紫色土母质的分布及其地质环境——紫色土再研究

紫色土的分布决定于其母质--紫色岩石的分布.紫色岩石是红层的主要部分.红层的形成有一定的水热条件限制,当今地表红层的分布状况却与当地的现实水热条件不完全相符.因此,只有从地质历史演进的角度看待今日红层岩石的分布规律.通过讨论红层分布的历史原因,认为紫色岩石的分布是全球性的,紫色土亦然.     

重庆岩溶区景观格局特征分析

借用景观空间格局指数分析重庆岩溶区景观格局框架, 辨识影响景观格局的驱动因素。结 果表明： 重庆岩溶区景观分布不均匀,少数几类控制着整体景观。嵌块体几何形状较复杂,被分割 程度较低,破碎化现象不明显, 空间异质化程度低。各亚区景观多样性, 均处于最大值2.81 的中 间段, 有一种或少数几种景观类型起支配地位。人工干扰程度和丰富度依I、II 和III 区地势降低 的态势而增加, 异质化程度、不均匀性和优势度则呈相反趋势。分维数差异不明显, 形状指数变幅 较大, 不同区景观嵌块体几何形状较复杂且差异悬殊。森林景观嵌块体密度和分离度按I、II 和 III 区的顺序依次增加, 耕地、园地和居民工矿用地则分别依次减少。边界密度除了III 区水域为 63.03 外, 其余都在1.82~9.14 之间。景观整体特征I 和II 区相似, 而与III 区存在显著差异。内地 质作用在大的环境背景下控制着岩溶区景观格局特征的基本框架, 外营动力在较短时空尺度上 决定岩溶区景观格局特征的纵深态势。研究可为区域岩溶景观格局调控、景观规划和生态经济的 持续发展等宏观决策提供科学依据和理论支撑, 为岩溶区区域生态安全评价积累数据基础。     

西南丘陵山区坡耕地水平梯田工程设计分析

坡耕地改梯田是坡耕地治理的一项重要工程措施,也是建设生态农业和实现农业机械化的重要内容之一.以重庆市三峡库区土地开发整理移土培肥工程万州区龙都街道等13个街道(镇、乡)土地整理项目的坡改梯工程为例,分析了岩层倾角、厚度和岩性与坡耕地形成和利用的关系,探讨了基于岩层分析的坡改梯设计方案.同时,为了避免实践中典型田块选取的主观性,采用数字高程模型(DEM)的坡度分析作为研究区坡度分析方法.结果表明:在5°以下的缓坡地、5°～15°的中坡地、15°～25°的陡坡地,设计田面宽度分别在19～30 m、8～20 m、7～10 m范围内,从而既能适应机耕和灌溉,又能最大限度地节省土石方量.由于石坎与田面的非整体性,在满足抗滑移稳定和地基承载力的要求下,1.8 m高石坎需砌筑一轮30 cm×30 cm×100 cm的丁字石,同时通过占地分析发现,条石坎占地损失远远少于块石坎.     

县级房产产籍管理信息系统的开发与应用--以重庆市北碚区为例

以MapInfo为开发平台，MapBasic为二次开发语言，开发了县级房产产籍管理信息系统，介绍了系统主要功能，针对房产产籍信息的利用，以重庆市北碚区为例，对系统进行了应用研究。     

Land use change and its corresponding ecological responses: a review

This paper reviews the research on land use change and its corresponding ecological responses. Patterns of land use changes in spatio-temporal level are produced by the interaction of biophysical and socio-economic processes. Nowadays, the studies derived from different socioeconomic conditions and scales show that at short-term scale, human activities, rather than natural forces, have become a major force in shaping the environment, while biophysical factors control the trends and processes of land use change under the macro environmental background. Providing a scientific understanding of the process of land use change, the impacts of different land use decisions, and the ways that decisions are affected by a changing environment and increasing ecological variability are the priority areas for research: (1) explanation of scale dependency of drivers of land use change; (2) quantification of driving factors of land use change; (3) incorporation of biophysical feedbacks in land use change models; and (4) underlying processes and mechanisms of ecological impacts of land use change.     

广州市近地层大气的湍流微结构和谱特征

本文利用UVW脉动风速仪资料分析了广州市区近地层大气的湍流强度、相关系数、尺度和速度谱,并获得了不同稳定度条件下的速度谱模式.结果表明,城市近地层大气湍流在惯性副区接近局地各向同性、速度谱符合Kolmogorov相似理论;气流方向上下垫面粗糙度的增加,使沿海城市近地层大气湍流能量(特别是铅直方向)比平坦、均匀下垫面上的增加.     

Explanation of land use in mountainous area,China: from field to village level

Few studies of land use change were particularly considered the hierarchical data structure originating from different scales and levels. Using interviewing data collected from 107 villages, 1,050 households and 4,780 fields between November 2003 and August 2005, the objective of this paper is to predict the occurrence of land use from field to village level in mountainous area, China, and to improve our understanding of the causes of land use. Household’s behavior in the choice of land use type is guided by multiple, often confiding, household objectives, subject to the available resources, possible productive activities, and external economic and biophysical constraints. For rice model, the household level variables cannot be substituted by village level aggregates. Aggregated variables at village level do not capture any of the variability at the household level. Village level variables can virtually be explained in virtue of the variables of field and household level. The households and the villages show significant clustering of the occurrence of rice, and they explain the 11.3 and 4.5% variance, respectively. For corn model, corn as dependent variable does not show any significant variance component. The variables of household and village level have lower effects on the occurrence of corn. There is a significant relation between slope of a field and the choice to cultivate corn and a significant random effect at the village level. However, cropland size, input–output, transportation cost, even family income in household level and road density and food market development in village level, at some extent, are controlled by slope. These variables do not influence corn cultivation significantly and that those are predominantly determined by slope. In a word, the household level can be crucial in explaining land use at the field level. Multilevel analysis can be applied to statistically model the occurrence of land use, and to explore a number of cross-scale propositions. An erratum to this article can be found at     

试论碳酸盐岩风化壳与喀斯特成土作用

作者发现,在碳酸盐岩形成的红粘上风化壳中,往往保留着基岩的残留结构和构造,通过野外观察、系统取样分析,本文以一种新的观点探讨了碳酸盐岩风化壳的形成过程,认为地下水的差异溶蚀和选择交代是喀斯特的主要成土作用,同时也讨论了环境因素对成土作用的影响。      

The effects of land uses on purplish soil erosion in hilly area of Sichuan Province,China

1 Introduction Food grain productivity of dry land per capitahas declined significantly during the past fewdecades (Parr et al. 1990). Bowman et al. (1990)and Blaikie (1985) indicated that the greatest lossin productivity comes from soil loss, withsecondary effects from loss of nutrients due toreduced organic matter and increased soil bulkdensity. Soil erosion has major ecological andeconomic consequences in densely populatedChina, particularly, in a large agriculture province,Sichuan…     

局地土地利用变化现实情景研究

局地土地利用变化表现为时序短、空间倾向性强且多为人类强制干扰, 其变化过程与结果 是区域尺度响应与反馈国家尺度、全球尺度最有效的途径。城市化、农业结构调整和土地整理是 目前我国局地土地利用变化的几种主要利用方式。城市化是一个不可逆过程, 农村景观转为城市 景观, 改变了诸如地表反照率、粗糙度等下垫面特征, 局地生境与物种的数量与种类发生改变, 逐 步形成以人类为主的均质化景观格局; 农户微观土地利用选择行为是局地农业产业结构调整的 原动力, 不同类型农户在投资、生产与经营等经济活动的差异将导致局地土壤结构、水分、养分等 土壤条件及环境改变; 土地整理是一个复杂的系统工程, 在一定程度上改变了局地土壤性状与土 壤生物, 更甚的是改变了局地斑块- 廊道- 基质模式的景观格局。因此, 为进一步加深局地土地利 用变化情景的理解, 厘定“人- 地协调系统”的理论框架, 进行局地土地利用变化的情景模拟和生 态环境效应研究将是未来局地土地利用变化的研究方向。