C.—W. M. O.—O. M. M.

Abstract

The intrusion of seawater in a tidal river is treated as a diffusion problem, characterized by a coefficient of longitudinal diffusivity.

In order to analyse the longitudinal diffusivity, a mathematical model is set up, consisting of two bodies of water, either one besides the other or one on top of the other. The two bodies are assumed to move relatively to each other, as a secondary effect of the tidal flow. It is moreover assumed that there is turbulent exchange of salt between the bodies.

It is demonstrated that the diffusion of salt into the river is greatest for an optimum value of the coefficient of exchange between the two bodies.

Exchange weaker or stronger than this optimum both diminish the salt intrusion.

The theory is applied to the Rotterdam Waterway, for which estimates of the exchange are made. Estimation of the reduction of the turbulence by stratification and hence of the vertical exchange, shows that the observed strong intrusion is explainable.

Intensified vertical mixing, for instance as provoked by compressed air, need not always result in less intrusion, and hence should be considered carefully.     

Progress and challenges in the architecture and service pattern of Earth Observation Sensor Web for Digital Earth

The Earth Observation (EO) Web is the data acquisition and processing network for digital Earth. The EO Web including Data Web and Sensor Web has become one of the most important aspects of the Digital Earth 2020. This paper summarised the history of the development and status quo of the major types of EO data web service systems, including architecture, service pattern and standards. The concepts, development and implementation of the EO Sensor Web were reviewed. Furthermore, we analysed the requirements on the architecture of the next-generation EO Sensor Web system, namely Spaceborne-Airborne-Ground integrated Intelligent EO Sensor Web system, and highlighted the virtualization, intelligent, pervasive and active development tendency of such system.     

Web service for biodiversity estimation using remote sensing data

Abstract

This paper presents a technique for the assessment and mapping of land biodiversity by using remote sensing data. The proposed approach uses a fuzzy model that encapsulates different ecological factors influencing biodiversity. We implemented our approach as a web service for the Pre-Black Sea region of the Ukraine.     

Developing a web-based spatial decision support system for geothermal exploration at the Olkaria geothermal field

ABSTRACT

Geothermal exploration is a complex process that spans a number of disciplines. Before a decision is made to drill a geothermal well, there is need for an extensive exploration process to determine the most suitable location. The process of evaluating and analyzing data from individual scientific disciplines can be complex and tedious. Attempts have been made at solving this problem using GIS-based tools but the uptake of these tools is often hindered by the limited knowledge of GIS by decision makers. This paper presents an approach for solving the geothermal exploration question through a web-based spatial decision support system (SDSS) that incorporates the various geosciences through a multi-criteria spatial decision analysis model. The results reveal a decision-making gap that is to be filled using a novel, automated exploration SDSS. This approach hypothesizes an easier and faster decision-making process. The research focuses on Olkaria, an active geothermal area in Kenya, East Africa and highlights a pragmatic approach to identifying priority areas for drilling. It evaluates contributions made by many disciplines in identifying potential sites ideal for harnessing geothermal energy and the gaps that emerge in an effort to synergize the results from the different disciplines.     

Bioaccumulation and trophic transfer of polybrominated diphenyl ethers (PBDEs) in a marine food web from Liaodong Bay,North China

The concentrations of 21 polybrominated diphenyl ethers (PBDEs) congeners were analyzed in organisms within a marine food web collected from the Liaodong Bay, North China. The total concentrations of PBDEs in all samples ranged from 0.87 to 91.4 ng g⁻¹ lipid weight (lw). BDE-47 was the predominant congener and had a concentration ranging from 0.30 to 36.1 ng g⁻¹ lw. The trophic magnification factors (TMF) of the PBDEs were calculated using the trophic levels obtained from the stable nitrogen isotope ratios. The TMF value of ∑PBDEs was 3.50 for the entire food web and 2.21 for the food web excluding seabirds. Four concentration ratios, BDE-99/BDE-100, BDE-99/BDE-47, BDE-153/BDE-154 and BDE-183/BDE-154, decreased linearly with the increase of the trophic levels in the invertebrates and the fishes (p < 0.01). The results suggested that the PBDEs were steadily metabolized in the trophic transfer process along the food chain.     

Chikyû Bankoku Sankai Yochi Zenzu Setsu: The First Japanese World Map with Latitudes and Longitudes and with an Extensive Japanese Explanatory Note

In the early 1780s, Nagakubo Sekisui, the first Japanese scientific geographer, published a world map containing latitudes and longitudes, based on Matteo Ricci's map of 1602. The map and its extensive explanatory text had a considerable impact on the educated classes of the late Edo Period (1603–1868) toward their new vision of the world. We are providing here an analysis of the map and the first complete English translation of Nagakubo Sekisui's most interesting, long explanatory text.     

Maps as Knowledge Aggregators: from Renaissance Italy Fra Mauro to Web Search Engines

Abstract

For many years geological students have been graduating from universities with little knowledge of how to use the cartographic language of line, letter, symbol and tone by which the distribution and spatial arrangement of earth science data can be best expressed. The author discusses the development of the teaching of geological cartography in the Department of Earth Sciences at the University of Leeds. Details of this innovation are set against the background of data obtained from a recent questionnaire on the practice of cartography as a discipline in departments of geology in British universities.     

A marine remote sensing spatial database engine for web publishing

To meet the requirements of efficient management and web publishing for marine remote sensing data, a spatial database engine, named MRSSDE, is designed independently. The logical model, physical model, and optimization method of MRSSDE are discussed in detail. Compared to the ArcSDE, which is the leading product of Spatial Database Engine, the MRSSDE proved to be more effective.     

A CRITICAL EVALUATION OF THE CITY LIFE CYCLE IDEA

The idea that cities or their neighborhoods, like organisms, experience a life cycle was very popular in policy-oriented U.S. urban studies literature of the 1970s. This paper presents a critical evaluation of the city life cycle idea. A brief survey of the city life cycle idea in recent literature is followed by a "double-barrelled" critical evaluation. First, the idea is examined and evaluated in terms of its use in, and implications for, the practice of social science. Second, the idea is evaluated as it influenced public policy and served to reinforce the interests of particular groups. Two conclusions are presented (1) that the largely uncritical use of the city life cycle idea allowed the idea to slip from being an image to being a cause in accounts of urban decline and (2) that the city life cycle idea, albeit flawed, was accepted and persisted because it servedparticular interests. The adoption of the city life cycle idea has had consequences both for the social sciences based upon it and for the cities and their inhabitants which became the targets of policies influenced by the idea.