水文学介绍用,英语翻译.doc

Hydrology 水文学 1 history The first hydraulic project has been lost in the mists of prehistory. Perhaps some prehistoric man found that pile of rocks across a stream would raise the water level sufficiently to overflow the land that was the source of his wild food plants and water them during a drought. Whatever the early history of hydraulics, abundant evidence exists to show that the builders understood little hydrology. Early Greek and Roman writings indicated that these people could accept the oceans as the ultimate source of all water but could not visualize precipitation equaling or exceeding stream-flow. Typical of the ideas of the time was a view that seawater moved underground to the base of the mountains. There a natural still desalted water, and the vapor rose through conduits to the mountain tops, where it condensed and escaped at the source springs of the streams. Marcus Vitruvius Pollio (ca. 100 B. C.) seems to have been one of the first to recognize the role of precipitation as we accept it today. 最早的水利工程在有史以前就已经销声匿迹了。也许史前的人曾发现横贯河流的一堆石头就能提高水位，足以淹没作为生长野生食用植物源泉的土地，而这样在干旱季节就能给植物浇水。不论水力学的早期如何，充分的的迹象表明，建造者们还不懂多少水文学知识。早期的希腊和罗马文献说明这些人承认海洋是一切水的主要源泉，但是不能想象降雨量会等于或超过河道径流量。当时典型的想法是海水从地下流到山脉底部，那儿有一个天然蒸馏器除去水中的盐分，水汽通过管道上升到山顶，在那里凝结，并从河流的源头流走。M.V.波利欧（大约公元前100年）看来就是像我们今天这样认识降水作用最早的人。 Leonardo da Vinci (1452-1519) was the next to suggest a modern view of the hydrologic cycle, but it remained for Pierre Perrault (1608-1680) to compare measured rainfall with the estimated flow of the Seine River to show that the stream-flow was about one-sixth of the precipitation. The English astronomer Halley (1656-1742) measured evaporation from a small pan and estimated evaporation from the Mediterranean Sea from these data. As late as 1921, however, some people still questioned the concept of the hydrologic cycle. 达芬奇（1452-1519）是提出水文循环现代观点的第二个人，但一直到P.贝罗特（1608-1680）才把观测的雨量与估算的塞纳河的径流量进行比较，说明河川径流量约为降雨量的1/6.英国天文家哈罗（哈雷）从一个小盘子中测得的蒸发量，并且用这一资料估算地中海的蒸发量。然而直到1921年，有一些人仍然对水文循环的概念表示怀疑。 Precipitati