Unfortunately， the physical features of this area are being degraded. The delta is beginning to sink. This is causing flooding to 91% of the area every year. This number is expected to increase as the sinking continues and more lakes and waterways are formed. With this flooding， alluvial deposits of soil and minerals are moved about and deposited in different areas. Over the course of the year， thousands of tons are moved. This erosion of the land is causing a continuous reshaping of the delta and sandbars in the river.
The ecosystem is still considered intact， but even it has been degraded. This has lead to an onslaughtonslaught n.冲击 of scientific research in the area. Many reserves have been set up to study wildlife and plant life in the area. There have been important findings in this area.
From the early days of military conquest to the need for hydroelectric power， the Danube River has been important to Europe. Its importance will no doubt increase as more commercial trade and scientific research is done in the area.
The Main
美茵河流淌
美茵河是莱茵河上的一条支流。莱茵河是发源于阿尔卑斯山的一道蓝色风景线，它起于瑞士东南部，而后流经奥地利、法国、德国、荷兰这些国家，并派生出了诸如内卡尔河、美茵河这些秀丽的河流。法兰克福就是依傍在美茵河畔的一个城市。
法兰克福的美茵河对岸的旧区，至今仍保留着十八世纪的古典气息，亦是苹果酒的出产地。穿过小巷便会发现一间间布置舒适的酒铺，您不妨在这里喝杯苹果酒。此处也有许多啤酒吧出售来自德国各地的啤酒。美茵河边的美术区位于美茵河旁边的博物馆街汇集了七所着名的美术馆及博物馆。国家艺术学院及美术馆是德国最权威的美术馆之一，展出由中世纪至现代西洋绘画作品的展品总数接近十万件。其他博物馆包括有展出古雕塑作品、德国邮政博物馆、德国建筑博物馆、德国电影博物馆、人类学博物馆及应用美术博物馆。
The Main is an important tributary of the Rhine in Germany， which it joins near Mainz and together with the MainDanube Canal it forms a link between the Rhine and the Danube. Cruising this waterway will take you through the beautiful BavarianBavarian adj.巴伐利亚的， 巴伐利亚人的 n.巴伐利亚人， 巴伐利亚方言(见Bavaria) countryside and past cities like Frankfurt， Wurzburg， Bamberg and Nuremburg.
The Main (pronounced in German like the English word mine) is a river in Germany， 524 km long， and one of the more significant tributaries of the Rhine river. It flows through the German states of Bavaria and Hessen. Its catchment basin competes with the Danube for water； as a result， much of its boundaries are identical with those of the European Watershed.
The Main is formed near Kulmbach by the joining of its two headstreamsheadstream n.源头， 发源地， the Red Main and the White Main. The former rises from the Frankish Alb， 50 km in length， and runs through Creussen and Bayreuth. The latter，s source is located in the mountains of the Fichtelgebirge； it is 41 km long. Major tributaries of the Main are the Regnitz， the Frankish Saale， the Tauber， and the Nidda.
The largest city along the Main is Frankfurt am Main (ford of the Franks). After the junctionjunction n.连接， 接合， 交叉点， 汇合处 of its headstreams， the Main passes the following towns and cities： Burgkunstadt， Lichtenfels， Staffelstein， Hallstadt， Zeil， Hassfurt， Schweinfurt， Volkach， Kitzingen， Marktbreit， Ochsenfurt， Würzburg， Karlstadt， Gemünden， Lohr， Marktheidenfeld， Wertheim， Miltenberg， Obernburg， Aschaffenburg， Seligenstadt， Hanau， Offenbach， Frankfurt， Hattersheim， Flrsheim， Rüsselsheim. By the time it flows into the Rhine opposite Mainz， it is a formidable river.
Extensive works have made the Main navigablenavigable adj.适于航行的 for river shipping from its mouth at the Rhine， via the RhineMainDanube Canal and the highly regulated Altmühl river， all the way to the Danube.
The Alster
阿尔斯特湖
汉堡是一座建在水边的城市，其着名的水域有阿尔斯特湖和通向德意志湾的易北河。
阿尔斯特湖位于汉堡市中心，如果站在湖畔，找一个好的角度，会发现，这里能看到欧洲最典型的城市风光，湖水、树木、古老的房屋与远处市政厅、米歇尔教堂的钟楼连成一片，但远近高低不同，加上阳光不同方向的折射，呈现在眼前的是一幅中世纪浓墨重彩的油画，漫步在湖畔，来到欧洲的感觉就显得非常真实了。
这个位于绿色的汉堡城市中心地带的大湖是帆船运动员的天堂。令帆船手们感到自豪的是这个面积160公顷大的湖泊(最深处只有2.5米)是一个艺术化的湖泊。
它是自13世纪起由一条阿尔斯特小河及流入这条小河的小溪汇合而建成。这些小溪直到今天仍然是帆船手们罗曼蒂克的跑道。汉堡人喜欢在阿尔斯特水域享受他们的“世外桃源”。
有谁不知道呢？在夏日啤酒加淋浴，就是这样生机勃勃，就像阿尔斯特湖本身一样。阿尔斯特的汽轮从处女堤出发，穿过湖面到达托尔。游湖的航线让你能欣赏迷人的城市侧影。环湖散步也非常值得，你可以尽情欣赏这座水畔绿城。
阿尔斯特湖分内湖和外湖。在两湖之间的是观赏汉堡全景的好地方，湖畔有美丽的湖畔公园。汉堡是德国最绿化的城市，整个城市近一半是水域和陆地，几乎每条街道都被树木和灌木包围。阿尔斯特公园在阿尔斯特湖绿色的岸边是汉堡市最受欢迎的公园，阿尔斯特公园内每天都有热闹的活动。在汉堡市中心附近有花木植物园、老城墙和着名的“花卉植物园”。这里建有一个有温室的植物园和欧洲最大的日本式花园，日本花园宁静、但给人的魅力却非常难忘。沿着水流，你可以直接到水上公园。
One of the bestknown German rivers， which is only 56 km long， has its source 25 km north of Hamburg. The river， whose upper course winds it through charmingcharming adj.迷人的， 娇媚的 meadowsmeadow n.草地， 牧场 and heathlandscapes， comes into being by a confluence of two smaller streams， the old and new Alster. These two little streams join at Stegen， a village in Schleswig Holstein. Its riverbed broadens increasingly as some former mill brooks join in and near Hamburg， the river attains a considerable breadth. In the city， it already forms a large basin， which is named “Auenalster”. The second basin is much smaller； it is called “Binnenalster”.
The “Binnenalster” separated by the Kennedy - and the historical Lombardsbrücke from the Auenalster appears urban. Impressive business buildings in Jungfernstieg， the most important shopping mall of Hamburg and Ballindamm surround this rectangularrectangular adj.矩形的， 成直角的 water basin. From here it is only a stone，s throw to the “Little Alster” which runs by the side of the town hall along a number of fleets through business quarters in the centre of the city and finally flows in to the Elbe.
In 1190， the river was dammed up to operate a mill. Near today，s Resendammbrücke by the Rathausmarkt (town hall square) was constructed a second bridge in 1250. The water， thus dammed up， flooded the lower parts and in consequenceconsequence n.结果， ［逻］推理， 推论， 因果关系， 重要的地位， there came into being a lake of approx. 190 hectare.