A Study of the Local Geometric Accuracy of Count de Ferraris's Carte de cabinet (1770s) Using Differential Distortion Analysis

The eighteenth century Carte de cabinet of count de Ferraris is the first large-scale (1:11?520) topographic map of the entire Belgian territory, making it a valuable source of historical information. In the past, a number of studies have tried to assess the geometric accuracy of this map, but they all suffer from restricted technical capabilities for computing and visualizing the distortions, and most of them only focus on a limited number of the 275 map sheets. This paper therefore seeks to provide the first systematic and in-depth investigation of the map’s local geometric accuracy. Recently, two Belgian government agencies georeferenced the Flemish and Walloon part of the Carte de cabinet with a high level of detail, using some 30,000 ground control points to link the old map to the modern topographic map of Belgium. These data sets represent a new and unprecedented potential source of accuracy information. However, the high number of control points and our desire to compute distortions in an exact, local, quantitative and continuous way meant prominent techniques for studying the geometric accuracy of old maps, such as displacement vectors, distortion grids, triangular nets and the popular MapAnalyst software, were unsuited for this task. To meet all our requirements a new technique called Differential Distortion Analysis, which is influenced by the treatment of distortions in map projection theory, was used instead. Its advantages, structure and application to the Carte de cabinet are discussed in detail. The new technique allows calculating and displaying the map’s local angular and surface distortions with a very high spatial resolution. Consequently, it was possible to identify trends in the obtained levels of accuracy and to relate these to historical facts about the Carte de cabinet’s production process. This has resulted in important new insights into the map’s geometric accuracy.     

结合多尺度几何分析和KICA的遥感图像变化检测

为了进一步提高基于独立分量分析ICA(Independent Component Analysis)的遥感图像变化检测精确度,更好地实现地表覆盖的动态监测,将多尺度几何分析和核独立分量分析KICA(Kernel Independent Component Analysis)相结合应用于遥感图像的地表覆盖变化检测。首先利用Contourlet变换、复Contourlet变换CCT(Complex Contourlet Transform)、非下采样Contourlet变换NSCT(Nonsubsampled Contourlet Transform)等多尺度几何分析对土地遥感图像进行多尺度分解;然后对分解后的数据进行核独立分量分析,通过核函数将数据映射到高维特征空间中,再在该空间中用ICA方法分离出互相独立的分量;最后将分离后的地表变化分量转化为图像分量,再采用最大类间方差法对变化图像进行分割,实现地表覆盖的变化检测。给出了本文方法和近年来提出的基于ICA、基于KICA、基于小波变换和ICA等变化检测方法的实验结果,并进行了分析和定量比较。实验结果表明,基于多尺度几何分析和KICA的变化检测方法能更好地分离出遥感图像的变化信息,其中基于NSCT和KICA方法的错判和漏检误差最小,且在边缘细节方面处理得更好,而基于Contourlet变换和KICA方法的检测效率相对较高。     

Managing the socio-ecology of very large rivers: Collective choice rules in IWRM narratives

Integrated water resources management (IWRM) has been lauded as an integrative and participatory form of governance. However, critics claim that actual implementation remains problematic, because of deep path dependencies and the entrenched interests. This paper investigates this claim by looking at the formation of collective choice rules in integrated water resources management reforms in China’s Yellow River and the Ganges in India. The two rivers provide a natural experiment—similarity in physical scale, complexity, and integrated water resources management reforms, but highly different in social and policy contexts. Using the Q methodology and Ostrom’s Institutional Analysis and Development (IAD) framework, we find that, despite differences in policy contexts, narratives amongst the stakeholders in the two rivers are surprisingly similar, including a continued role for a negotiated local approach, and the presence of normative incentives for collective action, underwritten by deep historical meanings of the rivers. These narratives in turn provide some explanation for the choice of collective rules in use. They suggest that a modified form of integrated water resources management, taking into account narratives and collective choice rules, is useful for the governance of very large rivers across different contexts.     

Assessing socio-economic impacts of wave overtopping: An institutional perspective

One way to address the assessment of strategies to control wave overtopping at seawalls and related coastal defence structures is to make use of Cost-Benefit Analysis. The institutional context in which Cost-Benefit Analysis takes place influences decisions on the types of values that are taken into consideration and the subsequent selection of valuation methods. We suggest to consider Cost-Benefit Analysis in a broad institutional framework when decisions are to be made on coastal defence strategies. It is argued that the institutional context provides the rules of the game on how a balance can be found between social, economic and ecologic functions of projects that protect societies against overtopping.     

昌黎黄金海岸沙丘动态变化及动因解析

利用多年实地观测数据,并结合多期遥感影像解译结果.系统分析了昌黎黄金海岸沙丘典犁地段的动态变化特征及其动因,结果表明:在盛行风作用下,受物源减少、植被固定和人为扰动等诸多因素影响.沿岸沙丘在整体向陆移动的背景下,移动距离由小到大依次为沙丘中段,北段、南段;沙丘迁移速度渐缓,由3.04 m/a减小到2.07 m/a;沙丘高度逐年降低,除个别年份高度呈现正增长外,其他年份均为负增长;沙丘向海坡坡度、背海坡坡度均减小,向海坡坡度变化更为明显.     

The German Bight (North Sea) is a nursery area for both locally and externally produced sprat juveniles

To better understand the role of the German Bight (GB) as a nursery area for juvenile North Sea sprat Sprattus sprattus we sought to determine whether the area may receive only locally or also externally produced offspring. We sampled juveniles during 3 trawl surveys in the GB in August, September, and October 2004 and applied otolith microstructure analysis in order to reconstruct their distributions of the day-of-first-increment-formation (dif). These were contrasted with spatial and seasonal patterns of sprat egg abundance in the GB and its adjacent areas, observed during 6 monthly plankton surveys. It was found that the majority of juveniles originated mainly from April/May 2004, coinciding with high spawning activity west of the GB, whereas spawning and larval production inside the GB peaked notably later, in May/June. This indicated that a large proportion of juveniles was produced outside the GB and transported subsequently into it through passive and/or active migration. Shifts to later mean difs from one survey to the next and length distributions indicative of the simultaneous presence of multiple cohorts, supported the notion that the GB is a complex retention and nursery area for sprat offspring from different North Sea spawning grounds and times. Later born juveniles had significantly faster initial growth rates than earlier born conspecifics, which was likely temperature-mediated, given the strong correlation between back-calculated growth histories and sea surface temperature as a proxy for thermal histories of juveniles (r² = 0.52).     

C-band和L-band雷达干涉数据西部冰川区域相干性对比分析

干涉雷达相干性问题是制约利用干涉方法提取中国内陆冰川相关参数的重要原因.本文在理论分析干涉空间失相干因素的基础上,从垂直基线、地面坡度和波长3个方面对比了雷达干涉数据在内陆冰川表面的干涉特性.以中国西部典型的内陆冰川(冬克玛底冰川)为研究区域,采用C-band的ENVISAT/ASAR和L-band的ALOS/PALSAR数据,对比分析二者在冰川区域相干性的差别,并给出了量化结果.研究表明,相比于C-band雷达干涉数据, L-band雷达干涉数据在内陆冰川区域具有更强的抗失相干的能力,更适合于内陆冰川相关参数的提取.     

模糊聚类分析在粤西芒果炭疽病流行区域划分上的应用

根据粤西 6个市 (县 )种植的 3个主要芒果品种芒果炭疽病 (Gloeosporium mangiferae P.Henn.et al)病情指数 ,应用模糊聚类分析方法 ,划选出粤西种植芒果的适宜区域。并指出干旱地区不利于该病发生     

自动气象站雨量误差分析及维护

在分析翻斗式雨量传感器产生误差的现象与原因的基础上,介绍了具体的调整和维护方法,并认为雨量调整涉及的问题较多,也比较复杂,只有在确定是由于传感器基点位置不正确而造成的雨量误差时,才做基点调整,且一般不提倡台站自行进行调整.     

Fuzzy synthetic evaluation of water quality of Naoli River using parameter correlation analysis

In order to improve the effectiveness of Fuzzy Synthetic Evaluation （FSE） models, a Parameter Correlation Analysis （PCA） was introduced into the FSE and a case study was carried out in the Naoli River in the Sanjiang Plain, Northeast China. The basic principle of the PCA is that the pairs of parameters which are highly correlated and linear with each other would contribute the same information to an assessment and one of them should be eliminated. The method of the PCA is that a correlation relationship among candidate parameters is examined before the FSE. If there is an apparent nonlinear or curvilinear relationship between two parameters, then both will be retained; if the correlation is significant （p〈0.01）, and the scatter plot suggests a linear relationship, then one of them will be deleted. However, which one will be deleted？ For solving this problem, a sensitivity test was conducted and the higher sensitivity parameters remained. The results indicate that the original data should be preprocessed through the PCA for redundancy and variability. The study shows that introducing the PCA into the FSE can simplify the FSE calculation process greatly, while the results have not been changed much.