.     

Simulation Experiments of Land Surface Physical Processes and Ecological Effect over Different Underlying Surface

Based on the existing Land Surface Physical Process Models(Deardorff, Dickinson, LIU, Noilhan, Seller, ZHAO), a Comprehensive Land Surface Physical Process Model (CLSPPM) is developed by considering the different physical processes of the earth‘s surface-vegetation-atmosphere system more completely. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feas...     

模拟退火算法在动态建立基准地价模型中的应用

阐述了传统基准地价评估模型建立流程将地价样本检验与模型建立分离的不足,引入了模拟退火算法思想,对目标函数、初始状态、新状态产生、新状态接受、初温、温度更新函数以及抽样准则、算法终止准则等关键问题进行设计,将地价样本检验、优化组合与模型建立有机结合,并设计了基于模拟退火算法的动态建立基准地价模型的流程,最后应用实例验证了方法的可行性。     

土地利用/覆被变化研究的实质分析 与进展评述

作为当前研究的前沿领域,LUCC研究所涉及的研究内容不仅丰富而且繁杂。本文从LUCC研究计划的根本目标出发,指出LUCC所研究的诸多科学问题之间存在着紧密的联系,其实质是因果关系,而且LUCC研究可以简单明了地归纳为三个研究构成环节（LUCC原因、LUCC状况和LUCC结果）和四个核心研究内容（LUCC驱动力与驱动机制、LUCC状况、LUCC效应研究与作用机制、LUCC模型模拟与土地可持续利用）,文章针对此四个方面的研究进展进行了综述。此外,作者对LUCC的研究趋势进行了展望,指出：LUCC研究的主要趋势是走向综合,LUCC的环境效应研究与LUCC微观机理与过程的研究是当前LUCC研究的两个热点,而研究尺度的综合和模型构建是LUCC研究的两大难点问题。