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Port City The port city provides a fascinating and rich understanding of the movement of people and goods around the world. We understand a port as a centre of land-sea exchange, and as a major source of livelihood and a major force for cultural mixing. But do ports all produce a range of common characteristics which justify classifying port cities together under a single group label Do they have enough in common to guarantee distinguishing them from other kinds of cities Ports and harbors A port must be distinguished from a harbor. There are two very different things. Most ports have poor harbors, many fine harbors see few ships. Harbor is a physical concept, a shelter for ships; port is an economic concept, a center of land-sea exchange which requires good access to a hinterland even more than a sea-linked foreland. It is landward access, which is productive of goods for export and which demands imports, that is critical. Poor harbors can be improved with breakwaters and dredging if there is a demand for a port. Madras and Colombo are examples of harbors expensively improved by enlarging, dredging (清淤) and building breakwaters. Once a port city, always a port city Port cites become industrial, financial and service centers and political capitals because of their water connections and the concentration which arises there and later draws to it railways, highways and air routes. Water transport means cheap access, the chief basis of all port cities. Many of the worlds’’ biggest cities, for example, London, New York, Shanghai, Istanbul, Buenois Airs, Tokyo, Jakarta, Calcutta, Philadelphia and San Fracissco began as ports — that is, which land-sea exchange as their major function — but they have since grown proportion in other respects so that their port functions are no longer dominant. They remain different kinds of places from non-port cities and their port functions account for that difference. A truly international environment Port functions, more than anything else, make a city cosmopolitan. A port city is open to the world. In it races, cultures, and ideas as well as goods from a variety of places, jostle, mix and enrich each other and the life of the city. The smell of the sea and the harbor, the sound of boat whistles or the moving tides are symbols of their multiple links with a wide world, samples of which are present in microcosm (缩影) within their own areas. Reasons for the decline of ports Seaports have been transformed by the appearance of powered vessels, whose size and draught have increased. Many formerly important ports have become economically and physically less accessible as a result. By-passed by most of their former enriching flowing of exchange, they have become cultural and economic backwaters or have acquired the character of museums of the past. Examples of these are Charleston, Salem, Bristol, Plymouth, Surat, Galle, Melaka, Suzhou, and a long list of earlier prominent port cities in Southeast Asia, Africa and Latin America. Relative significance of trade and service industry Most ports have few poor harbors, many fine harbors see many ships. Harbor is not a physical concept but also an economic concept, a center of connections of different politics, commerce and other different styles. Calcutta traded mainly with other parts of India and so on. Most of any city’’s population is engaged in providing goods and services for the city itself. Trade outside the city is its basic function. But each basic worker requires food, housing, clothing and other such services. Estimates of the ratio of basic to service workers range from 1:4 to 1:8. Their own way to develop and exist No city can be simply a port but must be involved in a variety of other activities. The port function of the city draws to it raw materials and distributes them in many other forms. Ports take advantage of the need for breaking up the bulk material where water and land transport meet and where loading and unloading costs can be minimized by refining raw materials or turning them into finished goods. The major examples here are oil refining and ore refining, which are commonly located at ports. It is not easy to draw a line around what is and is not a port function. All ports handle, unload, sort, alter, process, repack, and reship most of what they receive. A city may still be regarded as a port city when it becomes involved in a great range of functions not immediately involved with ships or docks. Cities which began as ports retain the chief commercial and administrative centre of the city close to the waterfront. The centre of New York is in lower Manhattan between two river mouths, the City of London is on the Thames, Shanghai along the Bund. This proximity to water is also true of Boston, Philadelphia, Bombay, Calcutta, Madras, Singapore, Bangkok, Hong Kong and Yokohama, where the commercial, financial, and administrative centers are still grouped around their harbors even though each city has expanded into a metropolis. Even a casual visitor cannot mistake them as anything but port cities. Cities which began as ports retain the chief commercial and administrative centre of the city close to the__________.

题目标签:清淤
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刷刷题刷刷变学霸
举一反三

【单选题】下列有关清淤说法正确的是()。

A.
人工清淤一般一年进行2~3次
B.
水力清淤一般是按先下游后上游的顺序,有计划地逐段进行
C.
机械清淤主要是用挖泥船、挖土机、推土机等工程机械来清理渠道淤积泥沙
D.
产生淤积的主要原因之一是渠道比降过大

【单选题】下列有关清淤说法正确的是()。

A.
人工清淤一般一年进行2~3次
B.
水力清淤一般是按先下游后上游的顺序,有计划地逐段进行
C.
机械清淤主要是用挖泥船、挖土机、推土机等工程机械来清理渠道淤积泥沙
D.
产生淤积的主要原因之一是渠道比降过大

【单选题】人工清淤的优点是()。

A.
效率高
B.
组织灵活
C.
受季节限制
D.
劳动强度低

【单选题】关于水力清淤,下列说法不正确的是()。

A.
要在在非用水季节进行
B.
要按先上游后下游的顺序
C.
要在水源比较充足的地区
D.
要按校核流量引入渠道