The interplay of geomorphic processes and soil development in an upland environment, Calabria, South Italy

Five representative soil profiles outcropping in the area around the Cecita Lake (Calabria, South Italy) were characterised by field work, chemical and mineralogical analyses, optical and scanning electron microscopy. Interactions among weathering, pedogenesis and geomorphic processes are emphasised, in an attempt to link the results obtained at different scales of observation. The important role of topography in controlling soil development or removal by erosive processes is discussed, in relation to the natural geomorphological context and the effects of human pressure. Both present-day and relict features were recognised in the studied soils, and discussed in terms of environmental conditions and climatic changes. The chemical composition of volcanoclastic components identified in some soil horizons with Andosol-like field appearance, coupled with pedogenetic features, contributed useful chronological constraints for the reconstruction of Late Quaternary geomorphic events.     

The perfect landscape

The “perfect storm” metaphor describes the improbable coincidence of several different forces or factors to produce an unusual outcome. The perfect landscape is conceptualized as a result of the combined, interacting effects of multiple environmental controls and forcings to produce an outcome that is highly improbable, in the sense of the likelihood of duplication at any other place or time. Geomorphic systems have multiple environmental controls and forcings, and degrees of freedom in responding to them. This allows for many possible landscapes and system states. Further, some controls and forcings are causally contingent. These contingencies are specific to time and place. Dynamical instability in many geomorphic systems creates and enhances some of this contingency by causing the effects of minor initial variations and small disturbances to persist, and grow disproportionately large, over time. The joint probability of any particular set of global controls is low, as the individual probabilities are < 1, and the probability of any set of local, contingent controls is even lower. Thus, the probability of existence of any landscape or earth surface system state at a particular place and time is negligibly small: all landscapes are perfect. Recognition of the perfection of landscapes leads away from a worldview holding that landforms and landscapes are the inevitable outcomes of deterministic laws, such that only one outcome is possible for a given set of laws and initial conditions. A perfect landscape perspective leads toward a worldview that landforms and landscapes are circumstantial, contingent results of deterministic laws operating in a specific environmental context, such that multiple outcomes are possible.     

关于线状地理特征空间关系的自然语言描述的形式化表达

目前的地理信息系统都使用定量的方法存储和查询空间信息,不能反映人们的定性思维方式,因此它表达地理空间信息的能力受到限制。在关于空间关系的自然语言描述的调查的基础上,本文定义了一组能反映线状物体空间关系的度量指标,结合反映拓扑关系的定量指标,使用决策树的数据挖掘算法,对调查结果进行分析,形式化了描述空间关系的自然语言词汇,建立了模糊的自然语言表达和图形的几何特征之间的联系。自然语言形式化后得到的规则可用于空间关系的自然语言查询系统。     

区域统计指标空间化技术及应用研究

社会数据的空间化是现代地图制图学研究的主要内容之一。本文提出了区域统计指标的概念并将其分为区域平均指标与区域总量指标两种类型,成功地将网格单元面积权重内插(GCAW I)法引入到区域统计指标的空间化工作中,应用GCAW I法实现了新沂市耕地标准亩指标的空间化表达,结果表明:运用GCAW I法进行区域统计指标的空间化不仅可以很好地避免传统方法的同一区域均匀分布、不同区域突变分布的缺点,而且经kriging插值后的地图很好地符合区域统计指标空间分布的特点,生成的3维可视化地图更加切合实际。     

A method for the selection of relevant pattern indices for monitoring of spatial forest cover pattern at a regional scale

When signing Agenda 21, several countries agreed to monitor the status of forests to ensure their sustainable use. For reporting on the change in spatial forest cover pattern on a regional scale, pattern metrics are widely used. These indices are not often thoroughly evaluated as to their sensitivity to remote sensing data characteristics. Hence, one would not know whether the change in the metric values was due to actual landscape pattern changes or to characteristic variation of multitemporal remote sensing data.     

Zonal Indices for Europe 1780–1995 and Running Correlations with Temperature

Zonal circulation indices with monthly and seasonal resolutions are calculated based on gridded monthly mean sea-level pressure (SLP) reconstructed back to 1780 by Jones et al. (1999): an overall zonal index for the whole European area between 30°W and 40°E, a normalized index for the North Atlantic Oscillation (NAO), and a similar index for Central Europe. For most of the early time up to the mid-nineteenth century we get preferred negative anomalies in the NAO index for winter and preferred positive ones for summer. The turning points in cumulative anomalies - during the 1850s for winter and during the 1870s for summer - indicate a transition period in circulation modes from the "Little Ice Age" to the recent climate in Europe. Running correlations (time windows of 21 years with time steps of one year) between zonal indices and regional temperature time series from Central England, Stockholm and two Central European regions are all indicating major instationarities in these relationships with a particular decline in winter correlations around the turn from the nineteenth to the twentieth centuries. Aspects of different circulation patterns linked with these variabilities are discussed.     

南海沉积物中C30-C32烷基二醇的检出及可能的古环境信息

从南海17962钻孔沉积物中检出了C30－C32长链烷基二醇类化合物。C30长链烷基二醇的碳同位素值在－30．17‰－－38．98‰之间,反映出其先质母体为水生生物,认为是海洋微藻－黄绿藻Eustigmatophytes。这类化合含量能够反映以黄绿藻为代表的海洋古生产力的变化：冰期时C30二醇的高沉积通量显示出南海南部末次冰期黄绿藻Eustigmatophytes初级生产力增高。计算C30和C32二醇的相对比值获得二醇参数（diols indices）,发现本柱状样二醇参数的变化指示了南海3万余年来的古海洋及古气候变化：南海经历了从半封闭到开放的演化,其气候经历了三次Heinrich冷事件,在Heinrich事件之间出现了一系列百年到千年尺度的气候事件,即D／O循环;全新世的Younger Dryas事件也有明显反映,说明南海与高纬度地区3万余年来的气候变化存在遥相关。     

Ecological and agricultural productivity indices and their dynamics in a sub-humid/semi-arid region from central Mexico

Using precipitation data from a semi-arid region in the highlands of central Mexico, historical values of productivity are assessed. Production models based on climatic indices are discussed. An empirical rain simulation equation shows that it is possible to reproduce the expected values of productivity from observed ecosystems and agricultural yields. A graphical method is proposed to estimate intrinsic growth rate and maximum sustainable yield. Spatial rainfall variability induced by orographic effects, introduces a chaotic semicyclic behavior as expected in a logistic simulation equation. Resilience and predictable drought-productivity tendencies can also be derived from this model.     

VECTOR ANALYSIS THEORY ON LANDSCAPE PATTERN （VATLP） IN SANJIANG PLAIN MARSH, CHINA

Landscape indices are popular for the quantification of landscape pattern. But all landscape indices being used so far are scalar quantity, which measure patterns without considering sufficiently the pattern size and the directionality together. Based on planar characteristics defined in mechanics such as centroid, moment of inertia, product of inertia, principal axes and so on, vector analysis theory on landscape pattern (VATLP) is explored here. Firstly we establish a coordinate system of centroidal principal axes (CSCPA) of a patch or patches. Some related new indices including those describing the direction of pattern distribution (patch orientation (PO), vectorial patch orientation (VPO)), and those indicating the shape of patch‘s equivalent ellipse (major axis (MJA), minor axis (M1A) and eccentric rate (ER)) are deduced. These landscape metrics are then applied to the pattern analysis of Sanjiang plain marsh, the study area. Two temporal vector-based data sets of the study area come from interpretation of remote sensing images M SS (1980) and T M (2000). The application of the theory captures some shape properties of riparian wetland in Sanjiang plain marsh. The dissymmetrieal featires of Sanjiang plain marsh around principal axes due to agricultural development could also be explained.